Article

Factors Affecting Conception Rate of Israeli Holstein Cattle

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  • Council on Dairy Cattle Breeding
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Abstract

Environmental and genetic effects on reproductive performance were estimated. Data included records of 194,579 inseminations of cows and 56,132 inseminations of heifers in 200 kibbutz herds from 1980 to 1981. Conception status was ascertained by veterinary palpation if no subsequent parturition was recorded. With subsequent parturition, the insemination closest to 277 days before parturition was considered successful. Largest differences in conception rate were between cows (40.4%) and heifers (64.3%) and among insemination month for cows (23.5 to 51.5%). Heritabilities of sire effect on conception rate were .016 for cows and .006 for heifers. Correlations between heifers and cows were .64 for inseminator and .54 for service sire. Low correlation between heifers and cows for herd effect (.17) indicates a management problem; low correlation between heifers and cows for sire effect (.27) suggests a different genetic mechanism for fertility. Significant improvement may be achieved in fertility by selection of service sires, sires, and inseminators if evaluations are based on a large number of observations. However, the major increase of conception rate may be expected from reducing adverse effects of summer conditions on reproductive performance.

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... L'intervalle entre le vêlage et la première insémination diminue (Silva et al. 1992) ou augmente (Stevenson et al. 1983b) avec le numéro de lactation de l'animal. Une réduction de la fertilité avec l'augmentation du numéro de lactation a été observée en bétail laitier (Boyd et Reed 1961, Gwasdauskas et al. 1981a, Hillers et al. 1984, Ron et al. 1984, Weller et Ron 1992, Osoro et Wright 1992. L'observation inverse a été faite en bétail viandeux (Mickelsen et al. 1986). ...
... L'observation inverse a été faite en bétail viandeux (Mickelsen et al. 1986). Les génisses laitières sont habituellement plus fertiles que les vaches (Ron et al. 1984). ...
... La politique d'insémination au cours du post-partum L'obtention d'une fertilité et d'une fécondité optimales dépend du choix et de la réalisation par l'éleveur d'une première insémination au meilleur moment du post-partum. En effet, on observe que la fertilité augmente progressivement jusqu'au 60ème jour du postpartum, se maintient entre le 60ème et le 120ème jour puis diminue par la suite (Hofstad 1941, Van Demark et Salisbury 1950, Shannon et al. 1952, Trimberger 1954, Erb et Holtz 1958, Touchberry et al. 1959, Boyd et Reed 1961, Olds et Cooper 1970, Bozworth et al. 1972, Whitmore et al. 1974a, Britt 1975, Williamson et al. 1980, Fulkerson 1984, Ron et al. 1984, Hillers et al. 1984, Eldon et Olafsson 1986. ...
... Hansen, 2000). It has long been known that fertility is reduced in lactating cows as compared to non-lactating heifers (Ron et al., 1984;Nebel and McGilliard, 1993). Given that milk yield has increased over time as fertility has declined, the possibility must be considered that the increase in milk yield is one reason that has contributed to the decreased fertility in dairy cattle. ...
... The experiment was conducted during the summer and it is also possible that heat stress reduced fertility. Although fertility in Holstein heifers does not always decline during the summer (Ron et al., 1984;Badinga et al., 1985), there is one report (Donovan et al., 2003) that heifers from a dairy farm in north central Florida inseminated in summer were more than four times less likely to become pregnant to first insemination than heifers inseminated during the rest of the year. It is also possible that the one sire used to inseminate all heifers was not a fertile bull. ...
... For order of parity, heifer was regarded as the reference for comparison. It is assumed that the heifer has higher conception rate in commercial dairy industry (Ron et al. 1984). Although, the situation in field was found to be different. ...
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Fertility traits are as important as production traits in crossbred bovine population. Assessment of the fertility of bull in any frozen semen production program and evaluation of the conception rate under actual field conditions provide valuable information. The objective of this retrospective study was to estimate the effect of genetic and non-genetic influence on conception rate of frozen semen bulls maintained at Bharatiya Agro-Industries Foundation (BAIF) Pune based on the conception rate in cattle population of small holder dairy farmer system. The data comprising of 1,08,238 insemination records pertaining to 83 Holstein Friesian pure and crossbred bulls available at BAIF Pune were used to analyze conception rate. The fixed effect solutions and covariance components were estimated by linear mixed model using the restricted maximum likelihood method in WOMBAT software. The genetic correlations were estimated using bivariate analysis between post thaw motility and conception rate. The study was based on fertility related information from cows maintained in different villages of India and thus reflects the actual fertility of frozen semen used. The study was suggestive of influence of very small fraction of genetic effect and higher impact of management effect on conception rate. Fertility-related information available from this study is an invaluable asset in decision making process of breeding policies.
... A recent study in nulliparous dairy heifers emphasized that most variations in conception rates was attributable to oestrus detection, pelvic size and breeding season (Donovan et al., 2003). The farm, the inseminator and semen deposition site also contributed to variations of fertility in ruminants (Ron et al., 1984;Donovan et al., 2004;Verberckmoes et al., 2004;Paulenz et al., 2005). In goats, a recent report by Salvador et al. (2005) clearly indicated that the depth of semen deposition is a determining factor for pregnancy rates, with higher fertility achieved when the insemination gun reached the uterus, as observed in the past by Ritar and Salamon (1983). ...
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Standard artificial insemination (AI) using a speculum in dairy goats does not result in acceptable fertility rates in nulliparous does. An explanation might be the difficulties to pass the cervical canal in nulliparous females with the insemination gun, increasing the time needed for semen deposition. Nulliparous Alpine dairy goats were used to evaluate whether time interval from insertion to withdrawal of the speculum is a factor influencing pregnancy rates to first AI with frozenthawed semen. Oestrus was synchronized using fluorogestone acetate intravaginal sponges (FGA, 40 mg) for 11 days, associated with 50 mg i.m. of cloprostenol and 250 IU i.m. eCG 48 ± 2 h before sponge removal. In the first experiment (n = 52; 3 herds), the average duration of the AI procedure was 42 ± 10 s, with a median of 39 s. AI performed in less than 39 s resulted in higher pregnancy rates (75%, n = 28) than AI lasting for more than 39 s (46%, n = 24). In the second experiment, does (n = 325; 5 herds) were randomly assigned into two treatment groups according to a short (20 s) or long (60 s) AI procedure. We showed that the duration of AI affected fertility after a first insemination, and that pregnancy rate was significantly improved using a short-duration AI (61.2%; n = 169) compared with a long-duration AI (44.2%; n = 156). We have previously shown in the ewe that genital stimulation during AI enhanced uterine motility. Other authors reported a negative correlation between increased uterine motility at the time of AI and fertility rates in small ruminants. The results of this study suggest that rapid semen deposition may limit the reflex activation of uterine contractions provoked by the speculum and the movement of the insemination gun, and thus ameliorates reproductive performance to first AI in nulliparous goats.
... A influência do mês possivelmente se deve ao stress climático e não à deficiência alimentar ao longo dos meses, pois os animais se encontravam em regime de estabulação total. O stress devido ao calor diminui a sobrevivência dos embriões (PUTNEY et al., 1988), diminui o número de vacas que concebem (RON et al., 1984), além de aumentar o número de estros não identificados (THATCHER & COLLIER, 1986), talvez porque o cio fique mais curto e a intensidade dos sintomas de cio, menos visível (WOLFENSON et al., 1988). ...
