饲粮蛋白质水平和限饲对冬毛期水貂生产性能、消化代谢和血清生化指标的影响

本试验旨在研究饲粮蛋白质水平和限饲对冬毛期水貂生产性能、消化代谢和血清生化指标的影响。选择150日龄健康美国短毛黑公貂40只,随机分为4组,每组10个重复,每个重复1只。Ⅰ、Ⅱ、Ⅲ组水貂分别饲喂蛋白质水平为22%、32%、42%的试验饲粮,Ⅳ组为限饲组,饲喂蛋白质水平为32%的试验饲粮,饲喂量为Ⅱ组的50%。预试期7 d,正试期53 d。结果表明:饲粮蛋白质水平对水貂的165日龄体重、体长、鲜皮长、鲜皮重、针毛长度和绒毛长度均无显著影响(P>0.05),但均以Ⅱ组的值最高。Ⅱ组的180和195日龄体重显著高于Ⅲ组(P<0.05),针毛细度和绒毛细度极显著高于Ⅰ、Ⅲ组(P<0.01)。饲粮蛋白质水平对水貂的干物质采食量无显著影响(P>0.05)。Ⅱ组的干物质排出量显著低于Ⅰ组(P<0.05),干物质、粗脂肪和碳水化合物消化率则极显著高于Ⅰ组(P<0.01),与Ⅲ组无显著差异(P>0.05)。Ⅱ组的沉积氮、净蛋白质利用率和蛋白质生物学价值显著或极显著高于Ⅰ、Ⅲ组(P<0.05或P<0.01)。Ⅰ、Ⅱ和Ⅲ组的血清白蛋白和球蛋白含量无显著差异(P>0.05),但Ⅱ组的血清总蛋白含量显著高于Ⅲ组(P<0.05)。Ⅱ组的血清谷草转氨酶活性极显著高于Ⅰ、Ⅲ组(P<0.01),血清碱性磷酸酶活性则显著低于Ⅰ组(P<0.05)。与Ⅱ组相比,Ⅳ组的针毛细度、绒毛细度、干物质采食量、干物质排出量、干物质消化率、粗蛋白质消化率、粗脂肪消化率、碳水化合物消化率、食入氮、沉积氮、净蛋白质利用率、蛋白质生物学价值以及血清谷草转氨酶活性显著或极显著降低(P<0.05或P<0.01),而血清谷丙转氨酶活性显著升高(P<0.05)。由此得出,冬毛期水貂饲粮适宜的蛋白质水平为32%。50%限饲对冬毛期水貂的体长、鲜皮长、鲜皮重、针毛长度和绒毛长度无显著影响,但是对针毛细度、绒毛细度以及蛋白质、脂肪和碳水化合物的消化率有显著影响。因此,在不影响水貂营养物质消化代谢和生产性能的基础上,适宜的限饲水平还有待于进一步研究。     

热应激对泌乳盛期奶牛的采食量和消化率的影响

[目的]探讨热应激对奶牛采食量和饲料中营养物质消化率的影响。[方法]通过采用单因子水平随机设计。[结果]奶牛热应激时采食量显著下降,在轻微和中度热应激期采食量分别下降3.65%和13.46%;营养物质的消化率也显著下降(P0.05),奶牛在轻度和中度热应激期粗脂肪的消化率分别降低了6.17%、13.03%;钙的消化率分别降低了25.09%、34.97%;磷的消化率分别降低了22.77%、36.27%。[结论]奶牛热应激时采食量显著下降(P0.05);饲料中营养物质消化率粗脂肪、钙、磷的消化率与非热应激期相比,差异显著(P0.05)。     

热应激对泌乳盛期奶牛的采食量和饲料中营养物质消化率的影响

[目的]探讨热应激对奶牛采食量和饲料中营养物质消化率的影响。[方法]通过采用单因子水平随机设计。[结果]奶牛热应激时采食量显著下降,在轻微和中度热应激期采食量分别下降3.65%和13.46%;营养物质的消化率也显著下降(P0.05),奶牛在轻度和中度热应激期粗脂肪的消化率分别降低了6.17%、13.03%;钙的消化率分别降低了25.09%、34.97%;磷的消化率分别降低了22.77%、36.27%。[结论]奶牛热应激时采食量显著下降(P0.05);饲料中营养物质消化率粗脂肪、钙、磷的消化率与非热应激期相比,差异显著(P0.05)。     

