Dairy Goat Herd Health Management and Preventive Medicine

It is useful to think of the dairy goat herd as divided into separate management subgroups, each with its own set of herd health and preventive medicine requirements. For the purpose of this discussion, the following groups of goats are identified: newborn kids to weaning; weaned kids to breeding; bred doelings and dry does; milking does; and bucks.

General Comments about Dairy Goat

Herd Health

Biosecurity is a critical element in maintaining disease-free herds. Commercial goat dairies should be managed as closed herds to minimize disease problems. Taking goats to shows and fairs should be discouraged. If showing is neces­sary for the financial well-being of the farm through the sale of breeding stock, then isolation and quarantine proce­dures should be followed for animals returning from out­side. A separation period of three weeks from the herd is warranted. From the disease control point of view, artificial insemination is preferable to introduction of bucks or trucking of does to other farms for breeding. Pest control is important and if cats are present on the farm, feeders should be designed so that cats do not use them as litter boxes.

Goats are very clever about undoing fasteners and gate closings, so gates and doors must be very secure to avoid unwanted escape and accidental access to feed and chemi­cal storage areas, which could result in engorgement tox­emia, bloat, or poisoning. Goats are also notorious for chewing on the materials from which their enclosures are constructed. Therefore, old barns with lead-based paints should be avoided as goat housing.

Goats are also very hard on fences because of their pro­pensity for climbing, and improper selection of fencing materials can be costly to owners. Fences with horizontal rungs or slats encourage climbing and destruction of fences. Chain link fences predispose goats to catching their limbs in the fence, with possible fractures resulting. If ver­tical slats or bars are used on gates or fencing, the spacing should be carefully evaluated to be sure that goats cannot become trapped and strangled, especially horned goats. For these reasons, electric fencing for goats is gaining in popu­larity. Successful use of electric fencing does require a period of training and adaptation for the goats, to avoid problems such as running through the fence on experienc­ing their first shock.

Goats, like sheep, are susceptible to predation due to their small size and lack of potent defenses. Kids are par­ticularly defenseless and may fall prey to raptors and ground-dwelling predators. Because the main defense of small ruminants is fleeing, the practice of tethering goats can be deadly where predators are common. Various defenses against predation are discussed in Chapter 4.

Goats, like other livestock, can experience suboptimal performance or overt disease from mineral deficiencies in feedstuffs related to soil composition in different parts of the world. The veterinarian and the producer must be aware of the mineral deficiencies occurring locally. Deficiencies well documented to cause financial loss in goats are selenium, iodine, cobalt, and copper. Fertilization, top-dressing of pastures, supplemental feeding, provision of trace mineral salt licks, or parenteral administration of needed substances can be used to address these problems, as discussed in Chapter 19. Another potential local prob­lem for goats is consumption of noxious or toxic plants.

Veterinarians who work with goats should encourage herd owners to have regularly scheduled herd health vis­its. When a knowledgeable veterinarian becomes familiar with the routine practices and seasonal activities of the goat herd, he or she is better able to spot incipient prob­lems developing in the herd and initiate appropriate interventions before costly losses occur. As with dairy cat­tle, reproductive consultation is a good place to begin to show the herd owner how the veterinarian can help improve production efficiency through pregnancy check­ing, heat synchronization practices, and out-of-season breeding programs. Mastitis control is an important area where veterinary inputs can improve herd productivity. Depending on climate and management practices, gastro­intestinal parasitism can be a serious constraint on dairy goat production and the veterinarian should work with the producer to develop a suitable parasite control pro - gram that effectively controls parasites while minimizing the development of anthelmintic resistance, based on the principles discussed in Chapter 10. Nutritional manage­ment of metabolic diseases such as pregnancy toxemia is another area of potential input. The development and implementation of practical and realistic caprine arthritis encephalitis (CAE) control programs are important con­cerns of goat producers that should involve the counsel of veterinarians. Veterinarians can also carry out necropsy examinations on all goats that die in a herd. This is an effective means of tracking unexpected disease develop­ments in the herd.

There have been efforts made to develop protocols for assessing the welfare status of dairy goats, in part by noting the presence, prevalence, and severity of certain health indicators such as ocular discharge, skin lesions, udder asymmetry, calluses on knees and hocks, and overgrown claws, among others (Anzuino et al.

