Carol Raczykowski Reviewed by Dr. William Holleman
(Reprinted from Pygmy Goat WORLD magazine with permission)
Sterility in the buck is usually the exception rather than the norm and is usually temporary. Male fertility is affected by such things as age, maturity, nutritional status, general health, endocrine balance and normality of sex organs. Sperm quality, nutrition, body weight, maturity, stress, disease, mating frequency, seasonal climatic changes, and management also play roles in male fertility. With so many things affecting fertility, it's a wonder that sterility is rarely a problem.
A buck kid starts mounting behavior as early as one day old. Puberty, the age at which spermatozoa is present in the ejaculate, can vary depending on breed, age and nutrition. Pygmy bucks are capable of breeding as early as 8-12 weeks of age, and they are one of the most outwardly sexually aggressive animals I've treated.
From the time of birth the male body begins to changing to prepare them for this experience. A buck is born with his urethral process and glans penis adhered to the inside of his sheath (prepuce) by the frenulum membrane. This adhesion makes it impossible for the buck to copulate until testosterone (a steroid) and practice mounting frees penis from the prepuce. He will then be able to fully extend his penis and copulate.
As this takes place, the buck kid will start urinating on front legs and beard and develop a strong odor. Part of his odor is due to the urine, but mostly it is a result of the influence of testosterone on the scent glands located near his horns. This behavior and odor make the buck more attractive to females and stimulates their estrus and receptivity.
The blubbering noise and behavior is one of the buck's comical displays. In the early 1990s, someone won $10,000 on the television program, America's Funniest Home Videos showing this behavior.
To a buck, this is serious business. He may paw the ground, wet on his chest and forelegs and exhibit mounting and thrusting behavior. He may nudge the doe and lick her genitalia and smell her urine. This precedes another comical action called flehmen in which the buck raises his head and curls his upper lip in odor detection mode; it looks like he is smiling. All of this usually occurs very quickly with a cooperative doe, and a successful breeding occurs when the buck mounts and ejaculates. Ejaculation is best confirmed by the buck's head jerking back immediately before he dismounts. The doe may react by moving her hindquarters forward, and a drippy discharge can usually be seen coming from her vulva.
To increase the volume of semen and concentration and number of the sperm, you can put the buck on a lead and allow him to make a few false mounts on the doe before he ejaculates. This may not work with all bucks, but it is sometimes done with great success in semen collection.
How the Reproductive System Works
Each intricate part of the buck's reproductive system has one or more function, and every one must operate properly for the whole system to work. The following is a brief description of the major parts and the roles they play.
The major function of the testes is to produce high quality sperm. Muscle contractions help sperm move from the testes into the ductus (or vas) deferens. From there the sperm travel through the abdominal cavity in the ductus deferens to the urethra where it exits the body through the penis. Sperm is stored several paces with various functions. The epidiydymis functions as a maturing station, and sperm are held there for up to 14 days before entering the ductus deferens. During this maturation process, the fertilizing ability and motility of the sperm is increased. When the sperm reaches the ductus deferens, it is mature.
On the sperm's journey various glands add their secretions. The prostate gland's secretion thickens the semen and helps regulate the acid base balance. The vesicular glands add fructose and citric acid to nourish the sperm. The bulbourethral gland secretes liquid that neutralizes the acidic urethra before the sperm travel along it in an ejaculate. After all the ingredients are added the sperm officially becomes semen capable of fertilization.
The penis' S-shaped sigmoid flexure is controlled by contracting muscles and, in turn, so is the erection. Erection is the result of sexual excitement that stimulates blood flow to specific tissues in the penis which increase pressure in the organ and straighten the sigmoid flexture. At the same time, retractor muscles relax and the penis is extended from the sheath. Ejaculation is a nervous system reflex, the result of muscular contractions that begin in the epididymis.
If the buck fails to ejaculate, one of the first things to check for is a condition known as a persistent frenulum. This membrane usually detaches as a buck matures but rarely it does not. To examine a buck for this, he is set on his rump and the sigmoid flexure is pressed from behind to manually extrude his penis. If you are not sure how to do this or what to look for, your veterinarian can help. Simple corrective surgery can fix the problem.
If the buck fails to impregnate does, it's time to investigate with a breeding soundness examination. This is also a good time to check for the presence of extra teats and other hereditary defects, such as hernias and jaw malformations. A buck with any faulty traits or who is hormonally unbalanced should not be used.
The first thing to look for in the physical examination is general health. Does the buck look healthy, including a shiny hair coat, clear eyes and nose? Feet, joints and teeth in good condition? Are his temperature, respiration and pulse normal? Is he too fat or too thin?
The reproductive organs should be examined next. This includes palpation of the testicles for size, symmetry and other normal values, and inspection of the prepuce and penis. The larger the testicles, for a given age, the better the sperm production. Bucks with above average scrotal circumference for their age and birth weight can be expected to produce offspring with earlier sexual maturity and greater fertility. Scrotal circumference can be measured with a measuring tape and then transcribed to a ruler. The measurement should be taken at the widest part of the scrotum with both testes held at the same level. The scrotum should be firmly attached.
The texture of the scrotum is important. Normal testicular tissue should feel resilient and approximately as firm as muscle. Some problems may be associated with texture and size/swelling. For example, testicular atrophy (marked by abnormal spermatozoa) results in elongation or smaller than normal testes. Abnormally small testes may indicate severe malnutrition or an intersex (genetic) condition.
