杂粕替代日粮中部分豆粕对蛋鸡产蛋性能及蛋品质的影响

选用45周龄京粉1号蛋鸡480只,随机分为5组,每组3个重复,每个重复32只鸡,饲喂不同比例杂粕代替豆粕的日粮,探讨不同日粮对蛋鸡生产性能及蛋品质的影响。结果表明,在蛋鸡日粮中添加5.48%棉粕、5%菜籽粕及10%棉菜粕替代豆粕,对京粉1号蛋鸡产蛋性能无显著影响（P＆gt;0.05）;同时每产1 kg蛋消耗的饲料成本玉米-棉粕和玉米-棉菜粕组,显著低于对照组（P0.05）;但由于不同日粮的适口性不同以及能量水平的差异导致各组采食量差异及显著（P0.05）,从而表明在满足有效氨基酸需要量的基础上,蛋鸡日粮粗蛋白质水平减低2个百分点是可行的。     

以可消化氨基酸为基础配制日粮对蛋用种母鸡繁殖性能和蛋白质代谢的影响

试验选用480只42周龄海兰父母代蛋种鸡,随机分为5组,每组3个重复,每个重复32只鸡。试验以可消化氨基酸为基础,用杂粕代替部分大豆粕配制日粮,研究了不同日粮对蛋用种母鸡繁殖性能和蛋白质代谢的影响。结果表明:氨基酸平衡的杂粕日粮以及氨基酸平衡的低蛋白质日粮对蛋用种母鸡的日产蛋率、料蛋比、种蛋合格率、受精率和孵化率等繁殖性能指标无显著影响(P>0.05),棉籽粕、菜籽粕、棉菜粕可分别代替5%、5.5%、10%的大豆粕;低蛋白质的氨基酸平衡日粮降低了日产蛋重(P<0.05);血浆尿素N含量以高杂粕日粮组最高,但各组差异不显著(P>0.05);血浆总蛋白含量,高杂粕日粮组比对照组高出78.74%(P<0.05)。     

杂粕型日粮添加不同酶谱的复合酶对蛋鸡产蛋性能和蛋品质的影响

旨在研究杂粕型日粮中添加不同酶谱的复合酶对蛋鸡产蛋高峰期产蛋性能及蛋品质的影响。选择1 440只300日龄、体重和产蛋率相近的海兰褐蛋鸡,随机分为5个处理,每个处理3个重复,每个重复96只鸡。对照1组饲喂玉米—豆粕型日粮,不添加复合酶;对照2组饲喂玉米—杂粕型日粮,不添加复合酶;试验1、2、3组在饲喂玉米—杂粕型日粮的基础上,分别添加复合酶1、2、3。试验期为70 d。记录并比较各处理组蛋鸡的产蛋性能和蛋品质相关指标。结果表明,与对照2组相比,试验1、2、3组的产蛋率、平均蛋重、日采食量和产蛋量均显著提高(P<0.05),料蛋比显著降低(P<0.05),其中试验3组的变化幅度最大;各试验组的产蛋率、日采食量和料蛋比与对照1组相比差异不显著(P>0.05)。试验1、2、3组蛋鸡的蛋品质与对照1组及对照2组相比差异不显著(P>0.05),且各试验组的蛋壳厚度与对照2组相比,均有提高的趋势,其中试验3组的提高幅度最大。结果提示,饲喂添加了复合酶的玉米—杂粕型日粮的处理组蛋鸡与饲喂玉米—豆粕型日粮蛋鸡的产蛋性能相近,不同酶谱的复合酶制剂对蛋鸡产蛋性能及蛋品质的改善程度有差异,其中甘露聚糖酶和蛋白酶含量较高的复合酶3效果最佳。     

在玉米-杂粕日粮中添加复合酶对商品蛋鸡生产性能及蛋品质的影响

将600只42周龄罗曼蛋鸡随机分为5组,每组5个重复,每个重复24只鸡。A组为玉米-豆粕日粮对照组,B、C组分别为用杂粕不同程度替代豆粕组成玉米-杂粕日粮试验组,D、E组分别为在B、C组基础上的加杂粕复合酶试验组,正式试验期为56d。试验结果表明,①在蛋鸡杂粕日粮中添加复合酶,在产蛋率上,处理E、处理B均显著高于处理C(P<0.05),但处理E、A、B、D各组间没有显著性差异(P>0.05);在平均日采食量、平均蛋重、料蛋比、破蛋率、软蛋率、脏蛋率的指标上,各处理组间差异不显著(P>0.05)。②在蛋鸡杂粕日粮中添加复合酶,在蛋形指数、蛋黄比例、蛋黄颜色、蛋壳比例、哈夫单位指标上,各处理组间差异不显著(P>0.05);在蛋黄指数上,处理A和处理E组差异显著(P<0.05);在蛋壳厚度上,处理A组极显著高于处理C组(P<0.01),处理E显著低于处理A(P<0.05)。     