Management of Newborn Kids to Weaning

Disease Problems

At birth, the major obstacles to survival are hypoxia, hypo­thermia, hypoglycemia, and susceptibility to infectious dis­ease. The latter is exacerbated by delayed or inadequate intake of colostrum rich in maternal immunoglobulins. The failure of transfer of passive immunity to newborn kids leads to increased morbidity and mortality throughout the postnatal period, particularly from septicemia in the first week of life, and later from pneumonia as kids reach weaning age and diminishing concentrations of maternal antibodies have not been fully replaced by immunoglobu­lins actively produced by the kid. Failure to disinfect the navel after birth and maintaining kids in a dirty environ­ment also can lead to increased incidence of omphalophle­bitis, septicemia, polyarthritis, and pneumonia. Diarrheal diseases are common in this period. Numerous etiologic agents can cause neonatal diarrhea over the first two weeks of life, as discussed in Chapter 10. After 2 weeks of age, coccidiosis is an increasing threat. A pneumoenteritis com­plex is sometimes seen in young kids, suggesting poor hus­bandry, heavy environmental pathogen loads, and inadequate colostral intake. Contagious ecthyma also may appear clinically in this age group if it is endemic on the premises or recently introduced.

Newborn kids should be inspected carefully for congeni­tal defects such as cleft palate, rectovaginal fistula, atresia ani, hydrocephalus, umbilical hernia, and ventricular sep­tal defect. The intersex condition is especially common in goats. Beta mannosidosis and mucopolysaccharidosis IIID are genetic diseases of Nubian kids. Kids identified with congenital defects should be culled immediately or desig­nated for meat production.

CAE virus infection is a major concern of dairy goat pro­ducers worldwide.

Management Practices

Kidding should be a well-anticipated event, not an unex­pected surprise. Being prepared for routine processing of kids at birth and being ready to respond to emergencies reduce neonatal losses. A clean, warm, dry, well-lit, well- bedded, well-ventilated kidding area should be designated and maintained. Appropriate supplies should be on hand such as towels for drying kids, feeding tubes for kids that do not suckle, and tincture of iodine for dipping navels. Monitoring activity in the barn or kidding area by video surveillance is becoming increasingly popular to ensure readiness at kidding. A colostrum management program relative to CAE control should be developed and in place before the onset of the kidding season. Evaluation of colos­trum quality and colostrum requirements are discussed with failure of transfer of passive immunity in Chapter 7. Colostrum management programs are discussed in the section on CAE in Chapter 4.

The timed induction of parturition using prostaglandin has become popular as a technique for assuring attendance at birth and facilitating CAE control activities. Protocols are discussed in Chapter 13, along with recognition and management of dystocia, resuscitation, and proper care of the neonate at birth.

Proper identification and record keeping are signs of a well-managed farm. For identification of neonates, plastic- backed paper collars are widely available for this purpose from animal supply outlets. Subsequent ear tattooing of kids is recommended for permanent identification and should be performed after 3 months of age. If done too early, the tattoo dots comprising individual numbers or let­ters expand and separate as the ear grows and the markings become difficult to interpret.

Kids can be housed in group pens, but should not be overcrowded. Pen design should allow easy and thorough cleaning. The spread of diarrheal agents is exacerbated by poor sanitation and overstocking. Early culling or market­ing of unwanted kids reduces kid populations and the attendant risk of increased environmental contamination and the spread of infectious disease.

Disbudding of kids to prevent horn growth is commonly practiced to prevent horn-related injuries between goats or to handlers later in life. In the United States, purebred dairy goats cannot be shown if they have horns. Disbudding is usually done between 3 and 14 days of age, depending on breed, size, and sex of kids, as described in Chapter 18. When buck kids intended for future reproductive use are disbudded, damage to the pheromonic scent glands adja­cent to the horn buds should be avoided, as it may reduce the buck's breeding efficiency later on. However, when buck kids are to be raised for meat or as pets, destruction of the scent glands is indicated.

Extra teats are common on doelings. These can be easily removed at the same time kids are disbudded, using curved scissors. If there is any doubt about which teats are the functional ones, extra teat removal should be delayed. Wattles can also be removed from goats at a young age with minimal trauma using curved scissors. Though wattles potentially can become snagged or traumatized, this hap­pens uncommonly and the decision to remove them is usu­ally based on cosmetic or humane considerations.

