Basic Camelid Reproduction/Breeding/Normal Birthing
LaRue W. Johnson DVM, PhD
Colorado State University
Reproductive Anatomy and Physiology
Llamas and alpacas can essentially be regarded as similar reproductively. Once having achieved sexual maturity they are capable of breeding any time of the year. Breeding seasons are chosen by management to avoid hot and frigid times of the year. Size of body does influence size of reproductive anatomy with the larger llama of course having somewhat larger tracts.
Female Anatomy is characterized by a relatively non-prominent vulva that rarely demonstrates tumefaction even at term pregnancy. The vaginal vault is variable in length depending upon parity history, normally being no longer than 25 cm. A cervix measuring 4-5 cm. will have 2-3 cartilaginous spirals in a clockwise pattern. Uterine anatomy of a nulliparous female features a very short body with two “stubby” symmetrical horns separated by a vertical intercornual septum. Ovaries found normally quite near the tip of uterine horns tend to measure 1.5 x .5 x .5 cm at puberty but will vary in size and symmetry as relates to follicular and luteal activity. Fallopian tubes are only slightly tortuous and enter the uterine horns via distinct papillae. Post pubertal ovarian activity (8-24 mos.) will be characterized by follicular waves at intervals of 12-21 days as evidenced by a single dominant follicle that will regress unless the female is bred. Receptive breeding at any time will cause LH release, however if a follicle is not 7-12 mm. in size and growing, ovulation will not occur. Breeding when a follicle is regressing has been observed to cause luteinization without ovulation. Following a normal breeding, ovulation tends to occur within 24-26 hours. Detectable progesterone levels above basal are readily observed by 7 days post breeding originating from a bulging corpus luteum of variable size (.5-1.5 cm.). Infertile mating will result in a return to follicular wave patterns as the corpus luteum is lysed beginning 12-18 days after ovulation. Successful breeding will be detected by persistence of serum progesterone levels above basal ranging from 1-13 nanograms per ml. Camelids are CL dependant throughout pregnancy which makes them susceptible to stress abortion as well as to being affected by exogenous steroid administration or topical application especially in the third trimester.
The male camelid at birth normally has testicles in the scrotum. Simulated breeding behavior is commonly observed as early as the first month of age. Unique features of male anatomy include a non pendulous scrotum with relatively small testicles relative to body size. While the fibro-elastic penis with a sigmoid flexure is comparable to classic ruminants, the penis is unique in having a cartilaginous tip that serves to dilate the cervix during copulation. There is only a very short urethral process characterized by a very small opening. Accessory sex glands include paired bulbourethral glands and a prostate. In the non-sexually aroused state, the prepuce points backwards causing urine to be directed posteriorly. As with the female, there appears to be a wide range of time for male puberty expression (12-36 mos.). Serum testosterone levels consistent with maturity are variably observed but should ideally be present by 18-24 mos. of age. Of note, elevation of testosterone levels seems to correlate well with eruption of the male’s fighting teeth. While young males have on occasion proven capable of successful breeding, it is generally unwise to assume good fertility before 24 mos. of age. South American managers do not normally use males for herd breeding until 36 mos. of age.
Breeding management markedly influences male behavior. Hand breeding generally causes a male to relatively aggressive to females presented for breeding. This often results in breedings that are not necessarily productive due to lack of ovulation. The current recommendation for hand breeding is to not attempt rebreeding more often than every 7 days to minimize non-productive attempts that traumatize as well as contaminate the female. Left to his natural instincts, a male in a pasture breeding situation will monitor the communal dunging area for perception of estrogen conjugates, demonstrate the flehman response and proceed to locate any female responsible for having urinated the encouragement. The receptive female will minimally resist the male’s approach, allow him to mount and soon assume sternal recumbency. Vocalizing by the male referred to as orgling accompanies his intromission attempts. With penis extended, his thrusts include a clockwise twisting of the glans which upon cervical contact will facilitate passage of the penis into the uterus. Duration of breeding is variable ranging from 5-45 minutes. Ejaculation occurs with pulsatile dribbles throughout the duration of copulation which normally continues in sternal recumbency. Volume of semen has been variably reported using various techniques, but suffice it to say the volume is relatively small (3-5 ml.) and consistency is extremely viscous markedly influencing post collection sperm motility.
