The primary goal of an alpaca breeding program is to efficiently and safely impregnate females with the least amount of stress for all parties involved. The role of the alpaca manager is to facilitate breedings to maximize a herd’s development. Doing this effectively requires some knowledge of reproductive biology, an understanding of basic genetics, and interpretation of behaviors that indicate reproductive status. Developing the ability to accurately identify aberrant aspects of reproductive performance also helps improve program efficiency.

This article gives an overview of some of the reproductive techniques used in South America. In addition, some troubleshooting tips are offered in an effort to provide the North American alpaca breeder with new insight and practical ways to sleuth and avoid reproductive problems within their herd.

While many North American breeders micromanage breedings, carefully choosing the right stud for a chosen female, this is not the typical arrangement elsewhere. In South America, one stud may reside in a group of females with the hope that he’ll impregnate them all. The best ratio of breeding males to females is discussed in great detail in South American literature. Karl Koford, the preeminent vicuna researcher of the l950’s, cites a preferred ratio among the large alpaca operations in Peru of 1 male alpaca for every 10 females. Alpaca researchers at La Raya during the l970’s cite 1 male to 30 to 40 females for maximal breeding. In larger herds with multiple males, Julio Barreda, one of Peru’s well-known alpaca breeders, recommends 3 males to 100 females or 8 males to 200 females. Finding the ideal ratio is elusive because the number of females an average male can breed varies a great deal depending on his unique capabilities and the conditions in which he lives. The track records of two studs, operating simultaneously in the same large herd in North America, illustrate this point. One male successfully impregnated 15 females in a two-year period, while the other impregnated 50. This result may be influenced by potency, dominance, or other variables. In large herds in which the males commingle, male performance and reproductive focus can be hindered because domination struggles interfere with breeding.

Males in South American herds have been known to copulate as many as 30 times per day for lengths of time ranging from 3 to 50 minutes. However, by the end of the week the same males may only copulate a couple of times daily, or not at all, despite the presence of open females. Physical exhaustion caused by excessive breeding and the demands of protecting turf and females from rival males can result in a decreased ability to breed.

Alpaca reproductive expert, Walter Bravo, PhD, has found that males who breed more than 4 times a day may actually be counterproductive. Male potency drops off sharply after 3 breedings in one day and is rarely effective after 5 breedings in a day. Males that breed too many females in a short period of time may, in essence, be shooting blanks. If their sperm is depleted, their amorous activities are likely to stimulate ovulation without achieving conception, resulting in an unbred female being out of the service pool for 15 to 20 days until her progesterone level declines sufficiently and receptivity returns. In large South American herds, where males are rotated on a weekly basis, it is possible for an individual female to be serviced by a succession of males who have been so active that their potency is depleted, resulting in the female passing through the South American breeding season (November through January) unbred. This way of breeding may account for the low fertility rates in some South American herds in which as many as 40% of the females in a herd will not produce a cria on an annual basis. The saddest irony is that a female that has been exposed to this kind of "breeding program," but has not become pregnant, may actually be labeled as infertile and culled due to no biological weakness on her part.

The South American literature on herd reproduction primarily discusses managing large alpaca herds. Behavioral research findings from study of the wild vicunas and guanacos are a valuable resource, and this information can be extrapolated and used to maximize breeding efficiency and safely manage alpaca males here in North America.

In South America, a territorial male becomes the sentry guarding a grazing area where he breeds his herd of females while repelling lesser males whose genes are literally chased and banished from the gene pool. In free-ranging guanacos and vicunas, only the strong, agile, and aggressive get to breed. Bachelor herds (groups of males of various ages) patrol the areas around the family groups (females, crias and one territorial male), always watching for a sign of weakness or faltering in the territorial male. Within the bachelor groups, the next generation’s territorial males are developing. Though alpacas are somewhat subdued compared to their wild brethren, these basic instinctual patterns persist in domestic camelids.

It is important for the alpaca manager to realize that amongst the wild camelids (vicunas and guanacos), the bachelor groups are generally compatible and aren’t overly aggressive towards one another. However, once a bachelor wanders into a territory with females and a territorial male, individuals within the bachelor herd may become increasingly aggressive with their herdmates.

