| Abstract: | Gilts that had already reached sexual maturity at the time of insemination showed a higher rate of oestrus and better litter size than immature animals. Therefore animals selected for breeding should have had at least one oestrous cycle. Onset of puberty can be judged by the occurence of a first oestrous with pronounced redness and swelling of the vulva, but without willingness to be mounted. Changing the housing or exercising the gilts, rendered necessary by the production process, had a stimulating effect on the onset of puberal oestrus. Age at onset of sexual maturity did not affect the performance of gilts in their first production cycle, but litter size was greater when the rate of weigth gain was high. |
