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山羊养殖多以肉用为主,肉用山羊的生产性能与养殖户的经济效益直接相关。本文分析了品种、年龄、性别、饲养方式、营养、环境等因素对肉用山羊生产性能（包括繁殖性能、生长发育性能、屠宰性能和肉品质）的影响,养殖业主可结合自身实际,采取综合措施,努力提高山羊的生产性能。 相似文献
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养猪的关键所在是母猪,而母猪的繁殖性能又起着举足轻重的作用,繁殖性能作为衡量母猪生产性能高低的一项重要指标,越来越受到种猪场及养殖专业户的重视。包括产仔性能和哺育性能,而产仔性能包括产仔数、产活仔数、初生成活率、初生重、初生窝重;哺育性能包括20日龄窝重（泌乳力）、断乳重、断乳窝重、断乳仔数、断乳成活率等指标。 相似文献
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<正>1严格选择品种选择优良的公母兔留作种用时,既要注重其生产性能(主要指产肉性能,如日增重、饲料消耗、出肉率等)的高低,也要注意其繁殖性能的高低。对于种兔来说,如果繁殖性能不高,过去的生产性能再高,利用价值也不大。所以,在选种时必须把繁殖性能作为重要指标,从高产的种兔后代选留种兔。所选的种兔生殖器官 相似文献
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猪繁殖性能障碍的防制对策 总被引：1，自引：0，他引：1
1猪繁殖性能障碍的临床表现特征及其分类1.1临床表现特征造成猪繁殖性能障碍的主要因素有遗传因素、疾病因素、营养缺乏及中毒、环境应激因素等,在临床上主要表现特征为不育、不孕、流产、胎儿畸形、产仔不足、产出弱仔、死胎、木乃伊胎、僵猪等。1.2猪繁殖性能障碍的分类根据先天性遗传因素和后天性环境因素对猪繁殖性能障碍的影响程度和性质,通常可分为永久性的不育、暂时性的不育和低繁殖力三类。2猪繁殖性能障碍的防制对策2.1遗传因素造成猪繁殖性能障碍的防制措施一是要坚决淘汰种猪;二是不能将有遗传疾患的猪留作种用。严禁近亲繁殖,… 相似文献
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血液蛋白多态性在选种中可视为一类附加性状。数量性状是由许多彼此独立的基因作用的结果 ,每个基因对性状的作用甚微 ,但遗传作用的机制仍服从孟德尔规律。牛的生产性能如产奶性能、生长性能和繁殖性能是通过有关生理活动来实现的 ,这涉及到酶、蛋白质等一系列生物活性物质的功能发挥 ,由于蛋白质 (酶 )多态性等生化性状与生同来 ,终生保持相对稳定 ,对外界环境保持相对独立性 ,如能找到生化性状对生产性能的预示物 ,就可提早选种 ,加快育种进度。本文综述了血液中血红蛋白、运铁蛋白、血清白蛋白位点的不同基因型多态性与产奶性能、繁殖性能、生长性能、疾病发生的研究进展情况 相似文献
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研究测定了杜大蒲猪的生长肥育性能、胴体品质和肉质特性。结果表明,杜大蒲猪生长速度较快,饲料报酬较高,30-100 kg平均日增重为725.23 g,料重比2.88。杜大蒲猪的屠宰率、眼肌面积和瘦肉率较高,分别为74.70%、43.38 cm2、64.53%。杜大蒲猪肉色、大理石纹评分和肌内脂肪含量分别为3.63、3.00、2.49%。每100 g背最长肌氨基酸总量、鲜味氨基酸含量和必需氨基酸含量分别为19.36、15.34、7.62 g;鲜味氨基酸占总氨基酸的比例和必需氨基酸占总氨基酸的比例分别为79.22%和39.36%。棕榈酸、硬脂酸、油酸和亚油酸含量分别为24.43%、11.59%、42.84%和9.85%。 相似文献
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In order to investigate the effects of benzoic acid on growth performance, nutrient digestibility, nitrogen balance and gastrointestinal microflora of piglets, we conducted a performance experiment and a separate balance study. The performance experiment involved four different dietary treatments: (1) basal diet (negative control); (2) basal diet supplemented with benzoic acid at 5 g/kg; (3) basal diet supplemented with benzoic acid at 10 g/kg; (4) basal diet supplemented with potassium diformate at 12 g/kg. Each dietary treatment was assigned to nine replicate groups, each consisting of two piglets. Live weight, daily weight gain, feed intake and feed conversion ratio were monitored as performance parameters over a 35-day period. Supplementation of the diet with benzoic acid resulted in a dose-dependent increase in feed intake and body weight gain and an improved feed conversion ratio. Piglets fed the diet supplemented with benzoic acid at 10 g/kg outperformed the control piglets in mean feed intake, body weight gain and feed conversion ratio by 9%, 15% and 6% respectively. Growth performance of the piglets fed the diet with benzoic acid at 10 g/kg was similar to that of piglets fed the diet supplemented with potassium diformate. In the balance experiment three groups of six piglets each were fed either a control diet or diets supplemented with benzoic acid at 5 or 10 g/kg respectively. Benzoic acid did not significantly affect nutrient digestibility but increased nitrogen retention. Piglets