title: Maternal low-dose porcine somatotropin treatment in late gestation increases progeny weight at birth and weaning in sows but not in gilts.
abstract: Birth weight positively predicts postnatal growth and performance in pigs and can be increased by sustained maternal porcine ST (pST) treatment from d 25 to 100 of pregnancy (term ∼115 d). The objective of this study was to test whether a shorter period of maternal pST treatment in late pregnancy (d 75 to 100) could also increase birth and weaning weights of progeny under commercial conditions. Gilts (parity 0) and sows (parities 2 and 3) were not injected (controls) or injected daily with pST (gilts: 2.5 mg•d(-1), sows: 4.0 mg•d(-1), both ∼13 to 14 μg•kg(-1)•d(-1)) from d 75 to 100 of pregnancy. Litter size and BW were recorded at birth and weaning, and dams were followed through the subsequent mating and pregnancy. Maternal pST injections from d 75 to 100 increased litter average progeny weight at birth (+96 g, P = 0.034) and weaning (+430 g, P = 0.038) in sows, but had no effect on progeny weight in gilts (each P > 0.5). Maternal pST treatment did not affect numbers of live-born piglets and increased numbers of stillborn piglets in sows only (+0.4 pigs/litter, P = 0.034). Maternal pST treatment did not affect subsequent reproduction of dams. Together with our previous data, these results suggest that sustained increases in maternal pST are required to increase fetal and postnatal growth in gilt progeny, but that increasing maternal pST in late pregnancy may only be an effective strategy to increase fetal and possibly postnatal growth in sow progeny.
authors.affiliation: Research Centre for Early Origins of Health and Disease, Robinson Institute, University of Adelaide, Southern Australia 5005, Australia. kathy.gatford@adelaide.edu.au
authors.forename: K L
authors.initials: KL
authors.lastname: Gatford
authors.forename: R J
authors.initials: RJ
authors.lastname: Smits
authors.forename: C L
authors.initials: CL
authors.lastname: Collins
authors.forename: M J
authors.initials: MJ
authors.lastname: De Blasio
authors.forename: C T
authors.initials: CT
authors.lastname: Roberts
authors.forename: M B
authors.initials: MB
authors.lastname: Nottle
authors.forename: W H E J
authors.initials: WH
authors.lastname: van Wettere
authors.forename: K L
authors.initials: KL
authors.lastname: Kind
authors.forename: J A
authors.initials: JA
authors.lastname: Owens
mesh_terms: D000273:Adipose Tissue / Q000502:physiology; D000818:Animals; D000831:Animals, Newborn; D001835:Body Weight / Q000187:drug effects*; D004435:Eating; D005260:Female; D013006:Growth Hormone / Q000008:administration & dosage / Q000494:pharmacology*; D007774:Lactation; D010298:Parity; D011247:Pregnancy; D013552:Swine / Q000254:growth & development*; D014886:Weaning
chemical_list: D013006:Growth Hormone