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Studies on milk production of Large White pigs
Abstract
1. A review of the literature relating to the frequency at which pigs suckle under natural conditions was made. The evidence indicated that the average interval between successive sucklings is approximately 1–1¼ hr.
2. A number of sows and their litters were continuously observed for varying periods of time under natural conditions and a similar average interval between sucklings was observed.
3. A review of the literature relating to the determination of milk production of sows was made. This showed that the majority of previous workers imposed, during the periods when the litters were being weighed before and after every suckling, a suckling frequency that did not simulate the natural behaviour of the animals. Evidence suggesting that the imposition of such unnatural conditions invalidated the findings, in so far as they might indicate the true milking capacity of the animals, was discussed.
4. An experiment to obtain direct evidence on the importance of the suckling interval in relation to the milk obtained by the pigs was carried out. Conclusive evidence was obtained that when suckling was allowed every hour, both the quantity of milk obtained by the litters and their live-weight gain in 24 hr. periods were much greater than was the case when suckling was allowed only every 2½ or 3 hr. In addition, the pigs on the hourly suckling frequency utilized their milk intake more efficiently.
5. An experiment was carried out in which an attempt was made to obtain, under natural conditions, a valid estimate of the 56 days' lactation yield of three Large White gilts. The method of weighing the individual pigs before and after suckling was used, and the animals were allowed to suckle every hour.
6. The estimated average lactation yield was 768 lb., with a range of from 882 to 655 lb., although it was suggested that the true yield might be some 5–10% higher. The figures obtained in this work were shown to be very much higher than the yields reported by most of the previous workers.
7. The nursing and suckling behaviour of the dams and their litters was studied. Observations of significance in relation to the variation in growth of pigs within a litter were made.
8. Data were obtained concerning the average amount of milk obtained by individual pigs at a suckling, the total amount ejected at a suckling, the effect of daylight and of darkness on the amount of milk obtained, the relative productivity of the individual mammary glands and the efficiency with which the milk intake was utilized by the individual pigs in the litter.
9. A close positive relation between milk intake and live-weight gain during the first 3 weeks of life was found. During the last 5 weeks of lactation, when supplementary food was available, this close relationship was not seen.
10. The growth rate of the suckling pig, as related to the supply of food, was discussed. The evidence available suggested that the supply of sow's milk was frequently insufficient to meet the requirements of the pigs for optimum growth.
11. The chemical composition of sow's milk in relation to the stage of lactation was studied.
... Suckling intensity is a major determinant of both mammary development and milk yield of sows. The effect of suckling intensity on potential milk yield and piglet growth has been extensively investigated [37][38][39][40]. In pigs, there are several sow-litter interactions including suckling intensity, litter size, suckling frequency and age and size of piglets that influence the potential milk yield of the sow. ...
... Heavier piglets are able to stimulate increased milk flow and may empty out mammary glands completely during feeding, unlike lighter weight piglets. Increased stimulation leads to greater oxytocin release and greater milk let-down and therefore increased piglet live weight gain [38,39]. Milk yield peaks were found at day nine of lactation in sows [38]. ...
... Mammalian milk is rich in lipids, carbohydrates, proteins and non-nutritional products, which are of functional significance to the growth physiology of the developing offspring [39,46]. Among the non-nutritional products immunoglobulin A, LF, macrophages and lysosomes help in protecting the digestive tract against potential pathogens [46]. ...
Lactoferrin (LF), a sialylated iron-binding glycoprotein, performs multiple beneficial functions including modulating immunity and improves neurodevelopment, health and growth performance. Maternal LF intervention for gilts (first parity sows) on the performance of gilts and their offspring remains unknown. In the current study gilts were fed with a commercial pig feed supplemented with 1g LF /day (treatment group) or 1g milk casein/day (control group) from day 1 post mating throughout pregnancy and lactation for about 135 days. The milk production and body weight gain was monitored. The immunoglobulin concentrations in the serum of gilts and piglets were measured using ELISA. Our study showed that maternal LF supplementation to the gilt (1) significantly increased milk production at different time points (day 1, 3, 7 and 19) of lactation compared to the control (p<0.001); (2) significantly increased body weight gain of their piglets during the first 19 days of life compared to the control group (p<0.05); (3) tended to increase pregnancy rate, litter size and birth weight, number of piglets born alive, and decrease the number of dead and intrauterine growth restriction (IUGR) piglets; (4) significantly increased the concentration of serum IgA in gilt and serum sIgA in piglet (p<0.05). In summary, maternal Lf intervention in gilts can improve milk production, pig production and serum IgA and sIgA levels, and therefore plays a key role in shaping the performance of their progeny.
... Previous research has tended to focus on the large between-litter variation in creep feed consumption (Aherne et al., 1982;Barnett et al., 1989). There is reason to believe that creep feed consumption also varies greatly within litters (Barber et al., 1955;Friend et al., 1970;Barnett et al., 1989) but a suitable method for measuring creep feed intake by individual piglets has been lacking. ...
... As large body size and rapid growth are likely to indicate greater developmental maturity, this model would predict that the large, faster-growing piglets would eat more creep feed during the period when digestive ma-turity is developing. Alternatively, piglets may consume creep feed in compensation for inadequate nutrition from milk (Barber et al., 1955;Algers et al., 1990). In this case, within a certain range at least, the smaller, slowergrowing piglets would be expected to eat more creep feed. ...
... Similar between-litter variation has been reported previously (Okai et al., 1976;Aherne et al., 1982;Barnett et al., 1989). These large differences may be due in part to differences in milk production by the sows (see Smith, 1952;Barber et al., 1955;Hemsworth et al., 1976). For example, Litter A experienced diarrhoea and poor weight gains about 10 days before weaning, probably owing to illness by both the piglets and the sow. ...
Pajor, E.A., Fraser, D. and Kramer, D.L., 1991. Consumption of solid food by suckling pigs: individ- ual variation and relation to weight gain. Appl. Anita. Behav. Sci., 32:139-155. Individual daily consumption of supplementary solid food ('creep feed') was measured from Day 10 to weaning at Day 28 for 39 piglets in four litters, and its relationship to body weight and weight gain up to Day 42 was investigated. Individual consumption was measured by combining the weight of the feed removed from the dispensers (monitored electronically) and a video image of piglet activ- ity at the feeder. Creep feed consumption varied greatly, both between and within litters. On average, pigs began feeding on Day 12 (range Day 10-28), intake was relatively low (usually
... Further study is required to confirm our proposed mechanism. Suckling intensity is a major determinant of both mammary development and milk yield of sows (Barber et al., 1955;Wilde and Peaker, 1990;Marshall et al., 2006;Riley et al., 2008). Therefore, increased litter size in COS group may provide a greater suckling intensity, which leads to greater oxytocin release and greater milk let-down in COS group. ...
... Increased colostrum intake might have enhanced growth velocity and immune status of piglets (Decaluw e et al. 2014). The increased supply of functionally important minor proteins, lipids, carbohydrates and nonnutritional products (Barber et al., 1955;Prunier et al., 2010) such as immunoglobulins, lactoferrin, macrophages and lysosomes in milk presumably provided increased immunoprotection and antimicrobial factors to the neonate (Bourne and Curtis, 1973). Part of the growth response to maternal COS supplementation may also be the result of the immunomodulatory effects of COS in significantly increasing the concentrations of serum IgM and sIgA, which led to a reduction in the incidence of early infectious diseases in the piglets. ...
Chitosan oligosaccharides (COS) are the hydrolyzed product of chitosan and have multifunctional health benefits. The objective of this study was to elucidate the effect of COS as a dietary supplement to gilts on their productivity and health, and that of their litters. Gilts were randomly assigned to either a treatment (n = 30) or control group (n = 30). The treatment gilts were fed a standard dry sow ration supplemented with COS at 0.12 and 0.24 g/gilt per d during gestation and lactation, respectively, and the control group was fed the standard dry sow ration only. The body weight, reproductive performance, milk production and litter size for each gilt and body weight of corresponding litters were recorded. The serum immunoglobulins (IgA, IgG, IgM) and secretory immunoglobulin A (sIgA) concentrations of gilts and piglets and fecal sIgA concertation of gilts were measured by Enzyme-linked immunosorbent assay (ELISA). Our study showed that maternal COS supplementation: 1) significantly increased gilt body weight in late pregnancy (P < 0.05); 2) significantly increased milk production of gilts at different stages (d 1, 3, 7 and 19) of lactation (P < 0.05); 3) significantly increased body weight gain of piglets at weaning (P < 0.05); 4) significantly increased the serum concentrations of IgM and sIgA in piglets, and sIgA in fecal sample of gilts (P < 0.05); and 5) tended to increase the pregnancy success rate (P > 0.05) in the treatment group compared to the control group. These results suggest that maternal COS intervention in gilts can improve gilt milk production, piglet pre-weaning growth and immunity parameters in both gilts and piglets.