饲粮赖氨酸和蛋氨酸水平对冬毛生长期银狐生长性能、营养物质消化率、血清生化指标及毛皮性状的影响

本试验旨在研究饲粮赖氨酸和蛋氨酸水平对冬毛生长期银狐生长性能、营养物质消化率、血清生化指标及毛皮性状的影响。选取70只120日龄、平均体重为(5 973±94)g的健康雄性银狐,随机分成7组,每组10个重复,每个重复1只银狐。采用二因子试验设计,赖氨酸添加水平分别为0、0.50%,蛋氨酸添加水平分别为0、0.25%、0.50%、0.75%,基础饲粮中赖氨酸含量为1.15%,蛋氨酸含量为0.66%。试验期51 d。结果表明:1)饲粮赖氨酸和蛋氨酸水平对冬毛期银狐生长性能无显著影响(P>0.05)。2)饲粮赖氨酸和蛋氨酸交互作用对营养物质采食量、排出量及消化率无显著影响(P>0.05);饲粮赖氨酸水平对营养物质采食量、蛋白质排出量及蛋白质消化率无显著影响(P>0.05),对干物质排出量、干物质消化率、脂肪排出量及脂肪消化率产生显著或极显著影响(P<0.05或P<0.01);饲粮蛋氨酸水平仅对干物质排出量产生显著影响(P<0.05)。3)饲粮赖氨酸和蛋氨酸交互作用对血清总氨基酸含量产生极显著影响(P<0.01),对血清总蛋白、白蛋白、尿素氮含量及丙氨酸氨基转移酶、天门冬氨酸氨基转移酶活性无显著影响(P>0.05);饲粮赖氨酸水平对血清总氨基酸含量产生极显著影响(P<0.01);饲粮赖氨酸水平对血清天门冬氨酸氨基转移酶活性产生极显著影响(P<0.01)。4)饲粮赖氨酸和蛋氨酸交互作用对毛皮性状影响不显著(P>0.05);饲粮赖氨酸或蛋氨酸水平对毛皮性状无显著影响(P>0.05)。从降低饲养成本和减少排放角度考虑,冬毛期银狐在基础饲粮中添加0.50%赖氨酸(实际含量1.65%)和0.25%蛋氨酸(实际含量0.91%)对银狐生产有利。     

饲粮粗蛋白质和粗脂肪水平对冬毛期雄性水貂生长性能、营养物质消化率及氮代谢的影响

本试验旨在研究饲粮粗蛋白质(CP)和粗脂肪(EE)水平对冬毛期雄性水貂生长性能、营养物质消化率及氮代谢的影响,以明确冬毛期水貂饲粮CP和EE的适宜水平。试验采用2×3因子试验设计,即2个CP水平(32%和36%)和3个EE水平(10%、20%和30%),共配制6种试验饲粮。选取84只(120±5)日龄健康雄性水貂,随机分成6组,每组14个重复,每个重复1只。预试期7 d,正试期85 d。结果表明:32%CP组水貂平均日增重(ADG)、蛋白质消化率、脂肪消化率、碳水化合物消化率及氮代谢各指标均显著或极显著低于36%CP组(P0.05或P0.01)。30%EE组水貂末重、ADG和氮沉积含量显著或极显著高于10%EE组(P0.05或P0.01);30%EE组水貂平均日采食量、料重比、干物质消化率、蛋白质消化率、碳水化合物消化率、食入氮含量和粪氮排出量显著或极显著低于10%EE组(P0.05或P0.01)。饲粮CP和EE水平对水貂脂肪消化率有显著交互作用(P0.05)。综合以上指标,在本试验条件下,饲粮CP水平为36%、EE水平为20%或30%时,冬毛期水貂可获得较佳的生长性能,且能够提高水貂对蛋白质的利用率。     