低豆粕日粮对产蛋鸡生产性能及蛋品质的影响

试验选用1 600只生产性能相同、体况良好的33周龄罗曼蛋种鸡,随机分为4组,在总蛋白质含量相同和满足必需氨基酸需要量的情况下,用价格较低的蛋白饲料取代蛋鸡日粮中豆粕,研究氨基酸平衡的低豆粕日粮对蛋种鸡生产性能和蛋品质的影响。结果表明:氨基酸平衡的低豆粕日粮对蛋鸡产蛋率、种蛋合格率、健雏率、蛋形指数、蛋比重、蛋壳厚度、哈氏单位等指标无显著影响(P>0.05),但当日粮中的豆粕含量降低8～15个百分点时,蛋种鸡的日平均蛋重、日采食量、受精率、孵化率等显著低于正常豆粕日粮(P<0.05),而考虑综合因素日粮中的豆粕含量降低8个百分点的第1组,与正常豆粕日粮相比,差异不显著(P>0.05),而且能降低饲料成本,可以提高蛋鸡养殖效益,具有实际意义。     

玉米-杂粕型日粮中添加蛋氨酸对肉鸡生产性能的影响

本试验旨在研究在杂粕日粮中添加蛋氨酸对肉鸡生产性能的影响。试验选用12栋标准化肉鸡舍,每栋鸡舍内饲喂1日龄、体重相近的AA肉鸡6,000只。试验分为4个处理组,每个处理3个重复,每栋鸡舍为一个重复组,处理1为纯豆粕日粮组,处理2为杂粕日粮组,处理3和处理4组分别在杂粕日粮中添加0.1%和0.2%的DL-蛋氨酸。结果表明,饲喂杂粕日粮组肉鸡平均日采食量、料重比显著高于纯豆粕日粮组(P<0.05);在杂粕日粮中添加蛋氨酸,可显著降低日粮的日采食量和料重比(P<0.05),对日增重有所改善;杂粕0.2%蛋氨酸添加组与纯豆粕日粮组相比,日增重、日采食量差异不显著(P>0.05),料重比显著降低(P<0.05);杂粕中添加0.2%蛋氨酸比0.1%蛋氨酸组,料重比显著降低(P<0.05)。因此,在杂粕日粮中,合理地补充外源性氨基酸可改善日粮的营养水平,提高肉鸡生产性能。     

两种蛋鸡高峰料的应用效果试验

本试验选用40周龄伊莎褐蛋鸡1350只,随机分成2组,A组为对照组、B组为试验组,各675只鸡。通过2种蛋鸡高峰料(杂粕型蛋鸡高峰料、豆粕型蛋鸡高峰料)进行蛋鸡产蛋性能的比较。结果表明,杂粕型比豆粕型蛋鸡日粮使蛋鸡的产蛋率提高2.4%(P<0.05)。平均蛋重、采食量、料蛋比差异不显著(P>0.05)。     

饲粮钙水平对49～56周龄黄羽肉种鸡繁殖性能和胫骨性能的影响

本试验旨在研究不同饲粮钙水平对49～56周龄黄羽肉种鸡生产性能、繁殖性能(产蛋性能、孵化性能、蛋品质)、血清钙和磷含量及胫骨性能的影响。选用49周龄父母代黄羽肉种鸡540只,根据体重分为6个处理,每个处理6个重复,每个重复18只。处理1为对照组,饲喂玉米-豆粕型基础饲粮,钙水平为2.75%,处理2～6为试验组,饲喂在基础饲粮中添加不同水平石粉替代沸石粉使钙水平分别为3.00%、3.25%、3.50%、3.75%和4.00%的试验饲粮,其他营养水平各处理基本一致。试鸡限饲粉料125 g/d,自由饮水,试验期8周。结果表明:饲粮钙水平对试鸡末重、平均日增重、平均蛋重、破蛋率、不合格蛋率、孵化性能、血清钙和磷含量、胫骨性能均无显著影响(P>0.05)。3.00%钙水平组试鸡料蛋比显著低于3.50%钙水平组(P<0.05),而与其他组差异不显著(P>0.05)。3.00%钙水平组试鸡产蛋率和日产蛋重显著高于除3.25%钙水平组外的其他各组(P<0.05)。根据双折线模型估测49～56周龄黄羽肉种鸡获得最佳产蛋率和日产蛋重的饲粮钙需要量均为3.00%,日摄入量均为3.75 g/d。     