... However, between birth and weaning, the piglets that suckled anterior teats gained more weight than the other piglets, confirming results from other studies (FRASER & JONES, 1975;PLUSKE et al., 2007;SKOK et al., 2007;PEDERSEN et al., 2011). This can be attributed to a greater milk intake after birth in piglets that suckle anterior teats, as it has been shown that the anterior mammary glands of the sow tend to produce more milk than the posterior ones (BARBER et al., 1955;SKOK et al., 2007), and there is a correlation between milk intake and growth of piglets until the third week of nursing (BARBER et al., 1955). In contrast, it is unlikely that the greater weight gain of AT piglets is due to differences in feed intake, as this is very low in suckling piglets during their first weeks of life. ...
... However, between birth and weaning, the piglets that suckled anterior teats gained more weight than the other piglets, confirming results from other studies (FRASER & JONES, 1975;PLUSKE et al., 2007;SKOK et al., 2007;PEDERSEN et al., 2011). This can be attributed to a greater milk intake after birth in piglets that suckle anterior teats, as it has been shown that the anterior mammary glands of the sow tend to produce more milk than the posterior ones (BARBER et al., 1955;SKOK et al., 2007), and there is a correlation between milk intake and growth of piglets until the third week of nursing (BARBER et al., 1955). In contrast, it is unlikely that the greater weight gain of AT piglets is due to differences in feed intake, as this is very low in suckling piglets during their first weeks of life. ...
The objective of this study was to investigate if piglets that suck anterior teats differ from the others in the litter in birth weight, if they have higher growth rate during lactation, and if this affects behaviour and post-weaning weight gain, when piglets change to a solid diet. For this, the teat order of 24 litters was determined during suckling. Piglets were weaned on the 28th day of age, and 24 groups were formed, composed of one piglet that sucked on the first two pairs of teats (AT) and three piglets that sucked on the other teats (OT). Even though weight at birth did not vary according to teat order, weight gain at weaning differed between the groups (AT: 6.64, S.E. 0.20kg, OT: 5.73, S.E. 0.13kg; P<0.001). After weaning, AT piglets spent more time lying (P<0.01) and less time eating (P<0.01) and vocalizing (P<0.01), than the other piglets. Other behaviours (agonistic interaction, escape attempt and drinking) did not differ between the groups. Piglets that sucked anterior teats gained more weight until weaning, suggesting they took in more milk; this fact might have lead them to have less contact with solid food before weaning, influencing their post-weaning alimentary behaviour. © 2015, Universidade Federal de Santa Maria. All rights reserved.
... Early studies of piglet suckling behavior and growth suggested that the more anterior teats are the most productive, and that piglets compete for the anterior positions. with the larger littermates generally winning their possession (Donald 1931 ; Barber et al. 1955). Actually, the position of a teat (anterior to posterior) is only a weak indicator of its quality. ...
... This is similar to most previous findings (e.g. Fraser and Jones 1975), and gives little support to the commonly held view that the piglets of high birth weight tend to appropriate the anterior places (Barber et al. 1955;Scheel et aI. 1911). ...
For 21 sows, teats were hand milked individually in a standard way during farrowing in an attempt to produce an index of teat quality. The piglets' teat selection and 14-day weights were then compared with the hand milking results. Of within-litter variation in 14-day weight, 38.6% was explained by 1-day weight, and only 4.6% extra variation by the index derived from hand milking. Use of the index gave no improvement over previous models involving 1-day weight and teat number (anterior to posterior). Hand milking showed a pronounced decline in colostrum yield from the most anterior teat pair (46.8 g) to the most posterior (13.7 g); this may help to explain the piglets' strong tendency to select anterior positions. Piglets of high, medium and low 1-day weight differed significantly in liveweight gain, but not in their selection of anterior or posterior teats. Key words: Colostrum, milk, piglet, sow, suckling behavior, teat quality
... It has been reported that the more vigorous piglets and those with higher birth weights assign themselves to the more anterior teats, obtaining greater chance of surviving and making particularly large live-weight gains during the suckling period (Donald, 1937;Barber et al., 1955;Fraser and Morley Jones, 1975;Hartsock and Graves, 1976;Horrell and Bennett, 198 1) . When piglets are of equal birth weights, the animals suckling towards the front end of the mammary gland show a strong tendency to become heavier (Fraser and Morley Jones, 1975). ...
... The method of determining specificity was particularly important in this study because measurements were not taken from the attachment to a particular teat but to an udder region (front or back). The literature on the differences in sow teat production has been contradictory; early studies (Barber et al., 1955;Gill and Thomson, 1955;Fraser and Morley Jones, 1975 found differences in yields, and possibly in composition, of milk (Smith, 1952), with a tendency for piglets suckling anterior teats to gain more weight than those suckling posterior teats (Hartsock et al., 1977). Nevertheless, more recent studies (Fraser, 1973(Fraser, , 1980 suggested that yield differences are due to a cause-and-effect relationship between the different elements of sow and piglet behaviour, and the relationship of behaviour to milk ejection. ...
Variability of pig weight at weaning can be a significant problem with some management systems. The purpose of the present study was to increase uniformity by assigning lighter birth weight piglets to the front teats (supposedly more productive). Thirty-four litters were randomly assigned in a repeated measurement, split-plot design. No difference was found (P > 0.05) in the litter weight between treatments (modified teat order versus intact ones). Variances of mean weaning weights (39 days of age) were also similar (P > 0.05). Heavier piglets showed a tendency to remain heavier independent of the udder region to which they were attached. It was concluded that no advantage was obtained in homogeneity and mean litter weight from modifying the natural teat order.
... The moment of milk ejection was considered when more than half of the piglets were actively stimulating the udder and suckling intensively for approximately 15 s without interspersing teat massage or moving around. The end of post-ejection massage was established when more than half of the litter had left the udder or was inactive next to it (Barber et al. 1955;Fraser 1980). ...
This study evaluated the effects of litter equalization with different weights and numbers of piglets relative to the number of functional teats on sow and piglet performance during lactation. Litters (n = 183) were equalized based on weight (light: 0.955–1.289 kg; heavy: ≥ 1.399–1.935 kg) and piglet number by total number of functional teats (Eq-0: same number of piglets and teats; Eq + 1: one extra piglet than the teat number). Sow body condition was evaluated during lactation. Piglets were individually weighed and evaluated for face, body, and joint injuries. Females lost more caliper units in heavy litters (-0.39; P = 0.05), with no interaction with Eq-0 or Eq + 1 (P = 0.11). There was no difference in the total number of piglets weaned (P ≥ 0.08) regardless of litter weight, number of piglets by functional teats, or their interaction. Weaning weight and average daily gain were positively affected (P < 0.01) in heavy (6.1 ± 0.1 kg; 227.9 ± 0.3 g/d) compared to light litters (5.5 ± 0.1 kg; 214.0 ± 0.3 g/d). Mortality was not affected by different groups (P ≥ 0.60). However, the percentage of piglets removed before weaning was higher for Eq + 1 (5.21 ± 0.75%) than Eq-0 litters (2.66 ± 0.49%; P < 0.01). Heavy litters had a higher percentage of piglets with facial, body, and joint injuries compared to light litters, regardless of the number of piglets by functional teats. Equalizing litters with one extra piglet resulted in a higher pre-weaning piglet removal rate. Body parameters of sows were not compromised comparing Eq-0 and Eq + 1.
... Pig producers have high loss in the first week after parturition, with the highest morbidity and mortality related to malnutrition and scours (Wheeler et al., 2001). Porcine milk is a unique feed for piglets from birth and functionally supports their growth and development physiology (Barber et al., 1955;Prunier et al., 2010). Milk LF has multiple biological functions including protection against pathogenic infection and optimizing growth and development of newborns; therefore, the determination of how the concentration of LF changes during the various stages of lactation is very important in pig production and health (Hurley, 2001). ...
