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Induction of Lactation and Adoption of the Orphan Foal

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Induction of Lactation and Adoption of the Orphan Foal
Peter F. Daels, DVM, PhD, Diplomate ACT, Diplomate ECAR
Author’s address: Keros – Equine Embryo Transfer Center, Passendale, Belgium.
Introduction
When facing an orcrophan foal due to the death of the mare or unwillingness to accept her
foal, it is critical to find an alternative to feed the foal and create a suitable social environment
for the upbringing of the foal. Most of the time, a nurse mare that will raise the foal as her
own can be located. In some regions of the country, specialized farms offer nurse mares. But,
in other areas, locating a nurse mare can be difficult. Other options include feeding a
replacement formula using a bottle or bucket. There are excellent milk replacements on the
market that enable us to feed an orphan foal to weaning age with excellent body development.
However, prolonged bottle feeding of an orphan foal often results in a horse with poor social
skills that can interfere with its future use.
The induction of lactation can offer practical and economical advantages. Lactation has been
induced in ruminants using steroids (progesterone and estrogen) as a short-term treatment
followed by a wide variety of drugs aimed at increasing prolactin secretion. These treatment
protocols have resulted in lactation with milk production ranging between 25 and 82 % of a
physiological, post-partum lactation. As a general observation, an induced lactation does not
start with a production of colostrum. Several products (domperidone and sulpiride) have been
used in recent years to increase endogenous prolactin secretion in mares either to advance the
onset of reproductive activity in anestrous mares in early spring or to counter the ill effects of
fescue toxicosis in pregnant mares at term.
Lactation can be induced in non-parturient mares that have foaled in previous years using a
treatment that includes estrogen, progesterone and a dopamine D2 antagonist (sulpiride or
domperidone). The initial treatment protocol for induction of lactation in mares consisted of a
2-wk treatment in which progesterone, estrogen, and a dopamine D2 antagonist (sulpiride)
was administered daily. Mares were milked 1-2 days after the start of sulpiride treatment, and
in some experiments, milking was continued after the end of treatment. The results of these
studies indicated that lactation can be induced in mares that have foaled in previous years.
Perhaps the most encouraging observation was that when regular milking (6-7x per day) was
continued after the end of hormonal treatment, milk production continued at a constant rate
for 7 or more days (see Figure 1).
A comparison between sulpiride and domperidone indicated that both products are effective
in inducing milk production. The quality of the milk produced during these induced lactations
appeared similar to a normal post-parturient lactation even though production of colostrum
was only observed occasionally (2). Several attempts have been made to induce the
production of colostrums but so far results have been disappointing and do not warrant
inducing a mare for the purpose of producing colostrums.
More recent studies indicate that progesterone and/or estrogen are essential for the induction
since a treatment based on sulpiride administration only does not induce lactation in
8th AAEP Annual Resort Symposium. Rome, Italy - January 19 - 21, 2006
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Milk quantity
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Daily milk production (liters)
Sulpiride treatment
Figure 1
ovariectomized mares. Field experience suggests that in normal cycling mares, the
supplementation of progesterone and estrogen may not be an absolute necessity and mares
will start making milk with sulpiride administration only. Some caution should be used and
certainly in anoestrus mares progesterone and estrogen are indispensable elements of the
treatment protocol. Our recommendation remains to include estrogen and progesterone in the
treatment protocol whenever possible. We have not observed seasonal differences in the
amount of milk produced when lactation is induced in cyclic mares in early spring (March)
and end of summer (September).
Over the years, we have developed a protocol for the induction of lactation that consists of a
minimum of one-week hormonal treatment with milking at the end of the treatment period.
We have also developed an effective method to make mares with an induced lactation adopt a
foal and nurse it until weaning age without further treatment.
Induction of Milk Production
The details of the treatment protocol detailed below were worked out in several experiments
that have been previously described (3) and are also based on our experience in our clinical
program.
Selection of Mares - Mares must have given birth and successfully nursed a foal at least once
in their life. Mares that have raised several foals tend to have a mammary gland that is more
developed and a more predictable maternal behavior. Mares must be in good body condition,
free of disease and mammary abnormalities, gentle and calm. Mares must be willing to stand
confined behind a contention bar for prolonged periods of time and have a history of being a
“good mother”. The success of the induction procedure does not seem to be influenced by the
age of the mare nor by the interval since the last foaling, although extremes should probably
be avoided.
