Productive performance of the single farrowing system for pigs

Abstract

This paper reports two experiments, the aims of which were to contribute to the development of the single farrowing production system for pigs. The first reports the induction of oestrus in three groups of 70 Duroc gilts (167 days old, body weight 93.6 kg) via the injection of either 1000, 600 or 400 IU of pregnant mare serum gonadotrophin (PMSG) plus 500, 200 or again 200 IU of human chorionic gonadotrophin (hCG) respectively. No significant differences were observed among these treatments with respect to the percentage of gilts entering oestrus, their fertility or their prolificacy. The average number of piglets weaned per farrowed gilt was 5.61, 5.66 and 6.69 (P<0.05) while the number of pigs weaned per induced gilt was 2.33, 2.67 and 3.34 respectively (P<0.05). The second experiment, designed to analyse carcass quality, involved 30 Duroc gilts aged 167 days and weighing 93.9 kg. Ten empty gilts were slaughtered at 197 days and at a mean weight of 112.1 kg, another 10 in which oestrus was induced with PG-600 but which were not allowed to nurse their piglets were slaughtered 4 days after farrowing and at a mean of 136.9 kg, and the remaining 10, which nursed their young, were slaughtered 10 days after a 21 day lactation period and at a mean body weight of 135.4 kg. The average daily weight gain during gestation was 0.418 kg. Weight loss during lactation was 0.159 kg day-1. The mean weight of the pigs at birth, when weaned and at 60 days post-weaning was 1.28, 4.5 and 18.2 kg respectively. The carcass length, carcass yield and the back fat thickness of the farrowing but non-nursing and the nursing gilts were significantly higher (P<0.05) than those of the empty gilts. The weight of their hams and forelegs were, however, lower with respect to overall carcass weight (P<0.05).