Effects of a strategic feed restriction on pig performance and health during the post-weaning period

Digestive and metabolic changes in pigs during the post-weaning period were studied to elucidate the effects of feeding strategies on pig performance and health. Sixteen creep fed litters were divided at weaning (5 weeks of ages); half the litter was fed ad lib (FF), while the other half was fed restricted (RF) from day 3 to day 8 after weaning (restrictive period: 50% reduction on day 3, another 50% reduction on day 4, minimum ration 100 g pig(-1) day(-1), the same amount on days 5 and 6, double the amount on days 7 and 8, and then ad lib). Food intake (per pen), weight and diarrhoea (individually) were registered daily for 14 days post weaning. Studies of faecal haemolytic E. coli (days 4, 5, 6, 8 and 14), blood plama levels of total cortisol and immunoreactive cationic trypsin (IRCT) (days 2, 6, 9 and 14) and body temperature (days 1, 2, 3, 5, 6 and 8) were done on two pigs per pen. During the restrictive period the RF pigs had significantly lower diarrhoea score, fewer number of antibiotic treatments and a lower proportion of faecal haemolytic E. coli than the FF pigs; however, the restrictive feeding also resulted in a significantly lower weight gain than for the FF pigs. Before and after feed restriction no differences were found between treatements (no peak in post-weaning diarrhoea (PWD) or haemolytic E. coli among the RF pigs when ad lib feeding was resumed). No significant differences in blood plasma levels of IRCT or total cortisol were observed between the treatments. The performance of the FF pigs was also relatively poor during the restrictive period as compared with the period after, which may partly be due to a peak in PWD and haemoyltic E. coli. Thus a strategic feed restriction during days 3-8 post weaning appeared to reduce the proliferation of haemolytic E. coli and the occurrence of PWD for 14 days post weaning.