During the induction period, mares must be fed as a nursing mare with a high proportion of
concentrate. Keep in mind that these mares were not pregnant prior to the lactation and that
they probably do not have the same capacity of ingesting large volumes of food as postpartum
mares. A higher than usual proportion of concentrate may help these mares.
Hormonal Treatment - The induction procedure starts with a clinical examination and a test
in confinement. Once the mare has been approved, she receives a single intramuscular
injection of estradiol-benzoate (50 mg/500 kg mare) and the same day she is started on daily
altrenogest administration (22 mg/day per os) and twice-a-day injections or sulpiride (1 mg/kg
IM, q 12 h).
Sulpiride is prepared as suspension in peanut-oil (100 mg/ml) and kept in sterile bottles 4C. It
is important to warm the oil-suspension and shake hard before injection. Alternatively,
domperidone can be used at twice the recommended daily dose. Human preparations are also
available for injection.
The mammary gland is inspected daily and the size and shape are noted. When the mammary
gland is significantly increased in size, has a “filed” appearance and/or milk drops are present
at the teat, milking can be started. Generally, milking is started on the 4th to 7th day of
treatment. Once milking has started, it is important to continue milking 5-7 times a day.
Keep in mind that mares have very limited storage capacity and that foals nurse at 30-60 min
intervals. Infrequent milking and accumulation of milk in the udder have a tendency of
causing a drying up effect.
Milking - Milking can be done by hand or with a milking machine. The majority of mares
adjust to these manipulations without much resistance. Mares that continue to resist hand
and/or machine milking should be considered poor candidates for adoption. For optimal milk
letdown and fast milking, administer 5 IU oxytocine IM 1-2 minute before milking. Machine
milking is done with a milking machine equipped for milking sheep and goats. The settings
we use are 120 aspirations/min, vacuum 22cmHg, alternation vacuum/rest 50/50. It generally
takes less than 1 minute to empty a lactating mare. When using hand milking: try using a
large Pyrex type measuring container - 32 ounce capacity. Milk directly into this recipient
shows at once how much milk has been obtained.
Duration of Treatment - After 3-4 days of milking, production should have reached 3-5
liters per day for a 500 kg horse. At this point, the mare is ready for adoption. In our hands,
mares that are not producing a significant amount of milk on day 7 (> 3 liters) are not suitable
adoption candidates. Altrenogest treatment is generally stopped on Day 7 and sulpiride (or
domperidone) treatment is continued until several days after adoption is completed.
Adoption Technique
Environment and confinement of the adopting mare – The best location for the adoption is
a closed stall with no contact with neighboring horses. It is critical to have a reliable
confinement system, for the safety of the handlers, the foal and the mare. It is important that
the setup is solid and inspires confidence. A situation whereby the handlers cannot rely on the
safety and integrity of the confinement material often results in tension and unnecessary
excessive disciplinary actions towards the mare. In our hands, a simple metal tube placed at
the level of the hip of the mare and solidly attached to both lateral walls of the stall offers the
best setup for a safe and relaxed adoption attempt (Fig. 2). The metal pipe should be
positioned in the back of the stall parallel to the back wall leaving only enough space for the
mare to stand comfortably. The mare should not be able to make significant lateral
movements. A solid ring in the back wall through which a rope can run from the mare’s halter
to the mare handler is helpful.
Figure 2. Mare placed behind contention tube.
Introduction of the foal - Several experiments were conducted to investigate the most
efficient system for adoption (3). In these studies, adoption was realized using one of two
methods.
The discipline method - Welch pony mares were placed in an individual stall and confined
behind a padded bar placed horizontally at chest height. Newborn foal was removed from its
natural mother at birth and presented immediately to the adoptive mare.
Mares were disciplined if they responded aggressively to the foal. Mares that initially
displayed high levels of aggression toward the foal received a tranquilizer once or twice
(acepromazine to effect). The disciplinary action was a simple action-reaction technique by
which the mare was discouraged to act against the foal. Gradually the actions shifted from
physical action to voice cues and within hours mares were conditioned not to react when the
foal attempted to nurse.
