Pork meat quality profile from pigs originating from two different production streams with and without antibiotics administered at weaning

This study examined the effects of dietary antibiotic supplementation at weaning (chlortetracycline; ATB) on carcass weight, fresh meat quality, and meat and fat composition in pigs. Animals were sourced from two commercial maternities with average (production stream-A; n = 1020) and lower (production stream-B; n = 1200) health status. At the end of the finishing phase, a sub-sample of 150 pigs from each of the antibiotic-treated and control groups was slaughtered from the two selected maternities with differing health status and herd management practices. Meat and fat quality from those animals were subsequently evaluated in the longissimus lumborum muscle. Compared to the control group, loins from production stream-A treated animals showed a lower ultimate pH (pHu; P = 0.04), greater drip loss (P < 0.001) and reduced marbling (P < 0.01), creating conditions conducive to a trend towards tougher meat (P = 0.09). Administering antibiotic-supplemented feed to production stream-B piglets resulted in loins that were paler in colour (higher Minolta L* value and lower Japanese Colour Standards score; P = 0.04 for both) and more tender (P < 0.01). Overall, the long-term effects of dietary antibiotic supplementation at weaning on pork meat obtained from the treated piglets were minimal, if not negligible, in terms of both biological and economical significance, regardless of the maternity of origin and herd management practices.