Effect of pmsg followed by HCG on estrus synchronization in weaned sows.
A total of 60 crossbred sows (Hampshire X Khasi Local) were selected a week after weaning and divided into two groups (30 in each). The sows in group-I were injected with 800 IU of PMSG followed by 400 IU of HCG 56 hours after PMSG. In Group-II served as untreated / control. Natural service was given to all estrus sows after 96 hours of hormonal treatment. It was noticed that 90 % of sow exhibited all the sign of estrus after 96 hours and 75 % of sows were sexually receptive to boar. The average interval between treatments to onset of estrus was 87.74 ± 10.72 hours. The duration of estrus varied from 40 to 56 hours with an average of 42.2 ± 3.24 hours in treatment group. Whereas, in control group it ranged from 27 to 52 hours with an average of 36.78 ± 4.12 hours. The furrowing rate was 88 and 90.9 % respectively in treated and control group, while the litter size was 10.37 ± 0.57 and 9.15 +0.34 and number of live born per litter was 9.24 ± 0.43 and 8.78 ± 0.27 respectively. Present finding suggested that it is possible to induce and synchronize fertile estrus with PMSG followed by HCG in weaned sows. The study also suggested that estrus synchronization followed by synchronized furrowing might be practiced to reduced pre-weaning piglet mortality during winter.