雌性水貂准备配种期日粮适宜脂肪水平的研究

为探讨水貂准备配种期日粮脂肪水平对日粮中营养物质消化率和水貂氮代谢的影响,确定水貂准备配种期日粮适宜脂肪水平。试验选取体重相近的健康母貂120只,随机分成4组,每组30只,分别饲喂以黄花鱼、膨化玉米和动物下脚料等配制的鲜全价饲料。饲粮蛋白质水平相同,为34%,脂肪水平分别为日粮干物质的8%、12%、16%和20%,试验从12月初至配种前,试验中期进行水貂消化代谢试验。结果表明:日粮脂肪水平对水貂干物质消化率和蛋白质消化率影响差异不显著(P>0.05),日粮脂肪水平对日粮中脂肪的消化率有极显著的影响(P<0.01),随着脂肪水平的增加,脂肪消化率有增加的趋势。准备配种期当日粮脂肪水平达到12%以上时,水貂的日采食量,日氮食入量和氮沉积极显著降低(P<0.01),当日粮脂肪水平为8%时,水貂的采食量与日粮脂肪水平为12%组差异不显著(P>0.05),蛋白质消化率、氮食入量、氮沉积都显著高于其他脂肪水平日粮组(P<0.01),同时粪氮和尿氮排出量与其他脂肪组差异不显著(P>0.05)。综合以上指标,考虑节能环保,并能有效提高水貂饲料利用率,减少饲料成本,得出准备配种期水貂日粮脂肪水平为8%即可满足水貂的生产需要。     

饲粮维生素B2添加水平对冬毛期水貂生长性能、毛皮品质、营养物质消化率及氮代谢的影响

本试验旨在研究饲粮维生素B2添加水平对冬毛期水貂生长性能、毛皮品质、营养物质消化率及氮代谢的影响。选取(135±5)日龄、体重相近的健康雄性短毛黑水貂90只,随机分为6组,每组15个重复,每个重复1只水貂。各组水貂分别饲喂在基础饲粮中添加0(Ⅰ组,对照组)、2.5(Ⅱ组)、5.0(Ⅲ组)、10.0(Ⅳ组)、20.0(Ⅴ组)、40.0 mg/kg(Ⅵ组)维生素B2的试验饲粮。预试期5 d,正试期63 d。结果表明:1)饲粮维生素B2添加水平对冬毛期水貂末重、平均日增重、平均日采食量无显著影响(P0.05)。Ⅴ和Ⅵ组水貂料重比极显著低于对照组(P0.01),与Ⅱ、Ⅲ和Ⅳ组差异不显著(P0.05)。2)饲粮维生素B2添加水平对水貂毛皮品质评分和体长无显著影响(P0.05)。Ⅴ组水貂绒毛长极显著高于其他各组(P0.01),Ⅳ和Ⅴ组水貂针毛长极显著高于Ⅰ、Ⅱ、Ⅲ和Ⅵ组(P0.01)。3)饲粮维生素B2添加水平对水貂干物质消化率、蛋白质消化率和脂肪消化率无显著影响(P0.05)。4)饲粮维生素B2添加水平对水貂食入氮、尿氮、粪氮和沉积氮无显著影响(P0.05)。Ⅴ组水貂净蛋白质利用率显著高于对照组(P0.05),Ⅴ和Ⅵ组水貂蛋白质生物学价值显著高于Ⅰ、Ⅱ和Ⅲ组(P0.05)。综合以上指标,从提高生长性能和减少饲料成本角度考虑,冬毛期水貂饲粮中维生素B2适宜添加水平为2.5 mg/kg(饲粮中维生素B2实际含量为5.49 mg/kg)。     