Castration, when indicated, is best carried out between 4 and 14 days of age. The reason for castration must be clearly defined. For meat kids, the intended market and the age at marketing determine the need for castration. In some ethnic markets, uncastrated goats are preferred. When the market calls for kids slaughtered by 8 weeks of age, castra­tion may not be required. If goats are kept longer for finishing, then they need to be castrated where the market will not tolerate a buck odor to the meat. If castrated males are destined to become pets, delaying castration until 6-8 weeks of age may reduce later problems with obstruc­tive urolithiasis, a common problem in pet wethers discussed in Chapter 12.

Vaccination and the timing of vaccinations of neonates depend a good deal on the overall herd vaccination pro­gram. If does have been vaccinated during the dry period and kids receive adequate colostrum from vaccinated does, then kids can be considered to be protected by maternal immunity for those specific diseases through the first six weeks of life. Because the waning of maternal antibody varies with initial concentration, vaccination of these kids should begin as early as 2 weeks of age with booster inocu­lations given at intervals prescribed for each vaccine.

Kids are immunocompetent at birth. If kids are born to unvaccinated does, vaccinations should begin during the first week of life and the kids should be boostered at least twice at suitable intervals. However, a study on vaccination of lambs with Clostridium perfringens type D toxoid dem­onstrated that lambs born of unvaccinated ewes did not mount notable antibody responses when the lambs were vaccinated at 1 and 21 or 21 and 42 days of age (De la Rosa et al. 1997). Prophylactic antisera may be used during the first week concurrently with bacterin-toxoids to protect kids while active antibody is forming. Tetanus antitoxin and C. perfringens type C and type D antitoxins are the products most commonly used in kids in this manner.

The vaccinations required for kids will vary with geogra­phy and management system. Nevertheless, a universal recommendation is the vaccination of kids for enterotox­emia due to C. perfringens type C and type D as well as for tetanus. This is the minimum vaccination program for kids. Vaccination for contagious ecthyma is fairly common. The first time it is done, all goats on the premises should be vaccinated. In subsequent years, only kids need to be vac­cinated because immunity persists in the adults. Maternal antibody may interfere with vaccination in kids vaccinated too early. Contagious ecthyma vaccination is discussed in detail in Chapter 2.

Other vaccines, such as brucellosis, paratuberculosis, foot and mouth, peste des petits ruminants or bluetongue vaccine, may be mandated or recommended as part of national disease control programs. Still other vaccines, such as anthrax, blackleg, leptospirosis, or rabies vaccines, may be used on the basis of knowledge that the disease occurs commonly in a specific region. Specific details about vac­cine availability and use in goats for various diseases are covered in each disease discussion throughout the text. Indiscriminate use of vaccines should be avoided, especially the use of live vaccines that are approved for use in other species but not goats. For example, live intranasal infectious bovine rhinotracheitis (IBR) vaccine is sometimes given to goat kids in the United States to control respiratory disease problems, though it is not established that the causative herpesvirus plays any role in respiratory disease in goats.

Where soils are selenium deficient, nutritional muscular dystrophy in young kids is a real concern, and parenteral administration of a combined vitamin E and sodium sele­nite injection to kids at birth or supplementation of the ration with selenium is indicated, as discussed in Chapter 19.

Feeding programs for kids are discussed in Chapter 19. Weaning may occur as early as 6 weeks or as late as 12 weeks of age, depending on the feeding system used and other management considerations. Regardless of the milk feed­ing regimen, it is important that kids be exposed to hay and grains early in life to promote proper rumen development. Abrupt cessation of milk feeding without adequate adapta­tion to solid feeds can predispose to indigestion, bloat, coc- cidiosis, and possibly polioencephalomalacia.

Management of Kids from Weaning to Breeding

Disease Problems

Coccidiosis and pneumonia are the dominant problems in this age group, particularly under conditions of confine­ment housing. The transition to a diet of solid feed facili­tates the consumption of more coccidial oocysts while feeding. With regard to pneumonia, the progressive decline of maternal antibodies and the stresses of weaning can pre­dispose kids to respiratory infections after 8 weeks of age. When kids are turned out to pasture during their first sum­mer, they are very susceptible to gastrointestinal parasitism and lung worms, due largely to the absence of a developed local immunity in the alimentary and respiratory tracts. The severity of clinical parasitism depends on the concen­tration of infective larvae on pasture, the stocking rate, weather conditions, and other factors, as discussed in Chapter 10.