fed the diets supplemented with benzoic acid at 5 or 10 g/kg retained 5% and 6% more nitrogen, respectively, than control piglets. Supplementation of benzoic acid did not influence the pH value or the concentration of ammonia in the gastrointestinal tract but reduced the number of bacteria in the digesta. In the stomach the number of total aerobic, total anaerobic, lactic acid forming and gram-negative bacteria was reduced; in the duodenum the presence of benzoic acid reduced the number of gram-negative bacteria and in the ileum the number of total aerobic bacteria in a dose-dependent manner. Benzoic acid also considerably reduced the concentration of acetic acid in the duodenum. In conclusion, the data of this study suggest that benzoic acid exerts strong antimicrobial effects in the gastrointestinal tract of piglets and therefore enhances growth performance and nitrogen retention. 相似文献
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In blood serum of dairy cows of the Slovak Pied breed with high and low performance, the levels of total protein, urea, amino nitrogen, non-protein nitrogen and uric acid were studied over the period of four to six weeks after calving. Total protein was determined by the Bio-La-test, amino nitrogen by means of ninhydrin, non-protein nitrogen by Berthelot agent and uric acid by Benedict agent. In comparison with dairy cows with low performance, the dairy cows with high performance had a statistically significantly higher level of total protein, urea, amino nitrogen and non-protein nitrogen. The differences in uric acid content were statistically insignificant. 相似文献
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1. The effects of dietary calcium, available phosphorus, amino acid and antibiotic supplements on the digestibilities of amino acids and growth of broiler chickens were investigated in two experiments. 2. The performance of chickens fed on diets containing high concentrations of calcium and available phosphorus was poorer with meat meal-based diets than with soyabean-based diets. Methionine supplementation improved the performance of chickens fed meat meal-based diets. 3. A high dietary content of calcium (25.9 vs 11.8 g/kg) reduced chick performance and the digestibility of glutamic acid, leucine and phenylalanine but increased the digestibility of lysine and histidine. 4. High dietary contents of calcium and available phosphorus (24.3 and 13.0 vs 11.8 and 4.0 g/kg) reduced chick performance and the digestibilities of most amino acids. 5. Antibiotic supplementation did not improve the performance of chickens, but increased the digestibilities of most amino acids in chickens fed on diets with a high calcium or high calcium and available phosphorus contents. 6. It was concluded that excess dietary calcium alone, or calcium and phosphorus together, reduced chick performance and the digestibilities of most amino acids. Growing chickens tolerated excess dietary calcium and available phosphorus better in well-balanced amino acid diets, such as soyabean meal or methionine-supplemented meat meal diets, than in poorly balanced amino acid diets, such as unsupplemented meat meal diets. 相似文献
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