a1 Russell Grimwade School of Biochemistry, University of Melbourne, Parkville, Victoria 3052, Australia
a2 Pig Research Unit, Mt Derrimut Field Station, University of Melbourne, Deer Park, Victoria 3023, Australia
1. Pig growth hormone (PGH) concentrations were measured in plasma samples from piglets of 3–4 to 7–8 weeks of age.
2. Plasma PGH concentrations decreased significantly with age. No difference was observed between the hormone concentrations of gilts and barrows.
3. Correlation coefficients were calculated between mean plasma growth hormone concentration over a 4-week period and several carcass characteristics and measures of growth rate. Plasma PGH over this period showed significant negative correlations with several measures of carcass backfat thickness at bacon weight. In barrows only, PGH concentrations showed a significant direct correlation with relative growth rate from 3 to 7 weeks.
(Received May 04 1974)
p1 Present address: Attwood Veterinary Research Station, Victorian Department of Agriculture, Westmeadows, Victoria 3047, Australia.