| dc.description.abstract | Series of three experiments were conducted to study the effects of improved uterine and placental environment during pregnancy by injection of the sows with gonadotropin prior to mating on the improvement of pigs’ growth phenotypes and then evaluated whether the improved growth phenotypes could be inherited into their offspring. Therefore, this technology could be used to produce superior pigs as finishers or as parent-stocks either in commercial or local swine breeds. The first experiment was designed to study the growth phenotypes of pigs born to sows injected with pregnant mare serum gonadotropin (PMSG) and human chorionic gonadotropin (hCG) prior to mating to improve endogenous secretions of pregnant hormones during pregnancy. The experimental sows used were 10 local breed sows with body weight ranges of 30-40 kg. Before mating, estrous cycles of the experimental sows were synchronized by injecting 0.5 mL prostaglandin twice with 14 days interval. The experimental sows were then divided into two groups, each consisted of 5 sows. The first group was injected with PMSG and hCG with dosage of 200/100 IU per sow at the same time with the second prostaglandin injection, while the second group was not injected with PMSG and hCG as a control. After showing estrous behavior, the experimental sows were mixed with selected boars for natural mating. The pregnant sows were maintained until farrowing and weaning. Parameters measured were body weights and body lengths and leg heights of the pigs at birth and weaning. The results showed that improved endogenous secretion of pregnant hormone by injection of the sows with PMSG and hCG prior to mating, improved prenatal growth and development of the fetus with the final results of increased birth weight by 76.92% and total birth weight of live pigs per sow by 2,65 twice as compared to control pigs. Pigs born to sows injected with PMSG and hCG prior to mating had higher survival rate with a dramatically decreased mortality and a higher pre-weaning growth rate that finally increased total weight of weaned pigs per sows dramatically by 1,07 as compared to control. It is concluded that the growth phenotypes of local pigs could be improved by improving the sow’s uterus environment during pregnancy. The second experiment was conducted to produce superior pigs with improved growth phenotypes and survival during postnatal growth by injecting the sows with gonadotropin prior to mating. The experiment consisted of 2 stages. In the first stage, 12 sows were divided into 2 groups i.e., sows injected with NaCl 0.9% as a control (NSO) and sows injected with PG 600 (SO) prior to mating. Parameters measured were growth phenotypes and survival at birth and during pre-weaning period. In the second stage, 24 of weaned pigs (age 8 weeks) from the first stage were selected (6 males and 6 females from NSO group and 6 males and 6 females from SO group) to be used for measurement of growth performance. The experimental pigs were raised and observed until the age of 28 weeks (7 month). The body weights were measured monthly. The results of the experiment showed that improvement of uterine environment by gonadotropin injection of the sows prior to mating dramatically improved birth weight with a very homogenous birth weight within litter size. Improved birth weight and within-litter variation of birth weight improved pre-weaning growth performance and survival that finally dramatically increased weaning weight and total weight of weaned pigs per sow. After weaning, pigs born to SO sows grew faster and had around 10 kg higher body weight as compared to control at the age of 7 month. It was concluded that superior pigs could be produced by improving endogenous secretion of pregnant hormone during pregnancy. The third 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 sows 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 were 138 pigs. During the experiment, the experimental sows were maintained in individual cage and fed with commercial feed and water was available ad libitum. The results of experiment showed that injection of the sows with PMSG and hCG prior to mating improved birth weight, body length, and leg heights with 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 pigs born to SO sows 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 sows with PMSG and hCG prior to mating improvedpostnatal growth phenotypes of pigs and the improved growth phenotypes were 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 that could be used either as a finisher or as a parent stock | en |