Lactoferrin (LF), a sialylated iron-binding glycoprotein, has numerous vital physiological functions including immunomodulation and protection against a large group of microorganisms, improving neurodevelopment, health, growth performance, and milk production. Lactoferrin occurs in human milk at a higher concentration compared with bovine milk, but little information is available on LF concentrations in porcine milk and the effects of sow parity on milk LF concentration. The objective of this study was to quantify the LF concentration in porcine milk and to compare that concentration between gilts and sows during lactation. We also investigated the effect of genetic background and litter size of the female pig on the LF concentration of porcine milk. The milk from 30 gilts and 35 sows was collected at 3 stages of lactation, namely colostrum, transition, and mature milk. Standard and experimental samples were analyzed by ultra-high performance liquid chromatography using a diode array UV detector. The following findings were reported: (1) porcine milk contained significant levels of LF with the highest concentration in colostrum, which decreased by ∼62% and ∼67% in transitional and mature milk, respectively; (2) mature gilt milk contained a 22% higher concentration of LF compared with sow milk, which was statistically significant; (3) breed line had an overall significant effect on the LF content of porcine milk; however, when the breed was considered, no significant difference was observed; and (4) LF concentration of porcine milk was not significantly influenced by the litter size. The presence of LF in a higher concentration in porcine milk suggests that LF is an important constituent of pig milk that might contribute to the optimum growth and development of piglets.
... One factor in that index is the quantity and quality of milk provided to piglets by nursing sows which affects the strength of the piglets and their potential as they mature. Related to that is the milk let-down reflex of sows which depends on many different hormones, especially prolactin and oxytocin [1][2][3]. Both of those hormones are stimulated by piglets massaging the udder [4]. ...
Operation of the farrowing house is essential to the productivity of a swine farm, requiring not only good management but also knowledge of the behavior of sows and piglets. Stress can negatively affect production in farm animals and could be a factor in production indexes. The objective of this study was to investigate the effect of artificial sucking sounds on the behavior of piglets and fecal glucocorticoid (FGM) concentrations of sows. A total of 30 sows were divided into two groups: a treatment group (15 sows) was exposed to artificial sucking sounds and a control group (15 sows) was not. Both groups received the same management; the two open-house system locations were separated by a distance of about 270 meters. The study had three key objectives: to compare farrowing indexes and to observe the sucking behavior of piglets using CCTV cameras. Fecal samples were collected daily for 21 days from the period after parturition to weaning to assess adrenal activity. The treatment group had a significantly higher average number of times piglets came to a sow’s udder, and sows had a shorter onset time for the first piglet to come to the sow’s udder than the control group (both P<0.05 ). The patterns and levels of FGM between the two groups were not different (both P<0.05 ), but the treatment group had better farrowing indexes than the control group ( P>0.05 ), particularly for litter weight gain and percent preweaning mortality. In addition, the weaning to first service interval of the treatment group was shorter than the control group ( P<0.05 ). This indicates that the artificial suckling sound probably has no adverse effect on adrenal responses of pig; however, it improves production indexes of postparturition sows.
... Numerous studies on nursing and sucking behaviour in pigs have shown that the absolute number of daily sucklings in a 24-h period varied considerably between the studies and the population used, depending on, for example, housing condition, breed, individual sow or observed week of lactation (e.g. Barber et al ., 1965;Hernandez et al., 1987;Jensen, 1988;Jensen and Recén, 1989;Bøe, 1991 andWattanakul et al ., 1997;Herskin et al ., 1999). Mostly, a number of around 24 daily sucklings (or an average frequency of around one suckling per hour) were reported to occur during the first 1 to 2 weeks. ...
The suckling frequency in 34 first-lactation sows and their litters in conventional farrowing pens was observed during a 35-day lactation period from birth to weaning. In order to quantify the ontogenetic development of this behaviour a non-linear regression function was used as a model. The maximum (MAX) of the curve was determined at day 8·5 (31·4 sucklings per 24-h period) and was considered as the biological beginning of the weaning process. The occurrence of MAX was shifted towards an earlier time by about 6 days earlier from small (4 to 7 piglets per litter) to large litters (11 to 14 piglets per litter). However, no significant influence of the litter size on the development of the daily suckling frequency and the average individual piglet weight was found. Nevertheless, there was a tendency for an inverse relationship between the litter size and the piglet weight during lactation and, further, for an increased daily suckling frequency during early lactation and a lower frequency during late lactation in larger litters. As a compensation for the decreasing suckling frequency piglets markedly increased their creep food consumption in the last week of the suckling period (day 28 to 35). The results indicate that the suckling behaviour in domestic pigs reflects sow-piglet relationships which are consistent with a theoretically predicted model of weaning conflict. Hence, it is suggested that modelling the suckling behaviour using well defined and comparable measures may be a suitable approach for the evaluation of the weaning process both in terms of sociobiology (e.g. weaning conflict, parent-offspring conflict) and of farm animal science (e.g. performance, housing conditions).
... However, there were marked differences in the early performance of these piglets depending on the feeding regime they experienced. Once cyclical suckling is established in piglets, the regular intervals under natural conditions range from 21-96 minutes in 1 to 51 days of lactation (Barber et al., 1955;Ellendorf et al., 1982;Newberry and Wood-Gush, 1984;Auldist and King, 1995;Arey and Sancha, 1996;Wechsler and Brodmann, 1996;Spinka et al., 1997). It is therefore surprising that in this experiment the piglets which were nursed at one hour intervals had the lightest body weight from day 8 onwards. ...
One hundred and forty-four piglets with an average birth weight of 1,67213.4 g were used to evaluate different feeding strategies for piglets reared from birth on a dummy sow. A 32 factorial experiment compared three nursing frequencies (1, 3 or 6 h intervals) and two feeding regimes (milk only, or milk combined with access to creep feed and water). The piglets which were nursed at one hour intervals had the lightest body weights at all days, and the poorest combined milk and creep feed dry matter conversion efficiency to piglet body weight gain in the second week. Piglets which were nursed at 3 h intervals had the heaviest body weight at day 15 and 22, but those nursed at 6 h intervals achieved similar body weight by days 29 (milk withdrawal) and 36. Piglets offered creep feed were observed to wean themselves before cessation of milk availability, and the timing of this self-weaning depended on the nursing frequency. The piglets nursed at one hour intervals weaned themselves between day 22 and day 29, those nursed at 3 h intervals weaned themselves between day 15 and day 22, whilst those nursed at 6 h intervals weaned themselves between day 8 and day 15. The piglets which were nursed at 6 h intervals had the highest total dry matter intake in weeks 3 and 4 when fed with milk, creep feed and water but not when fed milk only. They consequently had the poorest dry matter conversion efficiency in the fourth week and overall when fed with milk, creep feed and water, but not when fed milk only. It is concluded that the optimal management routine under these conditions is a 3 h nursing cycle with provision of supplementary creep feed and water.
... In fact, colostrum intake accounts for 88% of the variance in piglets' weight gains [81]. The weight gain of piglets during a nursing can also be used as a measure of colostrum intake [82] and this method is called the Weigh-Suckle-Weigh (WSW). However, different weight losses, such as faecal, urinary or metabolic losses, must be taken into account [83]. ...
An early and high intake of colostrum is a major determinant of survival during the early suckling period, when most losses occur. Indeed, piglets are born devoid of body fat and are dependent on colostrum as their sole energy source. Colostrum also has other essential roles for the developing piglet; most importantly, it provides passive immunity and nutrients to the piglet and permits thermoregulation. It also stimulates gastrointestinal development, muscle protein synthesis and the development of active immunity. Neonatal swine can efficiently use colostrum since they have a remarkable capacity to deposit large amounts of fat and can also absorb intact immunoglobulins for 24 h postnatally. The production of colostrum, however, is very variable between sows and the factors affecting this variability are not well known. Such studies are most difficult to carry out
since it is not easy to estimate colostrum yield. Indeed, the various methods that can be used to measure colostrum yield all have several drawbacks. The endocrine status of the sow undoubtedly affects the process of colostrogenesis and the underlying mammary changes associated with it. The composition of sow colostrum is well known, yet it is only recently that the presence of numerous bioactive compounds which can either protect piglets from infection or modulate their metabolism was detected in colostral secretions. There are indications that the composition of colostrum can be altered by some management components but further studies are necessary in that area.