Article
Full-text available
Com o objetivo de estimar os efeitos da idade ao primeiro parto (IPP), intervalo entre partos (IEP), tipos de parto (TP) e mortalidade (MORT) nos parâmetros genéticos, foram analisados 1.255 registros de mortalidade, 774 registros de intervalo entre partos, 1.255 registros de período de gestação (PG), 402 registros de idade ao primeiro parto e 3.344 registros de prenhez (PRE) de vacas da raça Holandesa do plantel do Centro Especial de Sistema Intensivo de Produção de Leite (CESIPL/EMBRAPA). As médias e os desvios-padrão foram: MORT 0,02396 ± 0,15; IEP 413,45 ± 94,58 dias; PG 275,25 ± 6,87 dias; IPP 1.493,23 ± 690,69 dias; PRE 0,46 ± 0,47; TP 0,03875 ± 0,19 e peso ao nascimento (PN) 39,17 ± 6,69kg. Analisaram-se os efeitos de mês, ano, grau de sangue, sexo, ordem do parto, peso ao nascer e tipo de parto. Os coeficientes de herdabilidade para IEP, PG, IPP e PRE foram, respectivamente, 0,18; 0,07; 0,13; e 0,24. E os coeficientes de repetibilidade para IEP, PG e PRE foram, respectivamente, 0,13; 0,45x10-1; e 0,15x10-6. Diante dos baixos coeficientes para herdabilidade e repetibilidade para parâmetros reprodutivos avaliados, conclui-se que se trata de animais que não devem ser utilizados quando o objetivo é uma boa resposta para a seleção. ________________________________________________________________________________ ABSTRACT The objective of the present study was to estimate the effect of fixed effects on production traits as well as genetic parameters, including heritabilities and repeatability. In total, 1255 registers were analyzed for mortality (MORT), 774 registers for calving interval (CI), 1255 registers for gestation length (GL), 402 registers for first calving age (FCA) and 3344 registers for insemination success (P). The data were collected at the CESIPL (Experimental Centre for Intensive Milk Production System) located on the road DF-100, Colônia Agrícola Itapeti, Distrito Federal - Brazil. The averages and the respective standard deviations for each reproductive trait were: MORT 0.02396 (0.15); CI 413.45 (94.58) days; GL 275.25 (6.87) days; FCA 1493.23 (690.69) days; PRE 0.46 (0.47). The value for difficult calving percentage (DC) was 3.875 % (0.19) and average calf birth weight (BW) was 39.17 kg (6.69). The effects of month and year of calving, degree of purity, sex, calving order, birth weight and type of birth were investigated as appropriate for each trait. The respective heritability coefficients for CI, PG, FCA and P were 0.18; 0.07; 0.13; and 0.24. The respective coefficients of repeatability for CI, PG and P were 0.13; 0,45x10-1; and 0,15x10-6. Thus, the coefficients for heritability and repeatability for reproductive parameters are low therefore unlikely to respond well to selection.
... A key finding from both of these experiments was the profound effect of inseminator on PR/AI. Most herd-level variation in conception rate among heifers is due to variation among inseminators (Ron et al., 1984). Barth (1993) reported that timing of AI, semen quality, semen handling, and inseminator expertise influenced fertility to AI in cattle. ...
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producers that raise heifers for herd replacements because of the proven genetic and economic advantages of using AI compared with using natural service bulls for breeding dairy cattle. For example, the August 1999 USDA Holstein Sire Summary estimates a Net Merit Dollars advantage of $72 per lactation for a cow sired by an average first-evaluation AI sire compared with a cow sired by an average first-evaluation natural service bull. This estimate is conservative because dairy managers can use semen from above-average bulls for AI and because the genetic merit of an average proven natural service bull is greater than that of an average unproven natural service bull (Fricke, 1997).
... Thus, cows that calved during autumn will have their service period during the housed winter time. In tropical or hot regions there are reports of an opposite trend with more COD during summer [35,36], but studies from the USA did not find seasonality to be important [9,37]. However, to avoid or minimize stress for gregarious diurnal animals, light is important for daily tasks and for recognising herd mates. ...
Article
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The aims of this study were to establish the incidence of cystic ovarian disease (COD) and its geographical and seasonal variation in Norway, investigate the effect of COD on culling rates, and describe the effects of COD on subsequent reproductive performance and its association to twins. Diagnosis of COD was made by veterinary surgeons in the field. Four statistical models were made all including herd as random effect: The four different dependent variables investigated were: 1) Diagnosis of COD between 40 and 165 days in milk or not; (n = 511,657); 2) Twins or singleton; data restricted to lactations with new calving (n = 156,661): 3) Culling/removal or not (n = 573,184): 4) Culling due to reproductive problems; data included only lactations which ended in culling (n = 234,232). Model 1, 3 and 4 applied Cox regression models, and model 2 logistic regression. Independent variables were parity, twins/singletons, calving season, herd size, region, COD occurrence in present lactation (if not dependent), and COD diagnosis in previous lactation. The incidence was 0.82% per lactation. COD increased with increasing parity, was smallest at herd size between 35 and 85 cows. Cows in 1st parity and calved in spring had lowest hazard of COD and hazard for COD diagnosis was highest in autumn with HR = 2.6 (1.9-3.4) compared to spring. There was an interaction between parity and season. COD incidence was lower south of 60°N. Cows which experienced COD had an increased odds of giving birth to twins OR = 2.2 (1.7-2.7). Of those that were culled, those with COD were culled more frequently because of reproductive problems; HR = 2.1 (1.9-2.3) for higher parity than 2. Having COD diagnosed in the preceding lactation was a hazard for diagnosis in the lactation studied. COD diagnosis is strongly associated with season (autumn calving) and parity. Herds north of 60°N have more COD. Occurrence of COD is associated with twin births as well as culling due to reproduction.
... Hillers et al. (29) found that month affected interval to first service but not conception rate. Ron et al. (47) showed that month had the greatest effect on conception rate in cows but not in heifers in Israel and that summer months were most adverse. They concluded that the effect was all maternal due to the stress of temperature and lactation, since winter-frozen semen was used. ...
... A influência do mês possivelmente se deve ao stress climático e não à deficiência alimentar ao longo dos meses, pois os animais se encontravam em regime de estabulação total. O stress devido ao calor diminui a sobrevivência dos embriões (PUTNEY et al., 1988), diminui o número de vacas que concebem (RON et al., 1984), além de aumentar o número de estros não identificados (THATCHER & COLLIER, 1986), talvez porque o cio fique mais curto e a intensidade dos sintomas de cio, menos visível (WOLFENSON et al., 1988). ...
Article
Full-text available
span> The objective of the present study was to estimate the effect of fixed effects on production traits as well as genetic parameters, including heritabilities and repeatability. In total, 1255 registers were analyzed for mortality (MORT), 774 registers for calving interval (CI), 1255 registers for gestation length (GL), 402 registers for first calving age (FCA) and 3344 registers for insemination success (P). The data were collected at the CESIPL (Experimental Centre for Intensive Milk Production System) located on the road DF-100, Colônia Agrícola Itapeti, Distrito Federal - Brazil. The averages and the respective standard deviations for each reproductive trait were: MORT 0.02396 (0.15); CI 413.45 (94.58) days; GL 275.25 (6.87) days; FCA 1493.23 (690.69) days; PRE 0.46 (0.47). The value for difficult calving percentage (DC) was 3.875 % (0.19) and average calf birth weight (BW) was 39.17 kg (6.69). The effects of month and year of calving, degree of purity, sex, calving order, birth weight and type of birth were investigated as appropriate for each trait. The respective heritability coefficients for CI, PG, FCA and P were 0.18; 0.07; 0.13; and 0.24. The respective coefficients of repeatability for CI, PG and P were 0.13; 0,45x10<sup>-1</sup>; and 0,15x10<sup>-6</sup>. Thus, the coefficients for heritability and repeatability for reproductive parameters are low therefore unlikely to respond well to selection. KEY WORDS: Correlations, genetic parameters, heritability, repeatability. Com o objetivo de estimar os efeitos da idade ao primeiro parto (IPP), intervalo entre partos (IEP), tipos de parto (TP) e mortalidade (MORT) nos parâmetros genéticos, foram analisados 1.255 registros de mortalidade, 774 registros de intervalo entre partos, 1.255 registros de período de gestação (PG), 402 registros de idade ao primeiro parto e 3.344 registros de prenhez (PRE) de vacas da raça Holandesa do plantel do Centro Especial de Sistema Intensivo de Produção de Leite (CESIPL/EMBRAPA). As médias e os desvios-padrão foram: MORT 0,02396 ± 0,15; IEP 413,45 ± 94,58 dias; PG 275,25 ± 6,87 dias; IPP 1.493,23 ± 690,69 dias; PRE 0,46 ± 0,47; TP 0,03875 ± 0,19 e peso ao nascimento (PN) 39,17 ± 6,69kg. Analisaram-se os efeitos de mês, ano, grau de sangue, sexo, ordem do parto, peso ao nascer e tipo de parto. Os coeficientes de herdabilidade para IEP, PG, IPP e PRE foram, respectivamente, 0,18; 0,07; 0,13; e 0,24. E os coeficientes de repetibilidade para IEP, PG e PRE foram, respectivamente, 0,13; 0,45x10<sup>-1</sup>; e 0,15x10<sup>-6</sup>. Diante dos baixos coeficientes para herdabilidade e repetibilidade para parâmetros reprodutivos avaliados, conclui-se que se trata de animais que não devem ser utilizados quando o objetivo é uma boa resposta para a seleção. PALAVRAS-CHAVES: Correlações, herdabilidade, parâmetros genéticos, repetibilidade. </span
... Fertility in the second TAI tended to be affected by sire. Herd-level or animallevel factors affect fertility in dairy heifers ( Donovan et al., 2003), and most herd-level variation in P/AI in heifers is caused by variation among inseminators and service sires (Ron et al., 1984). ...
