FACTORS INFLUENCING PUBERTY ATTAINMENT IN GILTS AND POLICIES THAT CAN IMPROVE MATING EFFICIENCY IN REPLACEMENT GILTS

Abstract

The objective of this study is to review the information regarding the development of puberty in gilts and how it influences subsequent reproductive performance such an understanding can be used to improve mating efficiency in gilts. The percentage of gilts in a herd strongly influences overall productivity. The first management decision that has to be made about gilts entering the breeding herd, is the timing of the first breeding. This largely depends on when puberty develops. Puberty in gilts is defined as the time when the first oestrus and ovulation occurs followed by regular oestrous cycles. On average, gilts attain puberty at around 6-7 months of age. In practice, it is not recommended that gilts are mated at puberty because they will have an inferior pregnancy rate and reduced litter size. Ovulation rate in gilts increases with the number of oestrous cycles after puberty. Various factors, such as nutrition, genetic background, season, social environment and boar contact, have been reported to influence the natural attainment of puberty in gilts. Growth rate and backfat thickness are also significantly related to the age when puberty develops. The age of gilts at puberty has a relatively high heritability(h2 = 0.3) higher than most other reproductive traits. Age at first
mating or age at first conception have been reported to influence subsequent reproductive performance. To optimize mating efficiency, puberty attainment and oestrus behaviour in gilts need to be studied.