Virtually all of the following information will be applicable for both domesticated South American Camelid (SAC) species, the llama and alpaca. The differences lie only in the relatively shorter normal gestation length of alpacas (330 + 10 days) as compared to llamas (345 + 14 days), and the smaller body size, birth canal and term fetus of the alpaca. The accepted terms of first, second and third stage parturition are observed in SACs. A unique feature is the strong tendency to birth during the daylight hours, with an observed peak at the midmorning hours, which has important implications when it comes to interpreting anticipated duration of first and second stage labors. If one were to characterize the anticipated camelid parturition, variable would suffice.
The following will describe in detail normal parturition as progress is made through the stages. In addition, pre, intra- and postpartum complications and recommendations for the dam will be described, as well as recommended technique for routine obstetrical manipulation.
The Last Trimester
Consideration needs to be given to the late gestation dam in the area of nutrition, grooming, foot care, parasite control and vaccinations. While there can no doubt be considerable difference of opinion as to timing and products involved for some of these procedures, there should be general agreement that anything done in the last trimester should be accomplished with a minimum of stress. Stress abortion is a reality in camelids that reaches a maximum effect in the third trimester. In addition, related to their susceptibility to abortion is the need to avoid any form of exogenous steroids including parenteral injections, ophthalmic as well as dermatologic preparations containing steroids. Body condition scoring will be invaluable as a guide to consider nutritional supplementation as regard caloric or protein supplementation however readily available and digestible calcium and phosphorus is of primary concern. My experience as both a llama and alpaca owner as well as a practicing veterinarian has found that rarely does a late gestation camelid dam truly need major supplementation changes that cannot be met by reasonable quality grass forage and perhaps up to 1/3 of the diet being alfalfa. That basic forage diet is adequately providing protein and calcium supplementation. If additional calories are needed, hand feeding a corn/oats/barley mix of up to 1/3 of the anticipated dry matter intake (2% of body wt.) would be adequate. Additional phosphorus will also be gained from that concentrate mix but if for some reason extra P supplementation is deemed necessary, it can most reasonably be accomplished by a salt mineral mix made available free choice containing mono ammonium phosphate. Minimally, the expectant dam should have a reduction of wool from the tail/perineal region but a total body shearing should have taken place prior to the local heat stress period. In addition, toe nails should be clipped, the combination of these procedures will increase mobility as well as metabolism having obvious benefits to fetal development. In spite of the likely adequate parasite control program of the herd, it remains a valid procedure to deworm the pregnant dam 4-6 weeks prior to delivery aiming to reduce the periparturient rise of egg shedding. Product selection is of course a variable influenced by the existing herd program as well as observed safety to dam and fetus. Any vaccination that takes place in the late gestation dam must be directed at increasing the specific antibody content of colostrum for cria protection. As such, it should ideally be providing passive protection to the cria against enterotoxemia types C&D as well as tetanus.
Independent of which horn the fetus develops in, the gravid uterus will be found to reside in the lower right abdominal quadrant during late gestation. Of note, however, in light of the preponderance (95+ %) of fetuses residing in the left horn, to now reside in the lower right quadrant, represents a 90o twist of the uterus. The late gestational fetus, though active, is somewhat restricted in mobility due to the combination of minimal amnionic and allantoic fluids as well as considerable reduction of abdominal space. As with most species, a late gestational rectal or ultrasound examination may reveal a fetus in the "wrong" position for normal delivery, however most manage a normal presentation, position and posture (3 Ps). Llamas have been observed to birth within 24 hours after an examination (rectal and/or ultrasound), which located the fetus deep in the abdomen. On the other extreme, SAC fetuses have resided with the head virtually engaging in the birth canal for several days/weeks before normal delivery occurred.
