A study of dietary energy density and genotype interactions on voluntary feed intake of the grower pig

Abstract

A trial was conducted to measure the voluntary feed intake of pigs drawn from two genetic sources when fed diets of different digestible energy concentrations. The genetic sources were Large White x Landrace commercial hybrids (CH) and Landrace (Landrace x Large White) pigs from the Sutton Bonington herd (SB). Two sexes were used (boars and gilts) and four diets were formulated with energy densities of 8.6, 10.7, 12.9 and 15 MJ DE/kg feed. All nutrients were adjusted to maintain a constant ratio with energy. Pigs were offered these diets ad libitum from 25 - 55kg liveweight in individual pens. After slaughter, backfat and eye muscle measurements were taken and hams dissected into component tissues. Meat quality was also evaluated : pH of ham and loin were taken at 45 minutes and 24 hours post mortem. The ‘Grau Hamm Paper Press’ method was used to evaluate water holding capacity. Depth of colour was determined by reflectance spectrophotometry.