In the early years of North American alpaca breeding, males were often run with a group of females in a manner much like the South American wild camelids, with 1 male running amongst a band of 10 to 15 females. Typically, males were allowed to develop an aggressive and intolerant attitude towards other males. As a result, the "herd sire" would occasionally become a management challenge, requiring his own pen to minimize fighting. Males in the permanent company of females sometimes develop intractable habits of intolerance towards other males. Proximity to females increases this aggression. Just as in nature, when a bachelor group of vicunas moves close to a territorial male, the individuals in the group begin exhibiting aggressive tendencies. Moving a tranquil bachelor herd of male alpacas into close proximity of a female group can trigger aggressive behavior as males jockey to control the fence line nearest the females. In a fenced setting, with a breeding male on a common fence with rival males, the interaction between the breeding male and the other males can be so distracting that the arrangement contributes to a decrease in mating activities.

Creating an on-ranch bachelor herd has several advantages for the alpaca manager. The greatest advantage is that male alpacas or llamas can be housed together in fairly large numbers. They must, however, be out of sight from females. In order to avoid the development of territorial aggressiveness when allowing a male to breed, the manager discourages the male from establishing his territory by bringing him to breed on "neutral ground." The male is only allowed to breed in this neutral zone and is then returned to the bachelor herd when his work is done. With this technique, the male never establishes "a harem" and therefore never establishes a "harem mentality." The breeding can be carefully monitored to assess the male’s breeding performance (willingness to pursue a female, confirmation of penetration and copulation for a desirable length of time). This method, which is sometimes referred to as "hand breeding," allows the luxury of absolute certainty as to the quality of contact while limiting a particular male to two breedings a day, thus assuring the male’s maximum potency with each breeding. This method also allows breeders to assess the female’s response to the male, thus monitoring the reproductive status of a given female. Lastly, the conception date can be precisely recorded. The only prerequisites to such a program are: the creation of an advantageous fencing scheme that moves males away from females, the creation of a neutral breeding pen, and the training of males so they can be haltered and moved easily between their herd setting and the neutral breeding pen.

Fortunately, most alpacas breed readily and do not have reproductive problems. When problems do occur, the cause can be simple or complex. Sometimes practical solutions are unknown because the alpaca manager is inexperienced, or they are simply forgotten. Following are the author’s "Seven Commandments to Wholesome and Fruitful Alpaca Sex."

Reproductive problems can occur in either sex. Often the female is suspected of being infertile when she does not become pregnant. Until the reason for lack of conception is positively determined, both the female and male should be considered as equal suspects.

As obvious as this suggestion may be, it is often overlooked because of inexperience or haste to breed. Animals selected for reproduction should be in optimum health. Females, stressed due to the social demands and nutritional needs of the last cria, are often pressed back into service before they have had time to recover. Animals should be body-scored before breeding commences. Animals who are emaciated or obese are compromised reproductively. Poor diet (too lean, rich, or imbalanced), parasite loads, and cria demands, all compromise reproductive capability. Female animals about to become pregnant must be strong and vigorous. This is especially important in alpacas because they have disproportionately large babies (often around 20 pounds) as compared to the size of the mother (often around 150 pounds).

If you are certain the male is potent and performing well, you’ll need to consider whether the female is a maiden or proven breeder. Solutions for a failure to conceive differ markedly between maiden and proven females.

The absence of courtship behavior (normally showing either receptivity or rejection) in the maiden female is important and may indicate several possible problems. Physical or behavioral immaturity, insufficient hormonal response, or even an incomplete reproductive tract may be possible causes. A good camelid veterinarian can help diagnose the particular causes of problems with a maiden. If courtship behavior is present in the maiden female but conception remains elusive, there are several possible causes, such as a persistent hymen (requiring a veterinarian’s intervention), too much fiber covering the vulva which thwarts the male’s efforts to penetrate, and a number of serious obstructions which may not be readily apparent.

If a proven female is not conceiving and the service sire is impregnating other females in a similar time frame, first study the female’s reproductive history. She may be a "slow" or "problem" breeder. Some females conceive steadfastly every year shortly after giving birth, while others consistently take a couple months or more to conceive. In addition, problems such as dystocia in the previous year’s birth may have compromised the animal’s reproductive soundness.

