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Breeding Management
CHAPTER
16 Breeding Management Lisa K. Pearson, Jacobo S. Rodriguez, and Ahmed Tibary
Breeding management of alpacas and llamas vary, depending on the production system in place; however, it is the goal of most producers for each female to produce one cria per year. In South America, the breeding season is restricted to the summer months because of weather and available forage and because the animals are housed on native pastures at high elevation. In North American management systems, breeding may be planned for early summer or fall to avoid the females giving birth during the cold winter months or the very hot summer months, which would place added stress not only on the female in late gestation and labor but also on the neonatal cria which is very sensitive to ambient temperature. It should be noted, however, that alpacas and llamas kept in good health and body condition will cycle year-round and that pregnancy is possible at any time. Selection of females for breeding is covered elsewhere in this text; however, it should be noted that a complete breeding soundness examination should be performed on any maiden female prior to breeding. This examination is performed to assess for any congenital abnormalities of the reproductive tract and to demonstrate cyclicity in preparation for breeding. Alpacas and llamas seem to have a higher rate of congenital defects compared with other domestic species, and identifying any abnormalities that may cause or contribute to infertility will save not only the female from repeated matings but also the producer time and effort in the breeding pen. It is important to emphasize that breeding management starts with a sound nutritional and herd health program. These aspects are detailed in other chapters of this publication.
Male Selection and Breeding Management Prospective herd sires should be selected on the basis of strict guidelines for conformation, production, and absence of congenital diseases. Males should be examined at birth for any obvious abnormality and then monitored for growth. Studies on sperm production capacity and factors affecting semen quality are still not as developed in alpacas and llamas as they are in other species. Testicular size remains one of the most important factors in the selection of males. All males should undergo periodic examinations for testicular growth (Box 16-1). A complete breeding soundness examination should be scheduled before intended use. Although owners may be starting males as early as age 2 years, a great proportion of these males will not pass the breeding soundness examination at this age. A final decision on the male’s reproductive ability should be made by 3 years of age.
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Young males that have been reared in separate pens may have difficulties getting started. It is important to start initiating young males by allowing them to be near a mating pair. Studies on the appropriate frequency of use of the male or the male-to-female ratio are lacking. Studies have shown that male llamas and alpacas can sustain a relatively heavy breeding schedule for 2 weeks, but thereafter they need to be replaced or rested. Scientific data on the appropriate frequency of mating of young males are not available. Male fertility should be monitored closely in relation to the early pregnancy status of all mated females. Breeding records should be maintained in detail and include dates, durations, and results of all breedings.
Testing of Female Behavior Female alpacas and llamas undergo puberty as early as age 4 to 6 months, when they attain the ability to develop follicles and show signs of receptivity. In our experience, several females have become pregnant at age 4 months when accidentally mated in a pasture situation. It is not rare for a llama to become pregnant at age 9 months, although this is not recommended because mating this early in life results in a very high rate of early embryonic loss or abortion, and most of these young females with early matings will exhibit stunted growth and poor conformation. The adequate age to mate a female for the first time is when it reaches 63% to 65% of its adult body weight and height.1 This age varies from 12 to 14 months; however, most North American producers will plan a first mating at 15 to 18 months of age. Growth and development of the female camelid is dictated by level of nutrition, although care should be taken to ensure that they do not grow too fast or attain a high body condition, as this may lead to orthopedic or metabolic diseases, which may impair fertility. The ideal body condition score (BCS) for a maiden female is 2.5 to 3 on a scale of 1 to 5. Once a female has reached an appropriate age and size, a breeding soundness examination must be performed to ensure that the female is suitable for breeding. Persistent hymen is a condition that should be assessed and treated. Transrectal ultrasonography will demonstrate the level of activity present in ovarian follicles. If a dominant follicle is present at the time of evaluation and the female is physically suitable to be bred, it may be teased to the male and mated, if receptive. If no dominant follicles are present or if the producer chooses to breed the animal at a later date, the best way to detect receptivity on the farm is by teasing. The female is teased to a breeding male over a fence, or in a small paddock if each animal is restrained by a handler with a halter and lead
Chapter 16 • Breeding Management
BOX 16-1
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Check List for Selection and Care of the Herd Sire
BREEDING STRATEGY • Selection starts at the mating plan decision. • Females and males selected to produce a herd sire should be almost flawless. • Care of the pregnant female during pregnancy may have an important effect on some phenotypic expression of genes. • Strict biosecurity measures should be maintained for the female during breeding and pregnancy. • A proper herd health protocol (vaccination, deworming, nutrition) should be followed. BIRTH TO 6 MONTHS • Start a detailed health record. • Record birth weight. • Look for any heritable defects. • Assess testicular decent. • Determine passive transfer status (failure versus adequate). • Monitor for normal growth. • Follow a proper herd health protocol (vaccination, deworming, nutrition). • Ensure reduced biohazards. • Wean at 6 months. • Start a sound nutritional program. 6 MONTHS TO 12 MONTHS • Maintain a detailed health record. • Carry out physical examinations (at least twice a year). • Take testicular measurements. • Allow interaction with other breeding males. • Monitor growth. • Ensure strict biosecurity measures, particularly if the animal is participating in shows. 15 MONTHS TO 18 MONTHS • Maintain a detailed health record. • Complete physical examinations (at least twice a year). • Record testicular measurements (every 6 months). • Perform testicular ultrasonography. • Ensure strict biosecurity measures, particularly if the animal is participating in shows. • Determine the genetic suitability of the male for breeding.