The vaginal stimulation method - The foal was held close to the mare’s head while the mare
received vaginal-cervical stimulation. The stimulation consisted of a vigorous massage of the
external portion of the cervix and some attempt to dilate the cervix. This stimulation was
applied twice (2 min each) at 10 min interval. During and after the stimulation the foal was
held at close proximity of the head and shoulder of the mare to allow the mare to sniff and
lick the back and buttocks of the foal.
Adoption took significantly longer for the mares that did not receive vaginal-cervical
stimulation than for mares in the vaginal-cervical stimulation condition. Under experimental
conditions, 14 out 16 mares adopted the foal immediately and maternal behavior developed
completely and immediately following the cervical massage. In the mares that did not
undergo vaginal/cervical stimulation, only 2 mares adopted immediately and the remaining 14
mares displayed aggressive and potentially harmful action towards the foal for anywhere from
4 to 24 hours. It is interesting to note that all mares finally adopted the foals and that maternal
behavior was complete and indistinguishable from that of mares that stayed with their own
foal.
Subsequently these methods were used in a commercial program using large Warmblood-type
mares (n=50) and client foals. All adopting mares were subject to a vaginal massage at the
introduction of the foal. Foals were presented for adoption from 1-2 days after birth to several
weeks. In this setting, using large sized mares, on average 3 out of 4 mares adopted
immediately and without aggression. In the remaining mares, firm disciplinary action
combined with positive reinforcement were needed and adoption was obtained in 90% of the
cases after 1-4 days. Again, it is important to note that the maternal behavior, once installed,
was complete. Clients very rarely observed “poor” maternal skills.
Growth of the foals – In the initial studies, foals and mares were not supplemented after
adoption and foals had to rely 100% on the mare’s milk production. Moreover, sulpiride
treatment was ended two days after adoption and mares and foals were turned out in pasture.
Under these (experimental) conditions, a significant delay in weight gain between adopted
and control foals was seen in the first two weeks and in some foals also in the second two
weeks (Fig. 3). However, at weaning age we were unable to demonstrate a statistically
significant difference in bodyweight between the adopted and control foals. While foals
lacked in body weight in the first two weeks, they appeared alert and growing normally
(subjective observation).
In our commercial setting, sulpiride treatment was continued for 7-10 days after adoption in
an effort to maximally stimulate the milk production. It is probably not useful to continue
sulpiride treatment beyond 20 days (total duration) because we and others have observed a
decreasing effect over time on prolactine secretion. On a few occasions, we have stopped
treatment and reinitiated treatment one week later to boost milk production.
All client-owned foals were supplemented with artificial milk 3-5 times per day (1-2 liters
each time). This was continued until the foals refused the artificial milk or when it was judged
that the mare produced sufficient milk. Although, we were never able to quantify the weight
gain in these foals nor evaluate objectively the impact of these interventions, we noted a very
high client satisfaction rate and it was felt that the lack of milk that likely existed during the
first days after adoption was sufficiently compensated to allow normal development of the
foal. Incidentally, the 2004 champion female foal of the French Warmblood Studbook was an
adopted foal still nursing the adoption mare. Subsequently, this method has been adopted by
several nurse-mare farms in Europe.
Figure 3 (adapted from Reference 3)
References
1. Quantitative and qualitative assessment of milk production after pharmaceutical
induction after pharmaceutical induction of lactation in the mare. Chavatte-Palmer, P,
Arnaud, G., Duvaux-Ponter, C., Brosse, L., Bougel, S., Daels, P., Guillaume, D.,
Clement. F., Palmer, E. Journal of Veterinary Internal Medicine 2002 (In Press).
2. Chavatte-Palmer P, Daels PF, Arnaud G, Duvaux-Ponter C, Brosse L, Guillaume D,
Rousseau S, Duchamp G, Clément F and Palmer E. Quantitative and qualitative
assessment of milk production after pharmaceutical induction of lactation in mares.
Proceedings of the Symposium on Equine Reproduction and Annual Meeting of the
Society for Theriogenology, San Antonio TX, 111.
3. Daels, PF, Duchamp G. and Porter, D. Induction of Lactation and Adoption of Foals
by Non-Parturient Mares. Proceedings of the Annual Convention of the American
Association of Equine Practitioners, vol 48, 68-71, 2002.