A very common cause of a failure to conceive in proven females is the presence of a uterine infection. An infection can make the uterine environment inhospitable for a fertilized egg or developing fetus. Typically, the first indication of an infection is that the female will ovulate (indicated by rejecting the male for 15 to 20 days following breeding), but be receptive to breeding a short time after this period. She is clearly cycling, but not conceiving. There may be no discharge or other overt sign that there is an infection. A uterine infection can be diagnosed by an experienced camelid veterinarian by culturing the uterus. Commonly, a uterine flush (or wash) is performed and the female conceives a short time later. The trick in administering the flush is to make sure the veterinarian passes the solution tube past the constricted cervix and delivers the solution directly into the uterus.

The author knows of a breeder who sold a perfectly good female for half price because the female had not become pregnant after six months of interaction with his stud. He later found out that his "stud" was infertile. The lesson here is that the male should never be overlooked when sleuthing reproductive problems. Don’t be fooled by loose advertising rhetoric. Understand that a "stud" is an animal that has actually impregnated females. Glossy, full-page advertising and aggressive promotion provides no guarantee that a stud is capable. Be sure to ask about a stud’s track record.

Data from research supports the theory that alpacas with bigger testicle size are more potent and more likely to impregnate a greater number of females as compared to alpacas with smaller testicles. During formation of ARI’s now defunct screening criteria, leading camelid veterinarians concluded that adult male alpaca testicles should each have a minimum measurement of 3.5 centimeters longitudinally. It is recommended that you measure the male’s testicles and observe them to be roughly equal in size and consistency.

After considering testicle size, one needs to consider the behavioral health of the animal. Does he pursue females persistently, heed to spit-off, and only appear minimally distracted by males in nearby pens? The male who is excessively aggressive or meek, easily discouraged, or obsessed with the whereabouts of nearby males, may be an inefficient breeder because of his aberrant behavioral patterns.

There are other considerations when assessing male performance. Male fertility should be viewed as a continuum with many variables affecting it. Most males are fertile, but some are more potent than others. Secondly, there are environmental factors that can affect male performance and fertility. There have been instances in which males suddenly became sterile after years of good performance. In all of the instances known to the author, a scientific reason was forthcoming. Possible causes for abrupt changes in performance include severe and prolonged heat, injury to the testicles, or penis sheath/penis damage caused by fighting. Bouts with disease or other injuries may also be the cause of the problem. Unusually hot weather leading to heat stress can render a male infertile for 60 to 90 days. Spring shearing and implementation of other cooling measures can reduce the possibility of lost performance caused by heat stress.

Mounting does not mean that penetration has occurred. Females with full coats on their posteriors are more challenging to penetrate and more problematic for a male. A heavily wooled female may simply be impossible to penetrate. Tail-wrapping or trimming the fiber from the tail and around the buttocks allows for surer access. As a warning to the reader, be aware that there have been tragic incidents in which the penises of stud animals have become ensnared in hair so badly that the blood flow was interrupted and a portion of the penis was lost. One of the most prolific studs in the llama business lost his reproductive capability due to this phenomenon. Occasionally, the stud may simply have a problem with bad aim and release semen on the exterior of the female after a lengthy mounting. If a male appears to have trouble finding the mark, make sure the mating is done with good breeding symmetry and check and direct the male to enhance his performance. If the male keeps repositioning, it may indicate that he is having problems penetrating.

Uninitiated males and maiden females can present special challenges. Many problems can be overcome by changing environmental cues to get the desired response. Males, who will mount females and each other at a very young age, are incapable of penetration until about 20 months of age at which time their penises can extend into a female’s uterus. Testosterone production is almost nonexistent in both male alpacas and llamas prior to 18 months. First-time males, who are physically capable and willing to breed, are sometimes sporadic performers, and are easily discouraged or slow to begin orgling and pursuing. Often the reluctant young males can be coaxed into breeding by allowing an older male to enter the breeding pen to pursue and mount the female in close proximity to the youngster. Usually, the young male becomes stimulated by his older brethren and begins orgling and wanting to mount. By the time the young male is fully ready to breed, the female may have already kushed, making the inexperienced male’s job much easier. With the rigorous chase component of the courtship completed, the older male is removed and the younger male is allowed to mount and breed. This technique of supplanting a younger male in place of an older male can accelerate the learning and reproductive performance of a young male by several months. However, there are limitations; few males consistently breed before 22 months of age.