rope. If the female spits or kicks at the male, it is not receptive. If it sits, it either has a dominant follicle within the ovary, or in some cases, it may have no significant hormonally active structures within the ovary. The behavior of nonreceptivity is correlated to the presence of a corpus luteum in the ovary and high serum progesterone levels. However, behavior is not always correlated to ovarian activity or serum hormone levels,
2 YEARS TO 3 YEARS • Maintain detailed health records. • Complete physical examinations. • Complete breeding soundness examinations (highly recommended). • If the animal passes the soundness examination, it is considered a young sire and may be used for breeding two to three times per week. • Start a detailed breeding record: behavior, breeding date, mating duration, spitting-off test results. • Use only females that have passed the biosecurity measures requirement for breeding. • Obtain an early pregnancy diagnosis. • Use a Q-sum technique to monitor fertility. • Monitor testicular growth every 6 months. • Three years is the age at which all males should be able to mate and impregnate females. • Determine the fertility of the male by age 3 years. 4 YEARS TO 5 YEARS (MATURE MALE) • Maintain detailed health and reproduction records. • Monitor the fertility trend. • Determine the yearly breeding success rate for maiden females, females with cria at the side, and barren females. • Complete physical examinations (twice a year). • Complete breeding soundness examinations prior to the breeding season. • Follow quarantine measures for females and males that are traveling. • Repeat breeding soundness examinations for the following: • Perceived fertility problem—physical or behavioral abnormalities • Heat stress • Transportation • Illness OLDER THAN 9 YEARS • Maintain detailed health and reproduction records. • Complete physical examinations. • Watch for testicular degeneration and age-related changes. • Complete breeding soundness examinations, as detailed above. • Follow biosecurity guidelines.
which underscores the importance of veterinary ultrasonographic examination for accurate determination. All camelids are induced ovulators, although a very small percentage of females ovulate spontaneously. It is our personal observation that a maiden female may present to the veterinarian with a corpus luteum in the ovary, even without mating. This stresses the importance of a breeding soundness
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examination, as females that ovulate spontaneously may tend to do so over their lifetime, and breeding management of these animals may require more intense monitoring.
Breeding Systems In-Hand Mating The system of in-hand mating is the most commonly used method in North American alpaca and llama production systems. Most matings are planned, taking into account pedigree, fiber size and production, color, and body size, among other features. If the male is some distance from the female, the female may be shipped to the male’s farm of residence for the breeding season. If the male is housed locally, the producer may choose to have the female monitored by the veterinarian for a dominant follicle, tease the female, and take it to the farm only for breeding. These coordinated movements of animals for breeding purposes are best achieved when the producer works closely with the veterinarian to ensure that the female is suitable for breeding and is receptive, which would entail the use of transrectal ultrasonography and possibly hormonal induction of ovulation. In this way, the probability of establishing a pregnancy is enhanced. Use of ovulation-inducing drugs is not uncommon. It is known that the male’s semen contains an ovulation-inducing factor, which, combined with the inflammation generated in the uterus during breeding, will cause ovulation.2 A veterinarian may dispense an ovulation-inducing drug for administration after mating to ensure that the female will ovulate. The most commonly employed agents are gonadotropin-releasing hormone (GnRH) agonists such as gonadorelin diacetate tetrahydrate (25 to 50 micrograms [mcg], intramuscularly [IM]) given one time after breeding. Human chorionic gonadotropin (hCG) (500 to 750 international units [IU], intravenously [IV]) has also been used but not as commonly as GnRH. Ovulation typically follows within 1 to 2 days. Administering a GnRH agonist to a female that is bred for a short period (too little time to generate significant intrauterine inflammation) or when mated with a subfertile male may be useful; however, the agent is used commonly even when a female is mated with a proven male, especially when the female ships to the farm for the breeding and then immediately returns to its home farm, to ensure ovulation and thus avoid repeated trips to the stud farm.
A
An additional use of a GnRH agonist is for planned breeding. If the breeding soundness examination demonstrates a dominant follicle in the ovary, the GnRH agonist may be administered to induce ovulation. The female should develop a new dominant follicle and be receptive for mating 14 days from the time of injection. This is useful for planning matings with males that are far away, have a full breeding schedule, or are currently showing or off the farm or just to facilitate planning a visit to the stud farm. In-hand mating is achieved by use of restraint of both the female and male by halter and lead rope. Often the female’s tail is wrapped with a self-adhesive bandage to decrease the amount of dust or manure on the tail hairs that may be introduced into the vagina and to reduce the risk of a hair ring forming on the male’s penis. Matings may occur in a grassy paddock, dirt pen, or other location where the footing is such that the male will be able to gain traction for copulation but not so harsh that the male or female will sustain injury. Concrete floors, gravel, and wood chips with large splinters are not suitable footing. A confined space such as small pen is ideal when the female has a nursing cria. The cria may be allowed to move freely around the pen during the mating, and the size of the pen prohibits the cria from moving far from the dam, which may cause the dam alarm and interrupt the mating behavior. The female may sit readily for the male, or the male may have to court the female and force it down. The female may remain in ventral recumbency with all limbs squarely underneath, or as the breeding progresses the female may kick the limbs out to the side (Figure 16-1, A).3 Frequently, the female may self-auscultate its flanks (see Figure 16-1, B). In our opinion, the side of self-auscultation is correlated to the horn of the uterus that the male is currently breeding. After a period, the female may shift its weight, causing the male to shift to the contralateral uterine horn. The female may then selfauscultate on that side. During all matings, the male’s penis should be monitored to ensure that it actively engages the female reproductive tract, and the length of the mating, as well as the date and the level of receptivity of the female, should be recorded. Good breeding records are instrumental in managing an efficient herd, and in cases of infertility, early pregnancy loss, or late-term problems, these records will assist the veterinarian in evaluating the case (Figure 16-2). Using these techniques of female selection, teasing, and mating with a proven male under supervision, a female should
B Figure 16-1 A, In-hand mating of alpacas in a small paddock. The female has passively shifted from the sternal position to lateral recumbency, with the limbs and neck outstretched. B, Pen mating of alpacas in a small paddock. The female is self-auscultating the right flank, suggestive that the male is breeding the right uterine horn.
