Domesticated animals rely on care providers to meet their physiological and behavioral needs. Consequently, management and nutrition are essential to animals' health and well-being. This is especially true in agriculture, in which production methods demand a high level of animal productivity. With continued advances, production systems have tended to become intensified, requiring continual adaptation in management and nutritional practices to ensure that they do not limit animal well-being, health, or production.
The tenets of biosecurity have been long recognized by veterinarians. However, throughout the past decades, interest in biosecurity as a scientific discipline has surged because of 1) disease outbreaks that have threatened to devastate agricultural economies, and 2) bioterrorism. In fact, the meaning of the term biosecurity and the structure and focus of biosecurity programs have evolved throughout time to more accurately reflect the scientific community’s evolving perception of disease as well as the needs of the consumer, the veterinary profession, and producers and owners.
The basic concept of cloning via nuclear transfer is that the nucleus of a cell, taken from a tissue sample of a donor individual, is transferred to an enucleated oocyte, and then the oocyte is stimulated to develop into an embryo. The embryo thus produced has the same genotype as the original donor individual.
Integrative veterinary medicine (IVM) is the practice of complementary and alternative therapies used in conjunction with conventional (mainstream) care. A key difference between complementary and alternative and conventional medicine is the strength of evidence supporting best practices. Mainstream medicine, when possible, bases its practices only on the most conclusive scientific evidence. In contrast, complementary and alternative bases its practices on evidence-informed practices—practices based on the best evidence available, even when such evidence does not meet the highest, strictest criteria for efficacy and safety. Nonetheless, as the scientific evidence for nondrug, nonsurgical techniques grows, the legitimacy and acceptance of integrative approaches continue to expand. In fact, the convergence of science-based integrative medicine, fear-free veterinary care, rehabilitation, and bond-centered practice is culminating in a new vision of what frequently constitutes a "typical" veterinary practice.
Appropriate management in the peripartum period can substantially reduce morbidity and mortality for large animal dams and their offspring. As much as 5% of foals, 5%–10% of calves, and 10%–15% of the annual lamb crops die before weaning in the US, with 50%–70% of neonatal mortality occurring in the first 3 days of life. A key aspect of managing the large animal dam includes appropriate nutrition and body conditioning in the pre- and postpartum periods to reduce the risk of pregnancy-related diseases such as pregnancy toxemia, hypocalcemia, and vaginal prolapse; as well as to optimize hygiene, colostrum quality, and fetal and neonatal growth. Appropriate anthelmintic therapy and vaccination of the dam several weeks before parturition will further protect dam and offspring from subsequent disease.
Pain delays recovery, negatively impacts patient well-being, and can affect the veterinarian-client-patient relationship. Although pain was previously a neglected area, it is now well recognized in veterinary medicine that providing optimal patient care includes management of pain. Optimal management of pain continues to evolve quite rapidly, including due to vastly improved comprehensive anesthesia care as well as the introduction of validated pain scales.
Stray voltage is a low-level current in animal housing that most commonly affects dairy cows and swine. Behavioral changes, such as avoidance of the area affected, are the typical signs. Diagnosis is based on seeing behavioral changes and performing electrical testing. To prevent the problem, periodic inspection and testing of voltage/current levels by an electrician is recommended, especially when there are changes to the farm's electrical system.
Several beef cattle management practices are capable of increasing enterprise profitability through increasing animal productivity, enhancing animal value, and/or decreasing cost of production. Animal disease results in economic loss through mortality, treatment expenses, and lost performance or productivity. An understanding of the economic impact of both clinical and subclinical diseases is important to developing a strategic herd health management program.
The dairy industry is in a period of economic volatility of historic proportions. An era of modest fluctuation in milk and feed pricing in the late 1990s to the early 2000s was followed by increases in milk prices not seen before. The period of high dairy profitability in early 2008 was soon dampened as the global recession of 2008–2009 led to reduced exports. Since then, milk prices have rebounded and dropped several times. More recently, all-time high US milk prices in 2014 have been followed by 5 years of a severe, industry-wide economic downturn. In mid-2019, it was estimated that >7,000 dairies had closed because of milk prices remaining below the cost of production for too long.
Around the world, goats are found in a wide variety of production settings, from intensively managed, very large dairies in the Netherlands to free-ranging small-farm herds in the African bush. Goats are particularly adapted to harsh, arid environments; however, they flourish even as pets in metropolitan backyards. Because they have a feed efficiency greater than that of other ruminants, as well as the ability to produce meat, milk, hides, and fiber, goats are a worthwhile investment for many producers across the globe, and they play a critical role in self-sufficient agricultural systems, particularly in countries with limited resources.