Bucks occasionally get orchitis, an inflammation in one or both testicles. This soft swelling (no heat) is usually physiologically caused and not infectious. This may have something to do with semen storage in the testicles but if it becomes a chronic problem, the testicles may harden and shrink, causing sterility.
Inspect the prepuce and penis for infection or injury. For example, in posthitis (pizzle rot) the prepuce will be inflamed with ulcerations or scabs and accumulation of urine and dirt. These lesions make breeding too painful or physically impossible. It can take a few days to a few weeks to treat this condition before the buck will be willing to breed.
Collection and evaluation of semen is part of a comprehensive breeding soundness exam. The best semen sample comes from using an artificial vagina, versus electroejaculation. Morphology, numbers, motility (movement) and longevity of the sperm are all important. The normal sperm count in a buck is about 2,000 per millileter. Too many malformed sperm indicate poor quality semen. Very young and very old bucks may have more sperm irregularities, as well as those who are deficient in selenium. A densometer can be used to count sperm, but semen color can give you some indication. Thick, milky semen is good. Thin, milky semen is mediocre and clear/amber semen may indicate poor quality. Sperm motility is difficult to check in collection samples. Physiology and biochemistry of the semen is also important. Semen evaluation is best left to a veterinarian or an experienced qualified semen collector/processor.
If he passes the breeding soundness examination with flying colors but he still not settling does, you need to consider other management possibilities. Is he overweight? Obesity definitely plays a big role in fertility. What are you feeding him? Feeds like timothy grass and clover with high estrogen content may suppress the antigens of a buck and in time the testicles may atrophy (shrink) and feel cold. An emaciated buck can become sterile. In either sex, the reproductive system is one of the first functions to shut down during starvation. Excess fat or thinness can be reversed with better management.
Reluctance or inability to mount may be due to painful hind legs, hips, stifles, hocks or feet, and the cause should be defined. Arthritis seems to be fairly common in older stud bucks. Is it due to excessive calcium in the diet or housing on cold, damp, bedding? All possible causes need to be considered. You can use a buck after injury, when he is healed, and if he is able to work, however, if you suspect a structural fault or disease, further use is not be recommended since he may pass these features. It is best to be very discriminate in propagating any negative traits; the buck is the major part of your herd.
A high fever in a buck can render him temporarily or permanently sterile. Sperm is produced at an optimum temperature, and this process is very sensitive to heat. If the temperature is increased dramatically, it affects the testicles and the quality and life span of sperm. A buck regulates the temperature of the scrotum and testes by controlling the distance they are from the body. When it is cold, the dartos muscle contracts to pull the testes closer to the body. When it is hot, the muscle relaxes and allows the testes to hang further from the body. When a buck has a fever it is almost impossible for his body to maintain the proper temperature for sperm production. Very hot weather can also render a buck temporarily sterile. Remember, the sperm in the ejaculate originated 4-6 weeks ago; what he produces today is a result of what happened way back then. This is an important fact to remember when you are looking for answers to a sterility problem or planning ahead for breeding.. Think in terms of more than just the last several weeks.
Infection may be another cause for sterility. If the penile sheath is injured it is vulnerable to infection. If the sheath is allowed to accumulate sebum (fatty secretion of the sebaceous glands) he may transmit coital vesicular exanthema which creates small ulcers on and around the vulva of the doe. For this and other reasons, cleanliness of the buck is very important, especially in a buck that is used heavily on a large variety of does from a number of herds. In heavy use, the buck's penis should be washed several times a month. The penis can be washed with soapy water, or a 1:5,000 dilution of Nolvasan™. Good hygiene can eliminate several problems that may eventually cause sterility.
Stones can become blocked in the urethra, causing sterility and sometimes death. When a buck or wether has a dietary imbalance of calcium and phosphorus, stones form in the bladder and move through the urethra. The urethra and ductus deferens join near the urinary bladder, so if the urethra is blocked neither sperm or urine will be able to exit the body. This is fairly common in wethers or bucks that are fed too much grain. Partial blockage is also possible. Treatment for this is difficult at best.
Other factors affecting sterility are anatomical defects, and other injuries and diseases. Scrotal hernias are seen in sheep and are presumed hereditary in that species. If a hernia (distention of one side of the scrotum with a movable loop of intestine) is identified and surgical correction is desired, the buck should be castrated.
Injuries or wounds involving the scrotum may result in purulent orchitis or periorchitis. Other causes of scrotal dermatitis include mange, bacterial infections, zinc deficiency and frost bite. Many different types of injuries may take place if two bucks are allowed to be in the same area while one is breeding; common ones are a broken penis and a broken leg.
Sperm granulomas are strongly correlated with the homozygous polled condition and can be avoided by culling all young bucks that are, by phenotype, homozygous for the polled gene. This condition is virtually unknown in the Pygmy, as it is a disqualifying fault in their Breed Standard. Another rarity is the protozoan parasite, Trichomonas. This protozoa has been observed in the semen of Alpine and Saanen bucks in France and Sardinia and in Angoras in South Africa. It infests the sheath and urethra of the buck, causing the quantity and quality of ejaculates, as well as libido, to decrease.
Testicular tumors in goats are rare but do occur.
It is possible to overwork a buck, especially when it is undernourished. Special attention should be given to the breeding buck's nutrition. Many bucks ignore their food during breeding season while increasing physical activity and the attentive owner should vary the diet to tempt him to eat.