饲粮锌添加水平对繁殖期雄性水貂繁殖性能、营养物质消化率及氮代谢的影响

本试验旨在研究饲粮锌添加水平对繁殖期雄性水貂繁殖性能、营养物质消化率及氮代谢的影响。选择健康后备种雄性水貂60只,随机分成5组,每组12个重复,每个重复1只貂。各组水貂分别饲喂锌添加水平为0(Ⅰ组)、50(Ⅱ组)、100(Ⅲ组)、200(Ⅳ组)、400 mg/kg(Ⅴ组)的试验饲粮。预试期7 d,正试期120 d。结果表明:1)Ⅰ组精子活力极显著低于Ⅱ组和Ⅲ组(P<0.01),显著低于Ⅴ组(P<0.05);Ⅰ组睾丸直径极显著小于Ⅱ组(P<0.01),显著小于Ⅲ组(P<0.05);Ⅰ组公貂成功配种次数极显著小于Ⅲ组(P<0.01),显著小于Ⅱ组和Ⅳ组(P<0.05)。2)各组干物质采食量、脂肪消化率差异不显著(P>0.05);Ⅲ组干物质排出量显著高于Ⅰ组(P<0.05);Ⅱ组干物质消化率极显著高于Ⅴ组(P<0.01),显著高于Ⅳ组(P<0.05);Ⅱ组和Ⅲ组蛋白质消化率显著高于Ⅴ组(P<0.05)。3)各组食入氮、尿氮、氮沉积、净蛋白质利用率、蛋白质生物学价值均差异不显著(P>0.05)。由此可见,饲粮锌添加水平为50～100 mg/kg(总锌水平140～190 mg/kg)时,水貂的繁殖性能较为理想。饲粮锌添加水平为100 mg/kg(总锌水平190 mg/kg)时,水貂的干物质采食量较高。饲粮锌添加水平对水貂的干物质采食量、脂肪消化率、氮沉积、净蛋白质利用率及蛋白质生物学价值影响不显著。     

饲粮粗蛋白质与外源褪黑激素水平对水貂生长性能、血清生化指标及营养物质消化率的影响

本试验旨在研究饲粮粗蛋白质(CP)和外源褪黑激素(MT)水平对水貂生长性能、血清生化指标及营养物质消化率的影响。选取90只50日龄体重一致的健康雄性水貂,随机分为6组,每组15个重复,每个重复1只水貂。采用3×2两因子试验设计,即3个饲粮CP水平(32%、36%和40%)和2个皮下埋植的外源MT水平(0、10 mg/只)。试验期64 d。结果表明:1)40%CP水平时,10 mg/只MT组水貂末重显著高于0 mg/只MT组(P<0.05);32%CP水平时,10 mg/只MT组水貂平均日增重显著高于0 mg/只MT组(P<0.05);饲粮CP和外源MT水平对水貂末重、平均日增重无显著互作效应(P>0.05)。2)32%和40%CP水平时,皮下埋植10mg/只MT可极显著降低水貂血清白蛋白(ALB)含量(P<0.01);32%CP水平的血清甘油三酯(TG)含量均显著高于40%CP水平(P<0.05);饲粮CP和外源MT水平对水貂血清ALB含量存在极显著互作效应(P<0.01),对血清总蛋白(TP)、尿素氮(UN)、TG含量和碱性磷酸酶(ALP)活性无显著互作效应(P>0.05)。3)10 mg/只MT组中,32%和36%CP水平的水貂干物质采食量极显著高于40%CP水平(P<0.01);0 mg/只MT组水貂中,32%CP水平的干物质采食量和干物质排出量极显著高于40%CP水平(P<0.01);饲粮CP和外源MT水平对水貂采食量、干物质采食量、干物质排出量和干物质消化率均无显著互作效应(P>0.05)。4)10 mg/只MT组中,36%CP水平的水貂粗脂肪消化率显著高于32%和40%CP水平(P<0.05),32%CP水平的水貂钙消化率极显著高于40%CP水平(P<0.01),32%CP水平的水貂磷消化率极显著高于36%和40%CP水平(P<0.01);0 mg/只MT组中,36%CP水平钙消化率极显著高于40%CP水平(P<0.01),32%CP水平的水貂磷消化率极显著高于36%和40%CP水平(P<0.01);饲粮CP和外源MT水平对水貂CP、粗脂肪、钙和磷的消化率无显著互作效应(P>0.05)。综合本试验各项测定指标可以得出,皮下埋植10 mg/只外源MT时,水貂较适宜的饲粮CP水平为32%～36%。     

