杂种公牛短期育肥实验

实验选取西门塔尔肉牛品种与本地杂交所生的二代杂种公牛进行育肥。这样的牛具有适应性强、增重快、肉质好、屠宰率高等特点,被选择的育肥年龄不宜过大,体重应在350-400kg为宜。采用异地育肥技术进行舍饲栓系短期育肥、实验其育肥性能和经济效益。结果,经过3个月短期育肥,实验牛平均日增重为1.6kg,每天牛平均获纯利1 137元,具有较理想的增重效果和经济效益,说明对西门塔尔肉牛品种与本地牛杂交所生的二代杂种公牛进行短期育肥是可行的。     

杂种公牛短期育肥实验

实验选取西门塔尔肉牛品种与本地杂交所生的二代杂种公牛进行育肥。这样的牛具有适应性强、增重快、肉质好、屠宰率高等特点,被选择的育肥年龄不宜过大,体重应在350-400kg为宜。采用异地育肥技术进行舍饲栓系短期育肥、实验其育肥性能和经济效益。结果,经过3个月短期育肥,实验牛平均日增重为1.6kg,每天牛平均获纯利1 137元,具有较理想的增重效果和经济效益,说明对西门塔尔肉牛品种与本地牛杂交所生的二代杂种公牛进行短期育肥是可行的。     

西门塔尔牛TMR饲喂与传统饲喂比较

[目的]肉牛全混合日粮(TMR)是一种将粗饲料、精饲料、矿物质、维生素和微量元素等其他添加剂充分混合搅拌均匀,将水分调到45%,能够满足肉牛营养需要的饲养技术。[方法]为了比较西门塔尔牛TMR饲喂与传统饲喂方式,在固原市瑞科丰农牧科技有限公司随机选取120头西门塔尔育肥公牛作为试验牛群,对照组和试验组各60头,试验组使用TMR日粮饲喂,对照组采用传统饲喂方式饲喂,观察育肥牛生长发育情况、体重变化。[结果]结果表明,TMR饲喂的肉牛平均体重(547.9 kg),比传统饲喂平均体重(509.24 kg),相对提高了7.6%(P0.01)。TMR饲喂平均日增重(1 331.6 g/d)比传统饲喂的平均日增重(1 194.5 g/d)相对提高了11.5%(P0.01),西门塔尔公牛育肥平均体重TMR饲喂785 kg,传统饲喂为752 kg,体重增加33 kg,提高4.4%(P0.05);西门塔尔育肥公牛平均利润TMR饲喂比传统饲喂利润增加1 529.5元/头。[结论]西门塔尔牛TMR饲喂比传统饲喂优势明显,应在肉牛生产中大力推广。     

青贮甜高粱与玉米秸秆饲喂肉牛效果研究

[目的]饲喂青贮甜高粱与玉米秸秆对肉牛增重的效果研究,选择11月龄、体重280Kg 的西门塔尔公牛20头进行饲喂效果对比试验。[结果]显示：对照组、试验组平均每头日增重为0.98 kg、1.45 kg。试验组比对照组平均日多增重0.47 kg,提高47.96%;净收益每头每天比对照组多9.78元。[结论]表明：青贮甜高粱饲喂育肥肉牛增重效果明显,经济效益较好。     

两个不同品种牛杂交后代育肥效果比较的研究

正确把握育肥杂种公牛品种,育肥月龄,出栏时间可以得到很好的育肥经漳效益和社会效益,[方法]选择健康无病,发育正常,膘情中等的西门塔尔×本地黄牛二代杂种公牛和荷斯坦×本地黄牛二代杂种公牛,从5月份开始统一进行科学饲养管理,测定其增重,饲料消耗及其6,8,10,12,18月龄体重变化,[结果]结果表明,正确把握育肥杂种公牛品种,育肥月龄,出栏时间可以得到很好的育肥经济效益和社会效益,反而牛随月龄的增长,生长速度下降,肌肉组织的生长速度逐渐变缓,日增重和饲料转化率降低,日增重成本上升,经济效益下降;因此根据当地的饲草料资源和实际生产状况.选择合理的杂交后代,适时育肥和出栏时间,以获得较好的增重和饲草料转化效果,提高育肥牛的经济效益和农牧民养牛的积极性。【结论】结果提示：试验A组牛平均日增重为1．18kg,每头牛平均获纯利245老,具有较理想的增重效果和经济效益;试验B组牛平均日增重为1,09kg,每头牛平均获纯刺185l元,A组具有较理想的增量效果和经济效益,说明,对西门塔尔肉牛品种牛杂交所产的二代杂种公牛进行短期育肥比荷斯坦奶牛品种牛杂交所产的二代杂种公牛效果和经济效益高,西门塔尔肉牛品种与本地牛杂交所产的二代杂种公牛进行短期育肥是本地可行的项目之一。     

