STUDIES OF THE INDUCTION OF ESTRUS IN SOWS BY GONADOTROPINS (PMSG AND HCG) AND IMPROVED FERTILITY

A group of 595 sows (Landrace, Large White and their hybrids) was given 5 ml PG 600 (400 I. U. PMSG and 200 I.U. HCG) intramuscularly at weaning and after 4-5 weeks of their lactation. Another group of 595 sows, of similar genotypes, was used as controls and maintained under the same environmental and housing conditions. Of the 595 treated sows, 548 (92.1%) showed oestrus 4.25 days post injection, and of these mated sows, 88.3% became pregnant and produced an average of 8.46 live piglets per sow. In the control group, 472 sows (79.3%) showed oestrus 5.78 days post weaning and were mated. Of these, only 362 (76.7%) became pregnant and produced art average of 7.75 live piglets per sow. The administration of PG 600 was therefor effective in minimising the appearance of oestrus and synchronising sows and in treating hormone disorders, piglet production was also significantly increased.