葡萄籽粕替代玉米对种鸡产蛋高峰后期生产性能、鸡蛋品质及新城疫抗体水平的影响

试验旨在研究葡萄籽粕对种鸡产蛋高峰后期生产性能、鸡蛋品质及新城疫抗体水平的影响。选取产蛋率、体重相近,健康状态良好的64周龄罗曼灰父母代种鸡810只,随机分为6组,每组5个重复,每个重复27只鸡。对照组饲喂基础日粮,试验组分别饲喂葡萄籽粕替代基础日粮中3%、4.5%、6%、7.5%、9%玉米的试验日粮(分别为试验Ⅰ、Ⅱ、Ⅲ、Ⅳ和Ⅴ组)。预试期7 d,正试期30 d。探讨日粮中添加不同水平的葡萄籽粕对种鸡产蛋高峰后期生产性能、鸡蛋品质及新城疫抗体水平的影响及其作用机理。结果表明:葡萄籽粕能够明显抑制种鸡产蛋高峰后期生产性能降低,对于日均产蛋量,试验Ⅲ组极显著高于对照组(P0.01),试验Ⅰ、Ⅱ组显著高于对照组(P0.05);试验Ⅰ、Ⅱ、Ⅲ组产蛋率较对照组分别提高了12.38%、14.76%、18.09%(P0.05),各试验组蛋鸡的日均采食量、料蛋比及破软蛋率与对照组相比差异不显著(P0.05);葡萄籽粕处理组鸡蛋的哈氏单位、蛋黄重及蛋壳强度均高于对照组,但随葡萄籽粕添加量的增加没有表现出规律性变化;葡萄籽粕能够降低鸡蛋胆固醇含量(P0.01);并能够提高种鸡新城疫HI抗体水平(P0.05)。综上,在种鸡产蛋高峰后期日粮中以葡萄籽粕替代玉米,可提高种鸡生产性能和新城疫抗体效价,改善鸡蛋品质,降低鸡蛋中胆固醇含量,且以替代6%的玉米效果较好。     

商品蛋鸡低能量日粮苏氨酸适宜需要量研究

本试验旨在探讨低能量日粮不同苏氨酸水平对产蛋高峰期海兰褐壳蛋鸡生产性能和蛋品质的影响,确定蛋鸡低能量日粮中苏氨酸的适宜水平。试验选取产蛋高峰期的海兰褐壳蛋鸡600只,随机分为5个处理,每个处理5个重复,每个重复24只鸡。采用玉米-花生粕型日粮,代谢能水平为10.89MJ/kg,苏氨酸共设5个水平,分别为:0.45%、0.50%、0.55%、0.60%、0.65%。结果表明:①低能量日粮不同苏氨酸水平对产蛋率、产蛋量有显著影响(P<0.05)。其中,产蛋率0.60%水平组显著高于0.50%组(P<0.05),其它各处理组间差异均不显著(P>0.05);产蛋量0.45%组和0.60%组显著高于0.50%组(P<0.05),其它各处理组间差异均不显著(P>0.05)。②低能量日粮不同苏氨酸水平对采食量、蛋重、料蛋比、破蛋率和日增重无显著影响(P>0.05)。③每产100kg鸡蛋所需的饲料成本0.45%组最低,经济效益最好。④低能量日粮苏氨酸水平在0.45%~0.65%试验范围内变化时,不会对鸡蛋蛋品质产生影响。综合考虑,蛋鸡低能量日粮中苏氨酸的适宜水平为0.45%,或总苏氨酸需要量为547mg/只·d。     

Yeast Culture Supplementation to Laying Hen Diets Containing Soybean Meal or Sunflower Seed Meal and Its Effect on Performance,Egg Quality Traits,and Blood Chemistry

