Dr Nina Bray
The aim of this paper is to outline the very basics of alpaca reproduction and neonatology for the first time breeder, whether the breeding is for the purpose of business or purely as a hobby. In writing the paper I aimed to explain concepts so that those with very little knowledge of reproductive systems could understand and apply this practically to their own situation.
Farming alpacas is a relatively new industry in Australia and as such a great deal of research is still being conducted to investigate the reproductive parameters of the alpaca.
In this paper I will endeavour to introduce you, the new breeder, to the basic principles of female and male alpaca reproductive physiology, normal mating behaviour, pregnancy detection, parturition as well as a brief overview of neonatology.
The Hembra (female)
As with many female livestock species, the alpacas reproductive organs consist of ovaries, oviducts (also known as fallopian tubes), uterus, cervix, vagina and vulva (Bravo, 1996).
The ovaries are responsible for the production of some of the reproductive hormones, as well as the ova. The oviducts transport ova to the uterus and the males' sperm towards the ovaries. They are also important in maintaining the embryo during its passage to the uterus, where it will be situated for the remainder of the pregnancy. The cervix is a fibrous circular, ring-like structure that separates the uterus from the vagina. The vagina is the 'passageway' between the uterus and vulva. The vulva is the external opening of the reproductive tract that is located below the anus (Bravo, 1996).
Understanding a brief outline of the hormones involved in the females' reproductive cycle is important when considering management practices that will be covered later in this paper.
Signals to the hypothalamus (a part of the brain) stimulate the release of gonadotropin- releasing hormone (GnRH), which in turn activates the pituitary gland to release luteinising hormone (LH) and follicle stimulating hormone (FSH). FSH stimulates the follicles to develop; while LH stimulates the ovary to release the ova (ovulate) from a mature follicle. The ruptured follicle then forms a corpus luteum (CL) 2-3 days after ovulation, which secretes progesterone. Progesterone will be secreted while a CL is present and helps to maintain a pregnancy. If no pregnancy occurs however, the uterus will secrete prostaglandin and the CL will regress, therefore diminishing the levels of progesterone present (Vaughan & D'Occhio, 1999). In non-pregnant alpacas the CL will regress in 10-13 days (Bourke, 1998).
On each ovary there are several follicles. These grow in overlapping 'waves' so that there is a constant production of mature follicles, with a new dominant follicle developing within 2-3 days of the previous dominant follicle regressing. A follicle will become dominant when the granulosal cells within that follicle secrete oestradiol (another reproductive hormone), so that the oestradiol levels rise above that of the surrounding follicles. The other smaller follicles present in that follicular wave regress (Vaughan & D'Occhio, 1999). There is approximately 10-12 days between the start of each follicular wave (McMillan, 1999). Mating may occur when there are follicles present, however it is only the follicles 7 millimetres or greater in diameter (the dominant follicle) that will ovulate to produce an ova and the ensuing corpus luteum. If the female is mated when a follicle is regressing she will not ovulate, but the follicle will become luteinised. The luteinised follicle will produce progesterone, but this will only occur for half the time that a normal corpus luteum would secrete progesterone, for example 5-6 days compared with 10-13 days (Bravo, 1996). If mating doesn't occur the dominant follicle will remain for 2-8 days and regress over the next 3-5 days (Vaughan & D'Occhio, 1999).
Regular use of ultrasound is the only accurate way to know where in her cycle an alpaca is. This is not practical in many situations, so McMillan (1999) has recommended that single matings at fortnightly intervals should be sufficient to attain a pregnancy in most females.
The female alpaca is an 'induced ovulator'. This means that unless she is mated, she will not ovulate. Ovulation is stimulated by physical contact, penile stimulation and 'orgling', a guttural sound made by the male during copulation. This stimulation causes the release of GnRH from the brain, resulting in a surge of LH to occur which triggers the release of the ova from the dominant follicle on the ovary. Ovulation usually occurs 24-72 hours after mating (Bravo, 1996).
Females become receptive, or reach puberty between 10-18 months (Jackson, 2002). They can be mated when they reach 12 months of age; however it is recommended that breeding occur at 15-18 months. Females should be 50 kilograms or two-thirds of their mature weight before breeding occurs (McMillan, 1999).
The Macho (male)
Male alpacas are born with a penis, testicles, epididymis, vas deferens, prostate and bulbourethral glands. Seminal vesicles are absent (Bravo, 1996).