Other disease problems also may occur in this group. There is a recurrent risk of enterotoxemia when concen­trates are fed. The neurologic form of CAE virus infection, a progressive paresis, is most often seen in kids between 1 and 6 months of age.

Management Practices

For housed kids, it is essential to maintain housing and feeding systems that minimize the incidence of pneumonia and coccidiosis, as discussed, respectively, in Chapters 9 and 10. Regarding coccidiosis, clinical disease can occur even on the most conscientiously managed farms. Therefore, in addition to good sanitary practices, it may be necessary to use a coccidiostat in the feed or water.

Currently, there are few if any vaccines that can be confi­dently recommended for controlling respiratory disease in young goats. The role of viruses usually implicated in bovine respiratory disease is unclear, and the available Pasteurella and Mannheimia bacterins are of unproven efficacy. There are no goat-specific respiratory virus vac­cines approved for use in goats in the United States. Reliable vaccines against mycoplasmal pneumonias, nota­bly for contagious caprine pleuropneumonia, are increas­ingly available in affected countries. In countries where vaccination for caprine brucellosis is carried out, kids are usually vaccinated between 3 and 8 months of age.

Regarding pasture parasites, young goats should be turned out to pastures that have not been in use for at least one year and should be kept on separate pastures from adults if possible. A broad-spectrum anthelmintic should be administered before turnout, and parasite loads moni­tored throughout the pasture season by microscopic exami­nation of composite fecal samples collected at pasture or, in the case of Haemonchus contortus, by application of the FAMACHA© system to identify clinically affected individ­uals, as discussed in Chapter 10. Tactical anthelmintic treatments can be given accordingly as needed. Veterinarians may need to advise producers on the proper use of the FAMACHA system and its interpretation.

When spring kids are weaned properly, fed optimally, and kept healthy, they can reach proper breeding size by the autumn of their birth year and subsequently kid on their first birthday. In North America, the target is 31.7 kg (70 lb) by 7 months of age for heavy breeds (e.g., Alpines, Saanens, and Nubians) and 27.2 kg (60 lb) by 7 months of age for light breeds (e.g., LaMancha and Toggenburg). Male and female kids should be segregated by 3 months of age to avoid unwanted breedings among sexually preco­cious individuals. External genitalia of all kids should be examined before breeding to identify any intersexes present.

In temperate regions, goats are seasonal breeders induced to begin estrous cycles by decreasing day length. There is much interest in manipulating the hormonal signals for estrus to permit goats to cycle year-round. Year-round breeding is particularly important to large-scale commer­cial milk producers who must provide a consistent volume of product on a year-round basis. The two main techniques for bringing does and doelings into heat during the nor­mally anestrous period of the year are the use of progester­one supplements and the manipulation of day length through confinement and exposure to artificial light. These and other useful techniques are discussed in Chapter 13 and elsewhere (Haibel 1990; Bretzlaff and Romano 2001). Breeding techniques and confirmation of pregnancy in doelings and does are also discussed in Chapter 13.

Management of Bred Doelings and Dry Does

Disease Problems

The major concerns in this group are pregnancy toxemia and abortion. Pseudopregnancies are also common in goats and may be recognized during this period by ultrasound evaluation or by the spontaneous release of uterine fluids with no attendant fetus or placenta. The lay term for this phenomenon is, appropriately enough, cloudburst. Goats that are obese when they enter the dry period are at increased risk for pregnancy toxemia, vaginal prolapses during late gestation, and dystocia at parturition.

Management Practices

Does in lactation are usually given a dry period coincident with the last two to three months of gestation. Bred doe- lings that have not yet milked are also non-lactating in advanced pregnancy. The key objective for these animals is proper nutritional management to avoid obesity in early gestation (late lactation) and to provide adequate nutrients to support the rapid growth of fetuses in the last trimester of pregnancy. This is particularly important regarding pregnancy toxemia. The disease can be avoided by curtailing grain in late lactation (early gestation) when milk production no longer justifies it. These goats can be carried through mid-gestation on a high-quality legume hay and little or no grain. Grain feeding should be resumed at the beginning of the last trimester and gradu­ally increased until term. In herds already experiencing a pregnancy toxemia problem, periodic checking of urine samples from does and doelings for ketones with com­mercially available powders or dipsticks helps to detect incipient cases.