Article
The objective was to determine if the 5-d Co-Synch+CIDR (controlled internal drug releasing insert) protocol can be used in dairy heifers for a synchronized timed artificial insemination (TAI) with one injection of PGF(2alpha) for first and second services. In experiment 1, heifers were assigned randomly to receive 1 (n=295) or 2 (n=298) injections of PGF(2alpha) in the 5-d Co-Synch+CIDR protocol. Corpus luteum (CL) regression was measured in one replicate (n=218). No difference in pregnancy per TAI (P/TAI; 46.1 and 48.6%) or CL regression (86.9 and 92.8%) was detected for 1 versus 2 injections of PGF(2alpha), respectively. In experiment 2, nonpregnant heifers (n=86) were assigned to a resynchronized 5-d Co-Synch+CIDR with 1 PGF(2alpha)/TAI or insemination at detected estrus. There was no difference in P/TAI (52.2 and 55%) between groups. In experiment 3, nonpregnant heifers (n=110) were assigned randomly to receive a CIDR (n=54) or no CIDR insert (n=56) in the 5-d Co-Synch protocol for resynchronization of TAI. Pregnancy per TAI was lower without the CIDR device (39.3 vs. 51.8%). In a commercial field evaluation, 416 heifers were synchronized for the first and resynchronized TAI with the 5-d Co-Synch+CIDR protocol with 1 injection of PGF(2alpha). Pregnancy per TAI on d 60 was 58.2 and 47.5% for first and second TAI, respectively; there was a sire effect to the second TAI. In conclusion, the 5-d Co-Synch+CIDR protocol with 1 injection of PGF(2alpha) is an effective reproductive management program for first and second TAI in dairy heifers.
... Grass et al. (1982) found that the breed resulted differences in age at puberty. Ron et al. (1984) studied on effects of heritability of sires on CR and found to be .016 for cows and 0.006 for heifers. ...
Article
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The present study was conducted to determine the conception rate of cows/heifers artificially inseminated at Upazila Livestock Office, Rajarhat, Kurigram. A total of 184 cows/heifers of different breed, age, season, body weight and par ity were selected and art ificial inseminat ion was per formed by using frozen semen. The cows were inseminated between 6-20 hrs. of onset of heat. All cows were examined for pregnancy by rectal palpat ion of genital tract at 80-90 days post AI. One hundred and seven were inseminated 1 or 2 t imes and 77 animals for 3 and more services. Out of 184 animals 101 animals were conceived and 83 animals did not conceived. The overall conception rates were 54.9%. A significant ly decreased conception rate (p<0.01) was observed in age group more than 8 years than other groups. Cows received insemination at parity 1 showed highest conception rate (73%) and cows received insemination at parity 6 showed lowest conception rate (25%). The overall and within group concept ion rate percentage in Local (52.9%) and Fr iesian cross (62.3%) cows/heifers were relat ively higher than that of Sahiwal cross (40%). However the difference was not significant (p>0.05).The conception rate was observed significantly higher (78.9%) in the cows which were inseminated in spring than the cows were inseminated in summer (29.8%), winter (72.1%) and rainy (35.7%) season. The conceptionrate was significant ly higher (p<0.01) in 1st and 2nd service compared with 3rd services (89.7% vs 6.5%). A proportion of cows, which failed to conceive in the first service repeated in second, third services and or more. Key words: Conception rate, AI, Friesian cross, Sahiwal cross, Parity
... re 10% higher in virgin heifers and 10% lower in 4th lactation and older cows. However Amin et al. (1981) reported that there was no significant difference between the breed groups in the number of services per conception (av. 2.6) or gestation length (av. 275.6 days). Grass et al. (1982) found that the breed resulted differences in age at puberty. Ron et al. (1984) studied on effects of heritability of sires on CR and found to be .016 for cows and 0.006 for heifers. Radioimmunoassay and Related Techniques To Improve Artificial Insemination Programmes For Cattle Reared Under Tropical And, Sub- Tropical Conditions. Proceedings Of A Final Research Co-ordination Meeting Organized By The Joint FAO/ IAE ...
Article
Full-text available
The present study was conducted to determine the conception rate of cows/heifers artificially inseminated at Upazila Livestock Office, Rajarhat, Kurigram. A total of 184 cows/heifers of different breed, age, season, body weight and parity were selected and artificial insemination was performed by using frozen semen. The cows were inseminated between 6-20 hrs. of onset of heat. All cows were examined for pregnancy by rectal palpation of genital tract at 80-90 days post AI. One hundred and seven were inseminated 1 or 2 times and 77 animals for 3 and more services. Out of 184 animals 101 animals were conceived and 83 animals did not conceived. The overall conception rates were 54.9%. A significantly decreased conception rate (p<0.01) was observed in age group more than 8 years than other groups. Cows received insemination at parity 1 showed highest conception rate (73%) and cows received insemination at parity 6 showed lowest conception rate (25%). The overall and within group conception rate percentage in Local (52.9%) and Friesian cross (62.3%) cows/heifers were relatively higher than that of Sahiwal cross (40%). However the difference was not significant (p>0.05).The conception rate was observed significantly higher (78.9%) in the cows which were inseminated in spring than the cows were inseminated in summer (29.8%), winter (72.1%) and rainy (35.7%) season. The conception rate was significantly higher (p<0.01) in 1st and 2nd service compared with 3rd services (89.7% vs 6.5%). A proportion of cows, which failed to conceive in the first service repeated in second, third services and or more.
... The lower P/TAI to the second TAI compared with the first TAI tended to be due to the sires. Herdor animal-level factors affect fertility in dairy heifers (Donovan et al., 2003), and most herd level variation is caused by variation among inseminators and service sires (Ron et al., 1984). The five-d Co-Synch + CIDR protocol (Figure 1) is an efficient reproductive management programme to achieve acceptable P/TAI in dairy heifers. ...
... Conception rates of lactating cows decrease from about 50% in the winter to less than 20% in the summer. However, fertility in the autumn (30%) is lower than that in winter, although ambient temperatures decrease and animals are no longer exposed to thermal stress (Ron et al., 1984; Cavestany et al., 1985). A seasonal study (Badinga et al., 1994) indicated variations in follicular dynamics during autumn, which were related to summer heat stress. ...
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The aim of this study was to characterize the immediate effects of heat stress on plasma FSH and inhibin concentrations, and its involvement in follicular dynamics during a complete oestrous cycle, and to examine a possible delayed effect of heat stress on follicular development. Holstein dairy cows were oestrous synchronized and randomly assigned to either cooled (n = 7) or heat-stressed (n = 6) treatment groups. During a complete oestrous cycle, control cows, which were cooled, maintained normothermia, whereas heat-stressed cows, which were exposed to direct solar radiation, developed hyperthermia. At the end of this oestrous cycle (treated cycle), both groups were cooled and maintained normothermia for the first 10 days of the subsequent oestrous cycle. Throughout this period, follicular development was examined by ultrasonography, and plasma samples were collected. During the second follicular wave of the treated oestrous cycle, a significantly larger cohort of medium sized follicles (6-9 mm) was found in heat-stressed cows than in cooled cows (P < 0.05). The enhanced growth of follicles in this wave in heat-stressed cows was associated with a higher plasma FSH increase which lasted 4 more days (days 8-13 of the oestrous cycle; P < 0.05), and coincided with a decrease in the plasma concentration of immunoreactive inhibin (days 5-18 of the oestrous cycle; P < 0.05). During the follicular phase (days 17-20 of the treated cycle), heat-stressed cows showed an increase in the number of large follicles (>/= 10 mm), and the preovulatory plasma FSH surge was significantly higher in heat-stressed cows than in cooled cows (P < 0.01). The effect of heat stress was also observed during the first follicular wave of the subsequent cycle: the postovulatory plasma FSH concentration was higher (P < 0.01), but fewer medium follicles developed, and the first follicular wave decreased at a slower rate in previously heat-stressed cows than in cooled cows (0.40 and 0.71 follicles per day, respectively). This study shows both immediate and delayed effects of heat stress on follicular dynamics, which were associated with high FSH and low inhibin concentrations in plasma. These alterations may have physiological significance that could be associated with low fertility of cattle during the summer and autumn.