At birth the male's fibroelastic penis (the organ of copulation) is attached to the prepuce, such that it can not be extruded (McMillan, 1999). Detachment of the penis from the prepuce begins at the tip of the penis, around 12-13 months of age and progresses towards at the base. The age at which complete detachment occurs varies, but should be complete by three years of age. Penile detachment is dependent on the level of testosterone, produced by the testicles, present in the blood (Bravo, 1996).
Testicles may or may not be palpable in the scrotum at birth. To be considered as a sire the male must have two palpable testicles present by six months of age. They should be of similar size, be firm but springy and move freely in the scrotum on palpation. Testicles are responsible for the production of testosterone and spermatozoa. Testosterone secretion is related to the age of the male, with a rapid increase in testosterone secretion at 20-21 months of age. Fertility has been found to be related to testicular size. As such a scrotal width of four centimetres or greater is recommended in breeding males (Bravo, 1996). Most males are fertile starting from 18 months to 3 years of age (Jackson, 2002).
The epididymis of the male connects the testicles with the vas deferens. It is a major site of fluid reabsorption and storage of non-motile spermatozoa. The vas deferens is a duct that begins at the tail of the epididymis and finishes at the urethra, via which spermatozoa pass during ejaculation. The prostate and the bulbourethral glands produce seminal fluid. The bulbourethral glands also produce viscous material present in alpaca semen. The prostate is on the top of the start of the urethra, while the bulbourethral glands are paired structures located near the root of the penis (Bravo, 1996).
Males are ready to breed when adequate testicular growth has occurred and the penis is free of its prepucial attachments, usually at 2 ½ to 3 years of age (Bravo, 1996).
Mating may occur in a paddock with the male introduced to a small group of females or in a more controlled situation with one male and one female in a pen. The latter method is easiest when records of paternity are required (Bravo, 1996).
In a group mating situations, once the macho is mating with one female the other receptive females present may be easily observed as they often sit in the cush position next to the mating couple or stand close by (Vaughan & D'Occhio, 1999).
Alpacas are non-seasonal breeders and as such are sexually active year round. For this reason females and males should be kept separately until breeding is desired. Consideration needs to be given to the desired time of breeding, and hence the time of parturition (McMillan, 1999). The average gestation of a hembra is 342 days (320-380 days) (Bourke, 1998). It is recommended that breeding occur in spring and autumn. This is because parturition will then occur in milder climatic conditions compared with that of winter and summer. During the heat of summer females sit for prolonged periods trying to keep cool, making it difficult for cria to access the mammary glands. Consequently they can rapidly dehydrate. In winter the hembra will sit in bad weather, once again obstructing access to the milk bar! (McMillan, 1999).
For mating to occur the female must be receptive and lie in sternal recumbency (the 'cush' position). If the female is not receptive she will avoid the male and display behaviours such as spitting, kicking and not adopting the cush position (Bourke, 1998). Females are usually not receptive in the presence of progesterone (eg. when they are pregnant or have an active CL). Females that have not been mated may also be non receptive for 1-2 days while a new follicular wave is developing (Vaughan & D'Occhio, 1999). Occasionally a female will be receptive to a male in the presence of an active CL if she is very submissive (Jackson, personal communication).
Once the male has been accepted by the receptive female she will allow him to copulate for a period of time determined by him. As the male alpaca is a dribble ejaculator, mating may take between five and fifty-five minutes; the average mating period is twenty to twenty-five minutes (Bourke, 1998). During copulation the male inserts his penis through the cervix and makes small thrusting movements. He will move the penis from one uterine horn to the other, depositing semen in both horns. This normal behaviour causes some damage to the uterine mucosa, which may lead to inflammation, oedema and haemorrhage (Bravo, 1996).
Repeat breeding at 24 hours after the initial mating is acceptable. While it does not cause any extra release of luteinizing hormone to stimulate ovulation, it will ensure adequate semen is present at the time of ovulation to increase the chance of fertilisation. Breeding three or more times should be avoided as it leads to excessive uterine damage. The uterus should be kept as healthy as possible for the future implantation of the embryo. The exact time of implantation is not currently known, however research performed suggests that it may occur between days 21 and 30 (Bravo, 1996).
There are several methods of pregnancy detection available. It is recommended that two methods of pregnancy detection be used at 45 days post mating to confirm a pregnancy (Bourke, 1998). Although the left and right ovaries are equally active and the corpora lutea associated with pregnancy have been identified on both ovaries, 98% of pregnancies occur in the left uterine horn (Vaughan & D'Occhio, 1999).
