Production of Superior Pigs as Breeding Stocks by Improving Maternal Uterus and Placental Environment during Pregnancy

Abstract

An experiment was conducted to study the inheritance of improved growth phenotypes in pigs born to sows injected with pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (HCG) prior to mating. Twelve sows were assigned into a randomized design with 3 groups and each group consisted of 4 sows as replications. The first group consisted of sows without PMSG and HCG injection prior to mating as a control group (NSO). The second group consisted of sows injected with PMSG and HCG prior to mating to improve endogenous secretion of pregnant hormones that improve prenatal growth of the piglets (SO). The third group consisted of female pigs born to PMSG and HCG-injected mother in SO group that were mated after maturity without PMSG and HCG injection (F1SO). The number of sows used in each group consisted of 2 sows with 11 litter size and 2 sows with 12 litter size at parturition and total of born pigs observed in this study was 138 pigs. The results of experiment showed that injection of the sows with PMSG and HCG prior to mating improved body weight, body length and leg heights and decreased within-litter variation that finally increased total weight of live born pigs per sow. Sows injected with PMSG and HCG prior to mating produced pigs with higher pre-weaning growth rate and higher survival rate with a higher weaning weight and total weaned pigs per sow. The female pigs born to SO sows produced piglets with similar growth phenotypes as their mothers that was significantly higher and better that the growth phenotypes of the pigs born to NSO sows. The results of this experiment strongly confirm that the improvement of uterine and placental environment by improving endogenous secretion of pregnant hormones during pre-implantation and during the whole pregnancy by injecting the mothers with PMSG and HCG prior to mating improve prenatal and postnatal growth phenotypes of pigsand the improved growth phenotypes are inherited to their offspring. It was concluded that this simple and relatively cheap technique could be used to improve growth genotype expression to produce a superior pigs either as a finisher or as a parent stock.