Performance and carcass quality of swine injected daily with bacterially-synthesized human growth hormone

In this study, growth rate, feed intake, feed efficiency and carcass quality were measured in pigs (24 barrows and 24 gilts, initial body weight = 23.0 +/- 4 kg) administered 0, .015, .030 or .060 mg/kg/day bacterially produced human growth hormone (hGH) until slaughter weight of 90 kg. Administration of hGH on the first treatment day resulted in a dose-dependent peak in serum concentration after 2 hrs and concentrations gradually returned to baseline by 22 hrs after treatment. Measurement of glucose, insulin and glucagon on the first and last days of treatment showed variable effects of treatment. In pigs treated with .015 mg/kg/day hGH average daily weight gain (.89 vs .82 kg, p less than .05) and feed intake (4.59 vs 4.25 kg, p less than .006) were increased, while feed efficiencies were not different among groups. The carcass data did not show consistent differences to indicate a hGH growth response. It is concluded that hGH may be effective in pigs for improving growth rate and at doses lower than those shown effective for porcine GH.