This study was designed to investigate the effects of yeast culture supplementation to laying hen diets containing 2 oilseed meals on performance, egg traits, and some blood parameters. A total of 180 Lohmann Brown laying hens 21 wk of age were allocated to 4 dietary treatments and fed for 16 wk. Two different basal diets were prepared; one contained soybean meal and the other contained sunflower seed meal. Both of the basal diets were supplemented with 0 and 2 g/kg commercial yeast culture product (Saccharomyces cerevisiae). Yeast culture supplementation to diets containing either oilseed meal did not significantly affect feed intake, hen-day egg production, feed efficiency, interior and exterior egg quality characteristics, serum levels of total protein, triglyceride, cholesterol, alanine amino transferase, aspartate amino transferase, and alkaline phosphatase. Body weight gain (P < 0.05), egg weight (P < 0.001), and serum uric acid (P < 0.05) were increased with yeast culture supplementation. The reduction in egg yolk cholesterol was significant (P < 0.001) in the groups fed yeast-supplemented diets. The results in this study demonstrated that yeast culture supplementation to the diets containing soybean meal or sunflower seed meal increased egg weight and decreased egg yolk cholesterol without affecting performance and egg traits, but serum uric acid concentration was increased.     

Utilization of alternative protein meals with or without multiple-enzyme supplementation in broilers fed low-energy diets

An experiment was conducted to study the effect of different protein meals, with or without enzyme supplementation, on the performance of broilers. A diet based on a combination of protein meals (15% soybean meal, and 5% each of sunflower meal, canola meal, rapeseed meal, and cottonseed meal) was compared with 4 other diets containing 15% soybean meal and 20% of sunflower meal, canola meal, rapeseed meal, or cottonseed meal. Experimental diets were formulated to contain 2,630 kcal of ME/kg and 0.95% digestible lysine, with all other essential amino acids set to meet or exceed the ideal protein ratios. Each diet was fed with or without supplemental exogenous enzyme (Rovabio Excel at 500 g/metric ton of feed) to 6 replicate pens of 50 chicks from 1 to 35 d posthatch as coarse mash. In the cottonseed meal-based diet, supplemental enzyme resulted in high 35-d feed intake and FCR compared with the cottonseed meal-fed groups with no enzyme. There was a significant (P < 0.05) diet × enzyme interaction for 35-d feed intake and FCR. Birds fed the sunflower meal-based diet had significantly (P < 0.05) higher final BW gain and lower FCR as compared with those fed rapeseed meal- or cottonseed meal-based diets, whereas the BW gain of birds fed the rapeseed meal-based diet was significantly (P < 0.05) reduced compared with birds in all other groups. In conclusion, in low-ME broiler diets formulated on a digestible amino acid basis, up to 20% sunflower meal and canola meal can be safely incorporated into the diet. Supplementation of Rovabio failed to exert any positive effect on production parameters when used with diets containing high levels of each of the common protein meals.     

Long-Term Feeding of Conjugated Linoleic Acid and Fish Oil to Laying Hens: Effects on Hepatic Histopathology,Egg Quality,and Lipid Components

The present study was conducted to investigate the effect of long-term feeding of conjugated linoleic acid (CLA) and fish oil on egg quality characteristics, production performance, liver pathology, and egg fatty acid content of laying hens. Single Comb White Leghorn laying hens (n = 112), 21 wk old, were placed in cages and randomly assigned to 4 diets (28 hens/diet, 4 replicates of 7 hens) containing 3.0% yellow grease (control), 2.75% yellow grease + 0.25% CLA (YG-CLA), 2.5% yellow grease + 0.25% CLA + 0.25% fish oil (YG-CLA-FO), and 2.75% yellow grease + 0.25% fish oil (YG-FO). The experimental diets were fed for 12 mo. Eggs were collected daily for 12 mo. Feed consumption, hen-day egg production, and feed efficiency were monitored. At the end of the trial, hepatic tissue was collected for histopathology. No effect of diet was found on feed consumption, hen-day egg production, feed efficiency, egg weight, yolk weight, shell weight, or Haugh unit. The YG-CLA and YG-CLA-FO diets produced an increase in CLA and saturated fatty acids in the egg and liver tissue with a concomitant reduction in monounsaturated fatty acids (P < 0.05). Feeding YG-CLA-FO and YG-FO increased the n-3 fatty acids in egg yolk and liver of hens (P < 0.05). No difference was observed in the number of fat vacuoles in the liver tissue. The total fat content of hepatic and abdominal fat pads did not differ among treatments (P > 0.05). Regardless of the diet, as the hens aged, egg weight, yolk weight, and egg total fat increased, and shell weight decreased (P < 0.05). These data demonstrate that eggs with increased n-3 fatty acids and CLA can be generated by minor diet modifications without affecting the production performance or health of birds.     