不同饲养条件对西门塔尔牛体重及相关血清代谢酶的影响

试验旨在研究散栏式饲养与栓系式饲养方式对西门塔尔牛生长过程中不同时期相关血清代谢酶水平变化的影响。选择体重相近(330 kg左右)、月龄相同(12月龄)、未去势、健康的50头西门塔尔公牛分为两组,每组25头牛。肉牛散栏式饲养为试验组,栓系式饲养为对照组。预试期为30 d,正试期为120 d,分别于10月、11月、12月、1月和2月进行对体重指标的测定,并定期采集血样。结果表明:在两种饲养方式中散栏饲养能提高西门塔尔牛日增重(P0.05),散栏全期西门塔尔牛平均日增重1268.37 g,显著高于栓系的969.76 g,提高了30.79%(P0.05)。在第3个月试验组血清谷丙转氨酶(ALT)含量极显著高于对照组(P0.01),其他月份组间差异均不显著(P0.05);在第3个月和第5个月试验组血清谷草转氨酶(AST)含量均显著高于对照组(P0.05);在试验全期,两组血清中碱性磷酸酶(ALP)组间差异均不显著(P0.05);本试验两组乳酸脱氢酶(LDH)含量组间无显著差异(P0.05),但两者相较于对照组均有降低趋势;在第3个月试验组血清肌酸激酶(CK)含量显著高于对照组(P0.05),第5个月极显著高于对照组(P0.01);散栏饲养方式能显著提高西门塔尔牛的日增重(P0.05)。     

不同精料饲喂量对德宏高峰牛育肥效益的影响

[目的]研究不同的精料饲喂量对德宏高峰牛育肥效益的影响,为养殖户进行德宏高峰牛育肥合理使用精料饲喂量提供理论依据。[方法]将试验分为4个组,每组10头,按试验1组、试验2组、试验3组、试验4组分别以每头每天1.5 kg,2 kg,2.5 kg,3 kg精料进行饲喂,通过90 d育肥,分析得出效益最好的精料饲喂量组。[结果]结果表明,试验1组平均日增重0.64 kg,每天每头牛可获利7.40元;试验2组平均日增重0.712 kg,每天每头牛可获利8.02元;试验3组平均日增重0.748 kg,每天每头牛可获利7.57元;试验4组平均日增重0.779 kg,每天每头牛可获利6.96元。[结论]德宏高峰牛育肥按每头每天饲喂精料2 kg经济效益最好,即按体重1%左右给予精料育肥德宏高峰牛效益最可观。     

不同精粗比对西杂公牛生长发育的影响

[目的]本试验旨在研究不同日粮精粗比对西杂青年公牛体重及体尺(体高、体长、胸围)的影响,为西杂公牛育肥提供理论依据。[方法]选择18头9月龄平均体重约270kg的西杂公牛,随机分为1、2、3组,分别饲喂精粗比为45∶55(低)、50∶50(中)和55∶45(高)的3种日粮。[结果]在日粮种类相同的情况下,西杂牛的日增重受精料水平的影响较大,但体尺的日增量受精料水平的影响较小。[结论]不同精粗比日粮的西门塔尔公牛的日增重不同,西门塔尔公牛采食精粗比较高的日粮,其增重速度较快。     

不同设计模式牛舍饲养肉牛效果对比试验报告

目的:以本地改良的1~1.5岁西门塔尔牛为主,通过不同设计模式牛舍育肥,测算育肥效果,推广不同设计模式牛舍育肥技术,提高养殖经济效益。方法:以双列式封闭和半封闭式牛舍为主,采用集中散养和拴系固定方式,在初始牛年龄、体重、日粮配方、饲养管理、饲喂量相同的条件下,进行饲喂肉牛后的效果对比试验,结合经济效益,分析育肥效果。结果表明:育肥90 d后,平均总体重、平均日增重试验B组﹥试验A组,经济效益试验A组﹤试验B组,获得的利润试验A组每头牛比试验B组每头牛少收入600多元。结论:在体重、日粮配方、饲养管理、饲喂量相同的条件下,不同设计模式牛舍育肥肉牛在日增重和经济效益方面,拴系固定育肥方式优于集中散养育肥方式,但就肉品质而言,如果有较好的市场,集中散养育肥方式的经济效益优于拴系固定育肥方式。     

