蛋鸡饲料利用率及其相关性状遗传参数的估计

用约束最大似然法(REML)估计纯种与杂种蛋鸡饲料利用率及其相关性状的遗传参数,材料源于一个正反反复选择(RRS)品种洛岛红和浅花苏赛克斯的饲料利用率的选择试验。6个世代有8388只试验鸡。各遗传组合在选择标准饲料利用率及其相关性状上存在着显著性差异,且杂种优于纯种。饲料利用率、产蛋率和产蛋量的遗传力为0.1～0.3,饲料消耗量为0.4,蛋重和体重为0.4～0.8。用母鸡组分估计的遗传力大于用公鸡组分估计出的。纯种与杂种在性状饲料利用率、蛋重、体重和产蛋量上表现为强正遗传相关(>0.7),在产蛋率和饲料消耗量上为中正遗传相关(0.4左右)。     

苎麻副产物饲喂夏南牛试验初报

为验证苎麻茎叶等副产物制成的青贮饲料作为粗饲料饲喂肉牛的效果,以6头夏南牛为试验动物,以苎麻副产物青贮饲料替代部分精料,在不同育肥期进行体重测量,并采用B超进行背膘厚（FT）、眼肌面积（LA）、肌间脂肪（IMF）活体测量,育肥8个月后屠宰测量净肉率。最终对各组数据进行个体差异显著性分析。结果表明育肥前2个月增重迟缓、第3—6个月持续快速增长,后2个月增重速度降低;背膘厚度（FT）1．024-0．16cm;眼肌面积（LA）133．15±5．06cm2;肌间脂肪（IMF）7．934-0．17％;净肉率46．65±0．71％。说明利用苎麻副产物青贮饲料喂养夏南牛是可行的,苎麻青贮饲料可代替部分精饲料,可减少25％的精饲料用量,降低饲喂成本,可以在苎麻产区推广这种饲养模式。     

轮生香茶菜的组织培养和快速繁殖

以轮生香茶菜带腋芽的茎段为外植体,研究植物激素对轮生香茶菜丛生芽及不定根分化的影响,建立了轮生香茶菜的快速繁殖体系.结果表明:带腋芽幼嫩茎段以MS 6-BA 2.0mg/L培养基诱导率最高,达100%;生根培养以1/2 MS IBA 1.0mg/L培养基生根率最高,达100%.     

Effects of mycoplasmal pneumonia of swine (MPS) lung lesion‐selected Landrace pigs on MPS resistance and immune competence in three‐way crossbred pigs

To clarify the genetic influence of mycoplasmal pneumonia of swine (MPS) lesion‐selected Landrace (La) on MPS resistance and immune characteristics in three‐way crossbred pigs (LaWaDa), the LaWaDa pigs were compared with the non‐selected crossbred (LbWbDb) and purebred (La) pigs. The MPS lesion score in the three lines was as follows: La line < LaWaDa line < LbWbDb line, with significant differences among the lines. The proportions of myeloid cells and T cells were lower and higher, respectively, in the LaWaDa pigs compared with those in the other two lines. Messenger RNA (mRNA) expression of interleukin (IL)‐6, IL‐10, transforming growth factor‐β, and interferon‐γ in peripheral blood was significantly increased after vaccination in the La and LaWaDa lines. IL‐4 mRNA expression in the LaWaDa line was intermediate to the La and LbWbDb lines. Furthermore, principal component analysis for immune traits and MPS lesions was executed to clarify the characteristics of each pig line. These findings suggest that the immune responses in the three pig lines are genetically distinct and that MPS resistance and some immunity characteristics from the La line were transmitted to the three‐way crossbred pigs.     

皮埃蒙特、利木赞牛三元杂交组合幼牛产肉性能研究

本文对皮埃蒙特公牛×西黄杂种母牛 (西门塔尔公牛×当地黄牛 ,下简称皮西黄 )、利木赞公牛×西黄杂种母牛 (下简称利西黄 )两组合的三元杂交种幼牛肉用性能进行了研究。结果表明 ,两个组合肉性良好。 9月龄体重分别达 2 88.4kg和 2 5 9kg;育肥期平均日增重达 879.4g和 846.1 g。皮西黄屠宰率、净肉率、胴体产肉率和熟肉率分别为 5 8.2 5 %、47.5 0 %、81 .94%和 65 .4% ,利西黄分别为 5 5 .33%、45 .67%、82 .0 9%和 67%。皮西黄肉骨比、肉脂比、胴体优质切块比例和眼肌面积分别为4.5 5、1 0 .86、35 .1 2 %和 73.70 cm2 ;利西黄分别为 4.61、1 0 .2 3、33.38%和 63.1 0 cm2 。皮西黄产肉性能强于利西黄。     

肉牛2号对放牧条件下西杂牛的增重效果

本文研究了放牧条件下使用肉牛生长促进剂的效果，通过为期６０天的试验，喂添加剂组和不喂添加剂组的增重分别为２５ｋｇ、１７．８ｋｇ，试验组平均比对照组提高７．２ｋｇ（Ｐ〈０．０１）。试验还表明：在低日粮水平下，添加该加剂具有显著的增重效果，试验组头均收益较对照组高３６元，投入产出比为１：３，经济效益十分显著，具有推广应用价值。     

微贮秸秆和未经处理秸秆育肥肉牛对比试验

本试验利用经秸秆发酵活干菌处理的农作物秸秆和未经处理的秸秆对１６头１２月龄西杂黄牛进行育肥对比试验。结果表明：试验组牛的日增重比对照组牛日增重多０．２４４ｋｇ，提高２７．９％，差异显著（Ｐ〈０．０５）。     

西杂牛与哈萨克牛育肥对比实验

对1417月龄12头西杂一代公牛和12头哈萨克公牛进行120天的育肥,西杂一代公牛平均日增重986.5±120.45g,屠宰率55.2%,净肉率44.2%;哈萨克公牛日增重498.2±96.30g,屠宰率46.5%,净肉率36.4%。西杂一代公牛比哈萨克公牛日增重提高98.0%,屠宰率和净肉率分别提高8.7和7.8个百分点。