Chapter 16 • Breeding Management
Registration number
Name:
Date of Birth:
Sire:
Dam:
Previous crias (sex/date): Last cria (sex/date): Season:
Sire for season:
Month 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 January February March April May June July August September October November December Procedures/Results legend T = Teasing (+ receptive/–spits) B = Breeding # (duration) Ov = Ovulation P4 = Progesterone PD = Pregnancy Diagnosis (+/–) PT = Parturition TRU = Ultrasound (Transrectal) TAU = Ultrasound (Transabdominal) BSE = Breeding soundness Exam UF = Uterine flush Tx = Treatment A: Abortion
Pharmaceutical legend Gn: GnRH hG: hCG O = Oxytocin P+ = Progesterone Pg = Prostaglandin F2α
Preventive treatments V: Vaccination P: Deworming
Reproductive Exam Results Date
Reason
Cervix
Uterus
Left Ovary
Right Ovary
Observation
Figure 16-2 Example of breeding record. Each female has one breeding record for the season, and this record can be consulted quickly, when needed.
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only need to be mated one time, especially if ovulationinducing pharmacologic agents are used. The practice of having a female mate repeatedly during the period of receptivity is not only excessive but may cause undue inflammation to the female’s reproductive tract and increase the likelihood of infection or trauma. Females that have not been submitted for a maiden prebreeding examination may be repetitively mated even when a physical limitation such as persistent hymen, ovarian hypoplasia, or other congenital defect prevents the establishment of a pregnancy.4 In these cases, repetitive mating becomes an issue of welfare of the animal. It has been demonstrated that conception rates were similar in alpacas which were mated either one time or one or two times daily for 3 days (up to six breedings during a period of receptivity).5
Pen Mating Pen mating systems are similar to in-hand mating systems in that one male is selected for one female; however, the two animals are allowed off-lead in a small pen and allowed to engage in mating behavior without the presence of human handlers. If the female has a nursing cria with it, care should be taken to monitor the behavior of all animals in the pen during the breeding. As in in-hand mating systems, the date and length of mating should be recorded.
1 : 15 to 1 : 30. In this system, males may copulate up to 18 times on the first day (see Chapter 15: Reproductive Anatomy and Physiology in the Male). In some breeding systems, males are removed after 7 to 14 days and reintroduced again 14 to 21 days later. Periodic behavioral testing in large groups allows the breeder to identify females that became pregnant within a certain period during the breeding season.
Pregnancy Diagnosis Timely and precise pregnancy diagnosis is an important aspect of breeding management. Techniques utilized for pregnancy diagnosis are discussed in detail elsewhere in this text. Breeders should be instructed to tease the female at 7 and 12 days after mating. Nonreceptive females at 14 days should be presented for an early evaluation of pregnancy by ultrasonography. A simple breeding system based on this teasing system is illustrated in Figure 16-3. Females that are not pregnant after three matings with proven males in this system should be submitted for a complete breeding soundness examination. We recommend scheduling pregnancy diagnosis at 14, 25, and 35 days and between 45 and 60 days. Additional examination may be warranted if the female has a history of recurrent Female passes BSE
Paddock or Pasture Mating In a paddock mating system, one male is selected for turnout in a small enclosure with multiple females. The advantages to this system are that it requires less human labor and the sire is known. The disadvantages include unknown date or duration of mating (unless witnessed) and less managed breedings. A veterinarian may evaluate the ovarian activity of the females prior to turnout with the male, but it is unlikely that the size of the follicle at mating would be known, and the possibilities for inducing ovulation using pharmacologic agents would be slim, unless the mating was witnessed. Scheduled pregnancy diagnoses may be more difficult without knowing the exact mating date. Some producers may elect to leave the male in with the females for a specific period to limit the variability in the stage of a pregnancy in various females, although if both the females and the males are reproductively sound and cyclic, the females should become pregnant fairly soon after the introduction of the male.
Female teased until receptive Measure dominant follicle by u/s Day 0: Breed Day 7: Tease
Receptive? Breed
Not receptive?
Day 14: Tease
Day 14: Ultrasound for pregnancy diagnosis
Receptive? Breed
Not receptive? Schedule ultrasound for day 21 pregnancy diagnosis
Day 21: Tease
Multiple-Sire Mating The multiple-sire mating system is the most traditional system of breeding camelids, in which a large group of females is turned out to pasture with several males. One advantage to this system is minimal management, as the animals remain out on pasture. The disadvantages include not knowing the specific sire of the progeny, the mating date or length, the level of receptivity of the female prior to breeding, or the size of pre-ovulatory follicle; also, fewer opportunities exist for early pregnancy evaluation by ultrasonography, including detection of multiple ovulations, twin pregnancy, or early pregnancy loss. In South America, a group of males may be introduced to a herd of females at a male-to-female ratio of ranging from
Receptive? Breed
Not receptive? Schedule ultrasound for day 28 pregnancy diagnosis
Day 28: Tease
Receptive? Schedule infertility work-up
Not receptive? Schedule ultrasound for day 35 pregnancy diagnosis
Figure 16-3 A 35-day breeding management scheme for alpacas and llamas. Use of this or a similar system will achieve the highest pregnancy rates and early identification of infertility.