半胱胺对育成期雄性水貂生长性能、营养物质消化率及氮代谢的影响北大核心CSCD

本试验旨在研究半胱胺对育成期雄性水貂生长性能、营养物质消化率及氮代谢的影响。采用双因子试验设计,选取56只(86±5)日龄、体重相近的健康雄性水貂,随机分为7组,每组8个重复,每个重复1只。Ⅰ组(对照组)饲喂基础饲粮,Ⅱ、Ⅲ、Ⅳ组分别饲喂在基础饲粮风干基础上添加60、90和120 mg/kg半胱胺的试验饲粮,添加方式为连续添加,Ⅴ、Ⅵ、Ⅶ组试验饲粮分别同Ⅱ、Ⅲ、Ⅳ组,添加方式为间隔添加(连续添加1周,间隔1周)。预试期7 d,正试期53 d。结果表明:1)间隔添加组的末重及平均日采食量、平均日增重显著或极显著高于连续添加组(P<0.05或P<0.01)。90 mg/kg组平均日采食量显著高于60 mg/kg组(P<0.05),60和90 mg/kg组料重比均显著低于120 mg/kg组(P<0.05)。半胱胺的添加方式和添加水平对水貂各生长性能指标的影响无显著交互作用(P>0.05)。2)间隔添加组干物质、粗脂肪消化率显著或极显著高于连续添加组(P<0.05或P<0.01)。半胱胺添加水平对水貂各营养物质消化率无显著影响(P>0.05),但均以90 mg/kg组最高。半胱胺的添加方式和添加水平对水貂各营养物质消化率的影响无显著交互作用(P>0.05)。3)半胱胺添加方式和添加水平均显著影响水貂食入氮(P<0.05),间隔添加组极显著高于连续添加组(P<0.01),90 mg/kg组显著高于60 mg/kg组(P<0.05),但对粪氮、尿氮排出量及净蛋白质利用率和蛋白质生物学价值无显著影响(P>0.05)。此外,半胱胺添加方式和添加水平对水貂尿氮排出量存在显著交互作用(P<0.05)。综合各项指标,育成期雄性水貂饲粮中半胱胺的适宜添加量为90 mg/kg,添加方式为间隔添加(连续添加1周,间隔1周)。     

不同填饲量对北京鸭胴体品质、体脂沉积和营养物质表观消化率的影响

旨在研究不同填饲量对北京鸭胴体品质、体脂沉积及营养物质表观消化率的影响。选取35日龄健康、大小均匀的W系雄性北京鸭96只,随机分成8个处理,每处理6个重复,每个重复2只鸭。基础日粮中加入0.5%的Cr2O3作为外源指示剂测定填鸭营养物质表观消化率,对照组自由采食,试验组在35和36日龄时分别填饲260和300g.d-1的基础日粮,之后5d各处理填饲量保持不变,分别为300、330、360、390、420、450、480g.d-1,试验期为7d。结果表明:(1)不同填饲量对北京鸭屠体率、全净膛率、胸肌率、腿肌质量和腿肌率影响不大(P>0.05),而对北京鸭胸肌质量影响显著(P<0.05),并随填饲量的增加呈现先升高后平稳的趋势,以胸肌质量为评定指标,采用直线折线模型进行估算的最适填饲量为390.7g.d-1。不同填饲量对北京鸭皮脂质量、皮脂率、腹脂质量、腹脂率、肝脏质量、肝重率和肝脂率均有显著的影响(P<0.05),但填饲量增加到一定值后,体脂沉积量保持稳定(P>0.05);(2)在填饲期,不同填饲量对北京鸭干物质和粗蛋白表观消化率影响显著(P<0.05),而对能量表观消化率影响不大(P>0.05)。以上结果表明,填饲能够快速增加北京鸭的体脂沉积,对胸肌生长发育影响显著,但随填饲量的增加,营养物质表观消化率下降,填鸭体脂沉积量不再增加。     

On-farm evaluation of the effect of coffee pulp supplementation on milk yield and dry matter intake of dairy cows grazing tropical grasses in central Mexico

Tropical grasses are the primary nutrient resource for cattle production in the tropics, and they provide low-cost nutrients to cattle. However, its production is constrained by seasonal changes and quality; hence, appropriate usage of relatively inexpensive agricultural by-products is important to profitable livestock production. The objective of the study was to evaluate the effect of supplementing coffee pulp to dairy cows grazing tropical grasses on milk yield and forage intake. Four multiparous crossed Holstein–Brown Swiss–Zebu cows of similar weight and milk yield were used. The effect of 10%, 15% and 20% inclusion of coffee pulp in dairy concentrates on milk yield and forage intake was analysed using a 4 × 4 Latin square design. Results showed that there were no significant effects (P > 0.05) in grass dry matter intake, milk yield, milk composition body weight and body condition score due to the inclusion of coffee pulp in the dairy concentrates. It is concluded that coffee pulp can be included at levels of 20% in the concentrate without compromising significantly (P > 0.05) milk yield, milk composition and grass dry matter intake. It also was concluded that cost of concentrate is reduced in 20% by the inclusion of coffee pulp.     

