Effect on pig performance of decreasing amino acid levels in practical grower diets of equal lysine content

Abstract

An experiment was designed to determine the adequacy of the dietary amino acid balance for the growing pig, as recommended by the Agricultural Research Council (ARC) in 1981. Forty-two entire male and 42 female pigs were given iso-caloric diets with progressively reduced amounts of crude protein (197-158 g/kg) but a fixed level of lysine (10.0 g/kg). With a reduction in dietary crude protein, growth performance declined linearly over the liveweight range 20 to 50 kg but was not affected between 50 and 80 kg liveweight. No clear trend was found for carcass characteristics at slaughter. The pattern of amino acids in the diet of highest crude protein content was generous relative to the ideal amino acid balance recommended by the ARC. This suggests that the ARC amino acid balance may not be ideal for the young growing pig.

Keywords:

• pigs
• crude protein
• ideal protein
• amino acid balance
• nutrition