... As in this study, Smith (1961) observed an increased creep feed consumption by the young of separated sows. Because creep feed intake is known to be inversely related to sow milk yield (Barber et al. 1955;Smith 1961) the dams of the partially weaned piglets in the present study probably had reduced milk production. ...
Thirty-six multiparous lactating sows were randomly allocated to 3 treatments to evaluate the technique of partial weaning to induce oestrus. The treatments were: (1) an uninterrupted rearing period (control), (2) daily separation of the dam and litter (beginning on day 14 of a 28-day lactation) for a 12 h period during daytime, and (3) daily separation of the dam and litter (beginning on day 14 of a 28-day lactation) for 12 h overnight. Plasma progesterone determinations indicated that only 3 of the partially weaned sows had ovulated in lactation. There was no treatment effect on the weaning to remating interval. Partially weaned sows had a lower body weight loss during lactation than the controls (P
... That piglets gained weight at a lower rate than those kept intensively may have been due to a lower milk yield from the sows. BARBER et al. (1955) found that sows allowed to suckle their young at 2 hour intervals pro- duced less milk than sows suckling at one hour intervals, and the low suckling frequency of sows in the Pig Park may have also had this effect. It is suggested that the frequent suckling bouts initiated in farrowing houses by social stimulation from nearby suckling sows and litters pro- mote milk production and piglet growth, even though some of these sucklings are unsuccessful and increase the interval between successful sucklings. ...
The suckling behaviour of domestic pigs living in a socially and ecologically rich outdoor environment was examined in order to obtain a baseline for comparison with behaviour in more restricted and barren environments. It was found that the piglets' growth rates were not consistently influenced by their suckling location along the udder, and that the concept of dominance at the udder was not justified. Crowding at the udder was probably an important factor prompting piglets to seek milk and solid food elsewhere, and two piglets switched from suckling from their own mother to suckling from another sow. True communal suckling was not exhibited. Piglets were responsible for locating their preferred teat and defending it from others. Sows did not attempt to prevent familiar piglets from other litters from suckling from them, although they sometimes terminated a suckling bout when disturbed by fights at the udder. Synchronization of suckling between litters was common. Suckling bouts did not always result in milk let-down, indicating that this is not a phenomenon exclusive to intensive housing systems. Weaning occurred naturally between 60 and 100 days after birth, and its timing varied both within and between litters but was not closely linked to the amount of aggression received from the sow.
... Maximising milk production in sows is important in optimising the growth rate of piglets pre-weaning. However, research in this field has been hindered by the difficulty of measuring milk yield in sows. The yield (volume removed by the young) of milk from the sow has been assessed by the weigh-suckle-weigh (WSW) technique (Barber et al . 1955;Lewis et al . 1978), by machine milking the sow after the administration of oxytocin (Hartman and Pond 1984), by weekly weight gains of piglets (Lewis et al . 1978), and also by the technique of isotope dilution (Rudolph et al . 1984;Pettigrew et al . 1987;King et al . 1989King et al . , 1993Toner et al . 1991). ...
Previous studies estimating milk intake using deuterium oxide (D2O) as a tracer have required sublimation of the sample fluid (usually plasma) to remove solids and retrieve total water. This procedure has been simplified by directly measuring the D2O content of plasma with a Fourier transform-infrared (FT-IR) spectrometer, removing the requirement for sample sublimation. Comparisons of samples that were split and then analysed as water of sublimation and as total plasma were performed. It was found that the direct analysis of the plasma could be achieved without a loss in fidelity of the results (sublimated v. plasma, r² = 0·976;n = 26). Linearity of assay standards was very high (r² > 0·997). The modified technique was used to determine the milk intake by piglets from litters of 7 sows during established lactation (Days 10-15). Water turnover (WTO) was shown to be the primary point by which differences in the piglet milk intakes were influenced. Differences in the milk composition had minimal effect on the milk intake determinations. Milk intake by each piglet was shown to be strongly correlated to piglet growth (r² = 0·59, P < 0·01). The relationship between milk intake and piglet growth was even stronger when examined based on the data from all piglet litters (r² = 0·84, P < 0·01).
... Piglets located at the posterior end of the udder tended not to move to the anterior end, and vice versa. The average duration of milk letdown observed in this study was shorter than that reported by Barber et al. (1955), Folley and Klaggs (1966)' Wh' lttemore and Fraser (1974)' Ellendorff et al. (1982, and Auldist and King (1995), who all reported sucking times in excess of 13 s. Differences may have arisen because of variation in determining the beginning and cessation of milk ejection, and the various methods used. ...
The mechanisms of increased growth of small piglets following split weaning were studied using a total of 10 sows and 100 piglets. Sows and their litters were allocated to a treatment group (piglets split-weaned) or control group (no piglets split-weaned). At day 22 of lactation, piglets in each litter were classified as either 'heavy' or 'light', with equal numbers in each group. 'Heavy' piglets were removed from sows at day 22 (s.e.m. 0.17) in split-weaned litters while 'light' piglets remained with their mothers for an extra week. At 29.5 (s.e.m. 0.21) days of age, sows from both split-weaned and control litters were weaned. Milk consumption was estimated between days 16 and 19 and on day 24 of lactation by weighing piglets before and after sucking. During milk letdown, the teats that piglets sucked from were noted. A video recorder was used to determine the frequency of natural sucklings, the proportion of unsuccessful sucklings, and the time taken for piglets to consume milk during ejection, over a 16-h period before and after split weaning. 'Light' piglets in split-weaned litters grew 61% faster (P < 0.001) than their counterparts in control litters and were 15% heavier (P < 0.01) at weaning. This was explained by a 49% increase in milk intake (64 v. 43 g/sucking, P 5 0.001). Increased milk intake was due to multiple teat swapping with an associated longer duration of sucking during letdown. 'Heavy' piglets weaned at 22 days were lighter at 29 days than their counterparts in control litters (P < 0.01). Gains in growth made by 'light' piglets in split-weaned sows over their counterparts in control litters had disappeared by the time pigs were 9 weeks old, and piglets classed as 'heavy' at day 22 of lactation remained heavier ( P < 0.001) at 62 days of age irrespective of treatment.
... The nursing interval during the night was 2 minutes shorter than during the day. Donald (1937), Schneider (1934, Wells et al. (1940), Shepperd (1929), Smith (1952a and Barber et al. (1955) have studied the nursing frequency of pigs. In generall the nursing interval varied from 60 --90 minutes with the majority being 60 minutes in length. ...
... A factor not examined here that may contribute to positional preference of young pine voles is difference between nipple pairs in milk yield. In some species, anterior 'nipples are sometimes more productive (S. scrofa- Barber et al. 1955;Donald 1937), whereas in other species posterior nipples seem more productive (A. binturong- Schoknecht 1984i F. silvestris-Ewer 1959, and nipple preferencescorrelate with patterns of productivity. ...
The suckling behavior of some mammals is characterized by preferences for anterior or posterior nipples and consistent return by individual young to particular nipples or nipple pairs. Some murid species also display tenacious nipple attachment. Pine voles (= woodland voles, Microtus pinetorum) have tenaciously clinging young and 2 pairs of abdominal mammae. We examined whether young pine voles preferred particular nipple pairs and whether young on the 2 pairs were differentially groomed or dislodged by their mothers. We also examined whether young showed fidelity to suckling location. Young pine voles preferred the hindmost nipples and were dislodged less frequently from those nipples than from the more anterior pair. We found no evidence that mothers differentially groomed young on the 2 pairs. Fidelity to nipple and nipple pair was greater in small than in large litters, which may reflect less competition for hind nipples in small litters and the need to consistently stimulate a nipple to ensure productivity.
... The various techniques that have been developed for measuring milk consumption each have advantages and disadvantages. For example, the 'weigh-suckle-weigh' method is difficult to apply to marsupials, as the young are permanently attached to the teat ( Barber et al. 1955;Coombe et al. 1960;Robinson et al. 1968;Lewis et al. 1978;Green and Newgrain 1979). Although reattachment of the quokka young is possible, this method may disrupt the normal suckling pattern of the young (Ashman et al. 1975;Pettigrew et al. 1987). ...