There are many potential infectious and non-infectious causes of late abortion in goats, as discussed in Chapter 13. To protect pregnant does from infectious abortion, no new animals should be introduced into the herd when pregnant animals are present. This includes breeding bucks. Any animal that aborts should be isolated immediately and the area where the abortion occurred quarantined and disin­fected. Attempts should be made to make a definitive diag­nosis of the cause of abortion. All fetal tissues and placentas not submitted for diagnosis should be buried or inciner­ated. In herds with a history of chlamydial abortion or past vaccination, each year's new crop of doelings should be vaccinated before breeding.

The dry period is the appropriate time to vaccinate preg­nant does to increase the concentration of specific anti­bodies in the colostrum and thereby enhance passive immunity in the kids. Vaccines, such as enterotoxemia, should be given to dry does three to five weeks before kid­ding. Where nutritional muscular dystrophy due to sele­nium deficiency is endemic, and selenium supplementation of the feed is not possible or permitted, selenium injec­tions can be given to dry does four to six weeks before kid­ding to protect the newborn kids, as discussed in Chapter 4. A note of caution is warranted, however. Parenteral sele­nium injection has been associated with abortions and death in pregnant ewes and at least one commercial prod­uct, Bo-Se’ (Merck Animal Health, Madison, NJ, USA), carries a warning on the product label that it should not be used in pregnant ewes.

Pregnant does with nematode gastrointestinal parasites may experience a periparturient egg rise with increased shedding of eggs around the time of kidding. This is a sur­vival strategy of the parasite to enhance the likelihood of infecting a new generation of hosts. Therefore, pregnant does should be given a broad-spectrum anthelmintic two to three weeks before kidding. Though no anthelmintic at proper dose has been definitively shown to cause abortion or teratogenic effects in goats, levamisole, and albendazole have been suspected to do so, thus inhibiting their use in pregnant does.

Management of Milking Does

Disease Problems

Not unexpectedly, mastitis is the major disease challenge in lactating does. A variety of pathogens has been identi­fied in milking goats, as discussed in Chapter 14. Mycoplasma mastitis can be epidemic in some herds with devastating results. Mastitis due to Staphylococcus aureus can also be costly and difficult to control if aggressive cull­ing of affected goats is not practiced.

Caseous lymphadenitis can occur in goats of all ages, but is particularly problematic in milking does. Abscessed lymph nodes most commonly occur on the head and neck. Using head catches to restrain milking does at milking increases the risk of abscess rupture and transmission of the disease.

The mammary form of CAE virus infection often occurs at the onset of lactation. It is manifested by a distinct hypogalactia or agalactia associated with a firm udder. This is perhaps the most threatening form of CAE, in that it strikes at the core of the animal's productivity. In herds with this problem, careful consideration should be given to implementation of CAE control programs, as discussed in Chapter 4.

The arthritic form of CAE virus infection also shows up more frequently in does once they have entered the milk line. Epidemiologic studies in France suggest that clinical manifestations of swollen carpi are more likely to develop in infected goats that are subjected to conditions that increase trauma to the joints (Monicat 1989). Such condi­tions might include having to jump on and off milking stands, repeated banging of the carpi caused by improper stall or feeder design, hard floor surfaces, or being forced to rest for extended periods on the carpi because of stall con­finement or tying up. Overgrown, inadequately trimmed hooves are another distinct predisposing factor.

Some weight loss is normal in early lactation, particu­larly in high-producing animals. However, the stresses of kidding and subsequent lactation may trigger clinical man­ifestations of weight loss in carrier animals subclinically infected with Mycobacterium avium subsp. paratuberculo­sis. Animals that continue to lose weight during lactation should be tested for paratuberculosis, as discussed in Chapter 10.

When milking does are pastured, gastrointestinal para­sitism must be anticipated as a potential problem. Though goats develop some age- and exposure-related resistance to parasites, it is not absolute. Even if adult milkers do not develop overt clinical parasitism, the subclinical effects of parasites on milk production may be significant (Farizy and Taranchon 1970; Hoste and Chartier 1998). Milk fever, or hypocalcemia, is uncommon in dairy goats relative to dairy cattle, but can be a recurring problem in certain herds. Management and feeding recommendations made for control of hypocalcemia in dairy cattle have not been proven applicable to goats, as discussed in Chapter 19. Abomasal displacement is another common problem in intensively raised dairy cattle that is virtually unknown in goats.

