Low Birthweight Piglets Essay -- Food, Pork Industry

Introduction Low birth weight piglets have high mortality and poor growth postnatally. The pork industry has strategies to increase the piglets’ birth weight. Maternal growth hormone treatment with developmental timing and dose difference increased fetal growth in pigs [1-4]. As GH cannot cross the placenta [5], the increase in fetal growth must due to changes in maternal metabolism and/or placental development and function. Placental weight was increased with maternal GH treatment [4]. However, none of the above studies has demonstrated the effect of maternal GH treatment on placental structural development and function in pigs; therefore, this is the gap that will be addressed in this study. Birth Weight Determinants of fetal growth and birth weight in pigs Birth weight is influenced by several factors during pregnancy, such as parity, maternal nutrition, uterine capacity and litter size. Pigs have two parity groups, sows and gilts. Sows are pigs which have given birth at least 3 times before, and gilts, are pigs that had never been pregnant. The low birth weight of the progeny from gilts might be due to first pregnancy. As gilts are growing when they pregnant, so mother and fetus were competing for limited nitrogenous substrates to meet their needs, and leads to low birth weight in fetus *gatford 2009 & Schoknecht 1993. Piglets from dam which has restriction in food intake or specific nutrients during gestation have reduced in birth weight. The progeny of gilts fed with protein-deficient diet (0.5% protein) in early (d 1 to d44) or late (d 82 to term) during gestation have lower birth weight compared to the control (with 13% protein in diet); whereas protein deficient diet throughout pregnancy caused the progeny weigh... ...reased maternal lean meat percentage *rehfeldt 2001. The backfat depth of pGH treated dams in *gatford 2010 was lower than the controls at farrowing and weaning *. This suggested that GH treatment can stimulate lean growth and inhibiting adipose tissue growth in pigs. The gestation length of sows, but not gilts was being shortened by long term GH treatment. Maternal GH treatment would also affect the concentration of maternal circulating metabolites and hormones. There was an increased in amino acids nitrogen and decreased in free fatty acids in maternal circulation by a 2 or 4 mg GH dose treatments from d 25 to d 51(gatford, 2000). Maternal plasma urea concentration was decreased by 28% by GH treatment with a dose ~15ug/kg from days 25 to 50 *gatford 2009. There was a similar finding in another study with maternal GH treatment in underfed gilts *gatford 2000.