无鱼粉日粮在蛋鸡生产中的应用研究

利用酵母和葵花粕代替日粮中的鱼粉组成无鱼粉日粮,以无鱼粉日粮和有鱼粉日粮对蛋鸡进行试验,结果为:饲喂无鱼粉日粮的试验组和饲喂鱼粉日粮对照组的产蛋率分别为67.96%和65.01%,差异不显著(P>0.05);只平均产蛋量为44.73g和42.41g,差异显著(P<0.05);平均蛋重为65.83g和62.29g,差异不显著(P>0.05);死亡率分别为1.69%和2.10%,差异不显著(P>0.05);试验组比对照组每生产1kg蛋饲养成本降低1.9%。因此无鱼粉日粮可代替鱼粉日粮在蛋鸡生产上应用。     

饲粮缬氨酸水平对蛋鸡生产性能、蛋品质及血清生化指标的影响

本文旨在研究饲粮不同缬氨酸水平对蛋鸡生产性能、蛋品质及血清生化指标的影响,并探讨蛋鸡饲粮中缬氨酸的最适添加量.试验选用720只体重相近的40周龄的海兰褐壳蛋鸡,随机分成5组,每组4个重复,每个重复36只鸡,分别饲喂缬氨酸水平为0.6％、0.7％、0.8％、0.9％、1.0％的饲粮,试验期为56 d.结果表明:1)0.8％水平组料蛋比和1.0％水平组平均日采食量分别最低,与其他各组均差异显著(P＜0.05);各组产蛋率、平均蛋重和日产蛋均重均无显著差异(P＞0.05).2)0.8％水平组蛋壳强度最大,1.0％水平组蛋清蛋白质含量最低,与其他各组均差异显著(P＜0.05)或有显著的趋势(P＜0.10);各组蛋壳厚度、哈夫单位、蛋黄颜色、蛋白高度、蛋黄和蛋清相对重均无显著差异(P＞0.05).3)0.8％水平组血清葡萄糖含量最高,显著高于其他各组(P＜0.05);0.8％水平组血清尿素氮和尿酸含量最低,总氨基酸含量最高,与其他各组均有差异显著的趋势(P＜0.10).4)二次曲线分析表明:当饲粮代谢能为11.31 MJ/kg、粗蛋白质水平为15.81％、赖氨酸水平为0.77％时,以料蛋比为评价指标,产蛋高峰期蛋鸡缬氨酸需要量为0.78％,以蛋壳强度和血清白蛋白含量为评价指标,缬氨酸需要量分别为0.81％和0.75％.由此可知,基础饲粮中添加一定量的缬氨酸可降低产蛋高峰期蛋鸡料蛋比,增强蛋壳强度和提高血清葡萄糖含量.     

发酵菜粕对蛋鸡粪便和饲料微生物菌群数量及蛋品质的影响

研究发酵菜粕对219日龄海兰褐蛋鸡粪便和饲料微生物菌群数量及蛋品质的影响。试验分为对照组和试验Ⅰ、Ⅱ、Ⅲ组,分别以0、4%、8%和12%发酵菜粕等氮替代日粮豆粕饲喂蛋鸡,以平板菌落计数法研究各组日粮和粪便中的微生物菌群数量,并测定其蛋品质。结果显示,发酵菜粕能显著减少蛋鸡日粮中大肠杆菌（P〈0.05）数量,增加乳酸菌（P〈0.01）、枯草芽孢杆菌（P〈0.01）、双歧杆菌、肠球菌和酵母菌数量;饲喂发酵菜粕日粮后,粪便中的乳酸菌（P〈0.05）、枯草芽孢杆菌（P〈0.05）、双歧杆菌、酵母菌和肠球菌等有益微生物菌群数量都有明显增加,试验I组蛋壳厚度（P〈0.01）、蛋黄颜色（P〈0.01）和哈氏单位（P〈0.05）均有明显增加,试验Ⅱ组的蛋黄颜色和哈氏单位有极显著增加（P〈0.01）,试验Ⅲ组的哈氏单位有显著增加（P〈0.05）,但三个试验组的蛋重均有显著下降（P〈0.05）。结果表明,发酵菜粕能显著增加蛋鸡日粮和粪便中有益微生物数量,减少日粮中有害微生物数量,4%~8%的添加量能提高蛋品质。     

低蛋白质氨基酸平衡饲粮对黄羽肉种鸡产蛋性能、蛋品质、孵化性能和氮排放的影响

本试验旨在研究低蛋白质氨基酸平衡饲粮对黄羽肉种鸡生产性能、蛋品质、孵化性能和氮排放的影响.选用30周龄健康的快大型岭南黄羽肉种母鸡288只,根据体重和产蛋率相近原则,随机分为4个组,每组6个重复,每个重复12只鸡.各组饲粮粗蛋白质(CP)水平分别为16％(对照组)、15％、14％、13％,各组的赖氨酸、蛋氨酸、色氨酸、...     