Chapter 16 • Breeding Management pregnancy loss. Progesterone analysis is used by several breeders as a method for pregnancy diagnosis, but it is not as accurate as ultrasonography and does not provide information on a possible twin pregnancy or early pregnancy loss.6,7 No placenta-associated glycoproteins are used for pregnancy diagnosis in camelids.8
Postpartum Breeding The female should be examined by a veterinarian in the immediate postpartum period, generally 24 to 38 hours after parturition. This examination is crucial for the dam and the cria, and postpartum examination of the placenta is also important. Neonatal cria examinations are discussed elsewhere in this text. A complete postpartum examination of the dam should include a general physical examination, even if the producer has been monitoring the dam’s temperature, appetite, and behavior, as well as a vaginal examination. A thorough examination will include evaluation of the perineum for any tears that may have occurred during parturition and for residual swelling of tissues. We prefer to use a sigmoidoscope for the vaginal examination of alpacas; however, in the postpartum alpaca or llama, often a larger tube speculum, 2 to 3 cm in diameter, may be used. The vagina should be evaluated for bruising, tears, or hemorrhage. Bruising commonly occurs around the vestibular sphincter and the lateral walls of the vagina and may have a blue hue several days after parturition. The cervix should be visually inspected for any tears, edema, or other trauma. The cervix remains open through the postpartum period as the dam passes the normal postpartum lochia. Postpartum complications are discussed in detail elsewhere in this text. Normal postpartum lochia is passed for 5 to 7 days and decreases in volume over time. Normal coloration ranges from white to brown to dark maroon, and producers should be advised that it is a normal physiologic response. Medical intervention may be warranted if the discharge is extremely malodorous and increases in volume over time or if the female develops a fever or signs of colic. Systematic uterine lavage in the postpartum female should be strongly discouraged. Transabdominal ultrasonography may also be performed at the time of the postpartum examination to evaluate the uterus and is absolutely indicated following cases of dystocia or retained fetal membranes. It should be noted that females that have an apparently normal parturition may have sustained injuries such as cervical or vaginal bruising or tears, uterine rupture, or postpartum hemorrhage, all of which are covered elsewhere in this text. Producers should be asked to save the placenta in a plastic bag or bucket in the refrigerator for examination by the veterinarian. The duration from parturition to passage of the fetal membranes should be recorded by the producer and should be less than 3 hours. A placenta that has not passed within 3 hours is considered retained, and the veterinarian should be contacted. Alpacas and llamas have placentation that is epitheliochorial, microcodyledonary, and diffuse. These types of placentae tend to detach from the endometrium quickly, often during parturition, and may be passed with the fetus, especially in cases of prolonged dystocia. Unlike the equine, which has a similar placentation, alpacas and llamas do not tend to retain only a section of the placenta. Mares often retain the
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tip of the nonpregnant horn, but camelids tend to either retain the entire placenta or pass it in its entirety. The placenta should be examined thoroughly. Both the allantoic and chorionic surfaces should be examined for any pathology, including avillous areas or signs of placentitis. The normal placenta is avillous at the cervical star, which is located at the tips of the horns that correspond to the uterotubal junctions, and in a small line along the cranial border of the uterus. The amniotic sac usually contains one hippomane, a mass of protein formed within the amniotic fluid. The hippomane is brown, is soft but not malleable, and, when cut, has a hollow core. The umbilical cord should be examined for excessive twisting, blood clots, or signs of funisitis. Small firm plaques at the base of the umbilical cord and on the amniotic membrane are a common insignificant finding. A placenta that had been retained for several hours or days may be difficult to evaluate on initiation of autolysis. Any placental abnormalities that are identified should be evaluated in light of the dam’s and the cria’s health. Placentitis should be considered if the placenta demonstrates diffuse or round focal areas of discoloration with brown, white, or yellow exudate. It should be noted that placentitis in camelid species is extremely rare and that autolysis should be suspected first, especially in cases where the dam and the cria are systemically healthy and the placenta has been either retained or kept at room temperature. Impression smears of any abnormal areas may demonstrate bacteria or fungal hyphae. These areas should be cultured for definitive diagnosis and antimicrobial sensitivities. Additionally, any abnormal areas of the placenta should be preserved in buffered neutral formalin for histopathologic evaluation. Placental evaluation and diagnostics are indicated for diagnosis of causes of abortion or stillbirth. Lactational anestrous has not been described in the alpaca or llama, and the female should resume normal ovarian activity after luteolysis and subsequent parturition. One study in llamas demonstrated that lactating animals had a shorter interval between follicular waves and a smaller diameter of dominant follicles but that the time from breeding to ovulation was not statistically different from that in nonlactating animals.9 The optimal time to use the postpartum female for breeding is 2 to 3 weeks after parturition, if it was uneventful, no complications developed, and ovarian activity progresses normally.10 Cases of dystocia, cesarean section, metritis, or trauma should be evaluated on an individual basis. Minor trauma may heal quickly, enabling an earlier breeding date. Females that undergo cesarean section should be evaluated after 60 days. Cases of dystocia are highly variable, and the veterinarian should assess the health of the female’s reproductive tract to determine the best breeding plan for the animal.
REFERENCES 1. Tibary A: Working with your veterinarian to devlop a herd health program. International Camelid Health Conference for Veterinarians, Columbus, OH, March 24-28, 2010, Ohio State University. 2. Adams GP, et al: Ovulation-inducing factor in the seminal plasma of alpacas and llamas, Biol Reprod 73:452-457, 2005. 3. Vaughan JL, Tibary A: Reproduction in female South American camelids: a review and clinical observations, Small Rumin Res 61:259-281, 2006.
4. Tibary A, Pugh D: Infertility in the female lamoid. In Proceedings of the Society for Theriogenology and American College of Theriogenologists Annual Conference, Columbus, OH, September 17-20, 2003. Pages 304-312. 2003. 5. Knight TW, et al: Effects of GnRH and of single versus multiple mating on the conception rate in alpacas. Proc of th NZ Soc Anim Prod 52:311312, 1992. 6. Tibary A, et al: Luteal insufficiency and progesterone supplementation. International Camelid Helath Conference for Veterinarians, Columbus, Ohio, March 19-23, 2008 (pp 231-240).
7. Bravo PW, et al: Hormonal indicators of pregnancy in llamas and alpacas, J Am Vet Med Assoc 208:2027-2030, 1996. 8. Drew ML, et al: Pregnancy determination by use of pregnancy-specific protein B radioimmunoassay in llamas, J Am Vet Med Assoc 207:217219, 1995. 9. Adams GP, et al: Effects of lactational and reproductive status on ovarian follicular waves in llamas (Lama glama), J Reprod Fertil 90:535545, 1990. 10. Bravo PW, et al: The postpartum llama: fertility after parturition, Biol Reprod 51:1084-1087, 1994.