We investigated the consumption of milk by the young quokka using the stable isotope deuterium oxide. The volume of milk consumed increased from 1.6 mL day–1 at 55 days post partum to 32.5 mL day–1 at 165 days. The daily energy intake ranged from ~22 to 151 kJ day–1 during pouch life. The crude growth efficiency (grams of growth per millilitre of milk consumed) increased from an average of 0.35 to 0.46 g mL–1 in the early stages of pouch life, and then decreased to 0.24 g mL–1 during Phase 2b of lactation. The crude growth efficiency measured in our study indicates that quokkas are equally efficient in converting milk energy to body mass as other marsupials reported in the literature. Measuring milk intake with this method offers a non-toxic, minimally invasive alternative to other techniques for measuring milk consumption in marsupials, when milk is the only source of water intake.
Variation in body weight (BW) of piglets at weaning is a drawback for successful implementation of multi-suckling (MS) systems. The current study investigated the combination of two intervention strategies, i.e. the timing of grouping and split-weaning, aiming to improve the BW gain of low birthweight piglets in an MS system and thereby reduce the BW variation at weaning on day 48 postpartum (p.p.). Eight batches of 5 sows with their litters were divided into 4 control (CTRL) and 4 treatment (TREAT) batches. In each litter, the second lowest (LBW) and highest (HBW) birthweight piglets from both sexes were selected as focal piglets. CTRL piglets were grouped on day 8 p.p. and no split-weaning was applied; TREAT piglets were grouped on day 13 p.p. and the three heaviest non-focal piglets per litter were split-weaned on day 35 p.p. Behaviour and feed intake were measured in focal piglets, and BW and mortality were measured in all piglets. Results showed that: (1) Throughout lactation there were no differences in BW or BW gain between CTRL and TREAT, nor were birthweight × treatment interactions found. (2) After grouping, there were no obvious differences between CTRL and TREAT in feeding and suckling behaviours on day 18, damage scores on snout, ear or tail and skin lesions on day 27, nor were birthweight × treatment interactions found. (3) After split-weaning, in week 6, piglets in TREAT tended to consume less feed than CTRL (P = 0.072). Low birthweight piglets in TREAT consumed numerically less feed and spent numerically less time contacting feed during the day than CTRL piglets. In week 6, there was a significant birthweight × treatment interaction in dry matter milk intake (P = 0.030), caused by a higher milk intake of TREAT-LBW piglets compared with CTRL-LBW piglets. In week 6, TREAT piglets tended to be present more at front and middle teats (P = 0.052) and tended to have lower snout damage scores (P = 0.084) than CTRL piglets. (4) Piglet crushing of all piglets in TREAT tended to be higher during the period when TREAT piglets were not yet grouped i.e. during days 9–14 than CTRL (P = 0.087). To conclude, split-weaning of the heavy piglets increased milk intake particularly of low birthweight piglets but this did not lead to a reduction in BW variation at weaning, as the increased milk intake was largely compensated for by a simultaneous decrease in feed intake.
A multi-suckling (MS) system for sows and piglets has been developed aiming to improve animal welfare. In this system, large variation in BW gain exists between piglets up to weaning at 9 weeks of age. We aimed to study the causes of variation in BW gain and DM intake of solid feed (DFI) (piglet + sow feed) of piglets during lactation in the MS system. A total of 15 sows and 60 focal piglets across three batches were studied. Individual intake of piglet and sow feed was measured by the dual marker method, and multiple variables were recorded. Multiple linear regression analysis with forward selection was conducted on BW gain and DFI after correcting for piglet sex and batch, using multiple explanatory variables including genetic background, birthweight (BiW), DM feed intake, behaviours and number of skin lesions. These factors jointly explained less than 45 % and 21 % of the variation in BW gain and DFI, respectively. In weeks 2–4, variation in BW gain was mainly explained by BiW (12.0 %) and play and nosing behaviours (7.6 %). In weeks 4–6 and 6–8, it was largely explained by DM intake of piglet feed with 15.1 % and 25.9 %, respectively. Individual variation in DFI in weeks 2–4 was explained by the presence at front and middle teats during suckling bouts (2.9 %), in weeks 4–6 by BiW (9.6 %), and in weeks 6–8 by the number of skin lesions (5.1 %). The unexplained variation in BW gain and DFI warrants further investigation.
The use of creep feeding for preweaning piglets is important to improve the performance of the piglets. The objective of this experiment was evaluate the effect of using or altering the position of piglet's creep feeder during lactation on piglet's performance and on behavior of piglets and sows kept in a hot climate environment. Forty-fi ve sows and their litters at 10 days of lactation were randomly distributed into three treatments: front feeder (FF)-near the side of the sow's head; back feeder (BF)-near the side of the rump of the sow; and no feeder (NF). All piglets were weighed individually to evaluate the average weight, weight gain and coeffi cient of variation of the weight. Behavior assessments of the piglets and sows were recorded in 3 period. At 15 and 21 d, piglets of the FF treatment were heavier (P ≤ 0.0001) than piglets of the other treatments. At 10-21d piglets of FF treatment had 76.2% less belly nosing behavior than the NF piglets (P=0.015). The treatments had no impact on behavior of the sows. The creep feeders positioned in the front of the farrowing crate increased piglet growth rate and decreased frequency of belly nosing behavior.
The first described, and still the most important, actions of oxytocin are its contractile effects on uterine smooth muscle (Dale 1906) and myoepithelial cells (Ott and Scott 1910). Not unnaturally, therefore, early investigators sought to establish release of the hormone during labor and lactation and found that this was indeed the case (see Tindal 1975). The highest concentrations of the hormone in plasma have been found at these times. Release in the female has also been claimed at other times of the reproductive cycle, including mating. Stimuli for secretion in the male animal are not so well established. Again it has been suggested that release also occurs during mating and that it may be associated with known stimuli for vasopressin, such as increased plasma osmolality and hemorrhage (Forsling and Brimble 1985). As with most hormones, understanding of the mechanisms of release has depended on the availability of sensitive assay techniques. Sensitive bioassays have been available for a number of years (Chard and Forsling 1976), but the number of samples which can be processed is very limited. Release has been monitored in many studies by recording intramammary pressure, but of course this approach is limited to the lactating female. Recordings have been made from putative oxytocin neurons (see chapter by Dreifuss), but again this approach is largely limited to studies in the lactating female.
1. Baby pigs were removed from the sow 36–48 h after birth and reared on a diet of reconstituted whole-milk powder until 28 d of age. The whole milk was either mildly or severely heated before spray-drying; the severe heating completely denatured the whey proteins.
2. When the two milks were given at a high level of intake, either at hourly intervals or twice daily, severe scouring and some deaths occurred, the incidence being higher among pigs receiving the severely heated milk. The severe heat treatment also reduced the nutritive value of the milk powder as measured by the performance of the pigs during the 1st week of life. However, no difference in the nutritive value of the two milks was apparent for the surviving pigs over the whole experimental period.
3. There were no deaths when the two milks were given at a moderate level of intake and at hourly intervals. The effect of heat treatment on performance was similar to that at the high level of intake.
4. The apparent digestibility of the nitrogen in the diet was similar for both milks. However, balance trials could not be carried out when scouring occurred, when differences between the milks were most likely to be apparent. The N retention was similar with both milks at 7 d of age, although retention was higher when the severely heated milk was given to pigs between 14 and 21 d of age.
5. The digestion of the two milks was studied in 28-d-old pigs. The ability of the severely heated milk to clot in the stomach was greatly reduced compared with that of the mildly heated milk, but the performance of the pigs was unaffected. No other differences in the digestion of the milks were found. The ability of the diet to clot in the stomach appeared to be unimportant at this age.
6. It is possible that a reduction in the clotting ability of the severely heated milk was responsible for the decreased efficiency of digestion during the 1st week of life.
In some mammals, young exhibit obvious preferences for anterior or posterior teats. In addition, individuals within litters may suckle consistently from the same teat or pair of teats—patterns of behavior termed teat fidelity and teat-pair fidelity, respectively. I examined if young prairie voles (Microtus ochrogaster) preferred particular locations of teats and exhibited fidelity to a particular teat or teat-pair. I marked individual young and scored location of teats suckled every other day from day 4 to day 16 postpartum. Young preferred the hind pair of teats over the middle teats and least preferred the front teats. Fidelity in choice of teat and teat-pair varied with litter size, being more pronounced in small litters. Advantages of suckling from hind teats are unknown. Enhanced teat fidelity and teat-pair fidelity in small litters probably reflect reduced competition for preferred locations of teats and the need for consistent stimulation of a teat to ensure adequate milk production.
