The influence of pre-weaning nutrition on subsequent growth and development of bacon pigs

Abstract

SUMMARYThe growth and carcass data were determined for pigs reared on two creep rations to different weights, and subsequently fattened with and without an antibiotic.Pigs weaned at a ‘standard’ weight of 43·8 lb. at 56 days of age grew more quickly over the range 120 to 210 lb. live-weight than pigs weighing 51·0 lb. at weaning. Both groups were fed according to a fixed scale related to live-weight. Heavy weaners growing slowly in the later stages had slightly thicker backfat measurements, indicating that they were at a more advanced stage of physiological development than the light weaners.The presence of antibiotic in the fattening ration caused no significant difference in growth rate or carcass measurements, but there were significant interactions between weaning weight and presence or absence of antibiotic in the fattening ration for length of carcass, and between sex and presence or absence of antibiotic for the traits of age at 70 lb. live-weight, carcass length and depth of mid-backfat.Weaning weight and rate of gain from 70 to 120 lb. live-weight were significantly and positively related to carcass length.It is concluded that further studies of the growth curve of the pig are required to determine the scope and importance of compensatory growth, and the interaction of growth rates in the different phases of the pig's life and their relationships to carcass traits.