Management Practices

The major goal in managing lactating does is to maximize their milk output in a cost-efficient manner. To accomplish this, both general health and udder health must be main­tained. The feeding program must optimize production and be tailored to suit the needs of individual goats, depending on their stage and level of lactation. In addition, a breeding and culling program that selects for superior milk production must be implemented. In support of these goals, health and production records, though they need not be elaborate, must be conscientiously maintained. In the United States, goat dairies have access to the Dairy Herd Improvement Association (DHIA), a national association managed at state level that helps dairy producers create and manage records and production data on the animals in their herds.

Preventive medicine procedures for milking does include vaccinations, foot care, and, when conditions dictate, deworming. Goats should be vaccinated at least twice a year for enterotoxemia, and in problem herds three times. Since one vaccination is given to dry does to enhance colos- tral antibody, these animals should receive one or two addi­tional vaccinations during lactation. Vaccine products aimed at preventing abortion, such as chlamydial vaccines, are given before breeding.

Proper foot care in the form of regular hoof trimming is extremely important. It reduces the likelihood of foot rot, teat injuries, abnormal gait, and general sore-footedness leading to decreased feed intake. The technique for foot trimming is described in Chapter 4. The frequency of trim­ming depends to a large extent on the amount of exercise goats get. Natural wearing or trimming occurs through ambulation, especially on rough or rocky surfaces.

Pastured milkers should be checked periodically for nematode parasites by fecal examination or, where H. con- tortus occurs, by the FAMACHA test, as discussed in Chapter 10. Milking does can be dewormed tactically as required, but there are two concerns. One is that certain anthelmintics have antifungal and antibacterial properties that can damage cheese cultures and disrupt cheese mak­ing. The second is that regulatory agencies often set a milk discard requirement following any sort of drug administra­tion, leading to economic loss to the milk producer. Anthelmintics used should be those approved for lactating animals and appropriate milk discard times must be observed.

Good udder health depends on selecting for does with good udder conformation and attachment, providing clean well-bedded living quarters for milking does, prop­erly functioning milking equipment, and an established protocol of udder hygiene during milking. Intramammary infusions of antibiotics at the beginning of the dry period can be used in herds with a subclinical mastitis problem and culture and sensitivity testing of milk samples before drying off can inform this practice. Clipping the hair on the udder and hindquarters decreases sediment in the milk.

Milk quality is an important issue in goat dairies. Too often in the past, milk odors and taints have dampened consumer acceptance of goat milk as a wholesome, desira­ble product. Buck contact with milking does should be kept to a minimum and bucks should not be maintained near milking parlors or milk storage areas because buck odor permeates the milk. Milking does should not be allowed to forage indiscriminately in unimproved pastures or wood­lands, because many plants may lead to off flavors or odors in milk. Proper handling of milk after extraction from the doe is extremely important. Excessive agitation and delays in pasteurization promote lipolysis of the fat in goat milk, adding to the so-called goaty flavor of the milk. “Off” fla­vors in milk are discussed further in Chapter 14.

High somatic cell counts in goat milk are a serious con­cern. For a variety of reasons, not all of which are eluci­dated, goats tend to have higher somatic cell counts than cattle, even when udder infections are not present. This causes regulatory conflicts when somatic cell count stand­ards set for cow milk quality are applied to goat milk. This, and other issues related to milking procedures and milk quality, are discussed in detail in Chapter 14.

Feeding for optimal milk production is discussed in Chapter 19. No matter what is fed, there must be adequate trough or feeder space for each and every doe in the milk­ing herd so that submissive does are not deprived of feed by dominant does. In addition, dominant does may be so busy bullying other goats that they may not eat adequately themselves and may need to be culled. Another point related to feeding is that the feeding of silage is associated, though not consistently, with the development of listeriosis in goats.

Management of Bucks

The reader will note that bucks are the last subgroup to be considered in this discussion. This reflects the typical position of the bucks in the herd when it comes to the implementation of herd health practices. The buck, by virtue of his offensive odor, is too often neglected in herd health programs. This omission should be conscientiously avoided, because healthy bucks play a key role in repro - ductive efficiency and overall improvement of herd productivity.

Disease Problems

Disease conditions unique to bucks are limited. Obstructive urolithiasis is probably the most important. Though more common in castrated males, urinary calculi can also cause obstructive disease in intact males and may result in their loss as breeding animals. The condition and its man­agement are discussed in Chapter 12. While not necessar­ily common, the presence of hoof diseases such as foot scald or foot rot can cause ambulatory and mounting problems in bucks that may notably reduce their breeding efficiency.