Effects of Different Dietary Crude Protein Levels on the Nutrient Absorbability in the Small Intestine of Lambs

This experiment was conducted to study the effects of different dietary crude protein levels on the nutrient absorbability in the small intestine of lambs.Three Kazakh lambs (30 kg body weight) fitted with permanent ruminal,duodenal and ileal fistula were selected.3×3 Latin square design was adopted.A dual-phase marker system with LiCr-EDTA and Yb-Ac as the liquid-phase or particulate-phase digesta flows maker was adopted to measure the true digesta flows at duodenal and ileal fistula,respectively.The results showed that nitrogen intake,total tract apparent digestibility,N deposition,the apparent digestibility of dry matter and organic matter were significantly increased with increasing levels of dietary crude protein (P<0.05),but had no significant effects on intestinal digesta flows (P>0.05).Increasing dietary crude protein levels had significant effects on most part of nutrients of duodenal digesta except fat and purine (P<0.05),while it only significantly effected CP,Ash,dry matter,neutral detergent fibre and acid detergent fiber of ileal digesta flows (P<0.05).In addition,intestinal absorbability of nutrients except for CP,Ash,dry matter,neutral detergent fibre and acid detergent fiber were significantly affected with increasing levels of dietary crude protein(P<0.05).The test provided basis for further study of the effects of dietary CP level on the digestibility and utilization of lamb.     

低温高能饲粮对笼养产蛋鸭生产性能及生化指标的影响

本文研究了低温高能饲粮对笼养产蛋鸭生产性能和生化指标的影响。结果表明 :(1)低温使日采食量、料蛋比显著升高 (P<0.01) ,使日产蛋量、产蛋率显著降低 (P<0.05) ;高能饲粮则使日采食量显著降低 (P<0.05) ,使日产蛋量、产蛋率有升高的趋势 ;在低温下提高饲粮代谢能水平使日采食量、料蛋比显著降低 (P<0.05) ,使日产蛋量、产蛋率有升高的趋势。(2)低温使血清中T3 水平显著升高 (P<0.05) ,而T4 水平略有降低 ;高能饲粮使T3 水平略有降低 ,T4水平略有升高。在适温下和低温下提高饲粮代谢能水平使T3 水平有升高趋势 ,而T4 水平有降低趋势。 (3)低温显著升高血清中游离脂肪酸和尿酸水平 (P<0.01) ,显著降低血清中葡萄糖水平 (P<0.05) ;高能饲粮显著升高血清中游离脂肪酸和葡萄糖水平 (P<0.05) ,使血清中尿酸水平有降低的趋势。在适温下和低温下提高饲粮代谢能水平有使血清中游离脂肪酸、葡萄糖升高的趋势 ,使血清中尿酸有降低趋势     

Effect of feeding cassava (Manihot esculenta Crantz) root meal on growth performance,hydrocyanide intake and haematological parameters of broiler chicks

The effect of feeding cassava root meal on growth performance, hydrocyanide intake, haematological indices and serum thiocyanate concentration of broiler chicks was investigated using 300-day-old male broilers. There were five dietary treatments arranged in a 2?×?2?+?1 factorial arrangement of two processing methods of cassava root (peeled and unpeeled) included at two levels (100 and 200 g/kg) plus a control diet (maize-based diet, containing no cassava root). Each treatment was replicated six times with ten birds per replicate. The feeding trial lasted for 28 days. Control-fed birds had the highest overall (P?P?P?P?P?P?P?P?P?P?P?P?P?P?相似文献   

Effect of different dietary energy levels on physio-biochemical,endocrine changes and mRNA expression profile of leptin in goat (Capra hircus)