... Calving interval, age at puberty, services per pregnancy and interval to onset of post-partum heat are considered important parameters to measure farm economy (Azizunnesa, 2002). Low production of dairy cows may be due to their poor genetic make-up, inadequate feeding and disease control and harsh environments (Jabber and Green, 1998; Shamsuddin, 1988). The cattle of Bangladesh are mostly non-descript indigenous type and among these Red Chittagong cows (RCC) is an important resource, having characteristics of small size, regular breeding, and good adaptability in hot humid climate (Habib et al., 2003). ...
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Fertility of Red Chittagong bulls (RCB) using Non-Return Rate (NRR), reproductive efficiency of Red Chittagong cows (RCC) using pregnancy rate and number of services per pregnancy and parasitic infestation of two different ages and sexes were studied. The NRR ranged from 53.1% to 70.6% with an overall mean of 63.9%. Overall pregnancy rate was 65.8% and about 1.4 services were required per pregnancy. Overall 47.7% animals were infested with parasites. Five species of parasites were detected in the faeces: Balantidium coli (40%), Paramphistomum spp (47.7%), Fasciola spp (5.8%), Coccidia spp (4.5%), and Moniezia spp (1.9%). The prevalence of parasites in animals over four years age was higher (P<0.05) than in animals below four years of age: the prevalence was higher in female than in male hosts (P>0.
... In contrast, all of the variables in older bulls tended to decrease as the THI (collection or spermatogenesis) increased in autumn, except for motility of fresh sperm at collection time. A similar effect is also visible in cows, as a long-lasting effect of heat stress affects the ovarian pool of oocytes and, consequently, the conception rate remains low during autumn (Ron et al., 1984;Badinga et al., 1985;Roth et al., 2001). However, in our study, the interaction between season THI (collection or spermatogenesis) did not affect the NRR56% of young and older bulls. ...
Article
Rising temperatures caused by climate change have adverse effects on cattle physiology, welfare, health, and reproduction. Heat stress in cows affects the oocyte and embryo directly through heat shock on cellular function. Fewer data are available on the effect of high temperatures on male fertility. Temperature-humidity index (THI) is a measure for assessing the risk of heat stress that combines the effects of temperature and humidity. The aim of this study was to determine the relationship between THI and fresh or frozen–thawed sperm quality of Holstein bulls kept in temperate climates. Bull sperm data of 29,170 ejaculates from 933 bulls collected at 3 Dutch artificial insemination centers between 2015 and 2018 were evaluated. The assessed variables included total sperm motility and morphology of fresh semen, and total sperm motility, morphology, and progressive motility of frozen semen 0 and 3 h after thawing. In addition, 56-d nonreturn rates were analyzed. The assessed effects were season and THI on the day of semen collection and during spermatogenesis (30 d before collection), bull, age of bull, year, and location. Bulls were divided into 2 categories according to their age: young (<36 mo) and older (>36 mo). Overall sperm quality of young bulls improved as age increased. No effect of THI on fresh sperm variables was observed in either young or older bulls. However, high THI at spermatogenesis negatively affected the cryotolerance of sperm cells. Sperm cells from young and older bulls showed a pronounced decrease (14–18%) of the assessed variables 3 h after thawing after the increase of THI during spermatogenesis in autumn. Remarkably, older bulls were more sensitive to THI at spermatogenesis compared with semen collection, showing up to a 3.8 times higher negative effect on frozen sperm quality. However, an elevated THI at semen collection produced a tendency toward decreased 56-d nonreturn rates as the age of the bull increased. Although this decrease was up to 4%, rising temperatures may still cause important economic losses in the future. For the first time, the present study confirmed that climate compromises not only sperm quality, but also dairy bull fertility.
... In such a data-set the assumption of normal distribution and equality of variances are violated. However, logistic regression model is found to be a better choice (Dyke and Patterson 1952, Ron et al. 1984, Hosmer and Lemeshow 1989 and hence adopted in the present studies. Thirunavukkarasu and Kathiravan(2006), Shamsuddin et al. (2013), Suresh Kumar and Pasupathy (2015) have used a binary logistic regression model for predicting the probability of conception rate in artificially inseminated bovines through fitted using various animal and management factors. ...
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The objective of the study was to identify the factors affecting variation in conception rate of buffaloes inseminated by Murrah bulls' frozen semen under field conditions. Total of 18,396 insemination records pertaining to 11,793 buffaloes that were inseminated artificially at BAIF's field AI centers during the period of June 2010 to December 2014 in 3 states. Logistic regression analysis was used to compute the odds ratio and probability of conception rate. Records were classified according to agroclimatic zones, lactation order, season of insemination and body condition score. Agroclimatic zones, lactation order and body condition score showed significant variation. The overall conception rate was 48.01%. Conception rate of western plain zone of Uttar Pradesh was higher than other zones under study. Body condition score 3 was favourable where probability of conception was 0.51. Conception rate of first parity buffaloes was lower than other parities with the probability of 0.46. Conception rate increased in second parity with probability 0.52. Highest conception rate was found in fourth parity with probability 0.53. There was marginal difference between second to fifth parity. Season of insemination did not affect conception rate, however, the distribution of artificial inseminations was higher during the favourable season than that during lean-season. It could be inferred that the factors like agroclimatic zones, lactation order and body condition score should be considered while evaluating the conception rates in buffaloes.
... An influence of parity on the length of the service period was also reported. However, the effect of parity on service period could be related to its effect on number of services per conception (Eneyew Negussie et al., 1998), conception rate (Hillers et al., 1984;Ron et al., 1984;Garcia et al., 1990) and estrus cycle (Mukassa-Mugerwa et al., 1991) thereby influencing the service period. Heifers do not conceive as readily as other cows and they require more services per conception than cows in the later parities (Eneyew Negussie et al., 1998). ...
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Abstract A survey was conducted for a year (2001/2002) in eastern Wollega and parts of western Shoa zone, Ethiopia, to investigate the mortality rate of Horro sheep reared under farmers condition, identify major clinical signs for sheep mortality, study the seasonality of sheep mortality and compare with mortality of sheep flock at Bako Agricultural Research Center. The average survival rates were 95.1%, 97.3% and 86.5% for sheep younger than 3-month, older than 3-month but younger than 12-month and older than 12-month of age, respectively. Survival rate was lowest in adults older than 12-months of age. Survival was significantly affected (at least at p<0.05) by season, flock size and sex of animals. Agro-ecology did not have significant (p>0.05) influence on survival rate of animals. Nevertheless, survival rate tended to be highest in mid-altitude areas as compared to highland and lowland areas for animals younger than 3-month and older than 12-month of age. The major reported clinical signs were coughing (23.8 %), diarrhea (23.5 %), swelling under the neck (23.5 %), circling movement (14.6 %), emaciation (8.5 %), orf (4.0 %) and others (2.1 %). Identification of the diseases associated with these clinical signs is a priority research area to design appropriate control measures.
... For low heritability traits (e.g., dystocia, calf mortality, and conception rate), each such locus would contribute upwards of one-third of the total genetic variance, and the absolute magnitude of effects is equal to the mean. It should be noted, however, that most traits with heritabilities less than .1 are categorical traits for which heritability on the underlying scale may be considerably higher (29,44). ...
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There is considerable interest in bovine DNA-level polymorphic marker loci as a means of mapping quantitative trait loci (QTL) of economic importance in cattle. Progeny of a sire heterozygous for both a marker locus and a linked QTL, which inherit different alleles for the marker, will have different trait means. Based on this, power to detect QTL, as a function of QTL effect, heritability of the trait, and number of animals tested was determined for 1) daughter design, marker genotype and quantitative trait values assessed on daughters of sires heterozygous for the markers; and 2) granddaughter design, a newly devised alternative design in which marker genotype is determined on sons of heterozygous sires and quantitative trait value measured on daughters of the sons. For equal numbers of assays, power increased with the number of daughters per sire (design 1) and sons per grandsire (design 2). For equal power and heritability less than or equal to .2, design 2 required half as many marker assays as design 1, e.g., with heritability of .2, QTL effect of .2 SD units, and type 1 error of .01, power was .70 if 400 daughters of each of 10 sires were assayed for the markers and .95 if markers were assayed on 100 sons of each of 20 sires with 50 granddaughters per son.
