The Nutritional Evaluation of Meat Meals for Poultry

SummaryThere is a wide variation in both the nutritional value to chicks and composition of meat meals. Toxins from oxidised fats or bacterial contamination have little effect on the nutritional value of meat meals. The high calcium content of raw materials used in meat meal manufacturing may lead to growth depression of chicks fed meat meal based diets that contain more than 1·2% calcium. The depression of growth on diets containing up to 2·5% calcium can be overcome by adding antibiotic to the diet.Large differences in the growth-promoting ability of meat meals have been attributed to the variation in the nature of the raw materials and the conditions used in their processing.The raw materials vary in protein, fat and ash content and the nutritional value of the protein is determined by the type of soft or hard offal used. Hard offal contains a large amount of collagen which has a low nutritional value due to deficiencies of several essential amino acids. On the other hand soft offal has a high nutritive value due to the greater amounts of muscle proteins rich in essential amino acids.Over a wide range of processing times and temperatures the nutritional value of meat meal protein is unchanged. However, after prolonged heating at extreme temperatures, the nutritional value and availability of essential amino acids decreases markedly.Other factors which affect the utilisation of meat meal diets by poultry are not apparent by chemical analyses and involve the effect of undigested peptides on the absorption of essential amino acids and bacterial deamination of amino acids in the lower gut.The growth rates of poultry on meat meal based diets are particularly sensitive to both the amount of meal meal and the types of cereal in the diet. The nutritive value of meat meals may be evaluated by chick growth tests, callagen and available essential amino acid content of the meat meal and plasma amino acid levels in chicks fed meal meal—based diets.