This study aims to assess the effect of different energy levels of restriction on physiological and genetic level adaptability. Eighteen adult nonpregnant does (average BW 33.56 kg) were used in the present study. The ewes were divided into three groups, viz., GI (n=6; control), GII (n=6; 30% feed intake of control), GIII (n=6; 40% feed intake of control). The study was conducted for 40 days covering a period of two estrous cycles. Blood samples were collected every ten days interval. The parameters studied were allometric parameters (viz., body weight, and body condition) scoring and physiological responses (viz., respiration rate, pulse rate, and rectal temperature) biochemical parameters (glucose, albumin, creatinine, cholesterol), hormones (T3, T4, cortisol, leptin) and mRNA expression profile of leptin in peripheral blood mononuclear cells (PBMC). The nutritional stress significantly (P<0.05) affected most of the parameters. There was a significant (P<0.05) reduction in Body weight, Body condition score and. The physiological responses were significantly (P<0.05) affected. Among the biochemical parameters mean serum glucose first increased significantly (P<0.05) and then stabilized in GII whereas as there was no change in serum glucose levels in GIII. Serum albumin significantly (P<0.05) affected in late stages of study. There was no significant (P<0.05) changes in serum creatinine. Among hormonal parameters there was significant decrease in T3 in both the groups; T4 increased significantly in GII on 10th day and then stabilized whereas no changes was observed in GIII. Cortisol levels increased significantly (P<0.05) in both GII and GIII. There was a significant (P<0.05) reduction in serum leptin levels in GII but in GIII significant reduction was observed only 10th and 30th day of study. The mRNA expression was significantly (P<0.05) upregulated in GII on 30th day followed by a significant downregulation whereas in GIII significant (P<0.05) downregulation was only seen on 30th and 40th days. It can be concluded from our study that animals can maintain near physiological homeostasis even at 40% energy intake levels. The animals have innate physiological ability to survive periods of nutritional stress by adjusting leptin levels which are required for maintaining the physiological normalcy.     

妊娠后期营养限制对母羊胃肠道葡萄糖转运载体相关基因表达的影响

本研究旨在研究妊娠后期营养限制对母羊胃肠道葡萄糖转运载体相关基因表达的影响。选取20只同期受孕的湘东黑山羊,随机分为2组,即对照组(自由采食)和限饲组(40%采食量限制),每组10只。预试期15 d(妊娠81~95 d),正试期39 d(妊娠96~135 d)。正试期结束后,屠宰并采取瘤胃、十二指肠、空肠、回肠以及盲肠的黏膜样品,利用实时定量PCR技术,检测Na+-葡萄糖共转运载体1(SGLT1)、Na+-葡萄糖共转运载体3(SGLT3)、易化葡萄糖转运载体2(GLUT2)和易化葡萄糖转运载体5(GLUT5)基因表达量。结果表明:限饲组与对照组相比,SGLT1基因表达量在瘤胃显著降低(P0.05),在空肠和回肠中有降低趋势(0.05≤P0.10);GLUT5基因表达量在盲肠显著降低(P0.05);而其他葡萄糖转运载体基因胃肠道表达量在限饲组和对照组差异均不显著(P0.05)。由此可见,母羊妊娠后期营养限制对胃肠道中葡萄糖转运载体基因表达有不同程度的影响,进而引起母羊机体内葡萄糖转运的改变。     

Digestibility of Buffel grass (Cenchrus ciliaris)-based diets supplemented with four levels of Gliricidia sepium hay in hair sheep lambs

The objective of this experiment was to evaluate the effect of supplementing increasing levels of Gliricidia sepium hay (GS) with different levels of inclusion of Buffel grass (BG) hay on digestibility by hair sheep lambs (2.5 to 3.5 months of age). Eight male lambs were used in a replicated 4?×?4 Latin square design with 21-day experimental periods (n?=?4). Animals were fed with BG with different levels of GS: 100 % BG (T1, control), 90 % BG?+?10 % GS (T2), 80 % BG?+?20 % GS (T3), and 70 % BG?+?30 % GS (T4). Dry matter (DM), neutral detergent fiber (NDF), and acid detergent fiber (ADF) intakes were not affected by treatments. The intake of crude protein (CP), organic matter (OM), and gross energy was higher (P?<?0.05) in those lambs fed with T4 diet than control. NDF and ADF digestibilities were higher (P?<?0.05) in T1 than in the other treatments. CP digestibility was higher (P?<?0.05) in T4 compared to T1, T2, and T3. The study showed that inclusion of GS up to 30 % with BG in forage-based diets of sheep does not affect DM and fiber intake nor influence DM and OM digestibilities but it increases CP intake and reduces NDF and ADF digestibilities.     