... Les effets relatifs à la saison sont plus contradictoires. En effet, la fertilité et la fécondité présentent (Mercier et Salisbury 1947, Thatcher 1974, De Kruif 1975, Gwasdauskas et al. 1975bRon et al. 1984, Taylor et al. 1984, Etherington et al. 1985, Udomprasert et Williamson 1987, Faust et al. 1988, Gregory et al. 1990b) ou non (Boyd et Reed 1961, Hillers et al. 1984, Moore et al. 1992 ...
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Notre travail poursuivait deux objectifs essentiels: mettre au point d'une part un système de collecte et d'analyse d'observations compatible avec l'activité journalière du praticien et, à partir de la banque de données ainsi constituée procéder d'autre part à une étude comparée chez la vache laitière et viandeuse, de l'influence des facteurs individuels et d'environnement sur les pathologies puerpérales et du post-partum ainsi que sur la fertilité et la fécondité. La première partie de notre travail (Chapitre 1: Introduction générale) a été dévolue à une analyse exhaustive au travers des données de la littérature des facteurs responsables des problèmes de reproduction. Ils peuvent se répartir en deux catégories: les facteurs individuels d'une part et les facteurs collectifs d'autres part. Au nombre des premiers il faut citer l'âge, la génétique, le niveau de production laitière, le type de vêlage, la gémellité, la mortalité périnatale, la rétention placentaire, la fièvre vitulaire, l'involution cervicale et utérine, les infectioins du tractus génital et l'activité ovarienne au cours du postpartum. A l'inverse les facteurs collectifs font davantage référence au troupeau qu'à l'individu. Ils concernent le choix d'une politique de première insémination, la détection des chaleurs, le moment de l'insémination, la nutrition, la saison, le type de stabulation, la taille des troupeaux et les caractéristiques sociologiques de l'éleveur. Cette revue de la littérature nous a permis de constater la grande diversité des effets observés à l'encontre des facteurs étudiés d'une part et le manque habituel d'harmonisation concernant les méthodes d'évaluation de ces effets. Deux chapitres de notre travail ont été consacrés à la présentation du logiciel de gestion de la reproduction GARBO. Celui-ci comprend deux aspects différents au demeurant complémentaires. Le premier plus propédeutique est basé sur le suivi mensuel de reproduction (Chapitre 2). Le second plus analytique comporte l'analyse mensuelle mais surtout annuelle des performances et pathologies de la reproduction (Chapitre 3). Au travers de différentes listes d'intervention, le programme assure le suivi sanitaire et zootechnique de chaque individu femelle depuis l'âge de 14 mois ou depuis son dernier vêlage jusqu'à la confirmation de la gestation ou de la réforme. Il contribue ce faisant à réduire les périodes de non reproduction. Parce qu'il fournit au vétérinaire une anamnèse physiologique, pathologique et thérapeutique, il lui permet d'affiner son diagnostic et de prendre en connaissance de cause une décision thérapeutique appropriée. Le programme a déjà fait l'objet de nombreuses améliorations, fruit de son expérimentation sur le terrain. Puisqu'il ne peut y avoir de gestion sans quantification, l'évaluation des performances de reproduction représente le second aspect au demeurant essentiel d'une démarche préventive de la reproduction. D'une manière générale, nous avons cherché à optimiser et à actualiser au maximum les données disponibles au sein de chaque troupeau. La mise au point d'un bilan de reproduction a été illustrée par la comparaison des performances enregistrées en 1992 dans 3 systèmes d'élevage, le premier ne comportant que des animaux viandeux allaitants de race Blanc Bleu Belge (n = 20). le second (n = 45) que des animaux laitiers de race Holstein Frisonne ou Pie Rouge et le troisième (n = 39) qualifié de mixte rassemblant des animaux viandeux traits ou allaitants de race Blanc Bleu Belge et des animaux de race laitière. Cette étude comparative est la première du genre et peut servir de référence au clinicien pour l'interprétation des performances de troupeau de sa clientèle. Cette étude comparée nous a permis d'identifier plusieurs faits. Quelle que soit la spéculation, les exploitations présentent de larges différences dans les performances moyennes de reproduction. Cette observation traduit vraisemblablement davantage les capacités différentes des éleveurs à gérer leur potentiel de reproduction que les différences liées à la race ou au type de production laitière ou viandeuse. Elle se trouve confirmée par le fait qu'au sein de chaque spéculation, certains troupeaux atteignent pour les différents paramètres étudiés, les valeurs considérées comme optimales. La fécondité des génisses exprimé par l'âge du premier vêlage est comparable quel que soit le type de spéculation allaitante (28 mois), mixte (29 mois) ou laitière (29 mois). Moyennant le respect de certains conditions sanitaires et nutritionnelles, il apparaît que la race viandeuse Blanc Bleu Belge est aussi précoce que les races laitières. La fécondité des vaches exprimée par le délai nécessaire à l'obtention d'une gestation est meilleure dans les troupeaux laitiers (111 jours) qu'allaitants (125 jours), les troupeaux mixtes présentant une situation intermédiaire (117 jours). Ce fait résulte essentiellement d'une première insémination plus tardive dans les troupeaux allaitants (84 jours) que mixtes (76 jours) ou laitiers (73 jours), suite à une période d'anoestrus plus prolongée identifiée indirectement par l'intervalle entre le vêlage et la première chaleur détectée par l'éleveur et respectivement égale en moyenne à 79, 67 et 59 jours dans les troupeaux allaitants, mixtes et laitiers. En effet, les trois spéculations présentent une fertilité comparable qu'elle soit exprimée par le pourcentage de gestation en première insémination (45 %) ou par le nombre d'inséminations nécessaires à l'obtention d'une gestation (troupeaux allaitants: 2.4, mixtes: 2.5 et laitiers: 2.3). La qualité de la détection des chaleurs caractérise les trois types de spéculation. Enfin, les troupeaux laitiers présentent une fréquence plus élevée de pathologies puerpérales (rétention placentaire et fièvre vitulaire) et du post-partum (métrites, kystes ovariens) que les élevages allaitants ou mixtes). Dans le chapitre 4, nous avons cherché à décrire la fréquence des pathologies puerpérales et du postpartum et à en identifier les facteurs de risque individuels ou d'environnement chez la vache viandeuse et laitière. Ont ainsi été étudiées la rétention placentaire, la fièvre vitulaire, l'involution utérine, les infections utérines et les kystes ovariens. Les valeurs fréquentielles observées (Tableau 59) sont les premières du genre pour les conditions d'élevage que nous connaissons. A ce titre, elles ont valeur de référence. Les pathologies puerpérales telles que la rétention placentaire et la fièvre vitulaire sont plus fréquentes chez la vache laitière que chez la vache viandeuse. La vache laitière se caractérise par ailleurs par une plus grande fréquence de retard d'involution utérine et de kystes ovariens que la vache viandeuse. L'infection du tractus génital constitue la pathologie dominante et sa manifeste avec la même fréquence dans les deux spéculations. D'une manière générale, la proportion de vaches atteintes par une ou plusieurs pathologies est plus élevée dans la spéculation laitière que viandeuse. Une fois quantifiée la fréquence des pathologies dans les deux spéculations, nous avons cherché à en identifier les facteurs de risque par la méthode des Odds Ratio et de la régression logistique. Certains se sont avérés être communs aux deux spéculations pour une pathologie donnée. Ainsi, l'âge de l'animal contribue à augmenter le risque de rétention placentaire et de retard d'involution utérine, la réduction de la longueur de la gestation celui de la rétention placentaire et la césarienne celui de l'infection utérine. De même, la gémellité augmente le risque de rétention placentaire et d'infection du tractus génital alors que la rétention placentaire et le retard d'involution