Bucks become quite aggressive in the breeding season and can injure each other while fighting. A common problem associated with fighting is the breaking off of a horn scur, with profuse bleeding from the poll. These poorly attached scurs occur when male kids are improp - erly disbudded and residual germinal horn bud tissue produces a regrowth of malformed horn. The profuse bleeding, though rarely serious, is a frequent cause of alarm. Proper disbudding prevents this problem, as dis­cussed in Chapter 18.

Bucks can also injure people, and workers should always exercise caution around breeding bucks. Never turn your back on a breeding buck as he can rear up and slam into you with his head (and horns if present), causing serious injury. Useful guidelines on working safely around goats are available (Ebert 2010).

In the breeding season, bucks express the behavior of urinating on themselves, particularly on the face and the back of the forelimbs. This can cause severe urine scald and secondary bacterial dermatitis. Petroleum jelly applied to the back of the forelimbs inhibits the development of serious problems.

Management Practices

To obtain maximum performance from bucks, they should be “tuned up” before the onset of the breeding season. There is a definite tendency for bucks to become thin as the breeding season progresses. This is most often physiologic rather than pathologic. Nevertheless, it underscores the need for bucks to be in excellent body condition before breeding begins. This requires regular deworming and proper feeding, as discussed in Chapter 19.

Of equal importance is proper foot care. Mounting does for breeding puts considerable strain on the back legs, and poorly trimmed feet can produce sufficient pain to inhibit the buck from performing properly, particularly if the buck is used heavily. Proper foot care is too often over­looked because herd keepers do not want to handle smelly bucks. Similarly, bucks should not be left out of herd­wide vaccinations simply because they are a nuisance to handle.

A complete reproductive examination should be per­formed on breeding bucks prior to use. This should include a general physical examination, genital examination, semen evaluation, and assessment of libido, as discussed in Chapter 13. This should not be done too long before the onset of the breeding season, because semen quality may be diminished during the season of deep anestrus.

If bucks are housed in groups year-round, they get used to each other and even at the onset of the breeding season are unlikely to do serious damage to each other by fighting. However, introducing a brand new buck, especially a younger or smaller one, to the group during the breeding season could prove fatal to the newcomer.

Clipping the beards and hair of bucks, especially on the forequarters, may reduce the generally offensive odor of the buck that results from urine retention on the hair.

This should be done before the onset of breeding activity. The presence of a buck near the does is quite helpful in detecting estrus. Fence line contact is adequate and the buck need not commingle with the does to elicit estrous behavior.

Table 20.1 Seasonal herd health management and preventive medicine calendar for dairy goats in North America.

Season Preventive activities

Fall Clean barn thoroughly before onset of bad weather

Check function of automatic waterers before freezing season

Clean and disinfect kidding pens and leave vacant Check goats coming off pasture for gastrointestinal parasites; tactical treatments if necessary

Check goats for lice; delouse entire herd if lice found and repeat in two weeks

Check and trim feet as needed, including bucks

Perform breeding soundness examination of bucks, including semen evaluation

Administer vitamin E/selenium prior to breeding if deficiencies expected

Winter Check goat housing for evidence of poor ventilation such as wet ceilings, wet bedding, or smell of ammonia

Correct ventilation deficiencies; identify and seal drafts

Check waterers for cleanliness and correct any leaks Restock necessary kidding and kid-rearing supplies Deworm and vaccinate dry does three to five weeks prior to kidding

Clip hair on udder and hindquarters of pregnant does

Check and trim feet as needed, including bucks

Spring Check and repair fences and gates around pastures and buildings

Remove sources of injury from lots and pastures and inspect for poisonous plants

Administer anthelmintics before turnout to (preferably uncontaminated) pasture

Check and trim feet as needed, including bucks

Summer Ensure adequate shade and water for goats in hot weather

Monitor herd for parasites using composite fecal samples from pasture

Examine bucks for general condition and genital abnormalities; deworm and/or provide extra feed as needed

Check and trim feet as needed, including bucks

Source: Guss 1977 / Dairy Goat Journal Publishing Co.

The above discussion is organized according to the needs of the various subgroups of animals within the dairy goat herd. Another approach to organizing herd health man­agement activities is by the calendar. A typical seasonal calendar of herd health activities for dairy goats in North America is given in Table 20.1.