饲粮能量水平对育肥后期锦江牛营养物质表观消化率、瘤胃发酵及血清生化指标的影响

本试验旨在探讨饲粮能量水平对育肥后期锦江牛营养物质表观消化率、瘤胃发酵及血清生化指标的影响。试验选取育肥后期、体重相近[(355.94±35.11)kg]的锦江牛35头,分为5组,每组4个重复,每个重复1~2头牛。按照《肉牛饲养标准》(NY/T 815—2004)中350 kg肉牛日增重(1.2 kg/d)所需净能的100%(A组)、106%(B组)、112%(C组)、118%(D组)、124%(E组)配制5种不同能量水平的饲粮,5种饲粮的综合净能(NEmf)分别为6.21、6.58、6.95、7.33、7.70 MJ/kg,粗蛋白质水平一致。预试期10 d,正试期128 d。结果表明:1)随着饲粮能量水平的提高,B组和E组平均日增重最高,但与其余各组相比差异均不显著(P>0.05);B组平均干物质采食量最高,但各组间差异不显著(P>0.05);与A组相比,其余组料重比均显著降低(P<0.05)。2)随着饲粮能量水平的提高,各组间营养物质表观消化率差异不显著(P>0.05)。3)与A组相比,D组和E组瘤胃液pH显著降低(P<0.05);B组和C组瘤胃液氨态氮含量显著低于其余各组(P<0.05);各组间瘤胃液菌体蛋白含量差异不显著(P>0.05),但B组数值最高;随着饲粮能量水平的提高,各组瘤胃液总挥发性脂肪酸含量呈上升趋势,其中B组瘤胃乙酸/丙酸显著低于A组(P<0.05)。4)B组和C组血清葡萄糖含量较A组分别显著提高了19.38%和14.72%(P<0.05);B组、C组和D组血清尿素氮含量较A组显著降低(P<0.05),而血清谷丙转氨酶活性和高密度脂蛋白含量较A组显著升高(P<0.05)。综上所述,本试验条件下,随着饲粮综合净能水平的提高,未对各组育肥后期锦江牛的营养物质表观消化率造成显著性影响。但适宜能量水平的饲粮有助于瘤胃微生物蛋白的合成和氨态氮的利用,同时有助于提高锦江牛的生长代谢水平,从而提高生产效益。结合各项指标得出,综合净能为6.58 MJ/kg比较适宜育肥后期锦江牛的生产需要。     

Performance and meat quality traits of beef heifers fed with two levels of concentrate and ruminally undegradable protein

The effects of two levels of concentrate and ruminally undegradable protein (RUP) on performance, intake, digestibility, carcass characteristics, meat quality traits, and commercial cuts yield were assessed. Twenty crossbred heifers (240 kg average body weight) were used. At the beginning of the trial, four animals were slaughtered as reference group and the 16 remaining animals were randomly assigned to four treatments, in a 2 × 2 factorial design: two levels of concentrate (40% and 80%, dry matter (DM) basis) and two levels of RUP (48.79% and 27.19% of CP). At the end of the trial, all the animals were slaughtered. There was no interaction (P > 0.05) between concentrate and RUP levels. Dry matter intake and nutrients digestibility was not affected (P > 0.05) by RUP level. Heifers fed the highest RUP level had greater (P < 0.05) average daily gain (ADG). Concentrate level did not affect (P > 0.05) DMI and ADG. Heifers fed diets with 80% concentrate had greater intake of TDN and EE, and lower intake of NDF (P < 0.05). The digestibilities of all nutrients, except the NDF, were greater (P < 0.05) for the 80% concentrate diets. The RUP levels did not affect (P > 0.05) the carcass characteristics and carcass gain composition. Heifers fed 80% concentrate diets had larger (P < 0.05) longissimus muscle area and lower gain of bones (P < 0.05). Concentrate level did not affect (P > 0.05) the composition of carcass gain. There was no effect (P > 0.05) of RUP and concentrate levels on meat quality traits and commercial cut yields.