16 Breeding Management Lisa K. Pearson, Jacobo S. Rodriguez, and Ahmed Tibary
Breeding management of alpacas and llamas vary, depending on the production system in place; however, it is the goal of most producers for each female to produce one cria per year. In South America, the breeding season is restricted to the summer months because of weather and available forage and because the animals are housed on native pastures at high elevation. In North American management systems, breeding may be planned for early summer or fall to avoid the females giving birth during the cold winter months or the very hot summer months, which would place added stress not only on the female in late gestation and labor but also on the neonatal cria which is very sensitive to ambient temperature. It should be noted, however, that alpacas and llamas kept in good health and body condition will cycle year-round and that pregnancy is possible at any time. Selection of females for breeding is covered elsewhere in this text; however, it should be noted that a complete breeding soundness examination should be performed on any maiden female prior to breeding. This examination is performed to assess for any congenital abnormalities of the reproductive tract and to demonstrate cyclicity in preparation for breeding. Alpacas and llamas seem to have a higher rate of congenital defects compared with other domestic species, and identifying any abnormalities that may cause or contribute to infertility will save not only the female from repeated matings but also the producer time and effort in the breeding pen. It is important to emphasize that breeding management starts with a sound nutritional and herd health program. These aspects are detailed in other chapters of this publication.
Male Selection and Breeding Management Prospective herd sires should be selected on the basis of strict guidelines for conformation, production, and absence of congenital diseases. Males should be examined at birth for any obvious abnormality and then monitored for growth. Studies on sperm production capacity and factors affecting semen quality are still not as developed in alpacas and llamas as they are in other species. Testicular size remains one of the most important factors in the selection of males. All males should undergo periodic examinations for testicular growth (Box 16-1). A complete breeding soundness examination should be scheduled before intended use. Although owners may be starting males as early as age 2 years, a great proportion of these males will not pass the breeding soundness examination at this age. A final decision on the male’s reproductive ability should be made by 3 years of age.
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Young males that have been reared in separate pens may have difficulties getting started. It is important to start initiating young males by allowing them to be near a mating pair. Studies on the appropriate frequency of use of the male or the male-to-female ratio are lacking. Studies have shown that male llamas and alpacas can sustain a relatively heavy breeding schedule for 2 weeks, but thereafter they need to be replaced or rested. Scientific data on the appropriate frequency of mating of young males are not available. Male fertility should be monitored closely in relation to the early pregnancy status of all mated females. Breeding records should be maintained in detail and include dates, durations, and results of all breedings.
Testing of Female Behavior Female alpacas and llamas undergo puberty as early as age 4 to 6 months, when they attain the ability to develop follicles and show signs of receptivity. In our experience, several females have become pregnant at age 4 months when accidentally mated in a pasture situation. It is not rare for a llama to become pregnant at age 9 months, although this is not recommended because mating this early in life results in a very high rate of early embryonic loss or abortion, and most of these young females with early matings will exhibit stunted growth and poor conformation. The adequate age to mate a female for the first time is when it reaches 63% to 65% of its adult body weight and height.1 This age varies from 12 to 14 months; however, most North American producers will plan a first mating at 15 to 18 months of age. Growth and development of the female camelid is dictated by level of nutrition, although care should be taken to ensure that they do not grow too fast or attain a high body condition, as this may lead to orthopedic or metabolic diseases, which may impair fertility. The ideal body condition score (BCS) for a maiden female is 2.5 to 3 on a scale of 1 to 5. Once a female has reached an appropriate age and size, a breeding soundness examination must be performed to ensure that the female is suitable for breeding. Persistent hymen is a condition that should be assessed and treated. Transrectal ultrasonography will demonstrate the level of activity present in ovarian follicles. If a dominant follicle is present at the time of evaluation and the female is physically suitable to be bred, it may be teased to the male and mated, if receptive. If no dominant follicles are present or if the producer chooses to breed the animal at a later date, the best way to detect receptivity on the farm is by teasing. The female is teased to a breeding male over a fence, or in a small paddock if each animal is restrained by a handler with a halter and lead
Chapter 16 • Breeding Management
BOX 16-1
163
Check List for Selection and Care of the Herd Sire
BREEDING STRATEGY • Selection starts at the mating plan decision. • Females and males selected to produce a herd sire should be almost flawless. • Care of the pregnant female during pregnancy may have an important effect on some phenotypic expression of genes. • Strict biosecurity measures should be maintained for the female during breeding and pregnancy. • A proper herd health protocol (vaccination, deworming, nutrition) should be followed. BIRTH TO 6 MONTHS • Start a detailed health record. • Record birth weight. • Look for any heritable defects. • Assess testicular decent. • Determine passive transfer status (failure versus adequate). • Monitor for normal growth. • Follow a proper herd health protocol (vaccination, deworming, nutrition). • Ensure reduced biohazards. • Wean at 6 months. • Start a sound nutritional program. 6 MONTHS TO 12 MONTHS • Maintain a detailed health record. • Carry out physical examinations (at least twice a year). • Take testicular measurements. • Allow interaction with other breeding males. • Monitor growth. • Ensure strict biosecurity measures, particularly if the animal is participating in shows. 15 MONTHS TO 18 MONTHS • Maintain a detailed health record. • Complete physical examinations (at least twice a year). • Record testicular measurements (every 6 months). • Perform testicular ultrasonography. • Ensure strict biosecurity measures, particularly if the animal is participating in shows. • Determine the genetic suitability of the male for breeding.
