Lipid Metabolism and Peroxidation in Broiler Chicks under Chronic Heat Stress

Abstract

The effects of taurine supplementation on growth performance, serum and liver concentrations of lipid, fatty acid composition and lipid peroxidation in the livers of broilers under chronic heat exposure conditions were investigated. The chicks with a similar body weight were equally assigned to one of three controlled-environment chambers. The brolier chicks, which were kept at 34°C were fed either with a control diet or the control diet supplemented with 0.8% taurine, whereas broiler chicks kept at 22°C were fed a control diet. Both of the BW and BW gains of broilers maintained at a temperature of 34°C were significantly lower than those of the control group, which was maintained at a temperature of 22°C (p<0.05). However, taurine addition in the diet of birds submitted to heat stress siginficantly improved BW gain (p<0.05). The feed intake of chicks declined with increases in temperature. The relative liver and gall bladder weights of chicks fed the control diet and maintained at 34°C were significantly lower than those measured in the control birds (p<0.05). However, dietary taurine was found to compensate for these reductions in liver and gall bladder weights. Relative weights of abdominal fat did not differ significantly among the three groups. Serum triglyceride concentrations were significantly lower in the chicks fed the control diet and maintained at 34°C compare to those measured in the chicks fed the control diet at 22°C (p<0.05). Heat stress resulted in a significant reduction in total lipid and triglyceride levels, but also increased the levels of total cholesterol in the liver (p<0.05). However, dietary taurine supplementation under the heat stress condition resulted in the recovery, to control levels, of serum triglyceride concentrations, as well as the amounts of total lipids, triglycerides, and cholesterol in the liver. The livers of chicks fed on taurine diets at 34°C showed significantly higher proportions of C14:0, C16:1, C18:1, C18:2, and 20:3, and lower C18:0 and C20:4 proportions than those of chicks fed on control diets at the same temperature (p<0.05). The total levels of saturated fatty acids decreased, but monounsaturated fatty acids and unsaturated fatty acid levels increased in chicks fed the taurine diet, as compared to chicks fed the control diet at 34°C (p<0.05). Peroxidizability indices were significantly lower in the heat-exposed chicks fed the taurine diet than in the non-taurine heat-exposed groups (p<0.05). In conclusion, dietary taurine results in an increase in the growth performances of chicks under heat stress conditions via improvements in lipid absorption and metabolism, as well as an induced reduction in lipid peroxidation.

Effects of Tannic Acid on Performance and Fatty Acid Composition of Breast Muscle in Broiler Chickens Under Heat Stress

“…In this study, the interaction effect of temperature and TA on the fatty acid composition of breast muscle of broilers was significant only for C14:1, C18:2n-6, C22:6n-3 and Sn-6 PUFA. These results were in contrast with the results of Shim et al (2006) who exposed broiler chickens to chronic heat stress with diets supplemented by taurin as an antioxidant. They reported that by adding taurin to the diet the total levels of SFA decreased, but MUFA and UFA levels increased, as compared to chicks fed the control diet under heat stress condition.…”

“…Effects of heat exposure on fat deposition have long been the subject of considerable controversy, but most of researchers suggested an increase in fat contents under heat stress conditions (Swain and Farrell, 1975;Howlider and Rose, 1987;Geraert et al, 1996). Shim et al (2006) showed that chronic heat exposure clearly altered the hepatic fatty acid profiles. They investigated lipid metabolism and peroxidation in broiler chicks under chronic heat stress and reported that the heat stress increased peroxidizability index and total saturated fatty acids (SSFA), while it significantly decreased monounsaturated fatty acids (MUFA) and total unsaturated fatty acids (SUFA).…”

Effects of Taurine Supplementation on Performance, Egg Quality, Blood Parameter and Liver Lipid and Lipid Peroxidation Levels of Laying Hens Fed High Fat Diet

“…종으로 oxidation 또는 peroxidation의 생성물로부터 세포막 보 호 (Li et al, 1993;Trachtman et al, 1993), 외인성 독성 물질 로 인한 세포막 손상 방지 (Waterfield et al, 1993;Ding et al, 1993), 고온 스트레스 완화 (박강희와 최형송, 1997;Shim et al, 2006)등의 생리적 기능이 알려져 있다. 또한, 타우린이 콜레 스테롤 및 지질대사에 미치는 영향에 관하여 활발한 연구가 진행되었다.…”

Physiological and Behavioral Responses of Young Chicks to High Ambient Temperature

“…Although there were no changes in plasma uric acid concentration in broiler exposed to long-term high temperatures (Yalçin et al, 2005), these levels were increased by short-term heat exposure (Lin et al, 2004). Shim et al (2006) reported a reduction in plasma triacylglycerol level by HT. Glutamic-oxalacetic transaminase (GOT) is released into blood when the liver and/or heart is damaged (Kalmansohn and Kalmansohn, 1961).…”