A frequently used buck will also be less fertile per doe than a buck that has rest periods between services. After around 3 ejaculations the sperm count is reduced, and after 7 ejaculations the buck produces immature sperm that are incapable of fertilization. Overuse can be hard to determine since bucks can settle a hundred or more does in one season, depending on his condition, nutritional level and general health. It is better to err on the conservative side.
Genetics, nutrition, sanitation and other good management practices play important roles in the buck's life.
From birth a buck's body prepares itself for its main function - breeding. It's up to you to make sure that the things you can control, like proper nutrition and a positive environment, are in his favor. After all, he is the single most important ingredients in your breeding program.***
BUCK HOUSING AND MANAGEMENT
Suzanne W. Gasparotto
HC 70 Box 70
Lohn, TX 76852
Phone 325/344-5775
Male goats have one purpose in life -- breeding. The instinct to reproduce is stronger than anything else -- even eating; bucks will often go off-feed when in rut. Producers should give much thought and preparation into buck housing, pasturing, and overall management. A primary consideration is good fencing. Good fences make good neighbors -- and prevent unplanned pregnancies -- by keeping does and bucks apart.
Do not pen or pasture bucks across a common fence from breeding-age does. Typical goat (or *field*) fencing will not prevent through-the-fence breeding. Don't depend upon gate chains or latches to keep does and bucks apart; wire gates shut and check them regularly. Rutting bucks and flagging does have been known to literally lift gates off hinges and "make a party." Does who get bred under such circumstances are known at Onion Creek Ranch as "party girls." Despite all our efforts, one or two does a year manages this feat.
The solution at Onion Creek Ranch has been to create a center alley 25 feet wide, with large paddocks to the left and right of it. Bucks are pastured on one side of the alley; does, on the other side. This of course means that bucks are up against other bucks during rutting season, so pasture fencing has been paneled over with 20 ft long by 4 ft high six-gauge "cattle panels" of 4" x 4" squares -- and they still beat up the fencing, but it contains them.
Polled (born without horns) bucks are pastured separately from horned bucks. When rutting season arrives in Texas' hot climate, bucks in a given pasture will select a buck to chase, harrass, mount, and generally treat as if he is a desired mate as they practice breeding techniques. If polled bucks are penned with horned bucks, that sought-after male is usually the less aggressive polled buck. Horns serve as radiators for removing heat from the goat's body. Polled bucks by definition have no radiators. This writer has lost two terrific polled bucks to death from heat stroke thanks to sexual harassment by multiple horned males.
At Onion Creek Ranch, there are three buck pastures. The old bucks (over eight years of age) are pastured together. Bucks 18-24 months old to eight years of age occupy another paddock. Males less than 18 months of age live in a third pasture. Since separate space for polled bucks usually isn't available, they are pastured with the youngest group of bucks over whom they can exert dominance.
When moving bucks into buck paddocks, the producer should be prepared for male-on-male activity to establish the new members' places in the pecking order. Goats are serious herd animals and have a fairly rigid pecking order within each herd. Minimize the problems that these actions will cause by (1) never introducing a single buck into a new herd; (2) taking climate/weather into consideration and moving them during the most favorable time of the day (coolest in hot climates and warmest in very cold climates, never during rain or snowstorms, etc.); and (3) penning bucks with other males of similar size and age. Example: Remove bucks from breeding pens and house two or more together for at least a week so that they can form their own mini-herd before moving them to the larger buck pasture. Think like a goat; both you and your goats will be less stressed.***
Breeding Management
Linda I. Spahr
York County Extension Agent
In the competitive world of market goats, good management cannot be stressed enough. A few does here or there not getting bred may not seem like an issue, but keep in mind that an open doe represents money spent without any return. There are several factors that will affect the breeding status of your does. There will always be those few does that you never see in heat or that never seem to get bred. They need to be culled; no excuses.
In this section we have discussed buck goat soundness, a very important part of the breeding equation. Lame or sick bucks don't breed does. It's time to look at factors that affect breeding from the female side of the equation.
Breeding Management
Doe goats of breeding age should be considered production units. Costs incurred by maintaining or supplementing this unit must be balanced by a return in the form of live, salable product. In other words if you have to feed more feed, call the vet more often or give more medicine, you have to be able to produce more live kids to balance the check book.
Flushing your does is one supplemental cost that should balance by producing more live kids.
Female goats are for the most part, easy to spot when they are in heat. An observant manager should be able to identify most does in heat by observing the females a few times a day. There are does that are nearly silent in their heat periods. Even the most observant managers may not be able to identify does in "silent" heat.
Goats are for the most part seasonal breeders. This means that they do not exhibit heat or periods of estrus year round. Most goats are fall breeders and will come into heat during the months of September thru February. Does experience estrus or come into heat about every 18-22 days during that period.
Does in heat will usually display several signs to let you and the buck know that they are ready to breed. The doe will bleat as if hungry or in pain, driving your close neighbors crazy. She will usually wag her tail from side to side constantly. In most does the vulva will swell slightly and appear reddened. Some does will have a discharge from the vulva that can make the tail look wet or dirty. Does will often refuse feed or will decrease their consumption of feed. You may notice your nannies urinating more frequently as they try to let the buck know they are interested.
If you have a group of nannies that don't seem to show many signs of heat, it may be necessary to bring an old, smelly buck into fence line contact to force them to display. When a buck has been introduced into the pasture next door the does will tend to pace back and forth along the fence or stand backed up to the fence, allowing the buck to smell them. Many times one doe in heat will cause other does to exhibit heat as well. Most folks who don't observe signs of heat in their nannies usually only have one or two does. These small producers will need to be very observant of any display of heat their nannies may exhibit. I like to mark the calendar when I observe a doe displaying unusual behavior. Eighteen to twenty-two days later, I can usually count on a repeat of the behavior, a good indication she is in heat.