Lawrieas meat science has established itself as a standard work for both students and professionals in the meat industry. Its basic theme remains the central importance of biochemistry in understanding the production, storage, processing and eating quality of meat. At a time when so much controversy surrounds meat production and nutrition, Lawrieas meat science, written by Lawrie in collaboration with Ledward, provides a clear guide which takes the reader from the growth and development of meat animals, through the conversion of muscle to meat, to the point of consumption. The seventh edition includes details of significant advances in meat science which have taken place in recent years, especially in areas of eating quality of meat and meat biochemistry.
This study was conducted to test the efficacy of the automatic liquid feeder(designated as NLRI) developed by National Livestock Research Institute, Korea for 7-day old early-weaning piglets. The other automatic liquid feeder imported from USA(designated as IALF) was used for a comparative purpose. A total of sixty piglets of 7 days of age were allotted to three treatments. The control group of 20 piglets was raised by their own sows until 21 days of age, while others were shifted to automatic liquid feeders of either NLRI or IALF on 7 days of age and reared during 14 days post-weaning. After then, all the piglets were fed nutritionally identical mash diets until 70 days of age. Compared with control group, body weight of piglets reared on automatic liquid feeders were lighter(P〈0.05) at 21 days of age [5.55kg (control) vs 4.97 (NLRI) and 4.98kg (IALF)], while heavier(P〈0.05) at 70 days of age(24.82kg vs 30.17 and 29.42kg). The results indicated that pigs reared on liquid feeding showed higher(P〈0.05) average daily gain than control pigs during the whole experimental period [346.7g (control) vs 425.8 (NLRI) and 416.1g (IALF)], while no difference was found in feed/gain (1.67 vs 1.78 and 1.84). There was no difference in growth performance and incidence of diarrhea between two automatic liquid feeders, NLRI and IALF. Compared with control group, intestinal villi tended to be shorter in liquid feeding group during the first week, but were recovered within two weeks. The results suggest that the automatic liquid feeder newly developed by National Livestock Research Institute, Korea can be successfully used for rearing young piglets weaned at very early age.
The overt behaviour of sows towards their piglets and piglets towards their dams in a non-nursing context was examined in 18 litters over the course of a 5-week lactation. Sows were housed either in typical, restrictive, commercial conditions or in a slightly larger area without the physical restrictions. In the latter conditions, “sniff” and “naso-naso” contact were performed more frequently. Other behaviours recorded climbing on the sow, biting the sow, biting piglets) did not differ between the two environments. The significance of the sniff and naso-naso contact result is discussed.
1. The percentage of intramuscular fat (and its iodine number), of moisture (fat-free), and of total, myofibrillar, sarcoplasmic, stroma and non-protein nitrogens in lumbar 1. dorsi muscles, and their ultimate pH, fibre diameter, cross-sectional area and weight (both absolutely and as a percentage of the total musculature) were determined at bacon weight in two male and two female litter-mate pigs from each of four pure-bred sows mated with one boar of the same breed. Such data were obtained for pigs of Large White, Landrace and Welsh breeds.
Scientific literature on pig behavior and its practical applications was reviewed and discussed. Areas were identified where behavioral research is likely to produce major benefits in productivity. It was noted that some husbandry practices appear to be out of harmony with the behavior of domestic animals, and that an imaginative research effort is needed to improve confinement rearing of pigs.
A dummy sow and feeding system was developed to rear piglets from 24 hours of age to at least 3 weeks. The dummy sow incorporated particular features associated with the real sow which appeared to stimulate the development of normal feeding behaviour in the form of nuzzling and sucking. Good growth rates were finally achieved after modification of the milk feed composition. The apparatus was designed to investigate the suckling behaviour of piglets as it occurs on the real sow. Some further applications are outlined.
Application of knowledge of the ethological characteristics of domestic swine (Sus scrofa) facilitates their efficacious management under extensive agricultural conditions. Domestic swine exhibit complex maternal and social behavior that includes nest building, communal nesting, and a high degree of tolerance of young that are not their own even to the extent of defending those young and often allowing them to suckle. Neonatal piglets are higly precocial; they typically establish a teat order within 24 h of birth, can readily identify their own dams by odor and sound, and integrate into the herd when 1 week–10 days of age. A varied environment that includes grass, brush and water enables swine to optimize behaviorally their own welfare. Maintenance of farrowing sows in small groups in which individual farrowing dates are closely synchronized fosters formation of stable social relationships and minimizes displacement of young piglets from their dam's udder by older piglets. Human mimicry of key elements of typical greeting rituals facilitates positive interspecific socialization. Sows positively socialized to people usually tolerate close human approach and touch even during and after farrowing, making this species particularly well suited to educational, recreational or other programs that involve the close observation of, or human interaction with, animals.
In this study, we investigated the development of the suckling behaviour and milk consumption in piglets as a response to sow grunting during the first 24 h after farrowing. Four Yorkshire and 6 Yorkshire-Finnish Landrace sows were observed in a commercial pig-breeding farm continuously for 5 h (the 5-h period) and then after 8, 12, 16, 20 and 24 h (the later periods) after the birth of the first piglet. The first (A) and the sixth (B) piglets in each litter were weighed at 5-min intervals during the 5-h period, and before and after the first suckling observed during the later periods.The number of grunt rate peaks per hour emitted by the sow increased from 1.3 at the first hour to 4.2 at 5 h and stabilized at a level of 1.5 at 8 h. The number of grunts within 15 s of the grunt rate peak increased after the first hour and remained fairly stable after the fourth hour.The occurrence of suckling behaviour increased during the whole observation period and significantly so when grunt rates were high. Massaging was rare before the sixteenth hour, after which it tended to increase when grunt rates were low. Seeking and fighting at the udder were significantly more common with higher grunt rates, whereas behaviour off the udder was significantly more common with low grunt rates.During the first 5 h after the onset of the farrowing, the A and B piglets gained weight usually during different 5-min periods with an average of 20 min between the gains. Both piglets were at the udder during 55% of the observed sucklings during the later periods, but gained weight simultaneously only during 10% of the sucklings.
Several studies indicate each piglet within a litter is affected differently by weaning and that these individual responses may be altered by the age of the litter at weaning. In the present study, eight litters of individually marked piglets (n=79) were randomly assigned to be weaned at 21 or 35 days (four litters per treatment), and behavioural and physiological measures were used to elucidate the relationship between age and weaning, and the within-litter variation in short-term responses to weaning that is thought to occur. Weights, vocalisations, littermate directed behaviours, suckling related parameters and salivary cortisol concentrations were recorded for individual piglets on both treatments from birth to 37 days of age. The time piglets spent at the udder, massaging or suckling, gradually increased over the preweaning period, as did aggression, nosing and chewing of littermates. Higher levels of aggression were found on the day of weaning relative to the 2 days following, whilst vocalisations did not peak until the day after weaning. Salivary cortisol was found to be lower for D35 piglets (day×treatment effect: F2,116(38)=2.67, P=0.073) and ‘high vocalisations’ twice as high on the day after weaning for D21 piglets compared to D35 (day×treatment effect: F2,146(8)=3.93, P
One hundred and one individually marked healthy piglets in 10 litters were followed from birth to 9 weeks of age in order to elucidate the relationships between weight changes and behaviour at weaning and regrouping. The piglets were weighed once a week and additionally at extra instances just before and after weaning and regrouping. The pigs were weaned by removal of the mother 6 weeks post-partum and the litters were mixed two by two, 7 days later, so that the pigs with weight rank 1, 3, 5 etc. in one litter were mixed with the corresponding pigs of the other litter. The behaviour of the pigs was recorded on video during 24 h before and after weaning and regrouping, and at 9 weeks of age (before moving to the fattening unit) by obtaining 20 s of continuous recording every fifth minute. Both weaning and regrouping markedly increased the frequencies of eating, drinking, aggression and submission, although the latter was only substantially increased by regrouping. Piglets having had the largest weight gain between 3 and 4 weeks post-partum (indicating good teat quality) ate less solids on all observations, except just before moving to the fattening unit, and drank less water before weaning. The same piglets had a lower relative weight gain at regrouping than their litter mates. During weaning, those pigs gaining more weight than their litter mates were more submissive, but there was no effect on aggression. When the pigs were regrouped, the pigs gaining more weight than their pen mates were more aggressive and those gaining less weight were more submissive. Aggression and submission were not observed in all pigs. During regrouping, those pigs showing submission were those that had used more productive teats that those that performed both aggressive and submissive behaviour. Pigs that showed aggression at regrouping were heavier than their pen mates and had a higher weight gain. In general, we conclude that the teat quality determines the nutritional change of the piglet at weaning, and also the degree of agonistic interactions at weaning and subsequent regrouping.