utérine favorisent l'infection du tractus génital dont la présence augmente le risque de retard d'involution utérine. A l'inverse, nous avons constaté un effet plus spécifique de certains facteurs en fonction de la spéculation surtout en ce qui concerne la rétention placentaire et la fièvre vitulaire chez la vache laitière ce qui laisse en présumer une pathogénie commune. La saison du vêlage influence davantage le risque d'une pathologie chez la vache laitière que chez la vache viandeuse. Ce fait reflète peut-être l'effet indirect de la production laitière à l'origine d'un métabolisme différent. Sur le plan pratique, il est intéressant de distinguer deux types de facteurs. Les uns sont davantage inhérents à l'animal. Ils sont par conséquent moins directement modifiables . Qualifiés de "marqueurs de risque", ils concernent le numéro de lactation, la longueur de la gestation, le nombre de veaux et la saison du vêlage. D'autres peuvent davantage être considérés comme des "facteurs de risque "proprement dit dans la mesure ou ils peuvent faire l'objet d'une attitude préventive ou curative de la part du vétérinaire. Ainsi chez la vache viandeuse le recours à la césarienne sera préféré au vêlage réalisé par traction pour diminuer la fréquence du retard d'involution utérine. Un suivi thérapeutique anti-infectieux de cette intervention chirurgicale ainsi que de la rétention placentaire sera de nature à diminuer la fréquence des infections du tractus génital et à favoriser la qualité de l'involution utérine. Chez la vache laitière, la prévention de la fièvre vitulaire et une meilleure détection du vêlage contribueront à réduire l'incidence de la rétention placentaire directement ou indirectement par la diminution de la mortalité néonatale. Ce faisant, le risque d'infection utérine sera réduit et ainsi la fréquence du retard d'involution utérine s'en trouvera diminué ce qui contribuera à réduire le risque de kystes ovariens. Le chapitre 5 a été consacré à l'étude comparée chez la vache laitière et viandeuse de la fertilité et de la fécondité ainsi que de leurs facteurs de risque individuels ou d'environnement. La fertilité et la fécondité ont été analysées respectivement par le pourcentage de gestation en première insémination et par l'intervalle entre le vêlage et l'insémination fécondante. Les pathologies puerpérales et du post-partum étudiées exercent d'une manière générale peu d'effet direct sur ces deux paramètres. En effet, chez la vache laitière, le pourcentage de gestation en première insémination ne se trouve diminué que par la rétention placentaire et par la présence d'une infection du tractus génital 41 à 50 jours après le vêlage tandis que la fièvre vitulaire est la seule pathologie à avoir une influence négative sur l'intervalle entre le vêlage et l'insémination fécondante. Il faut sans doute voir dans cette constatation l'effet positif exercé indirectement par la mise en place d'un suivi mensuel de reproduction. Celui-ci offre en effet au praticien la possibilité d'un dépistage et par conséquent d'un traitement précoce des pathologies rencontrées. Par ailleurs, il est possible que ces pathologies contribuent davantage à augmenter le risque de réforme de l'animal que celui d'infertilité ou d'infécondité. Au vu de notre étude, l'amélioration du pourcentage de gestation en première insémination constitue une priorité essentielle chez la vache laitière mais plus encore chez la vache viandeuse. Elle peut être espérée chez la première en évitant le recours à la césarienne, en prévenant la rétention placentaire qui prédispose aux infections du tractus génital, en évitant d'inséminer l'animal avant le 50ème jour du post-partum et en agissant sur les facteurs susceptibles de réduire l'anoestrus du postpartum Chez la vache viandeuse de race Blanc Bleu belge, la césarienne constitue un "mal nécessaire". La réduction de la fertilité qu'elle entraîne est le prix à payer mais non un obstacle à la politique de sélection viandeuse de plus en plus intensive menée dans cette spéculation. Le recours à des conditions optimales pour sa réalisation qu'elles soient de nature chirurgicales ou hygiéniques doit permettre de réduire les complications péritonéales et par conséquent à améliorer le pourcentage de gestation en première insémination. Nos résultats nous incitent par ailleurs à postposer après le 70ème jour du post-partum le moment de la première insémination chez la vache viandeuse et à ne pas recommander l'utilisation de spirales vaginales pour l'induction de la première chaleur après le vêlage. Sans doute, il serait intéressant d'étudier l'impact de solutions alternatives telles que la politique d'un sevrage précoce sur la réapparition rapide d'une activité ovarienne après le vêlage, facteur pouvant contribuer à réduire l'utilisation de traitements inducteurs. L'influence des variables antérieures est pratiquement nulle dans les deux spéculations à l'exception toutefois de la fièvre vitulaire chez la vache laitière. Cette observation devrait inciter le praticien a tenir compte du passé métabolique de l'animal pour décider du traitement préventif des animaux à risque.
... Relationship between maximum monthly temperature and pregnancy rates in Holstein cows Higher conception rate in heifers compared to multiparous cows with similar genetic merit for milk production has been repeatedly emphasized (Ron et al. 1984;Badinga et al. 1985;Pursley et al. 1997). Stress of lactation, propensity for clinical and subclinical mastitis and problems associated with calving in pluriparous cows are possible causes for the differences found between cow and heifer segments (Wolff and Monty, 1974;Gwazdauskas et al. 1981;Grohn and Rajala-Schultz, 2000;Schrick, et al. 2001;Santos et al. 2004). ...
... In contrary, Andersen-Ranberg et al. (2005) reported that months May, Jun, July and August (Summer months) showed high values for non-return to 56-d rate in heifers. Ron et al. (1984) reported highest heifer CR in February (67%) but CR in July was 65.4%. ...
... The current result agree with that reported by De Souza et al. (2016) who found that cows that served in the early morning had lower rectal temperature (38.96°C) and conception rate was (32.86%) compared with that cows mated in the afternoon rectal temperature was (39.60°C) and conception rate was 26%. Also, the results are agreement with that recorded by Folman et al. (1979) and Ron et al. (1984) who found that conception rate was lower during the hot season (22, 24 %) compared with the cool season (80, 52%) respectively. Similar trend was reported by Ono et al. (2016) who found that pregnancy rates were lower in summer 17.1 % than in winter 40.9 % in cows. ...
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In der Literatur wird immer wieder eine gesteigerte Morbidität zu bestimmten Jahreszeiten beschrieben, obwohl generell eine qualitativ und quantitativ ausgewogene Fütterung vorhanden ist. Das Ziel der vor-liegenden Untersuchungen war es, im Verlaufe eines Jahres systematische Stoffwechsel- sowie Leistungskontrollen bei Hochleistungskühen durchzuführen und diese in Beziehung zur Morbidität zu stellen. Dazu wurden bei 118 Schwarzbunten Milchkühen (52 Färsen, 66 Kühe; x̃ 8925 kg FCM/a, Laufstallhaltung) 10 Tage ante partum (d a.p.), drei sowie 28 Tage post partum (d p.p.) Kontrollen in Vollblut (V. jugularis) und Serum sowie Harn (Katheter) durchgeführt. Im Serum wurden die Beta-Hydroxybutyrat- (BHB)-, Glucose-, Freie Fettsäuren (FFS)-, Bilirubin-, Cholesterol-, Gesamtprotein-, Albumin-, Harn-stoff-, Kreatinin-, Calcium (Ca)-, anorganische Phosphat (Pi)-, Magnesium (Mg)-, Natrium (Na)-, Kalium (K)-, Chlorid (Cl-) Konzentrationen, die Creatinkinase (CK)-, Aspartat-Amino-Transferase (AST)- Akti-vitäten und Anti-Lipid A-Antikörper (ALA-AK)- Titer sowie im Harn die pH-Werte, fraktionierte NSBA-, Ca-, Pi-, Mg-, Na-, K- und Kreatininkonzentrationen ermittelt. Für die Mineralstoffe wurde die Fraktio-nierte Elimination (FE) berechnet. Weiterhin wurden Leistungsdaten und die Morbidität erfasst. Von 14 d a.p. bis drei d p.p. wurde die Futterration 1, jeweils totale Misch-Ration (TMR), und