Proper management can decrease the incidence of many disease conditions in horses. Informed management of the environment and diet, routine foot and dental care, and adherence to an appropriate deworming and vaccination program form the basis of a preventive health program. Client education is important for compliance; owners are more likely to follow recommended changes in husbandry programs once they appreciate the benefits, such as:
Disease in pork production is generally caused by multiple factors. Microbial pathogens are rarely the sole cause of a health problem on a pig farm. Clinical disease is usually the interaction of a pathogen with errors in management and a variety of contributing influences such as environment and host factors. Many pathogens are endemic in the swine population and yet some farms suffer heavy losses from disease, whereas the impact on other farms is much less because of management differences.
Sheep are a cornerstone of animal production around the world and number over 1 billion animals globally; in 96% of the countries recognized by the UN, the sheep population exceeds 1 million. The ability of sheep to survive in varied environments and to produce meat, milk, skin, and wool makes them an integral component of many agriculture-based economies. Sheep provide both income and food security for many people worldwide, particularly in countries with limited resources. Even in the US, where sheep have been classified as a minor species since 2000, 1 sheep-related products generated $5.8 billion in 2016 and every $1 invested in sheep and sheep-related production added nearly $2.90 to the US economy. 2
Proper management to prevent and control disease has historically been a higher priority in production animal medicine than in small animal medicine. However, appropriate management is just as important for small animals, whether their environment is a single-pet or multiple-pet household or a more intensive housing situation such as a kennel or cattery.
Dairy and beef producers should strive to increase reproductive efficiency as a key driver of economic efficiency in the sector, but also increasingly as a critical route to more sustainable food production. Reproductive efficiency, or pregnancy rate, is defined as the proportion of cows eligible to be bred that become pregnant during an estrous cycle (~21 days), and it determines the calving-to-conception interval.
Goats are spontaneously ovulating, seasonally polyestrous animals with peak breeding activity occurring in the fall when day length is shortening . As day length decreases, melatonin secretion from the pineal gland increases which activates pulsatile GnRH release from the hypothalamus. Hypothalamic GnRH secretion stimulates release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) from the anterior pituitary and promotes the growth of follicles, stimulating the onset of the hypothalamic-pituitary-gonadal axis in short-day breeders.
Most mares are seasonally polyestrous and cycle when the length of daylight is long. Anestrus occurs during the winter when daylight length is short. During anestrus, the ovaries are inactive with no significant follicles >10 mm or corpora lutea, so plasma levels of estrogen and progesterone are low. Therefore, the uterus is flaccid and the cervix may be closed but not firm and tight, or it may be thin, short, and dilated. As the length of daylight increases, mares undergo a vernal transition and the ovaries become active, with 3–4 waves of numerous large (>25 mm) follicles. The cervix and uterus have minimal tone. Mares have 3 or 4 prolonged intervals of estrus (periods of sexual receptivity to the stallion) during the vernal transition, but ovulation does not occur. The end of vernal transition is marked by a surge of luteinizing hormone that stimulates ovulation, after which a regular, 21-day interovulatory estrous cycle is established.
Management of commercial swine breeding herds involves a thorough understanding of reproductive physiology, genetics, nutrition, immunology, disease control, environment, and other factors. ( All.See also page Abortion in Pigs.) The closed-herd concept, which emphasizes preventive medicine strategies along with herd protection, minimizes the risk of disease loss when combined with intensive management, sound nutrition, and genetic selection. The breeding program should be evaluated at specified intervals to ensure that progress in both efficiency and productivity is being made. Several efficiency/production parameters to review when analyzing herd reproductive performance are shown in All.table numonly Measures of Reproductive Performance in Swine Relative to Industry Averagesa. The postweaning performance of a breeding herd's offspring can be measured through assessment of such parameters as feed conversion ratio, average daily gain, total days to market, and postweaning death loss.
Several key points are the basis of a sound flock reproduction health management program. First, sheep are short-day polyestrus breeders (ie, estrus occurs in response to shortening day length). Second, ovulatory season tends to be in fall and winter; anovulatory season during late winter, spring and early summer; the transition season occurs in the late summer months. Finally, there is considerable breed-to-breed variation in prolificacy and length of the ovulatory season.
A breeding soundness examination, which should take place before any dog or cat is purposefully bred, is the opportune time for veterinary input regarding good breeding practices. Because of pet overpopulation, dog and cat breeding should be left to educated and responsible breeders, to whom potential purebred puppy and kitten clients can be referred. Breeding soundness means a dog or cat is free from heritable defects based on phenotype evaluations such as radiography (eg, elbow dysplasia), ultrasonography (eg, renal dysplasia, tricuspid dysplasia), ophthalmoscopy (eg, cataract), physical examination (eg, patellar luxation) or specific DNA testing when available (eg, progressive rod-cone degeneration). Several resources are available to veterinarians negotiating purebred dog and cat genetic recommendations.
