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

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.

Efecto del catéter de inseminación y el orden de parto sobre parámetros de producción en ganado porcino

“…Los resultados del efecto del tipo de catéter sobre lechones nacidos vivos en este trabajo coinciden con los obtenidos por otros autores [7,8], pues no hubo efectos según el tipo de catéter; intracervical o intrauterino, utilizado en la inseminación artificial, sobre esta variable. El número de lechones nacidos vivos es similar al reportado por [9,10]. Se observa una tendencia, aunque no significativa, en las hembras que fueron inseminadas con el catéter intrauterino, que sugiere que hay mayor cantidad de lechones nacidos en total y muertos.…”

“…Las hembras multíparas presentaron un mayor número de lechones nacidos en total en comparación con las hembras de primer parto (cuadro 1). Similares resultados han sido reportados por [13,14,7,11,15,10]. Además, se ha descrito un pico máximo hacia el tercer parto (mediana = 15), sin embargo, hay mayor variabilidad en este grupo, con un coeficiente de variación de 20,2%, (cuadro 2).…”

Exogenous porcine somatotropin stimulates mammary development in late-pregnant gilts

“…On the other hand, Gatford et al (2010) injected 2.5 mg/d of pST to gilts and 4.0 mg/d to sows from days 25 to 100 of pregnancy and saw an increase in piglet birth weight. However, when 2.5 mg/d of pST was injected for a shorter period of time later in gestation (days 75 to 100), birth weight of piglets was increased in sows but not in gilts (Gatford et al, 2012). It is therefore apparent that discrepancies in results are linked to dosage, duration of treatment, and parity.…”