The period of estrus or heat in your goats will usually last between 12 and 48 hours. This period is referred to as "standing heat". Ovulation in the female occurs 12 to 36 hours after the onset of standing heat. If there is a discharge from the doe's vulva during the heat period, it will begin as a clear, sticky substance and become white toward the end of the heat period.
It is not a good idea to leave the buck in with the does for the entire breeding season. When the newness of a buck in the pasture has worn off the does become so familiar with the buck that they will not allow him to mount. As the newness wears off the buck tends to get lazy and the manager assumes all of the does are bred.
Turning your buck in with your does for about 45 days will cover two complete heat cycles and should be long enough to settle your does. Bucks in good condition should be able to service 20 to 30 does.
Prepare for breeding season by trimming feet, deworming, and vaccinating. You will need to make sure that your does are ready for the breeding season by worming them, trimming hooves and vaccinating the females. Vaccinations should be done before the start of breeding season and then again 4 to 6 weeks before the first expected kidding date. If you are planning to give your does one booster vaccination, it's best to wait until 4 to 6 weeks before kidding. The vaccination before kidding will allow some immunity to be passed to the newborn kid. Most producers use Clostridium Perfringens Types C & D + Tetanus toxoid vaccine. This vaccine is marketed by a variety of companies and each company calls the vaccine something different. One common brand name is Bar Vac CD/T. This particular vaccine sells for about $8.00 for a 50 ml bottle. This 50 ml bottle will give you 25/2 cc doses of vaccine. This vaccine is a fairly inexpensive way to provide protection for your herd.
Feet should be trimmed on the nannies as well as the buck before breeding season. Check for any sores or infections in the feet and legs. Nannies with sore feet may not stand for a buck or may get pushed away from feed at a critical time. Goats should also be wormed before they are bred. Nannies with a high worm load will not gain the weight necessary to make the flushing process effective. Goats should be wormed before the flushing begins.
One last thing you need to keep in mind as you plan your breeding season is general goat behavior. Goats establish a pecking order. If this order is disrupted by moving or regrouping, you will need to allow enough time for a new pecking order to be established before beginning breeding season. Pecking orders usually take 2 to 3 weeks to establish and may vary with the number and temperament of individual does.
Production managers need to be sure they do not breed does at too young an age. There are two schools of thought on this subject. There are those who will breed a female goat as soon as she is 7 to 10 months old, regardless of size and weight. A better practice is to use the mature estimated body weight as a guide when deciding to breed. A doe kid should be at 70 to 75% of her mature weight before breeding. In other words if you expect a doe to mature at 100 pounds you could breed her if she weighed between 70 and 75 pounds. Small doe kids tend to be less productive and they will never reach their potential weight if bred too early.***
Meat Goat Breeds, Breeding Management, and
4-H Market Goat Management
Bagley, MN January 28, 2006
Doug Thompson
Improvement Potential - Goats have some great advantages over cattle in terms of potential for improvement through a breeding program. First, does can be bred and bucks can be working in their first year, generally at 6-8 months so you can get a sense of improvement through breeding within the first year or year and a half. Second, with multiple births you have more animals to select from in choosing which stock you are going to keep to use in the future. These factors alone are said to account for an improvement potential at a rate four times faster than one could expect with cattle.
Reproductive Characteristics – Goats are
generally seasonal breeders though this varies
from breed to breed, between individuals, and differs from one climate to another.
Shortening day length in the fall, which sets up a yearlong cycle of reproduction, triggers their breeding season. Generally, does will come into estrus or heat for a two to three day period every 18-21 days in the fall until settled. The day-length trigger can be manipulated by putting goats artificial darkness or artificial light to promote off season breeding, which can be an advantage in timing the markets at some point down the line.
If this were used, the bucks would also have to be subjected to the same light manipulation since they have a specific rutting season from early fall through early winter. Hormone treatment is also widely used in other parts of the world, at least for
dairy goats, to get off-season breeding and ensure a more uniform milk supply through the year. There are some breeders that would try to work in two breeding in three years, which is possible.
Breeding Management - Important to any breeding program is proper nutrition and health management.
Does can be “flushed” with “improved” nutrition two weeks prior to the breeding season and lasting five weeks in order to increase egg release in increase kidding percentage. On the other hand, too high a plane of nutrition for too long, especially with high quality alfalfa hay can delay the onset of estrus in an entire herd of does.
Goat bucks are one of the most accursed animals on earth when it comes to breeding season. They become extremely aggressive and will expend an enormous amount of energy whether or not they are with does, so their nutrition has to lead that effort.
To understand that imperative, one has to picture a native herd of does in the wild with a dominant herd sire having to defend a harem of 30-40 does from younger bucks surrounding the harem and continually testing the dominant male. Aggressive behavior is the name of the game and it carries through today.
In dairy goats, small breeders tend to keep far too many bucks. So much so, that it has been light-heartedly suggested that dairy goats in the US are monogamous breeds. Of course, they are in fact polygamous and a mature buck can handle 30-40 does. Younger bucks would be at a ratio at least half of that.
Following breeding, to narrow the kidding season, you may want to remove the buck from the does. This certainly won’t make the buck happy. Bucks with does, unchallenged by other bucks, can become quite docile and live a “normal” existence, even in the breeding season.
