title: Effect of ractopamine and sex on growth, carcass characteristics, processing yield, and meat quality characteristics of crossbred swine.
abstract: One hundred twenty-eight 64-kg crossbred barrows and gilts were administered either 0 or 20 ppm of Ractopamine (RAC) in a pelleted corn-soybean meal diet that contained either 17.5 or 19.6% CP. Carcass quality was evaluated after slaughter at 100 kg. Dietary protein levels produced few significant effects; therefore, data were pooled for analysis. Pigs fed RAC exhibited improvement in feed efficiency (P < .01), ADG (P < .01), and number of days to slaughter (P < .01). Pigs fed RAC had 1.8 mm less fat (P < .05) and 3.4 mm more lean (P < .01) at the grading probe site. Gilts had 4.9 mm less fat than barrows at the probe site (P < .01) and also yielded an estimated 4.1% more lean (P < .01). Trimmed loins and bellies of animals fed 20 ppm of RAC were 230 g heavier (P < .05) than those of animals fed the control diet. Trimmed loins from gilts were 260 g heavier (P < .05), whereas barrows produced bellies that were 490 g heavier (P < .05) than those of gilts. The yield of processed ham was greater from both pigs fed RAC (P < .01) and barrows (P < .05). Loins of pigs fed RAC had lower cooking loss (P < .05), greater Warner-Bratzler shear value (P < .05), and higher fragmentation index value (P < .01). Although effects of sex were similar to or greater than the effects of 20 ppm of RAC, these effects were additive.
authors.affiliation: Department of Animal and Poultry Science, University of Guelph, ON, Canada.
authors.forename: B E
authors.initials: BE
authors.lastname: Uttaro
authors.forename: R O
authors.initials: RO
authors.lastname: Ball
authors.forename: P
authors.initials: P
authors.lastname: Dick
authors.forename: W
authors.initials: W
authors.lastname: Rae
authors.forename: G
authors.initials: G
authors.lastname: Vessie
authors.forename: L E
authors.initials: LE
authors.lastname: Jeremiah
mesh_terms: D000318:Adrenergic beta-Agonists / Q000494:pharmacology*; D000821:Animal Feed; D000818:Animals; D003433:Crosses, Genetic; D004435:Eating / Q000187:drug effects; D005260:Female; D005511:Food Handling; D006133:Growth Substances / Q000494:pharmacology*; D008297:Male; D008460:Meat / Q000592:standards*; D010627:Phenethylamines / Q000494:pharmacology*; D012737:Sex Factors; D013552:Swine / Q000235:genetics / Q000254:growth & development*; D015430:Weight Gain / Q000187:drug effects
chemical_list: D000318:Adrenergic beta-Agonists; D006133:Growth Substances; D010627:Phenethylamines; C060897:ractopamine