中国西门塔尔牛(草原类群)肉用品系选育与研究应用

[目的]选育中国西门塔尔牛(草原类群)肉用品系。[方法]采用现代家畜遗传学同质选配和开放核心群育种体系技术路线,引进美系、加系种公牛及冷冻精液及胚胎,导血选配和纯繁选配,纯种扩繁和扩大改良群相结合,选育西门塔尔牛肉用品系。[结果]选育西门塔尔牛肉用品系,生长性能明显提高,增幅15%~30%;在常规饲养条件下14~24月龄牛是体重增加和提高牛肉品质的最好时期,育肥出栏最佳年龄为22~26月龄;常规育肥平均日增重达到1.32±0.18kg,强度育肥120~180d,屠宰率可达到56%~61%,与肉用品种牛接近。[结论]选育西门塔尔牛肉用品系,可大力发展肉牛产业。     

Effect of extraction time and acid concentration on the separation of proglycogen and macroglycogen in horse muscle samples

The objective of this study was to determine whether the concentrations of proglycogen (PG) and macroglycogen (MG) in biopsy samples of horse muscle are influenced by extraction time or perchloric acid (PCA) concentration. In study 1, individual muscle-biopsy samples from 10 horses were divided into 4 parts each and then randomly subjected to 4 periods of extraction (10, 20, 60, or 120 min) with 1.5 M PCA. In study 2, individual muscle-biopsy samples from 6 horses were divided into 24 pieces each and then randomly subjected to 12 combinations of extraction time (10, 20, 30, or 40 min) and PCA concentration (0.5, 1.5, or 3.0 M). The results from study 1 indicated that PG and MG concentrations are affected only after extraction for 120 min; the PG concentration decreased significantly (P < 0.05), and the MG concentration increased (not significantly). In study 2, extraction in 3.0 M PCA yielded significantly lower PG and higher MG concentrations (P < 0.05) than extraction in 0.5 or 1.5 M PCA with each of the extraction times. The results of this study further support the existence of 2 glycogen pools and demonstrate that they are not an extraction artifact. The study also suggests that the 2 pools are stable during extraction over a range of extraction times and acid concentrations. However, if the exposure to acid is very long and, or, the acid concentration is high, some of the insoluble PG appears to be hydrolyzed and to enter the MG pool.     

小肽的吸收与转运及其营养作用

随着动物营养学研究的发展,蛋白质营养的研究也在逐步深入,由原来的粗蛋白营养发展到氨基酸营养,进一步发展到现在的小肽营养。本文就小肽的吸收、转运、营养及其在动物生产中的应用,以及目前小肽研究领域中存在的问题等方面进行阐述。     

西南大学学风状况调查及对策研究

学风是学校文化传统、办学理念、精神面貌的集中反映,是学校治学精神、治学态度和治学原则的综合体现,文中在对学生的学习态度、教学态度、学习环境等方面进行问卷调查的基础上,对学校学风的现状进行了分析,并提出了促进学风建设的建议,为加强学校学风建设,促进教育教学改革,培养和造就高素质人才提供理论指导和现实依据。     

Impact of milking characteristics and morphology of udder and teats on clinical mastitis in first- and second-lactation Norwegian cattle

Data from the Norwegian progeny testing program were used to examine the impact of milking characteristics and morphology of udder and teats on clinical mastitis in first- and second-lactation Norwegian cattle. The study was designed as a 1-1 matched case-control study with herd, parity, days in lactation and calving season as matching variables. Conditional maximum likelihood logistic regression was used to evaluate the effects of three primary (2 min milk, milk leakage and teat-end-to-floor distance) and six other study variables. Treatment records from the Norwegian health card system on acute and chronic clinical mastitis were used to define cases. The chosen model included 565 matched pairs. Significant risk factors of clinical mastitis were decreasing teat-end-to-floor distance (P = 0.02) and periparturient udder edema (P < 0.01).

Borderline effects were demonstrated by larger than herd-average teat diameter (P = 0.04), udder asymmetry (P = 0.05) and increasing 2 min milk (P = 0.08). Results were compared to a previous study on the same data with log_e somatic cell count as the dependent variable. Inclusion of teat-end-to-floor distance in the genetic improvement scheme may increase the efficiency of genetic selection for mastitis resistance.     