Generally, you can cut back on the doe’s ration to a maintenance level. In fact, it has been suggested that a higher amount of fiber and roughage at this point in the reproductive cycle is important in conditioning the rumen of the doe, so she is ready to efficiently consume more of the higher protein rations as she goes into milk production.
The last two months of the 5-month gestation are the most important in
resuming a higher plane of nutrition, since that is when the most growth of the fetus occurs and when the doe is gearing up for milk production.***
Fertility and Sterility in the Buck
Carol Raczykowski
Reviewed by Dr. William Holleman
(Reprinted from Pygmy Goat WORLD magazine with permission)
Sterility in the buck is usually the exception rather than the norm and is usually temporary. Male fertility is affected by such things as age, maturity, nutritional status, general health, endocrine balance and normality of sex organs. Sperm quality, nutrition, body weight, maturity, stress, disease, mating frequency, seasonal climatic changes, and management also play roles in male fertility. With so many things affecting fertility, it's a wonder that sterility is rarely a problem.
A buck kid starts mounting behavior as early as one day old. Puberty, the age at which spermatozoa is present in the ejaculate, can vary depending on breed, age and nutrition. Pygmy bucks are capable of breeding as early as 8-12 weeks of age, and they are one of the most outwardly sexually aggressive animals I've treated.
From the time of birth the male body begins to changing to prepare them for this experience. A buck is born with his urethral process and glans penis adhered to the inside of his sheath (prepuce) by the frenulum membrane. This adhesion makes it impossible for the buck to copulate until testosterone (a steroid) and practice mounting frees penis from the prepuce. He will then be able to fully extend his penis and copulate.
As this takes place, the buck kid will start urinating on front legs and beard and develop a strong odor. Part of his odor is due to the urine, but mostly it is a result of the influence of testosterone on the scent glands located near his horns. This behavior and odor make the buck more attractive to females and stimulates their estrus and receptivity.
The blubbering noise and behavior is one of the buck's comical displays. In the early 1990s, someone won $10,000 on the television program, America's Funniest Home Videos showing this behavior.
To a buck, this is serious business. He may paw the ground, wet on his chest and forelegs and exhibit mounting and thrusting behavior. He may nudge the doe and lick her genitalia and smell her urine. This precedes another comical action called flehmen in which the buck raises his head and curls his upper lip in odor detection mode; it looks like he is smiling. All of this usually occurs very quickly with a cooperative doe, and a successful breeding occurs when the buck mounts and ejaculates. Ejaculation is best confirmed by the buck's head jerking back immediately before he dismounts. The doe may react by moving her hindquarters forward, and a drippy discharge can usually be seen coming from her vulva.
To increase the volume of semen and concentration and number of the sperm, you can put the buck on a lead and allow him to make a few false mounts on the doe before he ejaculates. This may not work with all bucks, but it is sometimes done with great success in semen collection.
How the Reproductive System Works
Each intricate part of the buck's reproductive system has one or more function, and every one must operate properly for the whole system to work. The following is a brief description of the major parts and the roles they play.
The major function of the testes is to produce high quality sperm. Muscle contractions help sperm move from the testes into the ductus (or vas) deferens. From there the sperm travel through the abdominal cavity in the ductus deferens to the urethra where it exits the body through the penis. Sperm is stored several paces with various functions. The epidiydymis functions as a maturing station, and sperm are held there for up to 14 days before entering the ductus deferens. During this maturation process, the fertilizing ability and motility of the sperm is increased. When the sperm reaches the ductus deferens, it is mature.
On the sperm's journey various glands add their secretions. The prostate gland's secretion thickens the semen and helps regulate the acid base balance. The vesicular glands add fructose and citric acid to nourish the sperm. The bulbourethral gland secretes liquid that neutralizes the acidic urethra before the sperm travel along it in an ejaculate. After all the ingredients are added the sperm officially becomes semen capable of fertilization.
The penis' S-shaped sigmoid flexure is controlled by contracting muscles and, in turn, so is the erection. Erection is the result of sexual excitement that stimulates blood flow to specific tissues in the penis which increase pressure in the organ and straighten the sigmoid flexture. At the same time, retractor muscles relax and the penis is extended from the sheath. Ejaculation is a nervous system reflex, the result of muscular contractions that begin in the epididymis.
If the buck fails to ejaculate, one of the first things to check for is a condition known as a persistent frenulum. This membrane usually detaches as a buck matures but rarely it does not. To examine a buck for this, he is set on his rump and the sigmoid flexure is pressed from behind to manually extrude his penis. If you are not sure how to do this or what to look for, your veterinarian can help. Simple corrective surgery can fix the problem.
If the buck fails to impregnate does, it's time to investigate with a breeding soundness examination. This is also a good time to check for the presence of extra teats and other hereditary defects, such as hernias and jaw malformations. A buck with any faulty traits or who is hormonally unbalanced should not be used.
The first thing to look for in the physical examination is general health. Does the buck look healthy, including a shiny hair coat, clear eyes and nose? Feet, joints and teeth in good condition? Are his temperature, respiration and pulse normal? Is he too fat or too thin?
The reproductive organs should be examined next. This includes palpation of the testicles for size, symmetry and other normal values, and inspection of the prepuce and penis. The larger the testicles, for a given age, the better the sperm production. Bucks with above average scrotal circumference for their age and birth weight can be expected to produce offspring with earlier sexual maturity and greater fertility. Scrotal circumference can be measured with a measuring tape and then transcribed to a ruler. The measurement should be taken at the widest part of the scrotum with both testes held at the same level. The scrotum should be firmly attached.