rope. If the female spits or kicks at the male, it is not receptive. If it sits, it either has a dominant follicle within the ovary, or in some cases, it may have no significant hormonally active structures within the ovary. The behavior of nonreceptivity is correlated to the presence of a corpus luteum in the ovary and high serum progesterone levels. However, behavior is not always correlated to ovarian activity or serum hormone levels,
2 YEARS TO 3 YEARS • Maintain detailed health records. • Complete physical examinations. • Complete breeding soundness examinations (highly recommended). • If the animal passes the soundness examination, it is considered a young sire and may be used for breeding two to three times per week. • Start a detailed breeding record: behavior, breeding date, mating duration, spitting-off test results. • Use only females that have passed the biosecurity measures requirement for breeding. • Obtain an early pregnancy diagnosis. • Use a Q-sum technique to monitor fertility. • Monitor testicular growth every 6 months. • Three years is the age at which all males should be able to mate and impregnate females. • Determine the fertility of the male by age 3 years. 4 YEARS TO 5 YEARS (MATURE MALE) • Maintain detailed health and reproduction records. • Monitor the fertility trend. • Determine the yearly breeding success rate for maiden females, females with cria at the side, and barren females. • Complete physical examinations (twice a year). • Complete breeding soundness examinations prior to the breeding season. • Follow quarantine measures for females and males that are traveling. • Repeat breeding soundness examinations for the following: • Perceived fertility problem—physical or behavioral abnormalities • Heat stress • Transportation • Illness OLDER THAN 9 YEARS • Maintain detailed health and reproduction records. • Complete physical examinations. • Watch for testicular degeneration and age-related changes. • Complete breeding soundness examinations, as detailed above. • Follow biosecurity guidelines.
which underscores the importance of veterinary ultrasonographic examination for accurate determination. All camelids are induced ovulators, although a very small percentage of females ovulate spontaneously. It is our personal observation that a maiden female may present to the veterinarian with a corpus luteum in the ovary, even without mating. This stresses the importance of a breeding soundness
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examination, as females that ovulate spontaneously may tend to do so over their lifetime, and breeding management of these animals may require more intense monitoring.
Breeding Systems In-Hand Mating The system of in-hand mating is the most commonly used method in North American alpaca and llama production systems. Most matings are planned, taking into account pedigree, fiber size and production, color, and body size, among other features. If the male is some distance from the female, the female may be shipped to the male’s farm of residence for the breeding season. If the male is housed locally, the producer may choose to have the female monitored by the veterinarian for a dominant follicle, tease the female, and take it to the farm only for breeding. These coordinated movements of animals for breeding purposes are best achieved when the producer works closely with the veterinarian to ensure that the female is suitable for breeding and is receptive, which would entail the use of transrectal ultrasonography and possibly hormonal induction of ovulation. In this way, the probability of establishing a pregnancy is enhanced. Use of ovulation-inducing drugs is not uncommon. It is known that the male’s semen contains an ovulation-inducing factor, which, combined with the inflammation generated in the uterus during breeding, will cause ovulation.2 A veterinarian may dispense an ovulation-inducing drug for administration after mating to ensure that the female will ovulate. The most commonly employed agents are gonadotropin-releasing hormone (GnRH) agonists such as gonadorelin diacetate tetrahydrate (25 to 50 micrograms [mcg], intramuscularly [IM]) given one time after breeding. Human chorionic gonadotropin (hCG) (500 to 750 international units [IU], intravenously [IV]) has also been used but not as commonly as GnRH. Ovulation typically follows within 1 to 2 days. Administering a GnRH agonist to a female that is bred for a short period (too little time to generate significant intrauterine inflammation) or when mated with a subfertile male may be useful; however, the agent is used commonly even when a female is mated with a proven male, especially when the female ships to the farm for the breeding and then immediately returns to its home farm, to ensure ovulation and thus avoid repeated trips to the stud farm.
A
An additional use of a GnRH agonist is for planned breeding. If the breeding soundness examination demonstrates a dominant follicle in the ovary, the GnRH agonist may be administered to induce ovulation. The female should develop a new dominant follicle and be receptive for mating 14 days from the time of injection. This is useful for planning matings with males that are far away, have a full breeding schedule, or are currently showing or off the farm or just to facilitate planning a visit to the stud farm. In-hand mating is achieved by use of restraint of both the female and male by halter and lead rope. Often the female’s tail is wrapped with a self-adhesive bandage to decrease the amount of dust or manure on the tail hairs that may be introduced into the vagina and to reduce the risk of a hair ring forming on the male’s penis. Matings may occur in a grassy paddock, dirt pen, or other location where the footing is such that the male will be able to gain traction for copulation but not so harsh that the male or female will sustain injury. Concrete floors, gravel, and wood chips with large splinters are not suitable footing. A confined space such as small pen is ideal when the female has a nursing cria. The cria may be allowed to move freely around the pen during the mating, and the size of the pen prohibits the cria from moving far from the dam, which may cause the dam alarm and interrupt the mating behavior. The female may sit readily for the male, or the male may have to court the female and force it down. The female may remain in ventral recumbency with all limbs squarely underneath, or as the breeding progresses the female may kick the limbs out to the side (Figure 16-1, A).3 Frequently, the female may self-auscultate its flanks (see Figure 16-1, B). In our opinion, the side of self-auscultation is correlated to the horn of the uterus that the male is currently breeding. After a period, the female may shift its weight, causing the male to shift to the contralateral uterine horn. The female may then selfauscultate on that side. During all matings, the male’s penis should be monitored to ensure that it actively engages the female reproductive tract, and the length of the mating, as well as the date and the level of receptivity of the female, should be recorded. Good breeding records are instrumental in managing an efficient herd, and in cases of infertility, early pregnancy loss, or late-term problems, these records will assist the veterinarian in evaluating the case (Figure 16-2). Using these techniques of female selection, teasing, and mating with a proven male under supervision, a female should
B Figure 16-1 A, In-hand mating of alpacas in a small paddock. The female has passively shifted from the sternal position to lateral recumbency, with the limbs and neck outstretched. B, Pen mating of alpacas in a small paddock. The female is self-auscultating the right flank, suggestive that the male is breeding the right uterine horn.
