Effects of gender and genotype on the response of growing pigs to exogenous administration of porcine growth hormone.
Sixty crossbred pigs (Large White x Landrace) were used in a 2 x 2 x 2 factorial experiment to investigate the effects of gender (intact males vs females) and strain (A vs B) on the response to exogenous porcine growth hormone (pGH) administration (0 [excipient-treated] vs .1 mg pGH.kg live weight-1.d-1). All pigs had ad libitum access to their diet; pGH was administered daily from 60 to 90 kg live weight. All aspects of growth performance and body composition were affected to different degrees by gender and pGH. Strain A pigs had a higher capacity for protein accretion, superior growth performance and contained less fat in the eviscerated carcass and empty body compared with Strain B pigs. Within each strain, intact males ate more feed, had a higher rate of protein deposition and exhibited faster and leaner growth than females. Exogenous pGH administration increased average protein deposition and growth rate by 84 and 34%, respectively, and reduced average feed intake, fat deposition rate, feed:gain and carcass fat content by 14, 59, 37 and 33%, respectively. The magnitude of the changes in growth performance, tissue accretion rates and body composition elicited by pGH were independent of strain. However, within each strain the improvement in feed:gain and reduction in carcass fat measurements elicited by pGH were proportionately larger for females than for intact males.
Campbell
R G
RG
Animal Research Institute, Werribee, Victoria, Australia.
Johnson
R J
RJ
King
R H
RH
Taverner
M R
MR
D000818:Animals; D001823:Body Composition; D001835:Body Weight / Q000187:drug effects; D004435:Eating; D005260:Female; D005838:Genotype; D013006:Growth Hormone / Q000097:blood / Q000494:pharmacology*; D008297:Male; D012727:Sex Characteristics; D012867:Skin / Q000033:anatomy & histology; D013552:Swine / Q000235:genetics / Q000254:growth & development*
D013006:Growth Hormone