The texture of the scrotum is important. Normal testicular tissue should feel resilient and approximately as firm as muscle. Some problems may be associated with texture and size/swelling. For example, testicular atrophy (marked by abnormal spermatozoa) results in elongation or smaller than normal testes. Abnormally small testes may indicate severe malnutrition or an intersex (genetic) condition.
Bucks occasionally get orchitis, an inflammation in one or both testicles. This soft swelling (no heat) is usually physiologically caused and not infectious. This may have something to do with semen storage in the testicles but if it becomes a chronic problem, the testicles may harden and shrink, causing sterility.
Inspect the prepuce and penis for infection or injury. For example, in posthitis (pizzle rot) the prepuce will be inflamed with ulcerations or scabs and accumulation of urine and dirt. These lesions make breeding too painful or physically impossible. It can take a few days to a few weeks to treat this condition before the buck will be willing to breed.
Collection and evaluation of semen is part of a comprehensive breeding soundness exam. The best semen sample comes from using an artificial vagina, versus electroejaculation. Morphology, numbers, motility (movement) and longevity of the sperm are all important. The normal sperm count in a buck is about 2,000 per millileter. Too many malformed sperm indicate poor quality semen. Very young and very old bucks may have more sperm irregularities, as well as those who are deficient in selenium. A densometer can be used to count sperm, but semen color can give you some indication. Thick, milky semen is good. Thin, milky semen is mediocre and clear/amber semen may indicate poor quality. Sperm motility is difficult to check in collection samples. Physiology and biochemistry of the semen is also important. Semen evaluation is best left to a veterinarian or an experienced qualified semen collector/processor.
If he passes the breeding soundness examination with flying colors but he still not settling does, you need to consider other management possibilities. Is he overweight? Obesity definitely plays a big role in fertility. What are you feeding him? Feeds like timothy grass and clover with high estrogen content may suppress the antigens of a buck and in time the testicles may atrophy (shrink) and feel cold. An emaciated buck can become sterile. In either sex, the reproductive system is one of the first functions to shut down during starvation. Excess fat or thinness can be reversed with better management.
Reluctance or inability to mount may be due to painful hind legs, hips, stifles, hocks or feet, and the cause should be defined. Arthritis seems to be fairly common in older stud bucks. Is it due to excessive calcium in the diet or housing on cold, damp, bedding? All possible causes need to be considered. You can use a buck after injury, when he is healed, and if he is able to work, however, if you suspect a structural fault or disease, further use is not be recommended since he may pass these features. It is best to be very discriminate in propagating any negative traits; the buck is the major part of your herd.
A high fever in a buck can render him temporarily or permanently sterile. Sperm is produced at an optimum temperature, and this process is very sensitive to heat. If the temperature is increased dramatically, it affects the testicles and the quality and life span of sperm. A buck regulates the temperature of the scrotum and testes by controlling the distance they are from the body. When it is cold, the dartos muscle contracts to pull the testes closer to the body. When it is hot, the muscle relaxes and allows the testes to hang further from the body. When a buck has a fever it is almost impossible for his body to maintain the proper temperature for sperm production. Very hot weather can also render a buck temporarily sterile. Remember, the sperm in the ejaculate originated 4-6 weeks ago; what he produces today is a result of what happened way back then. This is an important fact to remember when you are looking for answers to a sterility problem or planning ahead for breeding.. Think in terms of more than just the last several weeks.
Infection may be another cause for sterility. If the penile sheath is injured it is vulnerable to infection. If the sheath is allowed to accumulate sebum (fatty secretion of the sebaceous glands) he may transmit coital vesicular exanthema which creates small ulcers on and around the vulva of the doe. For this and other reasons, cleanliness of the buck is very important, especially in a buck that is used heavily on a large variety of does from a number of herds. In heavy use, the buck's penis should be washed several times a month. The penis can be washed with soapy water, or a 1:5,000 dilution of Nolvasan™. Good hygiene can eliminate several problems that may eventually cause sterility.
Stones can become blocked in the urethra, causing sterility and sometimes death. When a buck or wether has a dietary imbalance of calcium and phosphorus, stones form in the bladder and move through the urethra. The urethra and ductus deferens join near the urinary bladder, so if the urethra is blocked neither sperm or urine will be able to exit the body. This is fairly common in wethers or bucks that are fed too much grain. Partial blockage is also possible. Treatment for this is difficult at best.
Other factors affecting sterility are anatomical defects, and other injuries and diseases. Scrotal hernias are seen in sheep and are presumed hereditary in that species. If a hernia (distention of one side of the scrotum with a movable loop of intestine) is identified and surgical correction is desired, the buck should be castrated.
Injuries or wounds involving the scrotum may result in purulent orchitis or periorchitis. Other causes of scrotal dermatitis include mange, bacterial infections, zinc deficiency and frost bite. Many different types of injuries may take place if two bucks are allowed to be in the same area while one is breeding; common ones are a broken penis and a broken leg.
Sperm granulomas are strongly correlated with the homozygous polled condition and can be avoided by culling all young bucks that are, by phenotype, homozygous for the polled gene. This condition is virtually unknown in the Pygmy, as it is a disqualifying fault in their Breed Standard. Another rarity is the protozoan parasite, Trichomonas. This protozoa has been observed in the semen of Alpine and Saanen bucks in France and Sardinia and in Angoras in South Africa. It infests the sheath and urethra of the buck, causing the quantity and quality of ejaculates, as well as libido, to decrease.