____________________________________________________________________________
This manuscript is reproduced in the IVIS website with the permission of the
American Association of Equine Practitioners www.aaep.org
... Thus, placement of the foal with a nurse mare can circumvent the issues related to hand-raised and prematurely weaned foals. Typically, sources of nurse mares include periparturient mares who had recently lost a foal; lactating mares prematurely weaned from their own foal (commercial nurse mare farms); mares with exceptional maternal behaviour that would adopt a second foal; or mares not bred displaying inappropriate lactation or that had a hormonally induced lactation (Daels 2006;Steiner 2006). ...
... Reported induction of lactation protocols in nonpregnant multiparous mares involves administration of steroid hormones (oestrogen and progestins), dopamine D2 receptor antagonists (domperidone and sulpiride) and PGF 2a which can be administered at the end of steroid treatment to induce luteolysis Daels et al. 2002;Chavatte-Palmer et al. 2002;Daels 2006). An increase and decrease in oestrogen, followed by a rise and decline in progesterone, coupled with a stimulus for prolactin concentration increase, are thought to be important in the successful induction of lactation in mares (Chavatte-Palmer et al. 2002). ...
... Ideally, foal grafting is done when a mare is in full lactation, whether induced or spontaneous. Described foal grafting protocols include vagino-cervical stimulation, exposure of a lactating mare and foal to a perceived threat such as another horse or dog, and hormonal manipulation Porter et al. 2002;Daels 2006). Other described ancillary methods include wrapping the mare's placenta on a foal to be grafted, rubbing a foal with the mare's faeces or using the halter from the nurse mare's biological foal on the new foal to be adopted (Houpt and Mills 2006). ...
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An 8‐year‐old mare was presented for induction of lactation and adoption of a 30‐day‐old twin filly. In each of the two seasons prior to presentation, the mare had delivered a foal that died shortly after birth. The mare had been bred by live cover ~25 days prior to presentation to the Illinois Veterinary Teaching Hospital, but no pregnancy diagnosis was yet performed. Upon arrival at the hospital, pregnancy diagnosis confirmed a viable singleton gestational vesicle. Lactation was induced with dopamine D2 agonists. Immediately before grafting, the mare was started on altrenogest to provide exogenous hormonal support for the pregnancy. After two consecutive days of PGF2α administration on Day 30 of gestation, the mare began to accept the foal, but by the next day, the mare had insufficient milk production and began to show signs of foal rejection. The mare was treated with acepromazine for sedation and stimulation of lactation, with concurrent analgesic support provided by flunixin meglumine and butorphanol. One ovulation was confirmed on Day 40, and a second ovulation was confirmed on Day 45 of gestation. On Day 47 of gestation, 11 days after adoption, serum progesterone concentration was 13.2 ng/mL. As this value was above the minimum level (≥4 ng/mL) deemed necessary to maintain pregnancy in the mare, altrenogest administration was tapered and ultimately discontinued on Day 50 of gestation. The pair remained at the hospital for treatment of leucopenia in the filly. On Day 61 of gestation, 25 days after adoption, continued maintenance of pregnancy was confirmed in the mare, full lactation had been achieved, and strong bonding between mare and foal was apparent. The pair was discharged from the hospital to the care of the owner.
... Colostrumis generated in the period immediately before and after calving (Boudry et al., 2008). The quality of colostrum in all farm animals is an important factor determining normal growth and development effectiveness of rearing offspring (Daels, 2006). Physicochemical properties of colostrum and milk differ significantly since colostrum is richer in biologically active elements, such as nucleic acids or amino acids derivatives whose concentration changes considerably in the hours and days after parturition. ...
... In the first 24 hours after parturition, highperformance cows are capable of producing as many as 25 liters of colostrum, 4-6 liters of which are consumed by the calf; sheep and goats produce 0.4-1.3 l of colostrum (Daels, 2006). The surplus of colostrum produced by cows, especially if it is high quality, may be preserved and then used as a source of immunoglobulins, minerals and biologically active substances not only in feeding calves, lambs, kids, or other farm animals, but it may constitute an element of human diet (Huguet et al., 2006;Pecka et al., 2012a;Hyrslova et al., 2016). ...