Two experiments were conducted with the aim of investigating whether non-nutritive nursings (nursings without milk ejection), when included into a regular rhythm of nursings with milk ejection, affect milk intake and body weight gain during early lactation in pigs. In experiment 1, when the piglets were 9 to 12 days old, 8 sows were forced to nurse every 70 min three times in succession. Between the nursings, 2 piglets had an additional opportunity to massage the sow's teats from which they had been suckling. Milk intake was estimated by the weigh-suckle-weigh method. Additional massage on the two teats had no influence on milk output from those teats on subsequent nursings. In experiment 2, on day 7 or 8 post partum 16 sows were forced to nurse at every 70 min for a period of 24 h. In nine of the sows (group MIN70 + 15), non-nutritive nursing were induced 15 min after each nutritive nursing. In the other group of seven sows (MIN70), there was no opportunity for this additional massage. The total duration of udder massage was considerably longer in group MIN70 + 15 (median 271 min vs. 165 min, Mann-Whitney U -test, p < 0.005) than in the other group that did not have the additional massage. Nevertheless, the weight gain during the whole 24 h period was the same in both groups (157 g vs. 141 g, Mann-Whitney U -test, n.s.). Both groups had nearly the same decrease in weight during the 24 h manipulation of nursing rhythm in comparison with the weight gain during a unmanipulated period 24 h one day before (group MIN70 + 15 decreased 28% and group MIN70 decreased 31%, Mann-Whitney U -test, n.s.). The results suggest that additional massage provided during non-nutritive nursings does not induce higher milk output during subsequent milk ejection, either locally or systemically.
The pig provides many examples of how principles of behavioural ecology and sociobiology can lead to insights into farm animal behaviour. According to parent-offspring conflict theory, parents should tend to give a level of parental investment somewhat below that solicited by the young. When closely confined during lactation, sows can do little to limit the amount of contact with the piglets, and the young stimulate a prolonged, high level of lactation. Certain alternative housing systems allow the sow to limit the stimulation she receives, and the resulting reduction in lactation can actually be advantageous to both parties. Communal care of offspring has both advantages and disadvantages in various species; these may help to explain why communal care occurs to a limited extent in pigs, and why sows isolate their litters in early lactation. Neonatal competition and mortality among newborn piglets have strong parallels in the “facultative siblicide” which adjusts brood size in numerous species of birds. These species typically produce slightly more young than are normally raised, and the number of siblings that survive is determined by the ability of the smaller young to withstand intense competition. The hypothesis that pigs have evolved a similar system of brood reduction may explain why piglet mortality is such an enduring problem and requires solutions different from those that work for other domestic species. Resource defence theory provides a functional framework for studies of aggressive behaviour. Factors determining the defensibility of a resource include its degree of clumping in time and space, and these suggest ways to reduce competition for food and other resources. However, aggression involved in establishing social dominance is more likely to be influenced by manipulating traits of the competing animals (competitive ability, familiarity) rather than the defensibility of resources. We conclude that principles of behavioural ecology and sociobiology provide a useful functional and evolutionary perspective to complement other approaches to the study of farm animal behaviour.
Nine suckling calves were allowed to afterstimulate their dams at three levels, ad libitum , for 3 min or none, at each suckling meal twice daily in a repeated 3 2 3 Latin square experimental design. Each experimental unit consisted of one cow-calf pair for 6 days. Milk yield was recorded and samples were taken at the morning meal on day 7 by hand-milking one quarter while the calf suckled the other three. Samples were analysed for fat content and 19 fatty acids (FA), summarized in five groups: locally synthesized FA, FA deriving mainly from blood serum (BSFA), saturated FA (SFA), unsaturated FA (USFA) and essential FA (ESFA). Variables were expressed as g g -1 fat, kJ g -1 fat, g kg -1 milk delivered at the recorded suckling meal and kJ kg -1 delivered milk. The only factors affected were milk yield, and BSFA, SFA, USFA and ESFA when related to the delivered milk. The relationship between levels of AS and milk yield was a second-degree polynomial.
Five experiments, involving the hand milking of 53 farrowing sows, examined aspects of colostrum yield during and soon after farrowing. The initial and abundant yield of colostrum from a teat (averaging 6 to 10 g/min) declined after several minutes of continuous milking. Thereafter, most colostrum was released in discrete ejections, possibly caused by discrete releases of oxytocin. Colostrum ejections varied greatly in their yield and duration, and were sometimes associated with the birth of a piglet, sounds of other sows nursing, or other factors.
Teats varied greatly in their yield. During the initial minutes of milking, the most anterior teats gave, on average, 3 to 5 times more colostrum than the most posterior teats, with a nearly monotonic decline from front to rear. However, the difference between anterior and posterior teats disappeared after several minutes of continuous milking. Stimulation of the anterior teats appeared to cause the release of more colostrum than did either the stimulation of the posterior teats or no stimulation of the udder at all. A strong sucking stimulus, applied to several teats by a milking machine, elicited a large, prolonged release of colostrum.
The results suggest that (1) much of the colostrum received by newborn piglets is obtained in discrete ejections rather than in a continuous manner; (2) appropriate stimulation of the udder by the piglets may be important to elicit maximum colostrum yield; and (3) a high initial yield from anterior teats, coupled with a higher yield when anterior teats are stimulated, may help to explain the piglets' preference for anterior positions on the udder.
Twenty sows and their litters were observed at regular intervals over the 1st week post partum to determine piglet-teat relationships. At 7 days of age, three piglets were exchanged between five pairs of litters, the other 10 litters remaining intact as controls. Observations of sucking were continued for another week. All piglets were weighed at 3, 7 and 14 days of age. Cross-fostering disrupted the teat sucking relationships of the whole litter compared with those of control litters, but the probability of sucking at the same teat in the 2nd week as in the 1st was less in fostered piglets than in their non-fostered littermates. The weight gain of fostered piglets during the 2nd week was reduced to 79% of that in their non-fostered littermates. Both disruption of sucking and reduction in weight gain were greater in those piglets that had to compete, on their foster mother, for the teat they preferred during the 1st week than for those whose teat was free.
Piglets in litters, paired according to farrowing date, were redistributed during the first day after birth according to two schemes. In scheme AC–BD, one sow of the pair received the heaviest and the third heaviest quarters of the combined litters (based on weight post partum ), while the other sow received the second heaviest and the lightest quarters. In scheme AB–CD, one sow received the heavier half, and the other the lighter half of the piglets. After 3 weeks under scheme AB–CD, the weight difference between the second and third quarters had become reversed, while under scheme AC–BD the difference was preserved. There was no evidence of a corresponding interaction in the selection of anterior or posterior teats. The rank correlation of the piglets' initial weight and suckling position was low for most sows. No marked differences were observed between fostered and unfostered piglets in the weight measures or suckling position. It is concluded that the growth of the piglets was influenced by the relative size of their litter-mates after redistribution, but that little of the effect could be explained by competition for the anterior teats.
Teat orders were determined for 76 litters of Large White and Large White × Landrace pigs. Regression analysis within litters revealed a relationship between suckling position and weight both at birth (P<0·01) and at 3 weeks of age (P<0·001), with the heavier piglets tending to occupy the more anterior teats. The correlation coefficients, however, were very small (r = –0·16 and –0·22 respectively). The correlation between birth weight and 3-week weight was much larger (r = +0·47); and a comparison of pairs of litter-mates showed that a difference in birth weight of 0·25 kg or more persisted at 3 weeks in the majority of cases, regardless of which piglet suckled the more anterior teat. Birth weight accounted for much more of the variation in 3-week weight than did teat number, and, when the effect of birth weight had been taken into account, teat number accounted for only an additional 2·3% of the variation. Even so, the anterior teats did appear to confer some advantage which was independent of that of the birth weight of the piglets suckling these teats. From the results of this and other studies it is concluded that there is only a weak relationship between suckling position and weight at birth and 3 weeks. Other unidentified factors are probably of more importance for the within-litter variation in weight gain of suckling pigs.
