Influence of exogenous growth hormone and gestational diet on sow blood and milk characteristics and on baby pig blood, body composition and performance

Sows (14) and gilts (6) were used in a 2 X 2 factorial experiment to evaluate the effect of diet and highly purified porcine growth hormone (pGH) on sow metabolic status and baby pig survival parameters. Injections were 10 mg/d pGH (GH) or sham control (SH). Diets consisted of a glucose-fat energy source (GF) or control (C). Treatments were administered the last 21 d before parturition (P). Serum GH concentrations were significantly elevated on d -19 P and d -4 P in sows receiving GH injections. Significantly elevated serum glucose and insulin concentrations were concomitantly observed in GH-treated sows, suggesting that the animals had developed a state of insulin resistance. Serum free fatty acids (FFA) were greater (P less than .01) on d -19 P for sows fed the GF diet. Fasted pigs from GH-C dams had greater (P less than .06) mean serum glucose concentrations than pigs from SH-C, SH-GF or GH-GF dams. Pigs from GH-injected sows had more (P less than .01) total body lipids at birth and tended to have increased mean FFA concentrations when compared to SH pigs. However, birth weight, number born live, number born dead, number that died and survival to 21 d were not affected by dam's injection or dietary treatment. Growth hormone injections resulted in a diabetogenic state in gestating sows and led to improved traits related to baby pig blood glucose homeostasis, including increased blood glucose, increased body lipids and a tendency toward increased liver glycogen concentrations. Injection X diet interactions indicate that dietary energy source should be regarded in future growth hormone experiments.