The breeding soundness examination (BSE) involves a complete and systematic evaluation of the reproductive potential of a given male, including mating ability and libido, general physical examination and inspection of the genital organs, and assessment of sperm production and quality. The BSE is not a direct evaluation of fertility: this can be confirmed only by successful production of offspring after breeding a fertile female. The specific male animal must be properly identified, and a detailed history is important because sub- or infertile males might require more exhaustive evaluation. The evaluation of mating ability and libido is possible only when collecting semen via artificial vagina or manual stimulation in the presence of a female in estrus. Therefore, mating ability is seldom evaluated in bulls and rams for routine BSE in which semen is typically collected via electroejaculation.
Embryo transfer has proved to be a powerful technology in genetic improvement of farm animals, primarily to propagate the genes of females of superior pedigree. In cattle, particularly in the dairy industry, breeding programs have been developed to promote genetic progress by strategic use of elite females via multiple ovulation embryo transfer (MOET) programs. In addition to conventional methods to produce embryos available for transfer, new technologies that produce embryos after cloning by somatic cell transfer or transgenesis are available; however, they are not widely used commercially.
Hormones are commonly used to manipulate the estrous cycle. The major indications for hormonal control of estrus are to induce luteolysis, induce ovulation of a mature follicle, suppress estrus, induce cyclicity in anestrous animals, and superovulate cyclic animals. Effective treatments for these manipulations of the estrous cycle vary between species. Additionally, a number of treatments currently lack regulatory approval; prescribing veterinarians should follow label instructions and adhere to relevant laws and regulations.
The digestive system of beef cattle is essential to their ability to acquire, digest, and absorb nutrients. One important aspect of the digestive system that is unique to ruminants, such as beef cattle, compared to nonruminants, is that four major digestive organs exist in place of the stomach. These organs are the rumen, reticulum, omasum, and abomasum. Their functions are often oversimplified, and they are commonly referred to as the “four stomachs.” These unique features enable cattle and other ruminant animals to survive and be productive on diets and feed resources that cannot support many nonruminant animals. Understanding the components of the ruminant digestive system and the roles they play is helpful when designing nutritional management programs or identifying the cause of nutrition-related digestive disorders.
During lactation, dairy cows have very high nutritional requirements relative to most other species ( All.see table Feeding Guidelines for Large-Breed Dairy Cattle). Meeting these requirements, especially for energy and protein, relative to intake capacity is challenging. Diets must have sufficient nutrient concentrations to support production and metabolic health, while also supporting rumen health and the efficiency of fermentative digestion.
The field of zoo and exotic animal nutrition continues to make advances that result in better diets. Exotic animal nutritionists in zoos and in the feed industry are studying problems and generating information on proper nutritional management for many species.
Although goats and sheep have several similarities, their nutrient requirements differ in several ways. Goats are predominantly browsing animals but will graze. Still, many of the principles useful for sheep feeding and nutrition are applicable for goats. Nutritional assessment, particularly as applied to energy intake, should be by body condition assessment. (Also All.see page Nutrition: Sheep.)
Horses are maintained for a much longer time than most farm animals and have more varied uses, as athletes and service and companion animals. Feeding programs, therefore, must sustain a long, productive, and athletic life and be varied according to individual needs, unlike food animal feeding programs. The feeding recommendations given below are based on both practical experience and scientific research. Detailed recommendations can be found in Nutrient Requirements of Horses, 6th Ed, published in 2007 by the National Research Council and Equine Applied and Clinical Nutrition, 2013, Geor RJ, Harris PA and Cohen M (eds), Saunders/Elsevier.
Pigs require a number of essential nutrients to meet their needs for maintenance, growth, reproduction, lactation, and other functions. The National Research Council (NRC), in its publication, Nutrient Requirements of Swine (updated in 2012), provides estimates of the amounts of these nutrients for various classes of swine under average conditions. However, factors such as genetic variation, environment, availability of nutrients in feedstuffs, disease levels, and other stressors may increase the needed level of some nutrients for optimal performance and reproduction. The NRC uses a modeling approach to take some of these factors into consideration in its estimates of requirements for energy, amino acids, calcium, and phosphorus, but requirements for other minerals and vitamins are estimated strictly from empirical data.
The economical and efficient production of sheep for meat, wool, show and/or pets is contingent on proper feeding, husbandry practices, and health care. All of these are influenced by dietary intake. Maintenance of breeding animals, a high percentage of the lamb crop weaned, growth of lambs, optimal weaning weights, and a heavy fleece weight and fleece quality are important to efficiency. The nutritional requirements for maintenance, reproduction, growth, finishing, and wool production are complex because sheep are maintained under a wide variety of environmental conditions; however, attempts should be made to ensure each production unit or individual sheep has adequate nutrient intake to be healthy and productive.