Responses to maternal GH or ractopamine during early–mid pregnancy are similar in primiparous and multiparous pregnant pigs

Abstract

Fetal growth is restricted in primiparous pigs (gilts) compared with dams who have had previous pregnancies (sows), as in other species. In gilts, daily maternal porcine GH (pGH) injections from day 25 to 50 of pregnancy (term w115 day) increase fetal growth and progeny muscularity, and responses in sows are unknown. Whether feeding the b 2 -adrenergic agonist ractopamine during this period increases progeny growth rates in either parity and fetal responses in gilts, have not been investigated. We hypothesised that fetal and placental growth and fetal muscle development would be increased more by maternal pGH and/or ractopamine during early-mid pregnancy in gilts than sows, since fetal growth is restricted in gilts causing lower birth weights. Large White! Landrace gilts and sows were injected daily with water (controls) or pGH (w15 mg/kg per day), or were fed 20 ppm ractopamine, between day 25 and 50 of pregnancy. Maternal pGH increased litter average fetal weight (11%, PZ0 . 007) and length (3%, PZ0 . 022), but not placental weight, at day 50 of pregnancy, irrespective of parity, and had the greatest effects in the heaviest fetuses of each litter. Maternal ractopamine increased average fetal weight (9%, PZ0 . 018), but not length. Muscle fiber diameter was increased by pGH in heavy littermates and by ractopamine in median littermates. Similar fetal growth responses to pGH and ractopamine in gilts and sows suggest that these hormones increase fetal nutrient availability similarly in both parities. We therefore predict that sustained pGH treatment will increase progeny birth weight, postnatal growth and survival, in both sows and gilts.

Betaine in the diet of sows in the first or second reproductive cycle

“…Uma possível resposta benéfica da betaína dietética sobre o desenvolvimento fetal estaria relacionada ao aumento nos níveis basais do hormônio do crescimento (HUANG et al, 2007) o qual atua na melhoria da transferência de nutrientes via placenta para os fetos (GATFORD et al, 2009), aumentando assim o peso ao nascer, fato que não foi observado no presente estudo (P>0,05).…”

Diet and exercise in an obese mouse fed a high-fat diet improve metabolic health and reverse perturbed sperm function

“…Testosterone was measured by stable-isotope dilution liquid chromatography coupled with a tandem mass spectrometry method using an API 5000 instrument using atmospheric pressure photoionization, as described previously (10,53). Cholesterol, FFA, and triglycerides were measured on a Hitachi 912 automated sample system previously described (26), and corticosterone was measured using a commercially available ELISA kit (KA0468; Abnova, Taipei City, Taiwan) per the manufacturer's instructions.…”

Maternal low-dose porcine somatotropin treatment in late gestation increases progeny weight at birth and weaning in sows, but not in gilts1

“…Greater birth weight increases in progeny of sows than in gilts in these studies might therefore reflect a greater capacity to mobilize maternal reserves and increase matemal plasma nutrient concentrations, possibly in part because of decreased rates of lean tissue deposition in the dam, or because of a greater capacity to increase nutrient transfer across the placenta in response to matemal pST treatment in sows than in gilts. In our previous studies of pST treatment in early-mid gestation, matemal plasma IGF-I concentrations increased similarly and matemal and fetal plasma urea concentrations decreased similarly in sows and gilts (Gatford et al, 2009). Matemal plasma insulin and matemal and fetal plasma glucose were not altered by pST treatment during early-mid gestation in either parity (Gatford et al, 2009).…”

“…In our previous studies of pST treatment in early-mid gestation, matemal plasma IGF-I concentrations increased similarly and matemal and fetal plasma urea concentrations decreased similarly in sows and gilts (Gatford et al, 2009). Matemal plasma insulin and matemal and fetal plasma glucose were not altered by pST treatment during early-mid gestation in either parity (Gatford et al, 2009). Dams were not blood sampled in the present study, although effects of pST treatment on BW and P2 backfat depth, which are crude measures of maternal nutrient mobilization, did not differ between parity groups.…”

“…Daily pST injections from d 25 to 50 or d 30 to 43 of pregnancy increase fetal growth in gilts (first pregnancy) or mature sows, even at low doses of 2 mg/d (Sterle et al, 1995;Gatford et al, 2000Gatford et al, , 2009. Continuing pST treatment to d 100 of pregnancy also increases progeny birth weight (Gatford et al, 2004(Gatford et al, , 2010.…”