Chapter 16 • Breeding Management
Registration number
Name:
Date of Birth:
Sire:
Dam:
Previous crias (sex/date): Last cria (sex/date): Season:
Sire for season:
Month 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 January February March April May June July August September October November December Procedures/Results legend T = Teasing (+ receptive/–spits) B = Breeding # (duration) Ov = Ovulation P4 = Progesterone PD = Pregnancy Diagnosis (+/–) PT = Parturition TRU = Ultrasound (Transrectal) TAU = Ultrasound (Transabdominal) BSE = Breeding soundness Exam UF = Uterine flush Tx = Treatment A: Abortion
Pharmaceutical legend Gn: GnRH hG: hCG O = Oxytocin P+ = Progesterone Pg = Prostaglandin F2α
Preventive treatments V: Vaccination P: Deworming
Reproductive Exam Results Date
Reason
Cervix
Uterus
Left Ovary
Right Ovary
Observation
Figure 16-2 Example of breeding record. Each female has one breeding record for the season, and this record can be consulted quickly, when needed.
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only need to be mated one time, especially if ovulationinducing pharmacologic agents are used. The practice of having a female mate repeatedly during the period of receptivity is not only excessive but may cause undue inflammation to the female’s reproductive tract and increase the likelihood of infection or trauma. Females that have not been submitted for a maiden prebreeding examination may be repetitively mated even when a physical limitation such as persistent hymen, ovarian hypoplasia, or other congenital defect prevents the establishment of a pregnancy.4 In these cases, repetitive mating becomes an issue of welfare of the animal. It has been demonstrated that conception rates were similar in alpacas which were mated either one time or one or two times daily for 3 days (up to six breedings during a period of receptivity).5
Pen Mating Pen mating systems are similar to in-hand mating systems in that one male is selected for one female; however, the two animals are allowed off-lead in a small pen and allowed to engage in mating behavior without the presence of human handlers. If the female has a nursing cria with it, care should be taken to monitor the behavior of all animals in the pen during the breeding. As in in-hand mating systems, the date and length of mating should be recorded.
1 : 15 to 1 : 30. In this system, males may copulate up to 18 times on the first day (see Chapter 15: Reproductive Anatomy and Physiology in the Male). In some breeding systems, males are removed after 7 to 14 days and reintroduced again 14 to 21 days later. Periodic behavioral testing in large groups allows the breeder to identify females that became pregnant within a certain period during the breeding season.
Pregnancy Diagnosis Timely and precise pregnancy diagnosis is an important aspect of breeding management. Techniques utilized for pregnancy diagnosis are discussed in detail elsewhere in this text. Breeders should be instructed to tease the female at 7 and 12 days after mating. Nonreceptive females at 14 days should be presented for an early evaluation of pregnancy by ultrasonography. A simple breeding system based on this teasing system is illustrated in Figure 16-3. Females that are not pregnant after three matings with proven males in this system should be submitted for a complete breeding soundness examination. We recommend scheduling pregnancy diagnosis at 14, 25, and 35 days and between 45 and 60 days. Additional examination may be warranted if the female has a history of recurrent Female passes BSE
Paddock or Pasture Mating In a paddock mating system, one male is selected for turnout in a small enclosure with multiple females. The advantages to this system are that it requires less human labor and the sire is known. The disadvantages include unknown date or duration of mating (unless witnessed) and less managed breedings. A veterinarian may evaluate the ovarian activity of the females prior to turnout with the male, but it is unlikely that the size of the follicle at mating would be known, and the possibilities for inducing ovulation using pharmacologic agents would be slim, unless the mating was witnessed. Scheduled pregnancy diagnoses may be more difficult without knowing the exact mating date. Some producers may elect to leave the male in with the females for a specific period to limit the variability in the stage of a pregnancy in various females, although if both the females and the males are reproductively sound and cyclic, the females should become pregnant fairly soon after the introduction of the male.
Female teased until receptive Measure dominant follicle by u/s Day 0: Breed Day 7: Tease
Receptive? Breed
Not receptive?
Day 14: Tease
Day 14: Ultrasound for pregnancy diagnosis
Receptive? Breed
Not receptive? Schedule ultrasound for day 21 pregnancy diagnosis
Day 21: Tease
Multiple-Sire Mating The multiple-sire mating system is the most traditional system of breeding camelids, in which a large group of females is turned out to pasture with several males. One advantage to this system is minimal management, as the animals remain out on pasture. The disadvantages include not knowing the specific sire of the progeny, the mating date or length, the level of receptivity of the female prior to breeding, or the size of pre-ovulatory follicle; also, fewer opportunities exist for early pregnancy evaluation by ultrasonography, including detection of multiple ovulations, twin pregnancy, or early pregnancy loss. In South America, a group of males may be introduced to a herd of females at a male-to-female ratio of ranging from
Receptive? Breed
Not receptive? Schedule ultrasound for day 28 pregnancy diagnosis
Day 28: Tease
Receptive? Schedule infertility work-up
Not receptive? Schedule ultrasound for day 35 pregnancy diagnosis
Figure 16-3 A 35-day breeding management scheme for alpacas and llamas. Use of this or a similar system will achieve the highest pregnancy rates and early identification of infertility.
