乌金猪日粮能量水平对生长性能和胴体品质的影响

本文旨在研究日粮不同能量水平对乌金猪生长性能及胴体品质的影响,采用模糊综合评定系统分析确定最佳生长性能和胴体品质所需的日粮适宜能量水平.试验采用单因子随机分组设计,选取体重15 kg左右的乌金猪90头,随机分为5组,每组18头.日粮能量水平分别为14.22、13.60、12.98、12.36和11.74 MJ/kg.结果表明,随日粮能量水平的降低,不同生长阶段的日增重逐渐降低,料重比逐渐升高,15～30 kg阶段日增重无显著差异(P>0.05).在60和100 kg体重时随日粮能量水平的降低,瘦肉重、瘦肉率和眼肌面积增加,脂肪重、脂肪率和背膘厚降低.通过拟合曲线确定15～30 kg、30～60 kg和60～100 kg阶段最佳生长性能所需的日粮适宜能量水平分别为14.01、13.15和12.98 MJ/kg.确定15～30 kg、30～60 kg和60～100 kg阶段时获得最优胴体品质时,适宜的日粮能量水平分别为11.13、11.36和11.71 MJ/kg.综合评定生长性能和胴体品质,15～30 kg、30～60 kg和60～100 kg阶段,乌金猪获得最佳生长性能的胴体品质的日粮适宜能量水平分别为13.55、12.81和13.20 MJ/kg.研究结果为乌金猪的合理饲养提供科学依据.     

Association between IGF-I, IGF-IR and GHRH gene polymorphisms and growth and carcass traits in beef cattle

Molecular biology techniques are of help in genetic improvement since they permit the identification, mapping and analysis of polymorphisms of genes encoding proteins that act on metabolic pathways involved in economically interesting traits. The somatotrophic axis, which essentially consists of growth hormone releasing hormone (GHRH), growth hormone (GH), insulin-like growth factors I and II (IGF-I and IGF-II), and their associated binding proteins and receptors (GHRHR, GHR, IGF-IR and IGF-IIR), plays a key role in the metabolism and physiology of mammalian growth. The objectives of the present study were to estimate the allele and genotype frequencies of the IGF-I/SnaBI, IGF-IR/TaqI and GHRH/HaeIII gene polymorphisms in different genetic groups of beef cattle and to determine associations between these polymorphisms and growth and carcass traits. For this purpose, genotyping was performed on 79 Nellore animals, 30 Canchim (5/8 Charolais+3/8 Zebu) animals and 275 crossbred cattle originating from the crosses of Simmental (n=30) and Angus (n=245) sires with Nellore females. In the association studies, traits of interest were analyzed using the GLM procedure of SAS and least square means of the genotypes were compared by the Tukey test. Associations of IGF-I/SnaBI genotypes with body weight and subcutaneous backfat were significant (p<0.05), and nearly significant for longissimus dorsi area (p=0.06), with the BB genotype being favorable compared to the AB genotype. No significant associations were observed between this polymorphism and weight gain or carcass yield (P>0.05). The IGF-IR/TaqI and GHRH/HaeIII polymorphisms showed no association with production traits.     

The effects of short-term recombinant bovine somatotropin treatment on fattening performance,carcass composition and visceral organ weights in karayaka lambs in Turkey

Recombinant bovine somatotropin (bST) was administered s.c. to lambs for 6 weeks to evaluate its effects on fattening performance, carcass composition and visceral organ weights. Twenty male Karayaka lambs were injected with 250 mg bST every two weeks. Body weight, live weight gain, feed intake and feed conversion rate were not affected by treatment. Head, feet, skin, liver, spleen, kidneys, filled and empty gastrointestinal tract, penis, testis, pelvic fat and internal fat weights were similar for the two groups. Lung weight increased by 17.4% (P < 0.01) and weight of heart decreased 22.7% (P < 0.05) in bST treated lambs. The only carcass characteristics that were affected by bST administration were limb muscle which increased from 1331 g to 1417 g (P < 0.05), loin fat which decreased from 275 g to 174 g (P < 0.01), shoulder fat which decreased from 26 g to 13 g (P < 0.01) and total fat/final weight percentage which decreased from 9.8% to 7.6% (P < 0.05). The results of this study show that prolonged release formulation of bST treatment reduces fat tissue, but does not significantly affect fattening performance or weights of visceral organs, muscle and bone.     