Testicular tumors in goats are rare but do occur.
It is possible to overwork a buck, especially when it is undernourished. Special attention should be given to the breeding buck's nutrition. Many bucks ignore their food during breeding season while increasing physical activity and the attentive owner should vary the diet to tempt him to eat.
A frequently used buck will also be less fertile per doe than a buck that has rest periods between services. After around 3 ejaculations the sperm count is reduced, and after 7 ejaculations the buck produces immature sperm that are incapable of fertilization. Overuse can be hard to determine since bucks can settle a hundred or more does in one season, depending on his condition, nutritional level and general health. It is better to err on the conservative side.
Genetics, nutrition, sanitation and other good management practices play important roles in the buck's life.
From birth a buck's body prepares itself for its main function - breeding. It's up to you to make sure that the things you can control, like proper nutrition and a positive environment, are in his favor. After all, he is the single most important ingredients in your breeding program.***
NEW BUCK BUYER
byMarvin Shurley
For The American Meat Goat Association
Select a herd sire with the utmost care and attention.
With all the new producers getting into the meat goat industry there are many questions being asked as to what breed of goats they should consider buying. There are many breeds and it really falls back on the producer to select what fits their individual taste in size, temperament, type, color, horned, polled, etc. A person would also be wise to investigate the local markets to see what sells for a premium in their area as this varies greatly across the U.S. due mainly to local ethnic influences.
Once a person has decided which type and breed of goat fits their individual needs as determined by independent research, then comes the time to purchase or trade for animals. At this time, if the potential producer is inexperienced in livestock, they would do well to enlist the aid of a knowledgeable "goat person" to aid them in selection. Be sure to let them know exactly what you want. Should you be able to find these exact animals, be prepared to pay a fair to premium price to fill your pens with your special goats.
Now that we've addressed some preliminary considerations to getting into goats, I'll get into the main purpose of this article. This is to admonish the newcomer to select their herd sire with the utmost care and attention. The reason for this is the fact that no other goat that you purchase will have as great an influence on your future in the industry as will the buck you purchase to service your does.
The producer knows what breed they want by now and so we go into selection. A very good suggestion at this time would be for the buyer to attend some breeding goat shows (if possible) which are being held for the specific breed that they are interested in. This is important because some of the finest representatives of any breed will always be present at theses events. Also this can give a person an idea as to what direction and phenotype (visual appearance) to breed towards should they be interested in the show segment of the meat goat, dairy goat, or fiber goat industry. Also at these shows they should have the opportunity to meet persons who are currently engaged in breeding the specific animals they are interested in. Industry publications are also an excellent source for names, addresses, and phone numbers of individual producers. After awhile the newcomer will begin to recognize names of some of the premier producers for the breed that they are interested in.
Now we contact the breeder whose animals best represent what we are looking for. Most of them will be happy to tell you what they have for sale, and the approximate prices for their animals. Having now gotten this far it is now time to make an appointment with the owner to view them. Please do this as far in advance as possible as most breeders are extremely busy people and will need some time to make sure their goats are available for viewing. You can't just drive up unannounced at many places and expect them to drop what they have going at that time; some may, but many won't.
Through your research you had already narrowed down your selections, but please remember not to be pressured into buying an animal not up to your standards. If you don't see what you want, thank them for their time and extend your search. No conscientious breeder will take offense if you are polite and explain your position. I wish to again remind you of your position; you are searching for the most important component of your future breeding program.
When you discover an animal you're interested in, attempt to find out all you can about him. Such as his birth rank; was he a single, twin, or triplet, or possibly a quadruplet. What was his birth weight? What was the animals average daily gain, weaning weight, and if an older animal, mature weight? If his sire and dam are on the premises ask to see them. If he is an older buck check to see if there are any of his offspring where you can see them.
While this article doesn't cover every aspect , I hope that it sheds some light on the buck selection process for our novice goat producer.
Mr. Shurley can be contacted at marvin@sonoratx.net
This article first appeared in Meat Goat News, a RRL Publication, in the March 1999 issue.Reprinted with permission of the author.
Conformation Traits For Breeding Bucks
A bucks main function in a profitable breeding operation is to get a high proportion of does bred early, during a mating period of six weeks or less. To achieve this bucks must be sound for breeding, they must be willing and able to serve a high percentage of does in heat and they must be free of any abnormalities of the penis, testicles, feet and legs.
Almost all bucks that are unsound for breeding can be detected during an examination for breeding soundness. This consists of a physical examination of testicles, legs and feet and a serving capacity test to measure a bucks serving capacity and to detect penis abnormalities and signs of arthritis.
The circumference of the scrotum is the best indicator of testicle size. The head and tail of the epididymis, which are the storage areas on the top and bottom of each testicle, are also examined for abnormalities.
The legs of a buck have a number of functions. Of these walking and load bearing are the most obvious, but all limbs need to be efficient shock absorbers as well. Hip arthritis, hock, knee, fetlock and stifle arthritis will effect a bucks breeding soundness. The hind leg has a weight bearing and propulsion role in mounting a doe. Bones of the hind leg are set at an angle so that the muscles, tendons and ligaments can assist the bones and joints in absorbing the concussion that results when the buck places its weight on the hindquarters, whether standing, walking or serving a doe.