... Lyophilization of colostrum, that is drying it in low temperature and under reduced pressure, is a much better preservation method than spray drying: it does not cause protein denaturation and the degeneration of immunoglobulins is reduced (Elfstrand et al., 2002). After the process of sublimation, the product preserves its organoleptic characteristics, and thanks to its porous structure, it may easily be rehydrated (Elfstrand et al., 2002;Huguet et al.;2006). In pharmaceutical industry preserved colostrum (for example through lyophilization) is used for the production of probiotics intended for stimulating the human immune system (Hyrslova et al.;. ...
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... In recent years, some reports have demonstrated that lactation without a preceding pregnancy has been induced using a treatment that includes estrogen, progesterone, and a dopamine D2 antagonist aimed at increasing prolactin (PRL) secretion in mares [2,6,31]; this has similarly been shown in cows [1,3,30]. Furthermore, another study has shown that there is no significant difference in body weight between the foals adopted by mares with induced lactation and the control foals that remained with their natural mothers at the age of weaning [4]. Studies using these treatment protocols have indicated that approximately 80% of treated non-pregnant mares lactated sufficiently to raise an orphan foal [31]. ...
... The obtained milk volumes per milking after correction for body weight were lower than those of naturally lactating mares [9], but were comparable with those of mares with induced lactation [2]. A previous report suggested that a mare with induced lactation was ready for adoption when milk production reached 3 to 5 l per day for a 500-kg horse [4]. In our present study, the quantity of milk obtained before the adoption of the orphan foal was adequate to meet the energy demand of the foal. ...
... Our study suggested that a mare with induced lactation might become pregnant in the first ovulation after the end of hormonal treatment. Furthermore, recent studies indicate that lactation can be induced in mares in a minimum of 1 week by a modified hormonal treatment [4,31]. These results mean that a barren parous mare with induced lactation and introduced to an orphan foal as a nurse mare early in the breeding season can give birth in the next season. ...
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The purpose of this study was to demonstrate that a barren parous Thoroughbred mare with lactation induced by hormonal treatment can be introduced to an orphan foal at the same farm and that the mare can become pregnant after the end of the hormonal treatment. An additional purpose was to investigate the changes in the plasma concentrations of prolactin, estradiol-17β, progesterone, follicle-stimulating hormone, and luteinizing hormone before, during, and after hormonal treatment. The difference in body weight between the adopted foal and the control foals, which were at the same farm and raised by their natural mothers, was 17 kg at 24 weeks old, when the foals were weaned. However, the adopted foal and the control foals had almost the same weight at 35 weeks old and later. The first ovulation after hormonal treatment was confirmed 10 days after the end of hormonal treatment and then the normal estrous cycle resumed. Furthermore, the changes in plasma progesterone, estradiol-17β, follicle-stimulating hormone, and luteinizing hormone showed regular patterns after the first ovulation. Conception was confirmed in the fifth ovulation. Meanwhile, another study demonstrated that conception was confirmed in the first ovulation after hormonal treatment. The present study is the first to demonstrate the hormonal profiles during and after induction of lactation in a Thoroughbred mare. This approach is useful for solving the economic and epidemic problems of introducing a nurse mare to an orphan foal.
... Altrenogest is a synthetic progestin commonly used in mare reproduction for behaviour modification, control of estrus, maintenance of pregnancy and uterine quiescence, and induction of lactation in nonparturient mares. [1][2][3][4] Such uses require altrenogest treatment ranging from 10 -120 days. Currently, only 1 oral altrenogest preparation is available in Australia with a demonstrated progestational effect in mares. ...
... Nowadays, PGF 2 a and its analogues are used widely and successfully throughout the horse breeding world, to treat prolonged dioestrus, shorten the dioestrous interval in mares that missed being inseminated or were infected in the previous oestrus, synchronise ovulation for embryo transfer or any other of the modern breeding technologies [28][29][30], and stimulate prolonged uterine contractions to expel accumulated uterine fluids in mares with endometritis [31,32]. In addition, PGF 2 a has been used to induce abortion [33,34] and parturition [35,36], as a possible treatment to stimulate maternal behaviour and thereby overcome foal rejection [37] and, occasionally, to stimulate erection and ejaculation in shy or reluctant stallions [38]. ...
