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Goat Medicine, Third Edition.

Goat keepers must assimilate much information regarding nutrition to raise healthy, productive animals. At least in the United States, some novice owners begin with abso­lutely no agricultural background. Their concept of nutri­tion has been molded by years of simply opening cans or bags of commercial pet food.

As a first step, one needs to learn the various nutritional requirements (i.e., energy, protein, fiber, vitamins, major minerals, trace minerals, and water) for whatever produc­tion is to be required of the goat. Types of production include maintenance, growth, finishing, gestation, milk production for raising kids, maximum milk production, and mohair or cashmere production. The educated owner can easily see analogies with regular dog food, puppy chow, and the limited diet necessary to stave off obesity in an older pet. But very rarely are goats fed a commercially pre­pared complete ration. After all, the importance of the goat in many parts of the world depends on its ability to subsist and produce on whatever grows there. It becomes neces­sary, then, to learn the nutritional value and relative cost of feeds available locally. This information can be gained from standard references, where concentrates are concerned, but forage quality is highly variable. The American goat keeper must either learn to accurately distinguish different types and maturities of forages, or make use of feed analy­ses to determine the nutrient content of hays and silages.

Voluntary dry matter intake (DMI) is another important consideration. What is the capacity of the goat to consume various feeds? Even more important, how much can the goat eat without deranging rumen function or the goat's own metabolism? Feeding any ruminant is first and fore­most a question of properly feeding a rumen vat full of bac­teria and protozoa. The energy, nitrogen, and all other requirements of bacteria must be met, and all nutrients must be provided in suitable proportions and at appropri­ate intervals to avoid malnutrition of the microbial popula­tion or its destruction via rumen acidosis.

As an additional complication, the digestibility of a given feedstuff varies with the energy and protein content of other components of the ration. Also, the energy content of a given feed or ration depends on the production function for which it is to be used. These and other problems give trained nutritionists much to argue about and go far beyond the scope of this book. The current chapter can only offer a brief overview of nutrition, while trying to make the specific requirements of the goat understandable to the veterinarian or owner. As the level of production of the goat increases, the feeding must also be improved, and therefore other sources of information must be consulted to permit fine-tuning of a ration. The nutrient require­ments of small ruminants, including goats, have been summarized (NRC 2007). An online ration balancer and calculator for the energy, protein, calcium, and phosphorus needs of the individual animal based on the equations used by the National Research Council (NRC) is also available (Gipson et al. n.d.) and makes the data more accessible to the potential user. A detailed mathematical model, called the Small Ruminant Nutrition System (Tedeschi et al. 2010) and based on the Cornell Net Carbohydrate and Protein System, has also been created to predict metabolizable energy, protein, calcium, and phosphorus requirements under various management systems. The computer pro­gram has been adapted for goats and is available for purchase through the Texas A&M University.

One final concern is the difference between the nutrient value of the feed offered and of the feed actually consumed (Brown and Weir 1987).