USE OF LOW-PROTEIN DIETS FOR YOUNG PIGS AT GROWING AND FATTENING

Abstract

The selection and breeding work aimed on improvement of meat traits of reared breeds and types of pig at farms of the republic does not always give the desired results and is delayed for years quite often. The reason for this phenomenon, in our opinion, is inadequate meeting of the requirements of selected animals for energy and amino acids taking part in synthesis of meat. The objective is to find the perfect combination of essential amino acids and energy in the diets, ensuring the maximum utilization for synthesis of meat in the body of animals. This task is complicated by the fact that the amino acid composition of animals’ body of different genotypes vary, and consequently, the amount of amino acids that they should receive in the diet is also different, i.e. the content of the so-called “ideal protein” for each genotype is to be individual. The aim of the study – is to establish the possibility of reducing of the crude protein level in diets for young pigs based on physiologically substantiated optimization of the amount of consumed essential and nonessential amino acids. The experiments confirmed the possibility of reducing the crude protein level in the diets for young pigs due to control of consumed essential amino acids and their correlation with metabolizable energy. For piglets at growing in 1 kg of compound feed per 1 MJ of metabolizable energy 0.85 g of
lysine is required, during the I fattening period – 0.73 g, during the II period – 0.62 g. The amount of remaining (including available) essential amino acids is controlled with respect to lysine: methionine with cystine – 60 %, threonine – 66 % and tryptophan – 19 %. This model for control of metabolizable energy and essential amino acids allows to reduce the level of crude protein in compound feeds by up to 10 % at increase of average daily weight gain at growing by 24 g (P k 0.05), during the I fattening period – by 29 g, and during the II period – by 11 g.