von drei d bis 28 d p.p. die Futterration 2 dargeboten. Ihre Kennzahlen schwankten im Verlaufe des Jahres wie folgt: Futter-ration 1 - Netto-Energie-Laktation (NEL) 66,0-72,7 MJ; Rohprotein (XP) 1469-1612 g; Rohfaser (XF) 1460-1669 g; Futterration 2 - NEL 140,3-153,9 MJ; XP 3182-3528 g; XF 2979-3564 g. Die klinisch gesunden Färsen und Kühe hatten vor der Kalbung im Harn pH-Werte und K-Konzentrationen über dem physiologischen Bereich im Sinne einer alkalotischen Belastung. Nach der Kalbung zeigten erhöhte BHB-, FFS-, erniedrigte Albumin- und Mg-Konzentrationen im Serum einen belasteten Energie- und Mineralstoffwechsel bei erhöhtem Kreatinin im Harn (p<0,05). Die BHB-, FFS-, Bilirubin-Konzentrationen, CK- und AST-Aktivitäten waren drei d p.p. signifikant am höchsten, die Cholesterol-, Albumin-, Ca-, Glucose-Konzentrationen, die ALA-AK-Titer im Serum und die pH-Werte, die NSBA-, Basen-, K-Konzentrationen und FE K im Harn signifikant am niedrigsten. Vier Wochen nach der Kalbung erreichten die Cholesterol-, Protein-, Harnstoff-, Mg-Konzentrationen im Serum, Mg-Konzentrationen im Harn und FE Mg signifikant das Maximum und die Kreatinin-, Na-, Cl-Konzentrationen im Serum signifikant das Minimum. An allen drei Kontrollzeitpunkten vor und nach der Kalbung lagen die Glucosekonzentrationen im Serum, die Kreatininkonzentrationen im Harn, die Zahl der neutrophilen Gra-nulozyten über und die Zahl der Lymphozyten unterhalb des Referenzbereiches. Im Vergleich zwischen Färsen und Kühen fielen bei den Kühen an mind. zwei von drei Kontrollzeit-punkten signifikant niedrigere Glucose- (min. 2,98/ 3,43 mmol/l) und ALA-AK-Titer im Serum (min. 74/ 109), Pi-Konzentrationen (min. 0,09/ 0,29 mmol/l) im Harn, höhere Albuminkonzentrationen (min. 28,35/ 29,55 g/l) im Serum sowie FE Ca (min. 0,31/ 0,24 %) als bei den Färsen auf. Diese Unterschiede sind vor allem durch die höhere Milcheinsatzleistung der Kühe bedingt. Dem entsprachen auch u. a. tendenziell drei d p.p. höhere BHB-, FFS- und Proteinkonzentrationen und niedrigere Pi-Konzentrationen im Serum. Es bestanden keine gesicherten Unterschiede an allen drei Kontrollzeitpunkten zwischen Färsen und Kü-hen bei den AST-Aktivitäten, Bilirubin-, Kreatinin-, Cl-Konzentrationen im Serum, Basenkonzentratio-nen im Harn, FE Mg sowie pH-Werten im Harn. Im Jahresverlauf traten Stoffwechselstörungen gehäuft in den Monaten Mai/Juni sowie September bis Februar auf: Die pH-Werte und die NSBA-Konzentrationen waren im Mai/Juni im Bereich starker azido-tischer Belastung und von September bis Dezember nahe der physiologischen Obergrenze. Die FFS-, Bilirubin- und Cholesterolkonzentrationen waren in den Monaten November bis Februar am höchsten und wiesen auf eine stärkere Energie-Fettstoffwechsel-Belastung hin. Im Mai/Juni waren sie am niedrigsten. Ähnlich verhielten sich die Harnstoff-, Ca-, Mg-, Na- bzw. K-Konzentrationen. Die CK-Aktivitäten wa-ren in den Monaten September bis Februar am höchsten; die ALA-AK-Titer hatten im Novem-ber/Dezember die höchsten Titer. Die Veränderungen korrelierten vor allem mit Rohfaser- und Tempera-turschwankungen. Die Morbidität betrug insgesamt bei Endometritis 27,1 %, Mastitis 19,5 %, Klauenerkrankungen 15,3 %, Fruchtbarkeitsstörungen 14,4 %, Retentio sec. 6,8 %, Gebärparese 4,2 %, Ovarzysten 5,1 % und bei Harnwegserkrankungen 3,4 %. Im Jahresverlauf wurden gehäuft Mastitiden im Mai/Juni während einer Hitzeperiode beobachtet, die durch azidotische Belastungen infolge Reduzierung des Rohfaser- zu Gunsten eines höheren Kraftfutter-anteils gefördert wurden. Bei Kühen, die im Mai/Juni abkalbten, traten auch die meisten späteren Fruchtbarkeitsstörungen auf. Klauenerkrankungen und Endometritiden häuften sich in den Monaten Nov bis Feb. Sie gingen mit Störungen im Energiestoffwechsel einher. Frühdiagnostisch fielen die Kühe mit späterer klinscher Mastitis vor der Kalbung durch signifikant höhe-re Glucosekonzentrationen (3,84 mmol/l) im Serum gegenüber den gesunden Kühen (3,53 mmol/l) im Sinne einer relativen Insulinresistenz auf. Drei und 28 d nach der Kalbung waren bei diesen Kühen be-sonders signifikant niedrigere pH-Werte und NSBA-Konzentrationen im Harn und 28 d p.p. signifikant höhere Protein- (88,4 g/l), Glucose- (3,84 mmol/l), Ca-Konzentrationen (2,53 mmol/l) bzw. ALA-AK-Titer (157,5) im Serum sowie Pi-Konzentrationen im Harn (1,03 mmol/l) als Ausdruck azidotischer Be-lastungen mit Entzündungsreaktionen unter Endotoxinbelastung auffällig. Die Kühe mit späterer Gebär-parese zeigten 10 d a.p. schon eine verminderte Futteraufnahme in Verbindung mit einer vermehrten Lipolyse durch gesteigerte Bilirubin- sowie reduzierte Pi- und NSBA-Konzentrationen. Drei d p.p. domi-nierte das Krankheitsgeschehen das Stoffwechselbild. Die Kühe mit einer Retentio sec. hatten gegenüber gesunden drei d p.p. signifikant niedrigere Na- (141,7/ 144,8 mmol/l) und Cl-Konzentrationen (97,5/ 101,0 mmol/l) im Serum sowie Na-Konzentrationen im Harn (1,0/ 8,5 mmol/l). Auch Kühe mit späteren Ovarzysten zeigten drei d p.p. signifikant niedrigere Na-Konzentrationen (0,8/ 8,5 mmol/l) und FE Na (0,007/ 0,115 %) im Harn als die gesunden Kühe. Dies deutet auf eine unzureichende Na-Aufnahme hin. Kühe mit einer subklinischen Endometritis 28 d p.p. fielen mit signifikant niedrigeren pH-Werten (8,18/ 8,41), NSBA- (70,7/ 116,5 mmol/l) und Basenkonzentrationen (161,0/ 218,0 mmol/l) im Harn auf, was auf eine verminderte Futteraufnahme hindeutet. Kühe mit späteren subklinischen Fruchtbarkeitsstörun-gen hatten schon vor der Kalbung signifikant höhere CK-Aktivitäten (81,8 U/l) im Serum als Zeichen einer stärkeren Belastung der Skelett- bzw. Uterusmuskulatur. Die Kühe mit Totgeburten hatten an allen drei Kontrollzeitpunkten höhere CK-Aktivitäten gegenüber den Kühen mit Lebendgeburten. Die Unter-schiede war drei d (160,1/ 98,9 U/l) bzw. 28 d p.p. (89,9/ 74,7 U/l) signifikant verschieden. Kühe mit Klauenerkrankungen, überwiegend Dermatitis digitalis, zeigten gegenüber gesunden Kühen vor der Kalbung signifikant höhere Kreatininkonzentrationen (110,0/ 130,5 µmol/l) im Serum als Zeichen eines erhöhten Muskelabbaus. Nach der Kalbung wiesen signifikant höhere BHB-Konzentrationen im Serum auf eine stärkere Belastung des Energiestoffwechsels hin. Insgesamt ergaben die Untersuchungen hauptsächlich engere Beziehungen zwischen Stoffwechsel und Morbidität in Form von höherer Mastitisinzidenz im Mai/Juni als Folge azidotischer Belastung nach Roh-faserreduzierung im Futter. Diese Phase schloss den Zeitraum schlechtester Gesundheit - einschließlich Fruchtbarkeit - ein. Gehäufte Klauenerkrankungen und Endometritiden gingen im letzten Jahresquartal in Verbindung mit stärkeren Belastungen des Energiestoffwechsels und Endotoxin-Belastung (ALA-AK-Titer) einher.
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Genetic parameters for conception rate in Holstein cattle were estimated from insemination data collected in western France in 1987–88. Data included 513020 inseminations of 250215 lactating cows. Sire, service bull, herd and cow variance components were estimated with the “tilde-hat” method. Both linear and threshold models were used and provided very similar results for the fixed effects. Conception rate was lowest in latest parities, before 60 days postpartum, in winter and on Mondays. With the linear model, the estimated heritability and repeatability of conception rate were 2 and 3.2%, respectively, and the service bull and herd components contributed 0.8 and 1.1% of the total variance, respectively. All variance components were 60% greater from the threshold model. The correlation between male and female fertility was small and slightly negative (−0.11). In spite of a low heritability, the genetic variability of female fertility was large, with a genetic coefficient of variation of 14%. The genetic correlations between conception rate at first insemination and 100-day yield traits were estimated by REML on 83 606 first lactation data. They were found to be antagonistic, with −0.60, −0.42 and −0.36 for milk, fat and protein yields, respectively, whereas the phenotypic correlations were only slightly negative (−0.02 to −0.04).