This is often used as it is a cheap initial method of pregnancy detection although it may be unreliable. During this test a mated female is penned with a male. If she is not receptive it is an indicator of the presence of an active CL secreting progesterone. This test can be done at 7 days post-mating to establish if ovulation occurred following mating. The test can be repeated at 15 days (the CL should have regressed if conception did not occur), 21 or 30 days. If she is continually not receptive it is likely that she is pregnant. Occasionally a submissive pregnant female will be receptive, so this should be borne in mind if using this method as the sole method of pregnancy detection (Bourke, 1998).
This method is the most reliable method of pregnancy detection (McMillan, 1999). Transrectal ultrasound can be performed from 15-20 days post-mating, however very skilled operators may be able to detect a pregnancy from 7-9 days using this technique. Using transabdominal ultrasound it is possible to detect pregnancies from 45 days post-mating (Bourke, 1998).
Rectal palpation is most accurate after 45 days post-mating, although some pregnancies may be felt by day 30 (Bourke, 1998). This should only be performed by trained veterinarians who can palpate changes in the size, shape and turgidity of the uterus. Hands that fit in surgery gloves that are size 7 or less are suitable for rectal palpation (Bravo, 1996).
This blood test measures the concentration of progesterone, secreted by the corpus luteum, in the female alpaca's serum. The test can be done 15-21 days after mating; this allows time for regression of the CL in non-pregnant females. If pregnant, the progesterone will be above 2 ng/ml, indicating that the CL is still functioning and pregnancy is likely (Bourke, 1998). During the middle of a pregnancy some females have less than 1 ng/ml of progesterone (Bravo, 1996).
Parturition in the alpaca is known as 'unpacking' or 'criation' (Jackson, 2002). Unlike other ruminants, alpaca parturition occurs predominantly in the morning. In fact, 90% of deliveries occur between seven and eleven in the morning. It is unusual to have any births after two o'clock in the afternoon (Bravo, 1996).
The process of parturition is divided into the three stages of labour. The stages will be briefly outlined below; however they are often not so distinct in real life.
The first stage can last from 2-6 hours. During this time the female may separate herself from the herd, urinate and defaecate frequently, hum to herself and appear restless and uncomfortable. The cervix relaxes and the foetus is positioned in the birth canal via uterine contractions (Bourke, 1998; Bravo, 1996).
This stage usually takes 60-90 minutes, during which time the female may get up and down repeatedly. Uterine contractions increase to expel the foetus, which usually presents at the vulva in a dorsal position with the head and forelegs protruding (Bourke, 1998; Bravo, 1996).If the female is lying on her side or in the cush position at the beginning of this stage, once the head and forelegs are expelled she will usually stand and deliver the remainder of the cria. The female may have some short rests during this stage (Jackson, 1998). The epidermal membrane, present in all camelids, covers all of the cria except the mouth, nostrils, anus, penis in males and vulva in females (Bourke, 1998; Bravo, 1996).
The placenta is usually expelled within two to six hours of unpacking (Bourke, 1998; Bravo, 1996; Jackson, 1998). Hembras do not usually lick the cria following birth like many ruminant species (Bourke, 1998; Bravo, 1996).
Most hembras will develop an udder just prior to, or after parturition. This is variable however, so monitoring the onset of labour via this method is relatively unreliable. In hembras that are having their first cria the teats may not be well developed, making suckling difficult for the cria. Observation of feeding is essential in ensuring the cria obtains adequate nutrition (Johnson, 1997).
The Normal Cria
Minimal interference is recommended following birth so that the cria and hembra can bond properly. There are a few procedures that are recommended.
Check that the cria is breathing well and the nose and mouth are clear.
Apply betadine solution (1%) to the umbilicus to reduce the risk of umbilical infections
Identify the sex
Check an anus is present
Check that the wax plugs present in the dams teats are removed (Jackson, 1998)
Check that the cria feels warm - put a finger in its mouth
Weigh the cria - 6kg+ is normal (Ryan, 1996).
A normal cria is lively and will move into the 'cush' position within 10-15 minutes and will stand and walk within one hour following birth. Once walking it will try to suckle, which should occur within two hours. A cria will lower its tail when it is suckling correctly, so there is usually no need to get in close to check this (Jackson, 1998). A normal cria should gain an average of one kilogram per week and double their birth weigh by one month old (Ryan, 1996).
Meconium, the first faeces a cria will pass, should be expelled within 24 hours (Jackson, 1998).
