【作者】 罗绪刚； 李素芬； 刘彬； 邵桂芝； 郭修泉； 余顺祥；

【Author】 Luo Xugang Li Sufen Liu Bin Sbao Guizhi Guo Xiuquan Yu shunxiang(Institute of Animal Science, Chinese Academy of Agricultural Sciences Beijing 100094)

【机构】 中国农业科学院畜牧研究所；

【摘要】 用49周龄北京红商品产蛋鸡120只进行试验,研究铬源及铬水平对热应激产蛋鸡产蛋性能、蛋品质、血清生化特性及免疫功能的影响。试鸡按2×3因子安排的完全随机设计依产蛋率随机分为5个处理组,分别饲喂不添加铬的玉米-豆粕型基础饲粮对照组和以三氯化铬或吡啶羧酸铬形式添加2.0、10.0mg/kg铬的试验饲粮,在热应激条件下(9:00～17:00维持36±2℃,其余时间28±2℃)饲养30天。鸡只自由采食与饮水。铬源对蛋壳厚度、蛋壳百分率、血清甘油三酯及全血T淋巴细胞转化率有明显影响(P<0.04),而对所观测的其余指标无显著影响(P>0.10)。铬水平对采食量、料蛋比、蛋壳厚度、蛋壳百分率、蛋黄颜色、血清甘油三酯含量、碱性磷酸酶活性(AKP)和全血T淋巴细胞转化率有明显影响(P<0.10),但对其余指标无明显影响(P>0.12)。其中添加2.0mg/kg铬组采食量高于对照组(P<0.04),而添加10.0mg/kg铬组采食量与对照组和添加2.0mg/kg铬组间均无明显差异(P>0.14):除第2周添加10.0mg/kg铬组蛋黄颜色未明显高于对照外(P>0.76),其它各周添加2.0和10.0mg/kg铬组蛋黄颜色均显著高于对照组(P<0.09);添加2.0和10.0mg/kg铬组料蛋比高于对照组(P<0.06),血清甘油三酯含量低于对照组(P<0.07),血清AKP活性高于对照组(P<0.07),但两添加水平组间无明显差异(P>0.64)。在蛋壳强度、蛋壳厚度、蛋壳百分率和全血T淋巴细胞转化率指标上观测到两因子的互作效应(P<0.01)。其中以三氯化铬形式添加10.0mg/kg铬组蛋壳厚度、蛋壳百分率及全血T淋巴细胞转化率高于对照组和其余各添加水平组(P<0.05),蛋壳强度高于对照织和除吡啶羟酸铬2.0mg/kg铬组外的其余各添加水平组(P<0.07)。本研究结果表明,两种铬源对热应激产蛋鸡的多数观测指标的作用效果相似,但三氯化铬在提高蛋壳品质和细胞免疫功能方面的作用效果优于吡啶羟酸铬;三价铬可改善热应激产蛋鸡蛋黄颜色和蛋壳质量,降低血清甘油三酯含量,提高热应激产蛋鸡的细胞免疫功能和血清AKP活性;热应激产蛋鸡获得最佳蛋壳品质及细胞免疫功能时的饲粮铬添加水平至少为10.omg/kg,而获得最佳蛋黄颜色、最大血清AKP活性和最低血清甘油三酯时需添加的铬水平为2.0mg/kg。更多还原

【Abstract】 An experiment was conducted using a total of 120 49-week old Beijing Red commercial layers to investigate the effects of dietary added chromium (Cr) source and Cr level on egg production performance, egg quality, serum biochemical traits and immune responses of heat stressed layers. Layers were randomly allotted by egg production rate to one of five treatments according to the completely randomized design involving a 2 X 3 factorial arrangement, and fed a basal corn-soybean meal diet (control) and the basal diets supplemented with 2.0 or 10.0 mg/kg Cr as either Cr chloride or Cr picolinate under heat stress (36 ±2℃ from 9:00 to 17:00, and 28±2℃ for the rest time of each day) for 30 days, respectively. Layers were allowed ad libitum access to feed and tap water. Chromium source affected (P<0.04) eggshell thickness, eggshell percentage, serum triglyceride (TG) concentration and blood T lymphocyte conversion rate, but had no effect (P>0.10) on other indices measured. Chromium level influenced (P<0.10) average daily feed intake (ADFI), feed/egg ratio, eggshell thickness, eggshell percentage, egg yolk color, serum triglyceride (TG) concentration, alkaline phosphatase (AKP) activity, and blood T lymphocyte conversion rate, but had no effect (P>0.12) on other indices measured. Layers fed the diet containing 2.0 mg/kg added Cr had higher ADFI (P<0.04) than those fed the control diet, but layers fed the diet containing 10.0mg/kg added Cr had similar ADFI (P>0.14) to layers fed the control diet or those fed the diet containing 2.0 mg/kg added Cr; Layers fed the diets supplemented with 2.0 and 10.0 mg/kg Cr had deeper egg yolk color (P<0.09) than those fed the control diet except for those fed the diet with 10.0mg/kg added Cr at week 2 (P>0.76); Layers fed the diets supplemented with 2.0 and 10.0 mg/kg Cr had higher feed/egg ratio (P<0.06) and serum AKP activity (P<0.07), lower serum triglyceride (P<0.07) than those fed the control diet, but no differences (P>0.64) for the above indices were observed between the layers fed the two added Cr level diets. Chromium source by Cr level interactions (P<0.01) were observed for eggshell strength, eggshell thickness, eggshell percentage and blood T lymphocyte conversion rate. Layers fed the diet containing 10.0 mg/kg added Cr as Cr chloride had highest (P<0.05) eggshell thickness and eggshell percentage and blood T lymphocyte conversion rate, and higher (P<0.07) eggshell strength than those fed all other diets except for the diet containing 2.0 mg/kg added Cr as Cr picolinate. The results from this study indicate that the two Cr sources had similar effects on most indices measured, but Cr from Cr chloride was more effective than Cr from Cr picolinate in improving eggshell quality and cell-mediated immune response of heat stressed layers; Chromium could improve egg yolk color and eggshell quality, and decrease serum triglyceride concentration and enhance cell-mediated immune response and serum AKP activity of heat stressed layers; And at least 10.0 mg/kg added Cr to the basal diet was required for the best eggshell quality and cell-mediated immune response, and 2.0 mg/kg added Cr for the best egg yolk color and highest AKP activity and lowest serum triglyceride.更多还原