Comparative digestibility and lipogenic activity in Landrace and Iberian finishing pigs fed ad libitum corn- and corn–sorghum–acorn-based diets

Abstract

Forty-eight finishing castrated male pigs (24 Iberian and 24 Landrace; 88.4 kg LW) were fed two diets differing in main carbohydrates sources, corn- (Diet C) or corn–sorghum–acorn (Diet A). After 28 days of experimental period, 24 animals (six per treatment) were slaughtered and digesta and carcass sampled to study digestion and lipogenesis activity. Iberian pigs showed a higher voluntary feed intake than Landrace pigs (3.5 vs. 2.7 kg/day; P<0.01), but no significant differences in the daily weight gain. Between diets, no significant differences were observed in the production data. However, the whole-tract digestibility was significantly lower with Diet A than with Diet C for OM, CP and monosaccharides. Whole-tract apparent digestibility of Iberian pigs was also significantly lower than of Landrace ( P<0.01), especially for those animals fed Diet A. As a result of feed intake and digestibility coefficients, Iberian pigs showed a higher intake of digestible OM (2910 g/day) than Landrace (2310 g/day), which was associated with higher ( P<0.05) backfat thickness, muscle fat content and lipogenic enzyme activities. Lipogenesis was not broadly influenced by the dietary treatments, except a significant decrease in the intermuscular adipose tissue with diet A. We conclude that digestibility and lipogenic enzyme activities were markedly influenced by the animal breed and to a lesser extent by the diet.