Colostrum, the first milk the female will produce, is thick and creamy in appearance and is essential in providing the cria with vital energy and antibodies. Antibodies are essential in fighting infection. The cria is born with almost no antibodies, therefore making the acquisition of colostrum from the female very important. Antibodies can be absorbed through the gut lining for the first 24 hours of life only, so it is essential to check that the cria is suckling. If it is doubtful that the cria has gained adequate colostrum, a blood test is available to check the concentrations of antibody (IgG) present (Jackson, 1998).
If little colostrum has been obtained by the cria and low concentrations of antibody are suspected, it is possible to supplement the cria by giving colostrum or plasma up to 24 hours postpartum. The plasma (containing antibodies) can be collected from a male or female alpaca that has been vaccinated with a 5 in 1 vaccine one and five weeks before blood collection. Plasma can be kept frozen for 12 months and thawed when it is required (Jackson, 1998; Ryan, 1996). 150 ml of plasma should be given via a baby bottle. Stomach tubing is possible but is not preferred (Jackson, 1998).
If 24 hours have passed then plasma supplementation is needed via the intravenous or intraperitoneal route. Oral supplementation will not be adequate as antibodies will not be absorbed by the gut (Ryan, 1996).
Reasons for Concern
There are several reasons that the breeder may need to call the veterinarian for assistance. Some of them are outlined below:
If the process of parturition does not appear to be progressing after two hours (once it has begun)
If the cria doesn't wriggle/struggle and attempt to walk following birth
If the cria is small (ie. less than 5kg)
If the cria is premature or dysmature - these crias have floppy ears and absent incisor teeth
If the cria was born in extreme cold/wet or heat
If the cria is not suckling properly and may need supplementation as outlined above (Jackson, 1998).
Uterine involution takes between 14-25 days in a female postpartum. Research has shown that rebreeding earlier than 14-21 days after parturition is associated with increased embryo loss and therefore it is not advised. Rebreeding may occur 3-4 weeks after parturition (Bravo, 1996).
Breeding alpacas can be a fun and fulfilling experience. As the alpaca is vastly different to most other livestock raised in Australia, a working knowledge of the unique reproductive features of the alpaca will make the breeding experience a lot more enjoyable.
Bourke, D.A. (1998). 'An introduction to the unique reproductive physiology and breeding activity of the SACs'. International Alpaca Industry Conference Proceedings, Fremantle,WA. 1998. pp.7-10
Bravo, P.W. (1996). 'Reproduction of the Female Alpaca'. International Alpaca Industry Seminar Proceedings, Qld. July 1996. pp.23-27.
Bravo, P.W. (1996). 'Anatomic and Physiologic Basis of Male Alpaca Reproduction'. International Alpaca Industry Seminar Proceedings, Qld. July 1996. pp. 17-21.
Jackson, G. (1998). 'Neonatal Workshop'. International Alpaca Industry Conference Proceedings, Fremantle, WA. 1998. pp56-58.
Jackson, G. (2002). 'A Year in the Life of an Alpaca Farm Manager'. Handout obtained on Murdoch University Veterinary School Food Animal Production and Medicine property visit, 15 May 2002.
Jackson, G. (2002). Personal communication, 15 May 2002.
Johnson, L.W. (1997). 'Neo-natal Care: Parturition'. International Alpaca Industry Seminar Proceedings, Sydney, NSW. July 1997. pp.81-85.
Johnson, L.W. (1997). 'Infertility Problems'. International Alpaca Industry Seminar Proceedings, Sydney, NSW. July 1997. pp.92-97.
McMillan, E. (1999). 'Female Reproduction'. Australian Alpaca Industry Conference Proceedings, Glenelg, SA. 9-11 July 1999. pp. 60-62.
McMillan, E. (1999). 'Male Reproduction'. Australian Alpaca Industry Conference Proceedings, Glenelg, SA. 9-11 July 1999. p. 63.
Ryan, D. (1996). 'Neonatology'. International Alpaca Industry Seminar Proceedings, Qld. July 1996. pp. 29-35.
Vaughan, J. (2002). 'Introduction to Camelids'. Handout obtained on Murdoch University Veterinary School Food Animal Production and Medicine property visit, 15 May 2002.
Vaughan, J & D'Occhio, M.J. (1999). 'The role of reproductive technologies in genetic improvement and multiplication of alpacas'. Australian Alpaca Industry Conference Proceedings, Glenelg, SA. 9-11 July 1999. pp.18-27.
Dr Nina Bray