The Effect of Feed Intake on the Reproductive Performance of First Parity Sows

Abstract

Thirty to forty per cent of sows in Irish herds are culled annually, one third of which are for reproductive problems such as anoestrus, anovulation and small litter size. Causes of reproductive failure include genetic, nutritional, environmental and behavioural factors. Failure to meet the nutritional requirements of sows during lactation and after weaning results in losses of liveweight and body fat (due to mobilization of body reserves) which can subsequently compromise reproductive performance. Although sows normally exhibit oestrus within one week of weaning, Sterning et al. (1990) observed that a large proportion of first parity sows showed a delayed return to oestrus. This results in a longer farrowing interval, fewer litters per sow per year and a reduction in herd output. The effects of malnutrition on reproduction are more severe in first parity than in multiparous sows (Kirkwood and Aherne, 1985). The objective of this study was to investigate the effects of low feed intake during lactation and postweaning on the subsequent reproductive performance of first parity sows.