Additive effects of L-carnitine and chromium picolinate on sow reproductive performance

Abstract

A total of 599 sows were used to determine the effects of added l-carnitine with or without chromium picolinate on reproductive performance. Experimental treatments were arranged in a 2 × 2 factorial with main effects of added l-carnitine and chromium picolinate. Starting on the first day of breeding, sows were provided a daily top dress containing the carnitine with or without chromium along with the standard gestation or lactation diet. The top dress was formulated to provide 90 mg/d and 250 mg/d of l-carnitine in gestation and lactation, respectively. Chromium from chromium picolinate was provided at 360 μg/d and 1000 μg/d during gestation and lactation, respectively. These inclusions were calculated to provide 50 mg/kg of carnitine and 200 μg/kg of chromium when sows were fed 1.8 kg/d of the gestation diet and an estimated 5.0 kg/d of the lactation diet (actual lactation feed intake was not recorded). Dietary treatments were administered daily through the initial gestation and lactation (parity 1), and a second gestation period (parity 2). At farrowing all pigs were cross-fostered across dietary treatments. During the first parity, there was a carnitine × chromium interaction ( P < 0.01) for first service farrowing rate. Added dietary chromium increased ( P < 0.01) first service farrowing rate, but there was no further increase when carnitine was added. No differences ( P > 0.05) were observed in number of pigs born alive, stillborn, mummies, or total born in the first or second parity. Added dietary l-carnitine decreased ( P < 0.05) wean to estrus interval, and tended to increase ( P < 0.08) the number of sows in estrus by d 7. In the second parity, supplementing both carnitine and chromium tended to improve (carnitine × chromium interaction, P < 0.08) farrowing rate. Based on all sows that started on test, for the two-parity period both added carnitine and chromium increased ( P < 0.01) the number of pigs born and born alive. These results show that carnitine and chromium supplementation additively increased farrowing rate and thus total number born alive over two parities.