First Stage Labor
In response to the vast hormonal alterations, myometrial contractions are initiated. The late gestational dam will be observed to behave somewhat differently from her normal routine. A common observation within a herd is for the individual to join the herd for feeding but then to withdraw and vocalize with humming. Given the environment of a pasture, the dam will seek some degree of isolation from her herd mates and may be observed to stare off into space. Uneasiness is most commonly expressed by changing of position or location, as well as frequent urination attempts. Normal cud chewing tends to be minimal and, in contrast, to many species pawing at the ground is extremely rare. If the dam has access to a shed or barn, they will often seek shelter in "the herd birthing location". This stage will vary in length and degree of uneasiness with notably first time mothers but as well with individual multiparous dams. For multiparous females, an anticipated duration would be 2 to 6 hours. Nulliparous females may actually give clinical expression of first stage labor for 24 hours or more. First stage labor is complete when the cervix has dilated and fetal membranes as well as the fetus move into the birth canal. The cervical star imprinted on the chorioallantois (CA) is approximately where the CA ruptures, allowing the amnion and fetus to proceed into the canal. Minimal spillage of allantoic fluid into the uterus occurs at this time.
Second Stage Labor
The presence of fetal membranes, usually amnion or observation of fetal parts, signals the onset of second stage labor. Only by having a continuous birthing watch can second stage labor be accurately defined in a birthing female. Too much attention will usually prolong second stage labor however. Binoculars or closed circuit TV monitors can be helpful in that regard. Most females will be predominantly in the standing position for delivery. When observed, rupture of the amnion is rather unspectacular in comparison to most species in that the volume of amniotic fluid in a normal term pregnancy is very slight. Again, variation of anticipated duration until second stage labor is complete exists. A veteran female having normal 3 Ps will often have completed delivery within 30 minutes, however up to 2 hours could be anticipated for a first time mother. For a normal cranial presentation, dorsal sacral position with normal head and extended shoulder, carpal, fetlock, posture, the nose and two feet will appear. Once the skull passes the vulvar lips, seemingly rapid progress occurs, leaving the head/neck dangling ventrally and with midradius and ulna thoracic limbs exposed. At this point an anticipated lull in progress occurs unless the cria is extremely small. The largest dimension of the fetus to pass through the birth canal is the shoulders. As such, either additional soft birth canal dilation must occur, or in the process of lying down and getting up, fetal rotation occurs, facilitating passage in a dorso-ileal position. Generally, once the shoulders have passed, the remaining delivery of trunk, pelvis and pelvic limbs is rapid. The umbilical cord is not compromised in this normal delivery until the chest is exteriorized, allowing the cria to begin breathing. Camelids are relatively obligate nasal breathers; as such the epidermal membrane that covers the entire fetal body, except oral cavity and rectum, will be covering the external nares until broken by vigorous breathing attempts or trauma. Normally this requires no intervention, for a vigorous baby will generally be shaking its head and attempting to breathe before chest expansion is possible or the umbilical cord is severed. Surprisingly, the average dam will not be active in cleaning the newborn cria but will be extremely interested in its well being. Additionally, any herd mates will nearly crowd the new mother away from her offspring in their attempt to check it out.
Third Stage Labor
Third stage begins essentially when the baby is delivered and ends with complete placental passage. If the cria is active and behaving in a normal precocious manner, it will attempt nursing as soon as ambulatory unless too many other than mother's four legs serve as distractions. The nuzzling and ideally true nursing efforts will accelerate the diffuse placental passage due to oxytocin release. Excessive human involvement at this stage causing dam anxiety will interfere with this natural chain of events. Under normal circumstances, once a portion of placenta appears at the vulvar lips, perceptible progress occurs such that in many cases, the placenta passes in the first hour, but should pass within 4 to 6 hours. Minimal straining normally accompanies placental passage. Placental inspection will impress the inspector in several ways, notably, the relatively small size, especially of the amniotic cavity. In addition, the umbilical stump will normally have a number of white plaques which by special histological stains are found to contain glycogen and calcium deposits. Fetal membranes retained longer than 24 hours may require professional help; however, in contrast to the mare, signs of colic, straining and fever are relatively rare. After placental passage, a short period (3 to 4 days) of mucopurulent discharge is observed. Within hours of a normal birth, the external birth canal will return to normal appearance. Uterine involution is relatively rapid such that the size being yet 10x normal at 24 hours postpartum will be observed to be only 2x normal by 10 days and back to normal and ready to rebreed by 20 days post partum.