Walking pattern viewed from behind a buck should pull his hind legs through, parallel to the direction of movement as he walks. He should not throw his legs inward or outward and the hind hoof should land in the print left by the front hoof. Post-legged and lame animals usually step short, whereas sickle-hocked animals commonly overstep, sometimes leading to stone damage of the pastern or dewclaw.
Preparing Bucks for the Breeding Season
By Jackie Nix
Let's face it. No one likes to handle bucks, myself included. They're big, smelly and strong. For this reason they are often overlooked in herd management. However, the male is vitally important. If a buck is not reproductively sound, the kidding rate will be reduced drastically and profits will be similarly affected. Therefore, in preparation for the breeding season, bucks should receive a little extra attention prior to being turned out with the does including: good nutrition, disease and parasite control, a breeding soundness exam, foot care and a general physical eamination.
Nutrition
It is very important that bucks be in good physical condition prior to the breeding season, but not too fat. An active buck with a high libido (sex drive) can literally forget to eat during the breeding season. An adult buck can be left thin but a yearling buck can actually be stunted permanently. A young buck needs nutrients not only for semen production and mating but also for his own body growth. It takes about 60 days for spermatozoa to form and mature inside the buck's reproductive tract. Therefore, it is vital that bucks receive adequate nutrition prior to as well as during the breeding season for optimum performance. If your pasture conditions are not adequate right now, you may want to consider a protein supplement to make sure that bucks are in peak condition going into the breeding season. This is especially true for young, immature bucks that are still growing. There are many commercial protein supplement products available including the Sweetlix 20% All Natural protein block formulated especially for goats. Choose the supplement option that works best for you.
Every goat producer should have a working knowledge of the nutritional needs of their animals. While the purpose of this article is not to teach ration balancing, on average a buck will require roughly 5% of his body weight in dry matter intake (the weight of the feed with all water removed) per day. For example, a 200-pound buck will eat 10 pounds of dry matter feed per day. If he is receiving hay that has a dry matter content of 80% (20% moisture), he will then consume 12.5 pounds of hay per day on an as fed basis (10 lbs./0.80 = 12.5 lbs.). An average meat or fiber producing buck will require 60% TDN (total digestible nutrients), 11% protein, 0.4% calcium and 0.2% phosphorus in his total diet. It is important to make sure that the calcium to phosphorus ratio is at least 2:1 to prevent urinary calculi formation. It is also important to point out that these nutritional requirements will vary according to age, breed of goat, activity level, desired weight gain, and other factors. Please consult a nutritionist, Cooperative Extension agent or veterinarian to formulate a ration according to the specific needs of your herd.
Disease and Parasite ControlDisease and heavy parasitic infections will also reduce a buck's sexual performance. Here are some steps that you can follow to control disease and parasites.
Follow a preventative program for internal and external parasites dictated by your local conditions.
Promptly treat any animals showing signs of infection.
Isolate new animals and animals returning from shows for a period of 30 days before adding or returning to the herd.
Vaccinate bucks for enterotoxemia and tetanus whenever does are vaccinated.
Be sure to have a postmortem examination (necropsy) performed for all suspicious deaths. In most states, the Dept. of Agriculture provides a service of free necropsies on livestock in state-run laboratories. Contact the Dept. of Agriculture in your state to receive more information about this service.
Breeding Soundness ExamBefore going on a long trip you probably give your car a tune-up and make sure that all the important parts are functioning correctly. The same concept applies for your bucks. You should physically examine all bucks prior to the breeding season each year to make sure that all "important parts" are functioning correctly. Just because a buck was sound a year ago doesn't mean that he's sound today!
You can begin by carefully examining the penis and prepuce (sheath). To do this, sit the buck on its rump with its back to you (as if you were going to shear him). Then gently push the prepuce down to reveal the penis. If the penis does not appear, gentle forward pressure in the area behind the scrotum will place pressure on the sigmoid flexure and thus protrude the penis. When inspecting, make sure that the penis and prepuce are not adhered together. Next check the penis for sores or cuts. Also feel the pizzle (thin process on the end of the penis) to make sure that no urinary stones are lodged there. Next visually feel the testes. Make sure that they are cool to the touch (heat may indicate a possible infection), roughly the same size, firm to the touch (not too hard or soft), and have no unusual lumps. If abnormalities are detected in the testes, the semen should be evaluated by a veterinarian or reproductive physiologist before allowing the buck to breed does.
Foot CareBucks should receive hoof trimming and an examination of their conformation prior to the breeding season. Foot care is very important since problems will hinder the buck from actively seeking out does and mounting them. Bucks who find it painful to walk or mount will be reluctant to ejaculate even if they do attempt to mount. Possible causes of feet and leg problems include foot rot, overgrown hooves, improper foot trimmings, injury, or CAE.
While you are handling the buck, check his eyes as well. Bucks rely on sight to find does in heat in a large pasture setting, so make sure that the buck's vision is not impaired by cataracts, pink eye, excessive hair or other causes.
In summary, it is of vital importance that bucks be reproductively sound prior to the breeding season. One can prepare bucks for the breeding season with good nutrition; regular health care and frequent foot care. Other precautions include breeding soundness examinations and general physical examinations prior to turning bucks out with does. If forage conditions in late summer are poor, you may want to consider supplementation to ensure optimum spermatozoa production in your bucks, especially for young, growing bucks.
Jackie Nix is a nutritionist with Sweetlix Livestock Supplement Systems and an authority on goat production. You can contact her at jnix@sweetlix or 1-800-325-1486 to ask questions or to receive more information about the Sweetlix line of supplement products for goats. ***
