荷斯坦奶牛牛嘴宽度影响因素分析及遗传参数估计

【目的】探究中国荷斯坦奶牛牛嘴宽度的群体规律,并估计其遗传参数。【方法】2021年7月至2021年8月分别在2个规模化奶牛场测定了628头泌乳期荷斯坦奶牛的牛嘴宽度及臀高、体高、体斜长和胸围等体尺性状,同时利用体斜长和胸围估计试验牛体重。利用SPSS 26.0软件分析了牧场、月龄和泌乳阶段等因素对牛嘴宽度的影响,以及牛嘴宽度与各体尺性状之间的相关关系;基于DMU软件采用单性状动物模型估计了牛嘴宽度的方差组分及遗传力。【结果】荷斯坦奶牛牛嘴宽度的群体平均值为17.28 cm,变异系数为5%,变异相对较小;牧场和月龄对牛嘴宽度均有极显著影响(P<0.01),泌乳阶段对牛嘴宽度有显著影响(P<0.05),牛嘴宽度随母牛月龄的增加呈逐渐增加的趋势,泌乳初期牛嘴宽度显著小于其他泌乳阶段(P<0.05);牛嘴宽度与各体尺性状之间存在极显著正相关(P<0.01);荷斯坦奶牛牛嘴宽度的遗传力估计值为0.28,为中高遗传力性状。【结论】牧场和月龄对奶牛牛嘴宽度影响极显著,泌乳阶段对奶牛牛嘴宽度影响显著,牛嘴宽度与臀高呈较弱相关。荷斯坦奶牛牛嘴宽度是一个具有中高遗传力的体尺性状。     

银杏叶提取物对发酵乳贮藏期理化和感官特性的影响

[目的]考察不同添加量银杏叶提取物对发酵乳贮藏期品质的影响。[方法]采用持水率、黏度、乳酸菌活菌数、抗氧化能力、感官评价方法测定不同添加量银杏叶提取物制备的发酵乳,并结合多元统计分析方法进行分析。[结果]银杏叶提取物对乳酸杆菌和链球菌的活力没有显著影响,为保证活菌数在1.0×107 CFU/g以上,建议该发酵乳最多冷藏9天。在酸奶中添加银杏叶提取物可提高其抗氧化特性。添加银杏叶提取物的酸奶样品与对照组在风味和口感方面存在差异,且添加量越大差异越明显。[结论]银杏叶提取物本身作为一种中成药,具有成为一种新的功能性酸奶成分的巨大潜力。     

规模化牛场粪污资源化技术研究及应用进展

现代规模化牛场发展迅速,为市民提供大量优良奶源和畜肉,但同时牛场产生粪便、污水等废弃物排泄量增加,大部分牛场不能规范化处理,粪污堆积在生产区域,不光对周围土壤、空气和水体造成污染,还影响牛场的正常养殖生产秩序,对生态环境危害严重,影响养牛业绿色可持续发展,因此牛粪的处理和资源化利用问题急需解决。为了稳定、无害的处理粪污,将规模化牛场粪污作资源化处理利用,不仅可以解决牛场粪污污染问题,还能实现粪污资源最大化利用,具有重要意义。本文分析了牛粪的营养成分以及规模化牛场粪污造成的环境污染问题,简述了粪污资源化利用的目的、原则和预期效果,介绍了牛粪资源化利用的现有途径和方式,其中主要包括能源化、基质化、饲料化、燃料化、肥料化、氧化塘发酵后再利用等方法,以期通过分析多种资源化处理技术,将其根据具体情况应用,或者多种技术搭配实施,避免单一技术存在的局限性,为不同养殖环境情况下的粪污处理提供参考,为现代化养牛业低碳可持续发展提供借鉴。在未来应继续加大规模化牛场粪污资源化利用力度,科学合理制定各地区养殖场的粪污处理规划和资源化利用模式,监测周围环境质量并作出有效控制,促进畜牧业健康发展,为畜牧业循环经济...     

A Study of Drug Residues in Milk Following Intrauterine Infusion of Antibacterial Drugs in Lactating Cows

Intrauterine infusion of nine antibacterial compounds caused detectable drug residues in 17 out of 165 cows or in 25 out of 1110 posttreatment milkings. Four cows treated with pyrolidinomethyl tetracycline suspension had drug residues at the first milking. One cow had residues after oxytetracycline treatment, two after procaine penicillin G, three after acriflavin and after chloramphenicol-dapsone and four after hibitane. Nitrofurazone, nitrofurathiazide and Hibitane Compound® did not cause detectable inhibitory residues in any milk sample.     