1. A study was made of the performance of eight litters of pigs housed under two widely different levels of ambient temperature during the suckling period and under uniform conditions from weaning to 200 lb. live weight.
2. There was no significant treatment difference in the amount of milk suckled, but the pigs exposed to the lower temperature consumed more solid food before weaning.
3. Up to weaning those kept at the higher temperature were the more efficient converters of milk and solid food into live weight.
4. There was a highly significant correlation between milk suckled and live-weight gain.
5. Probably through excessive handling, the pigs were under weight at weaning, but the postweaning performance appeared to be unaffected by the pre-weaning treatment.
6. The average milk yield of six sows from the 3rd to the 56th day of lactation was 275 kg. 605 lb.) (variations 202–347 kg. (445–764 lb.)). Yields have been compared with others published.
7. After allowing for maintenance requirements and weight gain or loss it is estimated that the sows required 412 Calories of net energy to produce 1 lb. of milk.
Consumption of solid food before weaning and growth before and after weaning were studied in 24 litters of eight to 13 Yorkshire × Landrace piglets per litter. From day 21 until weaning at day 28,12 litters were provided with a single two-space feeder, while the other 12 litters were provided with four similar feeders. Daily food intake by each litter was recorded throughout this period and feeding behaviour of individual piglets was filmed during the final 24 h. On the one-feeder treatment there were 4·1 (s.e. 0·6) piglets per litter which fed very little on the day before weaning (< 0·005 of sample video frames). These tended to have high birth weights and high growth rates on days 0 to 21, but low growth rates on days 28 to 42. Conversely, piglets which fed most on creep food were often those which had gained least on days 0 to 21. The four-feeder treatment increased average intake in the last 3 days before weaning and reduced the number of piglets which fed very little in the final 24 h to 0·6 (s.e. 0·3) per litter. However, neither average growth after weaning nor the occurrence of poorly performing individuals was different between treatments. Furthermore, regression analysis of factors related to weight gain from days 28 to 42 showed that feeding behaviour proportionately accounted for 0·02 only of within-litter variation and food intake on days 21 to 28 did not contribute significantly to between-Utter variation. These results suggest that low consumption of solid food before weaning is a predictor of poor growth after weaning, but not a cause.
1. Data are given on the changes which occurred in the composition of sow's milk during the course of 24 lactations. The mean percentages of the major constituents (192 samples) were: total solids, 20·0%: crude protein, 5·7%: lactose, 4·7%; fat, 8·6% and ash, 0·89%.
2. There were differences in milk composition between sows and between successive lactations, but these were only appreciable for milk fat percentage between sows.
3. A highly significant negative correlation ( P < 0·001; r = –0·62) was found to exist between the percentages of protein and lactose in the milk, quite apart from the general trend for protein content to fall with advance in lactation. Possible reasons for this are discussed.
1. A theoretical feeding scale, designed to supply the full nutritional requirements of the lactating sow and prevent weight loss (allowing approximately 8 lb. meal per sow and 0·8 lb. per piglet), was tested against a much lower but commonly recommended level (2 lb. meal per sow and 1 lb. per piglet). The meal (barley meal, 40%; ground oats 25%; middlings, 20%; white fish meal, 7·5%;, groundnut meal, 2·5%; dried grass meal, 3·8%; ground limestone, 0·3%; common salt, 0·3%; vitamins A, D and B 2 supplement, 0·6%) contained approximately 16·25% crude protein and had a digestible energy value of approximately 1300 Cal./lb. During pregnancies all sows were fed equal amounts of a meal containing approximately 13·0% crude protein.
2. Four pairs of Wessex Saddleback litter sisters were divided between the two treatments and records taken over three lactations of food consumptions, sow body weights, milk yields, milk compositions, litter growth rates, creep-feed consumptions and reproductive performances. Litter sizes were standardized between pairs of sows within the first 10 days after farrowing.
Samples of swine colostrum and milk were collected and analyzed for total solid, solids-not-fat, protein, ash, carotene, vitamin A, and ascorbic acid content. The mean values for the principal constituents on the 5th, 15th, and 55th days of lactation, respectively, were, in percentage figures: total solids, 20, 19, 20; solids-not-fat, 11, 11, 13; fat, 9, 8, 7; protein, 6, 5, 7; ash, 0.9, 0.9, 1.3. The mean vitamin A content was, in micrograms per 100 ml: colostrum, 132; milk 5th day, 33; 15th day, 22; and 55th day, 19. Swine colostrum and milk contained essentially no carotene. The mean ascorbic acid content was, in milligrams per 100 ml: colostrum, 19; milk 5th day, 13; 15th day, 11; and 55th day, 11.
No correlation between the composition of milk and breed or age was found. Supplementation of the ration with materials presumably containing unknown factors was without effect. Addition of vitamin A or carotene, however, produced an increase in the vitamin A content of colostrum and milk.
UNDAMENTAL studies dealing with the pig's development dur- ing gestation and lactation continue to receive considerable atten- tion. Comparisons between groups within the same experiment usually meet the needs of the investigator; however the value of reference growth curves in such work has not been fully investigated. A number of pre-weaning growth curves for swine have been pub- lished. They are of limited usefulness under present conditions for one or more of three reasons. (1) Many deal with bacon breeds fed under European conditions. (2) The conditions under which the sows were maintained during gestation and/or lactation are not stated. Because most nutritional studies are conducted under definitely stated conditions, i.e., pasture or drylot or in a combination of the two, it is important to know the details of treatment and management under which the individuals used in constructing growth curves were main- tained. (3) No measure of variation in the birth and weekly live weights is given. It is therefore not possible to determine the uni- formity of the populations from which the growth curves were
The composition of sow's milk has been studied less than that of milk of the other domestic animals. Several studies have been reported on the fat and vitamin A content of sow's milk, but most of these have been quite limited in scope. Reports from the Wisconsin Agricultural Experiment Station as early as 1897 stated that the fat content of normal milk from sows averaged 7.06 per cent. This study by Henry and Woll (9) was on only seven samples of milk. Later Woll (17) reported a mean fat percentage of 5.97 for five samples of sow's milk. Davies (6), in reporting on the composition of milk from vari- ous species of mammals, gave values ranging from 4.55 to 9.54 per cent fat for porcine milk. Hughes and Hart (10) reviewed the early literature on the gross composition of sow's milk. From the data of other workers, they calculated combined re- sults of 6.9 per cent fat. In their own work with two sows, they obtained a mean value of 5.3 per cent fat for normal milk and 5.1 per cent fat for colostrum. Willett and Maruyama (16) reported that the percentage of fat in sow's milk increased with the fat content of the ration. The average percentage of fat in the milk of sows on dry concentrates only was 6.1, and for sows on garbage only was 9.6 per cent. They also observed an increase in fat content of the milk with an advance in the stage of lactation. Braudc et al. (4) showed conversely that after the rapid change from colostrum to milk, the fat content decreased appreciably as the lactation advanced.
RECENT advances in the elucidation of the physiological mechanisms of lactation, particularly those mechanisms concerned in the transfer of milk from the mammary glands to the young, have revealed inadequacies and ambiguities in the terminology in common use in relation to lactational physiology. An example of such an ambiguity is the term 'to suckle', which is at present being used to denote the activity of the lactating mammal or the young or both. In 1947, one of us1 proposed a scheme, now generally adopted, which classified and defined the major physiological components of the total phenomenon which is called 'lactation', and which has done much to clarify terminology in this field. We should now like to put forward additional terms which, if generally accepted, we believe will render the above-mentioned scheme more comprehensive and will largely resolve the ambiguities still in existence.
A CONSIDERABLE amount of work has been carried out in recent years on the problem of the `let-down' of milk in the cow; but, so far as we are aware, nothing has been published on any such work on the sow. From the lactational point of view, the sow differs from the cow in several ways; she has, for example, an exceptionally strong control over the release of her milk. While the normal cow lets down her milk easily, it is normally impossible to obtain by hand any milk from the sow unless let-down is first artificially induced by the intravenous injection of an extract of the posterior pituitary lobe1. In addition, it is necessary to rope the sow during the process of obtaining the milk, and consequently the condition of co-operation which normally exists in the routine milking of the cow does not obtain.
Sow's milk: its production, nutritional properties and factors involved in its ejection from the mammary gland
- K G Mitchell
Quoted by Smith (1952 b)
- C P Vinogradsky