| The sow’s fixed-time artificial insemination(FTAI)technology is a new technique for artificial insemination without estrus identification,which is based on exogenous reproductive hormones to regulate sows’ estrus and ovulation,so that it can synchronize estrus and ovulation.In this experiment,1,327 primiparous sows were selected to explore the effects of unit dose of PMSG,sodium cloprostol,GnRH injection time point,Altrenogest and X drugs on reproductive performance of primiparous sows,so that it can provide a certain reference for the establishment of fixed-time artificial insemination procedures on primiparous sows.The main results are as follows:(1)In the A field,participating sows conception rate(79.49%)of the 800 IU PMSG group was higher(P<0.01)than that of the control group(43.33%),while participating sows conception rate(71.05%)of the 1000 IU PMSG group was higher(P<0.05)than that of the control group.In the B field,participating sows conception rate(85.63% VS 65.06%)and participating sows farrowing rate(83.75% VS 64.46%)of the 800 IU PMSG group were higher(P<0.01)than those of the control group,and its litter size(12.59±0.29 VS11.07±0.32)and the number of piglets born qualified per litter(11.31±0.27 VS 10.11±0.29)were higher(P<0.01)than those of the control group,and the number of feeding days of participating sow needed per total piglet was 1.92 days less than that of the control group,and the number of feeding days of participating sow needed per qualified piglet was 1.93 days less than that of the control group.(2)The estrus rate(53.62%)of the PGF2α+PMSG group primiparous sows was higher(P<0.05)than that of the control group(30.30%)on the 4th day after weaning,while there was no significant(P>0.05)difference between PMSG group(47.06%)and control group.The number of feeding days of participating sow needed per total piglet of the PGF2α+PMSG group was 0.88 day less than that of the control group,and 0.89 day less than that of the PMSG group.And the number of feeding days of participating sow needed per qualified piglet was 0.56 day less than that of the control group,and 1.02 days less than that of PMSG group.(3)Participating sows farrowing rate(91.80%)of the 72 h GnRH group was higher(P<0.05)than that of the control group(73.77%),while there was no significant(P>0.05)difference between the 64 h GnRH group(81.97%)and the control group.The litter size of the 72 h GnRH group(12.36±0.47 Vs 10.67±0.50)and the number of piglets born qualified per litter(10.91±0.46 Vs 9.58±0.44)were higher(P<0.05)than those of the control group,while there was no significant(P > 0.05)difference between the 64 h GnRH group(11.62±0.50,10.30±0.43)and the control group.The number of feeding days of participating sow needed per total piglet of the 72 h GnRH group was 2.83 days less than that of the control group,and 1.34 days less than that of the 64 h GnRH group.And the number of feeding days of participating sow needed per qualified piglet of the 72 h GnRH group was 2.92 days less than that of the control group,and 1.40 days less than that of the64 h GnRH group.(4)After weaning of primiparous sows,the feeding and management mode of delaying mating for one week by inhibiting estrus of altrenogest could significantly(P<0.01)improve the condition of backfat from weaning to mating(0.50±0.09 Vs-0.16±0.08).Compared with the control group,the feeding and management method of allylprogesterone+FTAI could significantly(P<0.01)increase participating sows farrowing rate(81.82% Vs 43.14%)of the thin backfat primiparous sows,and its number of feeding days of participating sow needed per total piglet was 1.01 days less than that of the control group and 0.88 day less than of the FTAI group,and its number of feeding days of participating sow needed per qualified piglet was 1.02 days less than that of the control group and 0.86 day less than that of the FTAI group.(5)The litter size(11.88±0.55)of the X drug group was higher(P<0.05)than that of the control group(9.85±0.61). |