饲粮能量水平对猪胴体品质和肉质的影响研究进展

能量是对饲料中三大主要有机营养物质水平高低的综合评价,能量水平的高低关系猪生长性能的好坏,同时又直接影响到猪的胴体品质和肉质。综述了能蛋比、能量饲料来源对胴体品质的影响和能量对肉质的影响情况。     

肉用黄牛育肥精料配方筛选研究

选健康西杂阉牛１８头随机分为３组分别接受３种育肥精料处理，结果表明：本试验最佳处理组试验２组较对照组日粮有更好的适口性，日头平均采食提高２．９％；ＡＤＧ提高２６．９％；精料增重比（Ｃ／Ｇ）下降１８．８３％；提高屠宰率５．７９％，净肉率４．２５％，背膘厚度１３．６４％，眼肌面积４．７６％；牛肉货架寿命延长４ｄ，大理石纹上升１个等级，脂肪颜色更佳。同时表明，加有聚醚离子载体类抗生素的试验２组较试验１组有更好增重速度，提高ＡＤＧ１０．２２％，降低Ｃ／Ｇ１０．１２％，提高了体脂沉积从而得到更理想的大理石纹与背膘厚度。     

植酸酶对肉鸡生产性能和胴体品质及肉质性状的影响

为了研究植酸酶不同添加量对肉鸡生长和胴体品质的影响。选择2周龄青脚麻鸡142只,随机分成4组。试验Ⅰ组、Ⅱ组和Ⅲ组用500g/t植酸酶分别代替60%、70%和80%的磷酸氢钙,试验Ⅳ组为对照组。试验结果表明:用植酸酶取代60%的磷酸氢钙,肉鸡的日增重和饲料报酬均优于其它试验组和对照组(P<0.05)。添加植酸酶后,肉鸡的屠宰率、全净膛率、半净膛率、腿比率和胸肌率与对照组相比较无显著差异;熟肉率、滴水损失率等肉质指标与对照组比较亦差异不显著,而肉的嫩度第Ⅲ组劣于其它各组。综上所述,在肉鸡日粮中以500g/t的植酸酶代替60%的磷酸氢钙可以提高肉鸡的生长性能,是最佳的替代比例。而对屠宰性能和肉质无明显影响。     

野鄂杂交一代猪与鄂西黑猪胴体性状的比较研究

以纯种野猪(♂)×纯种鄂西黑猪(♀)的杂交猪和鄂西黑猪为研究对象,在同样条件下饲养至80 kg屠宰,测量其体重、皮厚、背膘厚度、胴体长、胴体重、眼肌面积、花板油比例等胴体性状,研究比较野猪血缘对肉猪胴体品质和肉质性状的影响,同时比较野鄂杂交一代猪和杜长大猪肌肉中Cu、Fe、Ca等元素的含量。结果表明:野鄂杂交一代猪在屠宰率、眼肌面积、皮厚、瘦肉率方面比鄂西黑猪高,且差异极显著(P<0.01);野鄂杂交一代猪在背膘厚度、腿臀比例、花板油比例、脂肪率方面比鄂西黑猪低(P<0.05);野鄂杂交猪在胴体长度上比鄂西黑猪要长,但差异不显著(P>0.05)。野鄂杂交一代猪和杜长大猪在pH值、熟肉率方面差异不显著(P>0.05),都属于正常范围;野鄂杂交一代猪在肉色评分、大理石纹评分高于杜长大猪(P<0.05)。野鄂杂交一代猪肉中的Ca、Cu、Fe等元素的含量比杜长大低,其中Cu和Ca元素的含量有极显著差异(P<0.01),Fe元素的含量有显著差异(P<0.05)。     

性别对商品猪体尺性状、胴体性能及肉品质的影响

选择体重100 kg左右的商品猪120头,公猪去势,母猪不去势,研究了性别对猪体尺性状、胴体性能及肉品质的影响。结果表明:母猪组的腹围、倒数3~4腰椎膘厚和倒数3~4胸椎膘厚均显著低于公猪组(P<0.05);母猪组的平均膘厚和皮脂率均极显著低于公猪组(P<0.01);母猪组的倒数3~4胸椎肌肉厚度、活体瘦肉率、瘦肉率分别比公猪组提高11.52%(P<0.05)、2.80个百分点(P<0.01)、2.97个百分点(P<0.01);肉质性状母猪组与公猪组间差异不显著。     

铬对肉仔鸡生长性能、血清生化特性、免疫功能和胴体品质的影响

用294只3周龄Arbor Acres(AA)商品代肉公鸡进行试验,研究玉米-豆粕型基础日粮中添中两种铬源（三氯化铬和酵母铬）及4个铬添加水平（0、0.4、2.0和10.0mg/kg）对肉仔鸡生长性能、血清生化特性、免疫功能和胴体品质的影响。试鸡共分7组（两铬源共用零添加组）,试验期3周。结果表明,三氯化铬在提高肉仔鸡饲料转化效率及法氏囊相对重量上比酵母铬更有效（P < 0.10）,其余多数性能指标在两铬源间无显著差异(P > 0.10);日粮中添加2.0和10.0mg/kg水平铬可显著提高肉仔鸡的血清新城疫抗体效价和胸肌率(P < 0.05),铬水平对其余多数指标无影响(P > 0.10);除胸肌率(P < 0.03)外,其余指标均未观测到铬源与铬水平的互作(P > 0.10)。     

用脂肪细胞膜免疫技术提高猪胴体品质

为了在满足动物营养需要和有效控制疫病的基础上进一步提高动物生产体系的经济效益，满足市场不断变化的需求，一直在探索和发展新的促进动物生长和提高胴体品质的技术手段。在认识到激素类制剂的残留和危害后，一种更新的非激素途径——脂肪细胞膜免疫技术日益受到关注。它高效、安全和作用持久的特点成为具有广泛研究和应用前景的新技术。