猪mtDNA多态性的研究与应用

本文介绍了猪mtDNA的结构，以及mtDNA多态性的研究方法；综述了猪mtDNA多态性的研究进展与应用。     

貉源阿留申病毒VP2和NS1蛋白的抗原性预测

旨在预测和分析貉源阿留申病毒（RFAV） VP2和NS1蛋白的抗原表位特征，筛选阿留申病毒属较保守的B、T细胞抗原表位。本研究对RFAV的近全长基因组进行克隆及测序，对其VP2和NS1基因编码蛋白的理化性质、二级结构、翻译后修饰位点和抗原表位进行预测，并将预测的修饰位点、抗原表位与其他阿留申病毒种的序列进行比较分析，筛选相对保守的修饰位点和抗原表位。结果显示，获得的RFAV基因组长4 327 bp，编码VP2蛋白的636个氨基酸，编码NS1蛋白的641个氨基酸。VP2和NS1蛋白均为亲水性蛋白，二级结构以无规则卷曲为主。在阿留申病毒属内，VP2蛋白有3个保守的B细胞抗原表位，3个保守的T细胞表位，8个保守的翻译后修饰位点；NS1蛋白有1个保守的B细胞抗原表位，2个保守的T细胞抗原表位和7个保守的翻译后修饰位点。本研究成功克隆了RFAV近全长基因组序列，全面对RFAV的VP2、NS1蛋白抗原表位、翻译后修饰位点进行预测，并分析其在阿留申病毒属内的保守和变异特征，为阿留申病毒免疫研究提供参考。     

Radiological Observations of the Thorax and Abdomen of the Piglet

A contrast radiographic study of the urinary and gastrointestinal system was carried out in 43 animals, with the aid of barium sulfate, orally for esophageal, stomach, small intestine and large intestine studies; barium sulfate as an enema to complete the large intestine studies; sodium and meglumine diatrizoate intravenously for urography and iodipamide meglumine intravenously for cholecystography. Both unanesthetized and anesthetized or tranquilized animals were used in the study. The results of the study are illustrated, and contrasted with studies of a similar nature in other animals.     

Neospora caninum serostatus and milk production of Holstein cattle

OBJECTIVE: To determine whether Neospora caninum serostatus was associated with milk production among Holstein cattle in Ontario. DESIGN: Case-control study and cross-sectional observational study. ANIMALS: 3,702 Holstein cows in 83 herds (case-control study) and 3,162 Holstein cows in 57 herds. PROCEDURE: Herds in the case-control study were grouped on the basis of N. caninum abortion status. Herds in the observational study were considered representative of Ontario dairy herds. The N. caninum serostatus of individual cows was determined with a kinetic ELISA. Milk production was modeled to compare seropositive with seronegative animals while controlling for parity, days since parturition, and herd clustering. RESULTS: In the case-control study, 305-day milk production of seropositive cows was significantly less than milk production of seronegative cows in herds with abortions attributable to N. caninum infection and in herds with abortions attributable to pathogens other than N. caninum, but not in herds without abortion problems. In the observational study, 305-day milk production for seropositive cows was not significantly different from milk production of seronegative cows. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that the association between N. caninum serostatus and milk production in Ontario Holstein dairy cattle may depend on abortion status of the herd. In herds with abortion problems, regardless of cause, N. caninum-seropositive cattle produced less milk, whereas in herds without abortion problems, N. caninum-seropositive cattle produced the same amount of milk as seronegative cattle.     

热带牧草种质资源收集、保存与创新利用研究进展

我国拥有丰富的牧草种质资源,但我国牧草种质资源的研究水平还比较低。通过对热带牧草种质资源收集、保存与创新利用进行了系统的概括和归纳,简要评述了我国牧草种质资源研究中存在的问题并展望其应用前景。以期为促进我国热带牧草种质资源的收集和利用提供参考。     

猫传染性腹膜炎病毒核衣壳蛋白的表达及间接ELISA法的建立

本研究对猫传染性腹膜炎病毒（FIPV）N蛋白的编码基因进行克隆和原核表达,并在纯化重组N蛋白的基础上,建立了FIPV抗体间接ELISA检测方法。研究结果显示,该重组纯化的N蛋白具有良好的抗原反应性,可用于FIPV阳性血清的筛查,为我国出入境检疫部门监控FIPV疫情提供技术支撑。