Brooks M A, Grimes J L, Lloyd K E, Krafka K, Lamptey A, Spears J W
Department of Animal Science, North Carolina State University, Raleigh, NC 27695-7621.
Prestage Department of Poultry Science, North Carolina State University, Raleigh, NC 27695-7608.
Poult Sci. 2016 May;95(5):1096-104. doi: 10.3382/ps/pew018. Epub 2016 Mar 1.
The objective of this study was to evaluate the effects of dietary chromium (Cr), as chromium propionate, on measures of insulin sensitivity. Liver and muscle glycogen, and plasma glucose and non-esterified fatty acid (NEFA) concentrations were used as indicators of insulin sensitivity. In total, 288 newly hatched male Ross broilers were divided into 4 dietary treatments consisting of 0 (control diet analyzed 0.43 to 0.45 mg Cr/kg), 0.2, 0.4, or 0.6 mg supplemental Cr/kg diet, resulting in 4 treatments with 9 replicate pens per treatment containing eight birds per pen. At d 21, 2 birds per cage were removed based on the greatest deviation from pen mean BW, resulting in each pen containing 6 birds for the final analyses. Final BW were taken on d 40, and on d 42 two birds from each pen were sampled for plasma NEFA, glucose, and muscle and liver glycogen determination at the initiation and termination of a 22 h fast. The remaining 2 fasted birds were sampled after a 30 min refeeding period. No differences were observed in feed intake, BW gain, or feed efficiency on d 21 or d 40. Liver glycogen tended (P=0.10) to be greater in Cr-supplemented chicks in the fed state, and muscle glycogen concentrations tended (P=0.07) to be greater in Cr-supplemented chicks compared with controls following fasting and refeeding. Plasma glucose concentrations were not affected by dietary Cr in the fed, fasted, or refed state. Plasma NEFA levels were not affected by treatment in fed or fasted birds. However, plasma NEFA concentrations were lower (P<0.01) in chicks supplemented with Cr than in controls following fasting and refeeding, suggesting that Cr increased insulin sensitivity. No differences were detected among birds supplemented with 0.2 or 0.4 mg Cr/kg, and among those receiving 0.4 or 0.6 mg Cr/kg. Results of this study indicate that Cr propionate supplementation of a control diet containing 0.43 to 0.45 mg Cr/kg enhanced insulin sensitivity.
本研究的目的是评估作为丙酸铬的日粮铬对胰岛素敏感性指标的影响。肝脏和肌肉糖原以及血浆葡萄糖和非酯化脂肪酸（NEFA）浓度被用作胰岛素敏感性指标。总共288只刚孵化的雄性罗斯肉鸡被分为4种日粮处理组，分别为0（对照日粮铬含量分析为0.43至0.45毫克/千克）、0.2、0.4或0.6毫克/千克补充铬日粮，共4个处理组，每个处理组有9个重复栏，每个栏含8只鸡。在第21天，根据与栏平均体重偏差最大的原则，每个笼中取出2只鸡，最终每个栏含6只鸡用于最终分析。在第40天记录最终体重，在第42天，从每个栏中选取2只鸡，在22小时禁食开始和结束时采集血浆NEFA、葡萄糖以及肌肉和肝脏糖原样本进行测定。其余2只禁食鸡在30分钟再喂食期后采样。在第21天或第40天，未观察到采食量、体重增加或饲料效率的差异。在采食状态下，补充铬的雏鸡肝脏糖原含量有增加趋势（P = 0.10），在禁食和再喂食后，补充铬的雏鸡肌肉糖原浓度与对照组相比有增加趋势（P = 0.07）。在采食、禁食或再喂食状态下，日粮铬对血浆葡萄糖浓度均无影响。在采食或禁食的鸡中，处理对血浆NEFA水平无影响。然而，在禁食和再喂食后，补充铬的雏鸡血浆NEFA浓度低于对照组（P < 0.01），表明铬提高了胰岛素敏感性。在补充0.2或0.4毫克/千克铬的鸡之间以及接受0.4或0.6毫克/千克铬的鸡之间未检测到差异。本研究结果表明，在含0.43至0.45毫克/千克铬的对照日粮中添加丙酸铬可提高胰岛素敏感性。
