Influence of dietary L-carnitine and chromium picolinate on blood hormones and metabolites of gestating sows fed one meal per day

¹ Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506-0210

^* To whom correspondence should be addressed. E-mail: Goodband{at}ksu.edu.

	Abstract

Gestating sows (n = 44; parity = 2.0; BW = 208 kg) were used to determine the effects of dietary L-carnitine and chromium picolinate (CrP) on daily blood hormone and metabolite profiles. Diets were formulated as a 2 x 2 factorial with L-carnitine (0 or 50 ppm) and CrP (0 or 200 ppb) and were fed from breeding, through gestation, lactation, and 28 d into the subsequent gestation at which time blood collection occurred. Sows were fed 1 meal per day during gestation (2.04 kg from breeding until d 100 and 2.95 kg from d 100 until farrowing) and ad libitum during lactation. Sows were fitted with indwelling venous catheters and blood (plasma) was collected at feeding, then once every 15 min for the first 3 h after feeding, and at 6, 9, 15, 20, and 24 h after feeding. Post feeding and overall insulin and connecting peptide of insulin (c-peptide) was decreased for sows fed diets with (CrP) or L-carnitine and greatest for sows fed the control diet; however, sows fed both L-carnitine and (CrP) had intermediate response (L-carnitine x CrP, P < 0.01). Post-feeding glucose peak was decreased (P < 0.05) in sows fed diets with L-carnitine, CrP, or both versus the control and mean glucose concentration was decreased (P < 0.01) for sows fed diets with CrP. L-carnitine decreased (P < 0.04) NEFA concentration. Sows fed diets with CrP exhibited increased (P < 0.03) post-feeding and overall NEFA and greater (P < 0.02) fasting and overall glycerol. Overall plasma urea N (PUN) was lowest for sows fed the diet with L-carnitine; however, diets containing CrP had intermediate responses compared to the control (L-carnitine x CrP, P < 0.005) . Sows fed diets with L-carnitine had greater (P < 0.008) IGF-1 from 3 to 24 h after feeding and tended to exhibit greater (P < 0.06) overall IGFBP-3. Sows fed the diets with CrP had greater (P < 0.05) IGFBP-3 from 2 to 20 h after feeding. No differences were observed for glucagon, or triacylglycerol (P > 0.10). The changes in metabolites and metabolic hormones indicate that both L-carnitine and CrP influence energy metabolism of gestating sows; however, their effects on blood hormones and metabolites differ. Thus, the improvement in energy status from adding both L-carnitine and CrP may have an additive effect on reproductive performance of sows.

Key Words: sow, carnitine, chromium, hormonal regulation, metabolites