The present paper discusses the results of a trial study, which was carried out to demonstrate the potential beneficial effects of virginiamycin (VM) on sow and litter performance. VM was added to the sow food at the levels of 0, 20 and 40 mg/kg, for a period of two breeding cycles, covering pregnancy and lactation. VM supplementation of the sow food improved sow performance by: (i) decreasing sow weight loss from farrowing to weaning (first period:decreasing the duration of the reproductive cycle (first period: 154-5 v. 152-2 v. 151-2 days, P < 0-05; second period: 153-8 v. 151-5 v. 250-6 days, P<0-05) and (in) increasing milk fat content (second period: 63-7 v. 81-3 v. 83-3 g/kg, P<0-05).Litter performance was also improved in terms of: (i) litter size at weaning (first period: 8-16 v. 8-88 v. 9-18, P < 0-05; second period: 8-98 v. 9-30 v. 9-76, P < 0-05), (ii) body weight at weaning (first period: 5-78 v. 6-29 v. 6-56 kg, P < 0-05; second period: 5-88 v. 6-38 v. 6-60 kg, P < 0-05), (Hi) average daily gain (first period: 172 v. 189 v. 197 g, P < 0-05; second period: 178 v. 292 v. 198 g, P < 0-05) and (iv) food conversion ratio (first period: 0-356 v. 0-331 v. 0-324, P < 0-05; second period: 0-363 v. 0-334 v. 0-325, P < 0-05). These beneficial effects of VM were more pronounced at the higher of the two inclusion levels.
Seventeen to twenty-three females of lean (Pietrain, PI), fat (Meishan, MS), or intermediate genotype (PI x [3/4 Large White x 1/4 MS]), referred to as crossbred (CR), were injected between 60 and 100 kg live weight with 6 mg/d of porcine somatotropin (pST) and compared to similar numbers of control females receiving the vehicle only. Average daily gain increased similarly in the three genotypes (125 g/d). Feed conversion ratio tended to decrease to a higher extent in MS (-2.0 kg of feed/kg of gain) than in the other two genotypes (-1.1 and -.9 kg of feed/kg of gain for CR and PI, respectively). A significant genotype x treatment interaction was also observed for backfat thickness (BF) and fat, muscle, and bone development. Effects of pST in PI, CR, and MS pigs were, respectively, -6.2, -9.6, and -16.1 mm for BF and 3.0, 6.8, and 11.8% carcass muscle. The influence of pST on physical measurements of meat quality was rather low, although desirable effects (P less than .05) were obtained on the reflectance and water-holding capacity of PI and CR. Intramuscular fat content was reduced by approximately 1% in MS and CR but not in PI. The metatarsals of pST-treated animals had a higher water content (except in PI), a lower mineralization, and a lower breaking strength (except in MS). The existence of breed variations in the response to pST might result in changes of the relative merit of crossbreeding schemes.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.