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The aim of the study was to determine the changes in composition and physicochemical features (pH, density, thermostability and acidity) of mare colostrum and milk, and of protein fraction contribution (serum albumin, β-casein, γ-casein, α-lactalbumin, G class immunoglobulins) depending on lactation stage. The research material was colostrum and milk samples from 12 Arabian mares. Colostrum samples were collected within 2 h after parturition and milk samples were collected twice, in the 3rd and 6th weeks of lactation. The level of basic milk components decreased significantly (only lactose content increased) as compared to colostrum. Total bacteria count and somatic cell count decreased significantly with an increase in resistance and urea level. The changes observed were connected to differentiated contribution of particular protein fractions and their relative proportions. Lower levels of γ-casein (P ≤ 0.05), β-casein, serum albumin as well as α-lactalbumin were observed in colostrum as compared to those in milk. Any relationship between lactation stage and β-casein content was observed. Serum albumin and α-lactalbumin content increased in subsequent milkings. The level of G class immunoglobulins decreased significantly and its highest level was noted in colostrum. Any significant differences between the 3rd and 6th lactation weeks were obtained.
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We have developed a treatment protocol for the successful induction of lactation in mares. This treatment consists of estrogen, progesterone, and sulpiride administration for 1 wk. Mares with induced lactation are able to adopt and nurse a foal to weaning age. Authors' addresses: Equitech-nic, Le Mesnil Vicomte, France (Daels); Physiology of Reproduction and Behavior, INRA, 37380 Nouzilly, France (Duchamp, Porter).
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The induction of lactation is performed in ruminants by steroidogenic impregnation, followed by drugs intended to increase prolactin secretion. The aim of this study was to induce lactation in barren mares and to evaluate milk production. Five treated and 5 control mares were used in June and September in year 1, and 12 mares were used in year 2. Mares were administered a vaginal pessary (500 mg altrenogest and 50 mg estradiol benzoate) for 1 week. The 2nd week, another sponge with 100 mg estradiol benzoate was administered, together with 50 mg/100 kg body weight (BW) sulpiride in oil (IM q12h). All mares were milked by hand. Drug treatment was stopped after I L was obtained. Milk production and composition and plasma prolactin concentration were measured. In year 2, the same steroid treatment was applied, but mares received sulpiride (n = 6) or domperidone (1.1 mg/kg PO q12h) (n = 6). A milking machine and oxytocin injections 1 minute before the start of milking were used. In year 1, all treated mares started milking within 1-5 days after sulpiride treatment. Mean daily milk production was 0.88 +/- 0.52 L/500 kg BW. Milk immunoglobulin G (IgG) contents increased in all mares (IgG concentration range, 14-92 g/L). Plasma prolactin increased during sulpiride treatment (range. 27.7 +/- 2.9 to 43.7 +/- 6.7 ng/mL [before] to 289.0 +/- 7.8 ng/mL during treatment, P < .001). In year 2, results were similar to those in year 1, with peak IgG concentrations ranging from 4.2 to 106.7 g/L and a larger daily milk production (3.13 +/- 0.75 with sulpiride and 3.45 +/- 0.51 L/500 kg BW with domperidone). In conclusion, lactation can be induced in mares within 2 weeks, and some mares produce good-quality colostrum.
Quantitative and qualitative assessment of milk production after pharmaceutical induction of lactation in mares
  • P Chavatte-Palmer
  • P F Daels
  • G Arnaud
  • C Duvaux-Ponter
  • L Brosse
  • D Guillaume
  • S Rousseau
  • G Duchamp
  • Clément F Palmer
Chavatte-Palmer P, Daels PF, Arnaud G, Duvaux-Ponter C, Brosse L, Guillaume D, Rousseau S, Duchamp G, Clément F and Palmer E. Quantitative and qualitative assessment of milk production after pharmaceutical induction of lactation in mares. Proceedings of the Symposium on Equine Reproduction and Annual Meeting of the Society for Theriogenology, San Antonio TX, 111.
Induction of Lactation and Adoption of Foals by Non-Parturient Mares
  • P F Daels
  • G Duchamp
  • D Porter
Daels, PF, Duchamp G. and Porter, D. Induction of Lactation and Adoption of Foals by Non-Parturient Mares. Proceedings of the Annual Convention of the American Association of Equine Practitioners, vol 48, 68-71, 2002. ____________________________________________________________________________ This manuscript is reproduced in the IVIS website with the permission of the American Association of Equine Practitioners www.aaep.org