Effect of exogenous porcine somatotropin administration on nitrogen and energy metabolism in three genotypes of pigs.
Effects of exogenous administration of porcine recombinant somatotropin (rpST) on protein gain and metabolic rate were measured in three genotypes (castrated males) of pigs (Pietrain, Duroc and a crossbreed between Dutch Yorkshire and Dutch Landrace). Six pigs of each genotype were assigned at approximately 60 kg to receive pST doses of either 0 (C) or 14 mg (T) administered i.m. twice weekly over 10 wk. Pigs were housed in individual metabolism cages at a room temperature of 20 to 22 degrees C and received feed at 2.6 times maintenance. Protein gain (N x 6.25) was measured over the final 6 wk of the 10-wk test period. For 2 wk in the test period (wk 2 and wk 5), six pigs of each treatment x genotype group were placed in a large respiration chamber and energy balances (in protein and fat) and metabolic rate were measured. Rate of weight gain measured over the final 6 wk of the experimental period increased by 105 g/d (13%) with rpST administration (P less than .01). Daily protein gain over 6 wk was increased by 48 g/animal with application of rpST (P less than .001). There was a genotype x treatment interaction (P less than .01) for protein gain. Daily protein gain in Durocs with pST treatment was increased (39%) more than in crossbreds (31%). Daily fat gain was decreased by 42 g/animal (P less than .001) by T. Daily heat production with rpST was increased by 12 kcal/kg.75, which is comparable to a 12% increase in the maintenance energy requirement.
Verstegen
M W
MW
Dept. of Anim. Nutr., Agricultural University, Wageningen, The Netherlands.
van der Hel
W
W
Henken
A M
AM
Huisman
J
J
Kanis
E
E
van der Wal
P
P
van Weerden
E J
EJ
D000818:Animals; D001833:Body Temperature Regulation; D004063:Digestion; D004734:Energy Metabolism / Q000187:drug effects*; D005838:Genotype; D013006:Growth Hormone / Q000494:pharmacology*; D008297:Male; D009584:Nitrogen / Q000378:metabolism*; D011994:Recombinant Proteins / Q000494:pharmacology; D013552:Swine / Q000235:genetics / Q000378:metabolism*; D015430:Weight Gain
D011994:Recombinant Proteins; D013006:Growth Hormone; D009584:Nitrogen