Piray Ali Hossein, Foroutanifar Saheb
Department of Animal Science, College of Agriculture and Natural Resources, Razi University, PO Box 6715685418, Kermanshah, Iran.
Biol Trace Elem Res. 2021 Dec;199(12):4713-4720. doi: 10.1007/s12011-021-02589-2. Epub 2021 Jan 17.
Studies investigating the effects of Chromium (Cr) supplementation on unstressed broiler chickens have reported an inconsistent association between Cr supplementation and broiler chickens' responses. We conducted a dose-response meta-analysis of previous studies to assess the dose-response associations between Cr supplementation and performance parameters, carcass traits, blood metabolites, and immune indices of non-stressed broiler chickens. The results showed that Cr supplementation was not associated with feed intake, body mass gain, and feed conversion ratio. There was a J-shaped relationship between Cr supplementation and carcass relative weight, and Cr supplementation at about 1145 μg/kg diet produced the highest response. However, supplemental Cr had no effects on the other carcass traits, including breast, leg, abdominal fat, and liver relative weights. There was a strong evidence of nonlinear associations between Cr supplementation and the blood concentration of high-density lipoprotein (HDL) and low-density lipoprotein (LDL) cholesterol (P < 0.05). The maximum reduction in blood LDL concentration was observed when Cr was supplemented at about 540 μg/kg diet, and Cr at the dose of 588 μg/kg of diet caused the greatest enhancement in the blood HDL concentration. However, supplementation with Cr did not change the blood total cholesterol and triglycerides concentrations. Additionally, a strong inverse association was found between Cr supplementation and blood glucose concentration. Furthermore, positive linear associations between Cr supplementation and the relative weight of bursa and thymus and the antibody titer to Newcastle disease vaccine were detected. However, supplemental Cr had no effect on the spleen relative weight and titer against avian influenza vaccine. Findings from this meta-analysis demonstrate that Cr supplementation is positively associated with carcass relative weight, blood HDL concentration, and immune response and inversely associated with blood glucose and LDL concentrations in non-stressed broiler chickens.
研究铬（Cr）添加对未受应激肉鸡影响的报告显示，Cr添加与肉鸡反应之间的关联并不一致。我们对先前的研究进行了剂量反应荟萃分析，以评估Cr添加与未受应激肉鸡的生产性能参数、胴体性状、血液代谢物和免疫指标之间的剂量反应关系。结果表明，Cr添加与采食量、体重增加和饲料转化率无关。Cr添加量与胴体相对重量呈J形关系，日粮中添加约1145μg/kg的Cr产生的反应最大。然而，补充Cr对其他胴体性状没有影响，包括胸肌、腿肌、腹脂和肝脏相对重量。有强有力的证据表明，Cr添加量与高密度脂蛋白（HDL）和低密度脂蛋白（LDL）胆固醇的血液浓度之间存在非线性关联（P<0.05）。当日粮中添加约540μg/kg的Cr时，血液LDL浓度降幅最大，日粮中添加588μg/kg的Cr可使血液HDL浓度增幅最大。然而，补充Cr并未改变血液总胆固醇和甘油三酯浓度。此外，还发现Cr添加量与血糖浓度呈强烈负相关。此外，还检测到Cr添加量与法氏囊和胸腺相对重量以及新城疫疫苗抗体效价之间呈正线性相关。然而，补充Cr对脾脏相对重量和禽流感疫苗效价没有影响。这项荟萃分析的结果表明，在未受应激的肉鸡中，Cr添加量与胴体相对重量、血液HDL浓度和免疫反应呈正相关，与血糖和LDL浓度呈负相关。