Chapter 16 • Breeding Management pregnancy loss. Progesterone analysis is used by several breeders as a method for pregnancy diagnosis, but it is not as accurate as ultrasonography and does not provide information on a possible twin pregnancy or early pregnancy loss.6,7 No placenta-associated glycoproteins are used for pregnancy diagnosis in camelids.8
Postpartum Breeding The female should be examined by a veterinarian in the immediate postpartum period, generally 24 to 38 hours after parturition. This examination is crucial for the dam and the cria, and postpartum examination of the placenta is also important. Neonatal cria examinations are discussed elsewhere in this text. A complete postpartum examination of the dam should include a general physical examination, even if the producer has been monitoring the dam’s temperature, appetite, and behavior, as well as a vaginal examination. A thorough examination will include evaluation of the perineum for any tears that may have occurred during parturition and for residual swelling of tissues. We prefer to use a sigmoidoscope for the vaginal examination of alpacas; however, in the postpartum alpaca or llama, often a larger tube speculum, 2 to 3 cm in diameter, may be used. The vagina should be evaluated for bruising, tears, or hemorrhage. Bruising commonly occurs around the vestibular sphincter and the lateral walls of the vagina and may have a blue hue several days after parturition. The cervix should be visually inspected for any tears, edema, or other trauma. The cervix remains open through the postpartum period as the dam passes the normal postpartum lochia. Postpartum complications are discussed in detail elsewhere in this text. Normal postpartum lochia is passed for 5 to 7 days and decreases in volume over time. Normal coloration ranges from white to brown to dark maroon, and producers should be advised that it is a normal physiologic response. Medical intervention may be warranted if the discharge is extremely malodorous and increases in volume over time or if the female develops a fever or signs of colic. Systematic uterine lavage in the postpartum female should be strongly discouraged. Transabdominal ultrasonography may also be performed at the time of the postpartum examination to evaluate the uterus and is absolutely indicated following cases of dystocia or retained fetal membranes. It should be noted that females that have an apparently normal parturition may have sustained injuries such as cervical or vaginal bruising or tears, uterine rupture, or postpartum hemorrhage, all of which are covered elsewhere in this text. Producers should be asked to save the placenta in a plastic bag or bucket in the refrigerator for examination by the veterinarian. The duration from parturition to passage of the fetal membranes should be recorded by the producer and should be less than 3 hours. A placenta that has not passed within 3 hours is considered retained, and the veterinarian should be contacted. Alpacas and llamas have placentation that is epitheliochorial, microcodyledonary, and diffuse. These types of placentae tend to detach from the endometrium quickly, often during parturition, and may be passed with the fetus, especially in cases of prolonged dystocia. Unlike the equine, which has a similar placentation, alpacas and llamas do not tend to retain only a section of the placenta. Mares often retain the
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tip of the nonpregnant horn, but camelids tend to either retain the entire placenta or pass it in its entirety. The placenta should be examined thoroughly. Both the allantoic and chorionic surfaces should be examined for any pathology, including avillous areas or signs of placentitis. The normal placenta is avillous at the cervical star, which is located at the tips of the horns that correspond to the uterotubal junctions, and in a small line along the cranial border of the uterus. The amniotic sac usually contains one hippomane, a mass of protein formed within the amniotic fluid. The hippomane is brown, is soft but not malleable, and, when cut, has a hollow core. The umbilical cord should be examined for excessive twisting, blood clots, or signs of funisitis. Small firm plaques at the base of the umbilical cord and on the amniotic membrane are a common insignificant finding. A placenta that had been retained for several hours or days may be difficult to evaluate on initiation of autolysis. Any placental abnormalities that are identified should be evaluated in light of the dam’s and the cria’s health. Placentitis should be considered if the placenta demonstrates diffuse or round focal areas of discoloration with brown, white, or yellow exudate. It should be noted that placentitis in camelid species is extremely rare and that autolysis should be suspected first, especially in cases where the dam and the cria are systemically healthy and the placenta has been either retained or kept at room temperature. Impression smears of any abnormal areas may demonstrate bacteria or fungal hyphae. These areas should be cultured for definitive diagnosis and antimicrobial sensitivities. Additionally, any abnormal areas of the placenta should be preserved in buffered neutral formalin for histopathologic evaluation. Placental evaluation and diagnostics are indicated for diagnosis of causes of abortion or stillbirth. Lactational anestrous has not been described in the alpaca or llama, and the female should resume normal ovarian activity after luteolysis and subsequent parturition. One study in llamas demonstrated that lactating animals had a shorter interval between follicular waves and a smaller diameter of dominant follicles but that the time from breeding to ovulation was not statistically different from that in nonlactating animals.9 The optimal time to use the postpartum female for breeding is 2 to 3 weeks after parturition, if it was uneventful, no complications developed, and ovarian activity progresses normally.10 Cases of dystocia, cesarean section, metritis, or trauma should be evaluated on an individual basis. Minor trauma may heal quickly, enabling an earlier breeding date. Females that undergo cesarean section should be evaluated after 60 days. Cases of dystocia are highly variable, and the veterinarian should assess the health of the female’s reproductive tract to determine the best breeding plan for the animal.
REFERENCES 1. Tibary A: Working with your veterinarian to devlop a herd health program. International Camelid Health Conference for Veterinarians, Columbus, OH, March 24-28, 2010, Ohio State University. 2. Adams GP, et al: Ovulation-inducing factor in the seminal plasma of alpacas and llamas, Biol Reprod 73:452-457, 2005. 3. Vaughan JL, Tibary A: Reproduction in female South American camelids: a review and clinical observations, Small Rumin Res 61:259-281, 2006.
4. Tibary A, Pugh D: Infertility in the female lamoid. In Proceedings of the Society for Theriogenology and American College of Theriogenologists Annual Conference, Columbus, OH, September 17-20, 2003. Pages 304-312. 2003. 5. Knight TW, et al: Effects of GnRH and of single versus multiple mating on the conception rate in alpacas. Proc of th NZ Soc Anim Prod 52:311312, 1992. 6. Tibary A, et al: Luteal insufficiency and progesterone supplementation. International Camelid Helath Conference for Veterinarians, Columbus, Ohio, March 19-23, 2008 (pp 231-240).
7. Bravo PW, et al: Hormonal indicators of pregnancy in llamas and alpacas, J Am Vet Med Assoc 208:2027-2030, 1996. 8. Drew ML, et al: Pregnancy determination by use of pregnancy-specific protein B radioimmunoassay in llamas, J Am Vet Med Assoc 207:217219, 1995. 9. Adams GP, et al: Effects of lactational and reproductive status on ovarian follicular waves in llamas (Lama glama), J Reprod Fertil 90:535545, 1990. 10. Bravo PW, et al: The postpartum llama: fertility after parturition, Biol Reprod 51:1084-1087, 1994.