THE EFFECT OF WEIGHT LOSS DURING LACTATION ON WEANING TO FIRST SERVICE INTERVAL, FARROWING RATE TO FIRST SERVICE AND SUBSEQUENT LITTER SIZE IN SOWS
C.M.P. Weldon and G. Bilkei

Abstract
The objective of the study was to determine the relationship of weight loss during lactation on subsequent reproductive performance of sows. The reproductive data on seven indoor European pig breeding units of similar climate, similar genetics, health status and under identical reproductive management and feeding were evaluated. Sows were categorised according to lactation weight losses of <5%, 5-10%, 11-15%, 16-20% and >20%. Weaning to service intervals, farrowing rates and total-born litter sizes were compared. Lactation weight losses exerted a quadratic effect (P>0.01) on weaning to service intervals. When analysed across parity categories, with parity category included as a fixed effect, the weaning to service intervals appeared to be minimised at lactation weight losses of >5%. Weaning to service intervals increased (P>0.05) when lactation weight losses increased above >11% for parity 1 sows, but not until lactation weight losses exceeded 20% for parity 2 and above. There was a parity effect observed (lactation weight losses of >10%, P>0.05; and lactation weight losses of >10 %, P=0.01). Lactation weight losses >10% had P>0.05 that of >20%, a P> 0.01 negative effect on subsequent farrowing rates to first service. Lactation weight losses >10% resulted in a significant reduction in litter size.
Implication: The sows' reproductive performance can be improved by reducing their lactation weight losses.

Add to Basket