日粮中添加不同比例棉副产品对绵羊生产性能、营养物质消化率及血液生化指标的影响

试验旨在研究日粮中添加不同比例棉副产品对绵羊生产性能、养分表观消化率和血液生化指标的影响。选取30只健康巴尔楚克绵羊,随机分为5组,每组6只羊,各组分别饲喂由配合精料50%分别与50%麦秸（对照组）、25%麦秸和25%棉秸（Ⅰ组）、50%棉秸（Ⅱ组）、45%棉秸和5%棉籽（Ⅲ组）、40%棉秸和10%棉籽（Ⅳ组）混合的颗粒饲料,试验期60 d。结果显示：①绵羊总增重、平均日增重随着棉花秸秆添加比例的增加而降低,其中Ⅱ组绵羊总增重、平均日增重最低,显著低于Ⅲ组（P<0.05）;②日粮中添加不同比例的棉副产品后绵羊瘤胃液氨态氮出现不同程度的升高或降低,各组间总挥发性脂肪酸（TVFA）、丙酸浓度无显著差异（P>0.05）;③各试验组粪氮、尿氮和摄入氮量无显著差异（P>0.05）,而中性洗涤纤维和酸性洗涤纤维表观消化率随着棉副产品添加比例的增加极显著低于对照组（P<0.01）;④棉副产品添加比例对绵羊血液中白细胞数、红细胞数、血红蛋白浓度、总蛋白、白蛋白、球蛋白、血清铁、钠、氯、钾含量均无显著影响（P>0.05）,但随着棉副产品比例的增加,绵羊血液中镁的浓度显著提高（P<0.05）。综上所述,日粮中棉副产品添加量达到50%时,其游离棉酚浓度超过300 mg/kg,对绵羊的生产性能及健康具有一定负面影响,棉花秸秆添加量控制在低于25%的范围为宜。     

Effects of Different Dietary Cotton by-products Levels on Production Performance,Nutrient Digestibility and Blood Biochemical Indexes of Sheep

The study was conducted to determine the effects of different dietary cotton by-products levels on production performance,nutrient digestibility and blood biochemical indexes of sheep.30 healthy sheep were chosen and randomly divided into 5 groups with 6 sheep per group. The feed of each group was that 50% formula concentrate feed was mixed with 50% wheat straw (control group),25% wheat straw and 25% cotton stalk (group Ⅰ),50% cotton stalk (group Ⅱ),45% cotton stalk and 5% cotton seed (group Ⅲ),and 40% cotton stalk and 10% cotton seed(group Ⅳ), respectively. The experiment lasted for 60 d. The result showed that:① The total weight gain and ADG of sheep showed a decreased with the increase of cotton stalk added proportion in the diets, and the total weight gain and ADG of group Ⅱ were significantly lower than group Ⅲ (P<0.05).② The concentration of NH₃-N was increased or decreased at different levels after adding different proportions of cotton by-products,and the TVFA and propionic acid concentration were not significantly affected (P>0.05).③ There was no significant difference of intake nitrogen, fecal nutrogen and uninary nitrogen among groups (P>0.05),but apparent digestibility of NDF and ADF showed a downward trend with the increase of cotton by-products added proportion in the diets,which were extremely significantly lower than control group (P<0.01).④ There were no significant differences among groups of the blood white cell count,red cell count,hemoglobin concentration,total protein,albumin,globulin,serum iron,sodium,chlorine and potassium content (P>0.05),but serum magnesium was significantly increased with increases of gossypol content in the diets (P<0.05). In conclusion,when the cotton by-products addition level in diets reaches 50% caused the free gossypol concentration in the feed more than 300 mg/kg, it would has certain negative effects on the production performance and health of sheep,and the cotton stalks add ratio in the diet should be controlled in the range of lower than 25%.