effects of dietary chromium(III) picolinate on growth performance, blood measurements, and respiratory rate in pigs kept in high and low ambient temperature

• Published in: Journal of animal science Vol. 87; no. 5; pp. 1695 - 1704
• Main Authors: Kim, B.G, Lindemann, M.D, Cromwell, G.L
• Format: Journal Article
• Language: English
• Published: Champaign, IL American Society of Animal Science 01.05.2009; Am Soc Animal Sci
• Subjects: air temperature; animal growth; Animal productions; Animals; Biological and medical sciences; blood chemistry; blood glucose; Blood Glucose - analysis; body weight; breathing; chromium; Cold Temperature; cortisol; Diet - veterinary; Dietary Supplements; feed additives; feed intake; Female; Fundamental and applied biological sciences. Psychology; heat stress; Hot Temperature; Hydrocortisone - blood; liveweight gain; Male; picolinic acid; Picolinic Acids - administration & dosage; Picolinic Acids - metabolism; Respiration; Stress, Physiological - physiology; swine; Swine - blood; Swine - growth & development; Swine - physiology; swine feeding; Terrestrial animal productions; Vertebrates; weanlings; Thermal stress; Measurement; Farming animal; Growth; Rate; High temperature; Blood; Heavy metal; Pig; Vertebrata; Meat animals; Mammalia; Chromium; Artiodactyla; Performance; Ungulata; Low temperature
• ISSN: 0021-8812; 1525-3163
• DOI: 10.2527/jas.2008-1218

Three experiments were conducted to investigate the effects of thermal stress and dietary Cr on growth performance and physiological variables in weanling pigs. In Exp. 1, a total of 54 pigs (BW of 5.95 ± 0.84 kg) were allotted to a 2 x 3 factorial arrangement using 2 ambient temperatures (23.7 or 40.5°C during d 14 to 28 postweaning) and 3 dietary concentrations of Cr (0, 1,000, or 2,000 μg/kg) as Cr(III) picolinate. In Exp. 2, a total of 54 pigs (BW of 5.94 ± 1.29 kg) were allotted in the same treatment arrangement but with different ambient temperatures (26.5 or 16.0°C during d 14 to 26 postweaning). In Exp. 3, a total of 36 pigs (BW of 6.40 ± 0.72 kg) were allotted in the same treatment arrangement with ambient temperatures of 25.9 or 13.8°C during d 14 to 28 postweaning. During d 0 to 14 of all experiments, a neutral ambient temperature (NT) was maintained. In Exp. 1, pigs in high ambient temperature (HT) gained less BW (575 vs. 663 g/d; P < 0.001) and consumed less feed (926 vs. 1,074 g/d; P = 0.001) than pigs in NT during d 14 to 28. However, G:F was not affected by ambient temperature (0.623 vs. 0.618 g/g; P = 0.702). Dietary Cr had no effect on growth performance. Pigs in HT had less plasma cortisol (42.0 vs. 53.7 ng/mL; P = 0.012) and glucose (6.68 vs. 6.96 ng/mL; P = 0.018). Respiratory rate of pigs in HT was greater compared with the pigs in NT (114.6 vs. 65.0 breaths/min; P < 0.001) on d 27. In Exp. 2 and 3 (pooled), pigs in low ambient temperature (LT) had decreased G:F (0.636 vs. 0.663 g/g; P < 0.01) associated with a tendency toward a greater ADFI (1,026 vs. 942 g; P = 0.079) during d 14 to 26 (28). Ambient temperature or dietary Cr supplementation had no effect on blood measurements. In Exp. 3, the respiratory rate measured on d 22 and 27 was less (43.2 vs. 54.2 breaths/min and 42.2 vs. 57.0 breaths/min, respectively; P < 0.001) in the pigs in LT than the pigs in NT with no effects of dietary Cr supplementation. These results indicate that growth performance is affected by thermal stress and plasma cortisol is decreased by heat stress, but these effects are not moderated by dietary Cr.