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A dynamic simulation model was used to predict the long-term effects of published heat stress-associated fluctuations in conception rate (CR) and milk production (MP) on the monthly MP pattern in Israel. The model results showed that the pattern of seasonal decline and rise in CR, and hence conception occurrences, produces a similar pattern of MP. This pattern closely resembles that of actual MP in Israel in 1987 and in 1988. On the other hand, seasonal correction factors for MP have no marked effect on the shape of the MP curve. These results show that in order to stabilize MP throughout the year, the prevention of seasonal (summer) decline in CR would be more effective than direct efforts to prevent seasonal MP decline.
Article
Both milk production (MP) and conception rate (CR) of primi- and multiparous cows (P+M) in Israel are characterized by the same summer-autumn trough and winter-spring peak. Although there is no causal link between CR and MP (a simulation-model study explained the connection), monthly CR determines the number of dry cows 7 months later, at 2 months pre-calving. Inevitably, when the number of dry cows is low, MP is high, and vice versa. Replacement heifers (RH) in Israel have a consistently high (64%) CR throughout the year. The same simulation model was used to investigate the effect of manipulated RH breeding on the herd MP pattern. When RH breeding was confined to the 3-month July to September (J-S) period during which CR is lowest for post-partum P+Ms, the monthly MP pattern in an otherwise year-round breeding dairy herd was the diametric opposite of the one produced by all-year RH breeding. When a uniform monthly quota was set for RH and P+M conceptions, and monthly RH conceptions were restricted to complement monthly P+M conceptions, the herd MP pattern became almost level. There did not appear to be any economic penalty attached to the planned RH conception system. In practice it will not be possible to adhere to a strict monthly quota of conceptions, since there is a 1 to 2 month lag between insemination and confirmed conception. Estimates of individual farm monthly CR could be used, where available. Alternatively, if 40% of all RH inseminations were performed in J-S, the MP curve would be much flatter than under the present non-planned system of RH insemination.
Chapter
Throughout East Africa, animal feed resources fluctuate seasonally and are often of limited availability. Finding alternative feed resources that can sustain animal production during the long dry season is an essential need. Cactus is a drought tolerant and succulent feed resource available throughout the year in Eritrea. This study was conducted to evaluate the effect of increasing levels of spineless cactus inclusion in the diet of sheep fed urea-treated barley straw. Twenty-four fat-tailed Highland male sheep with a mean live weight of 21.1kg were randomly assigned into four treatments (T1–T4). Animals in T1 received ad libitum amount of urea (5%) treated barley straw (UTBS) alone, while those in T2, T3 and T4 received ad libitum UTBS supplemented with 175g, 350g and 525g of spineless cactus (dry matter basis), respectively. With increasing level of cactus, there were significant increases in DMI (p < 0.001) and body weight performance (p < 0.05), while water consumption decreased (p < 0.001). The highest DMI was found in the last two treatments (101.8 and 96.5g/kgBW0.75d, respectively) as compared to the first two treatments (94.4 and 87.6g/kgBW0.75d). The water intake was significantly decreased with the progressive increase in cactus. The highest body weight gain (51.9g/day) was found when sheep received 350g dry matter (DM) of cactus (T3), while the lowest was in the control diet (26.8g/day). The metabolism trial demonstrated that available energy intake was directly related to performance in the feeding trial. In conclusion, feeding cactus with UTBS can significantly increase animal performance and feed intake, and reduced water intake. KeywordsCactus-Ruminant-Eritrea-Dry season-Intake
Article
Breeding receipts from three AI units were merged with Ontario Dairy Herd Improvement Corporation and Record of Performance production records. Data comprised 53,705 heifer, 41,253 lactation 1, 14,688 lactation 2, and 3054 lactation 3 records by daughters of 2150 sires represented in 15,877 herd-year-seasons of birth. Three measures of heifer fertility, three measures of cow fertility, and three measures of production were investigated. Measures of heifer fertility were ages at first and last breeding and number of inseminations per conception. Cow fertility traits were days from calving to first breeding, days open, and number of inseminations per conception. Production traits were breed class average milk, breed class average fat, and fat percentage. Relationships among these nine traits for the first three lactations were estimated using a maximum likelihood multiple-trait procedure. The linear mixed model for each trait included fixed effects of herd-year-season of birth and genetic groups of sire and the random effect of sire. Transformations of the data for nonnormality had no influence on the estimates of genetic and phenotypic parameters. The heritability of .12 for age at first insemination, which was higher than other heifer fertility traits, indicated that selection would result in genetic response. Genetic and phenotypic correlations between heifer fertility and cow fertility and production traits in all three lactations were not different from zero. There was no genetic antagonism between fertility and subsequent production traits.
Article
Amir, D., Bat-El, M., Kalay, D. and Schindler, H., 1982. The contribution of bulls and cows to the seasonal differences in the fertility of dairy cattle in Israel. Anita. Reprod. Sci., 5: 93--98. Semen collected from dairy Israeli-Friesian bulls in the winter and summer was pelletedfrozen and used for inseminations in the collection season, in the other season, and after a 12-month storage period. The semen quality, as assessed by the percentage of ejaculates with initial poor motility and low sperm density and the percentage of spermatozoa surviving the freezing--thawing process, and those revealing acrosomal and tail abnormalities after thawing, was slightly and non-significantly lower in summer than in winter. The fertility of semen collected in both seasons was not affected by a 12-month storage period. The use of winter semen in summer did not improve the low fertility of cows in that season compared with those inseminated with summer semen. It appears from the results of this study that the summer decrease in the fertility of the inseminations is due to the adverse effect of this season on the fertility of the cows.
Article
Variation in conception rates (based on birth of a live calf from first insemination to a high-fertility service sire) of 1,406 Holstein females was studied at one or two service periods (1,824 records) in 41 artificially inseminated herds. Fertility did not vary significantly between herds. Conception rates ranged from 43 to 94% in 27 paternal half-sib groups of heifers (P < 0.05 on an average of 23.4 heifers per half-sib group) and from 33 to 91% in 36 paternal half-sib groups of parous cows (P = 0.05 on an average of 22.7 parous cows per half-sib group). The heritability of conception rate was estimated from intrasire correlations of paternal half-sib groups to be approximately 8.5%. A comparison of the records of daughters at both service periods from 22 sires showed a trend toward an interaction between sire and parity of daughters (P ≠ 0.07). The value of selection in improving conception rate is discussed.
Article
Measures of yield and fertility were obtained from breeding receipts of artificial insemination and records of test-day yield. Estimates of heritability were by Henderson Method 3, maximum likelihood, and restricted maximum likelihood. Heritabilities for measures of yield varied, but most were within the range of earlier estimates. Measures of fertility had heritabilities from 0 to .03. Alternative upper bounds were placed on days open, number of services, and service period, and always the measure with the lesser bound had higher heritability for first parity. Measures of yield for early stages of lactation had slight positive phenotypic correlations with fertility whereas those for measures of cumulative yield later in lactation increased in relation to effect of gestation. Genetic correlations of first-parity yield and most measures of fertility were positive and less influenced by stage of lactation than phenotypic correlations. Antagonism moderated for second parity. Most genetic correlations were not significantly different from zero for third parity. Considerable genetic antagonism of yield and fertility may be of limited consequence because estimates of genetic variance of fertility were near zero.
Article
Genetic correlations between Predicted Difference for first and second, first and third, and second and third lactations milk were .82, .62, and .94 and for Predicted Difference percent fat .94 for the three associations. Regression coefficients for following on previous lactation Predicted Difference were less than unity; thus, Predicted Difference from first lactation might be overweighted when age adjusted and pooled with second and third lactations. Regressions of Predicted Difference milk of sons on sires for first, second, third, and pooled lactation records were .32 +/- 18, .42 +/- .21, .56 +/- .31, .35 +/- .15, and intraclass correlations between half brothers were .09 +/- .08, .28 +/- .11, .25 +/- .11, and .12 +/- 10. Predicted Differences for second and third lactations were, thus, near the theoretical expectation of .5 and .25 for regressions of son on sire and between half-brother correlations but lower for Predicted Differences of first and pooled lactations. Variance of Predicted Difference of first lactation between sires of sons was small compared with the variance of sons within sires. It was postulated that effective selection on the sire-to-sire path on Predicted Difference of first lactation had reduced predictability on the sire-to-sire improvement path. An interaction of sire by number of lactations may be inferred from the incomplete genetic correlations between Predicted Differences of first and following lactations and from the reduction in the variance between sire in first but not in later lactations. Progeny tests of single lactation seem warranted for the production profile of dairy sires.