Reproduction in the gilt. 5. The effect of the presence of the mature male during rearing on puberty attainment

Abstract

ABSTRACTForty Landrace × (Landrace × Large White) gilts were randomly assigned at 70 days of age to each of two rearing treatments. The two treatments were: (1) gilts reared with gilts but kept in complete isolation from other pigs, and (2) gilts reared with visual, aural, olfactory and limited tactile contact with a mature boar. At 160 days of age, all gilts were subjected to a pen change and housed adjacent to either a mature boar for the first time, or to a different mature boar from that with which they had contact during the rearing phase. In addition, gilts were exposed to a mature, vasectomized boar for 30 min each day. They were served twice at second oestrus and the reproductive tracts were examined at slaughter 21 days later to determine ovulation rate and embryo survival. The presence of a mature male during the rearing phase had no effect on the attainment of puberty. There were no significant differences between treatments 1 and 2 for age at puberty (168·1 and 166·9 days respectively), weight at puberty (74·0 and 75·7 kg respectively) and the interval from movement and boar introduction to puberty (8·3 and 7·4 days respectively). The rearing treatments also had no effect on ovulation rate or embryo survival.