日粮能量和蛋白水平对肉鸡腹脂和血脂的影响

对７０８只（公、母各半）５～９周龄黄羽肉鸡进行３个代谢能水平（１３．４，１２．５，１１．６ＭＪ／ｋｇ）和３个粗蛋白水平（２２．４％，１９．４％，１６．４％）交叉的饲养试验，以探讨日粮代谢能和粗蛋白水平时黄羽肉鸡腹脂和血脂水平的影响。日粮代谢能和粗蛋白水平对腹脂有明显影响，腹脂随日粮代谢能水平的升高而升高（Ｐ＜０，０１）。随粗蛋白水平的升高而降低（Ｐ＜０．０５）。日粮能量和蛋白水平对板油的影响与腹脂相似。日粮代谢能水平对肌胃脂无明显影响；日粮粗蛋白水平对肌胃脂重无明显影响，但对肌胃脂率有一定影响（Ｐ＝０．０７）。日粮粗蛋白和代谢能水平对血浆极低密度脂蛋白（ＶＬＤＬ）、甘油三酯、胆固醇及总脂浓度均有显著影响（Ｐ＜８．０５），８周龄血浆ＶＬＤＬ浓度随日粮代谢能的升高而降低（Ｐ＜０．０００１）；血浆总脂和胆固醇浓度均随日粮代谢能、粗蛋白水平的升高而降低（Ｐ≤０．００１）。肉鸡８周龄血浆ＶＬＤＬ水平明显存在日粮能量和蛋白的互作效应（Ｐ＜０．０１），而血浆甘油三酯、胆固醇和总脂水平不存在明显的能量和蛋白的互作（Ｐ＞０．０５）。

EFFECTS OF DIETARY METABOLIZABLE ENERGYAND PROTEIN LEVELS ON ABDOMINAL FATAND PLASMA LIPIDS LEVELS OF BROILERS

The experiment for crossed two factors was conducted with 708 male and female broilers fed on diets containing three metaboliable energy(ME) levels( 13. 4, 12. 5, 11. 6 MJ / kg) and three crude protein (CP) levels( 22. 4 . , 19. 4% , 16. 4% ) to investigate the effects of dietary ME and CP levels on fat deposition and plasma lipids levels in broilers of 5 to 9 weeks of age . Dietary ME and CP levels had significant effects on abdominal fat( AF) . AF was increased with increasing dietary ME( P < 0. 01) , and decreased with increasing dietary CP(P < 0. 05) . Dietary ME and CP levels had similar effects on leaf fat compared with AF. Dietary ME had no sig - nificant effect on gizzard fat . Dietary CP had no significant effect on gizzard fat weight , but it affected gizzard fat percentage( P= 0. 07) . Both dietary CP and ME levels affected signifi - cantly plasma very low density lipoprotein(VLDL) , triglyceride, cholesterol and total lipid concentrations( P < 0. 05) . Plasma VLDL concentration at 8 weeks of age was decreased when dietary ME was increased( P < 0. 0001) . Both plasma total lipid and cholesterol concentrations were decreased as dietary ME or CP was increased( P < 0. 01) . There is apparent interaction effects between dietary energy and protein for plasma VLDL concentration( P < 0. 01) , whereas there is no the apparent interaction effect for plasma triglyceride , total lipids and cholesterol Concentrations.