Path analysis of peripartum and postpartum events, rectal palpation findings, endometrial biopsy results and reproductive performance in Holstein-Friesian dairy cows

Peripartum events, rectal palpation findings, histological and bacteriological results of endometrial biopsy, and postpartum disease variables were included in a path analysis of reproductive performance for 55 Holstein-Friesian cows from one herd. Both logistic and least squares regression were used. Based on this model, dystocia had both direct and indirect sparing associations on poor reproductive performance. A larger corpus luteum on the ovary ipsilateral to the previously non-gravid horn at Day 26 postpartum indirectly was associated with a decreased likelihood of poor reproductive performance through reduced isolation of Actinomyces pyogenes from the uterus and reduced inflammation in the stratum compactum. In the model, A. pyogenes indirectly increased poor reproductive performance through reduced number of lymphocytic foci and increased inflammation in the stratum compactum at Day 26. Increased numbers of lymphocytic foci had a direct sparing effect on poor reproduction. Stratum compactum inflammation was associated with a direct and indirect increase in the likelihood that a cow would experience poor reproductive performance via increased occurrence of cystic ovarian disease. Presence of a larger follicle on the ovary ipsilateral to the previously gravid horn had a direct beneficial effect on reproductive performance.     

Enzootic pneumonia: comparison of cough and lung lesions as predictors of weight gain in swine.

A prospective cohort study was undertaken in a commercial swine herd to determine the relationship between weight gain and the occurrence of enzootic pneumonia (EP). Estimates of the association between EP and weight gain were obtained from multiple linear regression models, using coughing episodes or slaughter checks as indicators of EP status. Models were estimated for pigs in 2 different age groups: roasters (n = 1084, sold at 32 to 50 kg) and market hogs (n = 1162, sold at 100 to 110 kg). The relationship between presence of lung lesions at slaughter and previous coughing episodes was also investigated. Throughout the study period, clinical evaluations were performed weekly, and coughing episodes recorded for each pig. Lungs were inspected at slaughter, and scores were expressed as the percentage of the lung with gross pneumonic lesions. Coughing and lung scores were significantly correlated, after adjusting for other covariates (R = 0.32 and 0.59, respectively, for market hogs and roasters). However, the agreement beyond chance between coughing history and lung lesions at slaughter was poor among both roasters and market hogs (kappa = 0.17 and 0.07, respectively). Although very specific, weekly assessment of coughing was not a sensitive indicator of lung lesions at slaughter. In multiple regression, lung score was a highly significant predictor of lower final weight in pigs of both age groups (P < 0.001 in the selected regression models).(ABSTRACT TRUNCATED AT 250 WORDS)     

Mitral valve prolapse in 3-year-old healthy Cavalier King Charles Spaniels. An echocardiographic study.

Clinical studies have shown that Cavalier King Charles Spaniels (CKCS) have a high prevalence of mitral valvular insufficiency (MVI). Echocardiography has the potential to disclose early valvular changes, and the present prospective study was designed to investigate the occurrence of mitral valve prolapse (MVP) in young CKCS without heart murmurs, and to correlate the degree of MVP with the clinical status of the dogs by including CKCS with MVI as well. The study was based on blinded evaluations of echocardiographic recordings of mitral valves from 34 CKCS and 30 control dogs. Thirteen (87%) of 15 three-year-old CKCS without heart murmurs had MVP (2 total and 11 partial), as compared with 1 (7%) of 15 three-year-old normal Beagle dogs (P < 0.0001), and none of 15 three-year-old normal Medium Size Poodles (P < 0.0001). Of 19 CKCS with MVI, MVP was found in 84% of the entire group and in 100% of dogs with pulmonary congestion or edema. The occurrence of total MVP tended to be higher in the group with MVI (47%, 9/19), when compared with the younger CKCS without heart murmurs (13%, 2/15, P = 0.06). MVP was positively associated with excessive heart rate variability (P = 0.003). The radius of curvature of the anterior mitral valve leaflet in systole was significantly reduced in dogs with MVP when compared with those without (P < 0.0001). In conclusion, this study shows that CKCS at an early age have a high occurrence of MVP. This suggests: 1) A genetic predisposition of CKCS to MVP; and 2) That MVP is a pathogenetic factor in the development of mitral valvular insufficiency. Follow up studies may add further support to these proposals, and clarify whether echocardiography may be an aid in selecting CKCS for future breeding.     

如东县鸡腿病病因的调查研究

本文对如东县４０个养鸡户的鸡腿病进行了门诊与跟踪调查。从传染病、营养代谢病及饲养管理三个方面对发病原因进行了初步的探讨。结果表明：营养缺乏和代谢紊乱（特别是钙、磷）是该县鸡腿病的主要原因，传染性腿病如疑似病毒性关节炎、禽脑脊髓炎、葡萄球菌性关节炎等也不容忽视。