Feeding and nutrient requirements of meat goats
Goats raised for meat need high quality feed and require an optimum balance of different nutrients to achieve maximum profit potential. Because of their unique physiology, meat goats do not fatten like cattle or sheep do, and rates of weight gain are smaller. Consequently profitable meat goat production can only be achieved by optimizing the use of high quality forage and browse and the strategic use of expensive concentrate feeds. This can be achieved by developing a year round forage program allowing for as much grazing as possible throughout the year.
Feeding requirements of meat goats
In determining feed requirements for goats, it is important to know what is meant by quality feeds with respect to goats as opposed to cattle. Goats are not able to digest the cell walls of plants as well as the cow because feed stays in their rumen for a shorter time period. Trees and shrubs, which are poor quality roughage sources for cattle, may be adequate for goats because goats avoid eating the stems, don't mind the taste and benefit from the relatively high levels of protein and cell solubles in the leaves of these plants. On the other hand, straw, which is of poor quality due to high cell wall and low protein, can be used by cattle but will not provide even maintenance needs for goats because goats don't utilize the cell wall as efficiently as cattle.
Goats must consume a more concentrated diet than cattle because their digestive tract size is smaller with regard to their maintenance energy needs. Relative to their body weight, the amount of feed needed by meat goats is approximately twice that of cattle. When the density of high quality forage is low and the stocking rates are low, goats will still perform well because their grazing/browsing behavior allow them to select only the highest quality forage from that on offer. Thus, they are able to perform well in these situations, even though their nutrient requirements exceed those of most domesticated ruminant species.
Nutrient requirements of meat goats
Meat goats require nutrients for body maintenance, growth, reproduction, pregnancy, and production of products such as meat, milk and hair. The groups of nutrients that are essential in goat nutrition are water, energy, protein, minerals and vitamins. The daily nutrient requirements are different for bucks, young goats and does with a high production potential and at various stages of development and production. Weanling goats, followed by does during the last month of gestation and high lactating does, and yearlings, require a higher quality diet than average lactating does, adult bucks and dry does.
In order to feed them adequately, goats should be grouped according to their nutritional needs. Therefore, weanling goats, does during the last month of gestation, high lactating does and yearlings should be grouped and fed separately from the rest of the herd having lower nutritional needs. In a grazing situation, animals having the highest nutritional requirements should have access to lush, leafy forage or high quality browse. In a stall feeding situation the animals should be offered the highest quality hay available. Whether grazed or stall fed, goats should be supplemented with a concentrate feed when either the forage that they are grazing or the hay that they are fed do not contain the necessary nutrients to cover their nutritional requirements.
Goats should always have access to sufficient high quality water. Production, growth and the general performance of the animal is affected if water is not available in sufficient amounts. Water needs vary with the stage of production, being highest for early lactating does, and during the dry season when forages are dry. Goats can get all the water they need out of the feed when consuming lush and leafy forages, or when grazing forages soaked with rain water or a heavy dew. However, water is almost always needed by some members of the herd such as lactating does.
Energy comes primarily from carbohydrates (sugars, starch and fiber) and fats in the diet. The amount of fat that can be included in the diet is limited and should not be more than 5% of a diet because it depresses ruminal fermentation. Excess energy is stored in the body as fat.
When the levels of protein are low in the diet, digestion of carbohydrates in the rumen will slow down and intake will decrease. Inadequate levels of protein in the diet can affect growth rate, milk production, reproduction and disease resistance negatively, because insufficient amino acids are getting to the intestines to be absorbed by the body. Unlike energy, excess of protein is not stored in the body of the goat. Therefore, it is important to feed enough protein to cover the nutritional requirements of the animal. Protein nutritional requirements vary with developmental and physiological stages and level of production.
Goats require many minerals for basic body function and optimum production. a complete goat mineral or a 50:50 mix of trace mineralized salt and dicalcium phosphate provided free choice is advisable under most situations.
Major minerals likely to be deficient in the diet are salt (sodium chloride), calcium, phosphorous and magnesium. Most forage are high in calcium, so calcium is low only if high grain diets are fed, which would be unusual for goats. Low quality, weathered forages will be deficient in phosphorous, especially for high and average lactating does. The ratio of calcium to phosphorous in the diet is important and should be kept about 2:1.
Grass tetanus can occur when goats in early lactation are grazing lush, leafy grass/legume pastures. Under those conditions, it is advisable to provide a mineral mix that contains 5 to 10% magnesium.
Trace minerals likely to be low in diets are copper, zinc and selenium. Selenium is marginal to deficient in many areas, and many commercial trace mineralized salts do not contain it. Trace mineralized salts that include selenium should be provided to the goat herd at all times. Goat keepers should make sure that the trace mineralized salts they buy contain selenium.
Vitamins are needed by the body in very small quantities. The vitamins most likely to be deficient in the diet are vitamin A and D. All B and K vitamins are formed by bacteria found in the rumen of the goat and are not considered dietetically essential. Vitamin C is synthesized in the body tissues in adequate quantities to meet needs.
Vitamin A is not contained in forages, but carotene found in green, leafy forages is converted into vitamin A in the body. In addition, vitamin A is stored in the liver and fat of goats during times when intake exceeds requirements. Goats consuming weathered forages or forages that have undergone long-term storage should be fed a mineral mix containing vitamin A, or should receive vitamin A injections.
Vitamin D may become deficient in animals raised in stalls. Animals should have frequent access to sunlight because it causes vitamin D to be synthesized under their skin, or they should receive supplemental vitamin D. Good quality sun-cured hays are excellent sources of vitamin D. A deficiency in vitamin D results in poor calcium absorption leading to rickets, a condition where the bones of young animals and joints grow abnormally.