First-time females are sometimes difficult to read behaviorally. This can be frustrating for the manager who attempts to monitor behavior to assess receptivity or conception. Rejection is obvious in an older female as evidenced by body posture, threats and spitting at the male, but a young female may do nothing more than be reluctant or refuse to be forced down. Often young females respond as much to their lowly social status in the herd as they do to the hormonal changes in their bodies brought about by conception. A behavioral change, however subtle, may be the only visible indicator of a young female’s reproductive status. Young females sometimes will allow themselves to be bred after they are pregnantÑÑprobably due to submissiveness. Being attentive and ready to separate a breeding pair, especially when the male is aggressive and strong, is often necessary when working with young females. Because maiden females are often difficult "reads", controlling the male by keeping him on a lead rope usually allows the handler to carefully assess the female’s response before she is overwhelmed by a more experienced partner. If she is given a few extra seconds to muster a response to a male whose advances are controlled at the end of a rope, she is more apt to respond to her hormonal message of being pregnant and reject the male.

Breeders wanting to maximize financial return may breed females when they are too young. Females reach biological maturity between 12 and 24 months of age and occasionally not until 30 months. However, there have been rare instances of females conceiving as young as 5 months of age. A conception in a female this young is undesirable and will endanger both the dam and cria. Do not assume that a female weanling is safe from the interests of males sharing a common pasture.

A breeder may elect to breed a female based on her reaching a prescribed minimum body weight of 88 pounds, or an age of 12 to 14 months, which is an age often cited in South American literature. These weights and ages are helpful benchmarks, but they need to be considered in the context of the South American setting where breeding is viewed as an annual event that coincides with the three-month wet season. Because pastures are rich during the wet season and sparse at other times, all breedings occur only once a year. Therefore, breeding can only occur at approximately 12 months of age or not again until 24 months. Peruvian breeder, Julio Barreda, believes that females bred at 12 to 14 months are at greater risk and more likely to lose their offspring or their lives as compared to older females, especially if birthing occurs during a poor wet season with marginal forage.

A survey of five longstanding North American alpaca operations found that the average age for introducing females into a breeding program is 18 months, with individual animals being bred for the first time from 15 to 30 months. In choosing a date for breeding, breeders considered the female’s behavior, the season, and the female’s overall size and health. Generally, spring and fall babies are desirable with spring babies carrying the highest preference. The well researched book, Llama and Alpaca Neonatal Care (B. Smith, K. Timm and P. Long, 1996, Clay Press) suggests waiting to breed females until they are between 15 and 18 months with a body weight of greater than 90 pounds.

A somewhat different consensus is developing in Australia and New Zealand regarding the appropriate minimum breeding age for females. Roger and Clyde Haldane, pioneers of the alpaca business in Australia, regularly breed females at 12 months providing they show receptive behaviors and are approximately 100 pounds in weight. The now defunct New Zealand alpaca research station at Tara Hills on South Island conducted studies that support Haldane’s practice. In the Tara Hills experiment, about 60% of females conceived at 1 year of age. The Haldanes believe that there are no adverse effects in breeding yearlings provided the diet is of consistently good quality. They also believe that the lengthy (approximately 342 days) gestation of alpacas allows the safe breeding of yearlings because the developing embryo does not grow rapidly until the last trimester and the female is fully mature when she is ready to birth. This practice, however, does not address the nutritional demands and stresses caused by lactation on the young female that is barely mature at the birth of her first cria.

Breeding behavior is enhanced in the correct setting. People talk of romantic locations and although the needs are different, a romantic setting needs to be set for alpacas too. A properly constructed breeding pen in an area out of the sight of male groups and in a quiet part of the property will enhance a breeding program. Minimizing distractions enhances performance. The pen should be large enough to allow the customary chase, but small enough to control the interaction and assure the female will interact with the male. The breeding pen should be flat and free of obstructions. The male is most efficient on flat ground, centered over the female in a sternal position. If the male has to struggle to balance himself, he may not achieve the desired prolonged penetration. Sloping terrain or a female too close to a fence for a male to mount her correctly are common contributors to compromised male performance.

Pre-breeding (courtship) and rejection can be fast and somewhat violent. Rejection may include attempts to jump the fence or push through a gap in a gate. This can result in injury. The breeding pen should be strongly constructed and built to prevent airborne departures or injuries caused by legs and/or necks becoming entangled in fencing.

After discussion of these reproductive problems, we must remember that most camelids breed readily without human interaction. Our involvement should only enhance the process and correct situations that are preventing speedy and efficient conception and reproduction.