不同激素处理富源本地黄牛与短本杂一代黄牛同期发情试验

为了比较不同品种的黄牛用不同激素处理后的同期发情效果,以筛选出适合本地不同牛群及环境的较优杂交方案.将137头健康空怀黄母牛(其中本地黄母牛72头,短本杂一代黄母牛65头)分为4个组,第1、2组为本地黄母牛,第3、4组为短本杂一代黄母牛,分别用2种不同的方法进行同期发情处理.第1、3组注射三合激素;第2、4组注射促排3号-氯前列烯醇-促排3号.结果表明,第1组、第2组、第3组、第4组经不同的激素处理后,发情率分别为59.38%、87.5%、58.62%、86.11%,第2组的发情率显著高于第1组(P＜0.05),第4组的发情率显著高于第3组(P＜0.05),而第1组和第3组、第2组和第4组的发情率差异不显著(P＞0.05).结果提示发情率的高低与品种的相关性不大,促排3号-氯前列烯醇-促排3号可能是较适合富源黄母牛的同期发情方案.     

平凉市肉牛产业生态经济系统分析及预测

[目的]为进一步完善和优化平凉市肉牛产业生态经济系统结构,协调和理顺系统关系,提高系统功能和效益,促进系统保持持续、稳定、协调、高效发展。[方法]运用系统分析法和热力学定律,描述和分析了系统的结构和功能。[结果]从系统调控的角度提出平凉市肉牛产业系统应围绕产业配置资源,合理调控产业要素（环境、结构、技术、投入）,释放肉牛产业内在活力,形成种、养、加一体化,产-供-销一条龙的多结构、多功能、多出路的经济发展模式。[结论]依系统现状展望未来发展趋势,最终达到生产、生态、经济、社会效益的良性循环和可持续发展。     

三种浮萍对养殖废水中氮、磷的净化效果研究

本试验研究了3种浮萍(芜萍、少根紫萍、青萍)对3种不同稀释倍数的猪场厌氧废水中的N、P净化效果,结果显示:污水中TN、TP浓度随浮萍处理时间增加而持续降低;少根紫萍对N、P净化率都超过了75%,净化能力优于芜萍和青萍。综合考虑,少根紫萍可作为四川盆地内净化养殖废水中氮、磷的优化品种。     

郏县红牛产业发展现状、存在问题及对策

郏县红牛是由河南省平顶山市郏县经过长期不断选育而形成的地方优良品种.近几年,由于生产生活方式的改变,郏县红牛产业新的问题凸显.因此,本文主要分析了郏县红牛产业面临的问题,同时提出一些相应的对策,从而使郏县红牛在未来的发展中发挥自身独特的优势,进而增加农民收入.     

Responses to Selection against Clinical Mastitis in the Norwegian Cattle Population

The genetic trend for clinical mastitis was estimated for Norwegian Cattle, a population in which mastitis resistance has been included in the breeding programme since 1978. More than 1.2 million first-lactation daughters, with clinical mastitis records registered from 1978 to 1995, bred by 2043 sires, were analysed with a linear sire model. For bulls born from 1974 to 1990 a flat genetic trend for clinical mastitis was found. However, bull sires born from 1983 onwards, selected on a breeding goal with increased weight on mastitis relative to milk production, showed consistently larger and favourable selection differentials for mastitis relative to bull sires born earlier, which had an average selection differential of approximately zero. This will influence genetic trend in the population through their sons, which were born from 1990 onwards.     

牛皮蝇幼虫病的流行及防制

牛皮蝇幼虫病是一种常见的寄生虫，在我国许多地区都有发生，引起牛的生产性能下降，造成经济上的损失。本文主要阐述病原体形态特征、生活史、流行规律、危害及诊断方法，并提出综合防制措施。     

不同饲养管理条件下黄牛的同期发情试验

[目的]为了便于集中配种或胚胎移植。[方法]采取了三种方法：一次PG改进法、CI-DR＋PMSG＋PG＋LHRH-A3法、PMSG＋PG＋LHRH-A3法处理三种不同饲养管理条件下的黄牛,诱导同期发情。[结果]表明四次处理的同期发情率分别为100%、100%、98.8%、82.4%,人工授精或胚胎移植受胎率分别为27.3%、80%、76.5%、59.2%。[结论]从经济角度表明一次PG改进法、PMSG＋PG＋LHRH-A3法是比较切合实际,也比较理想的同期发情方法,效果也比较理想。     

Descriptive Study of 32 Cases of Doxycycline‐Overdosed Calves

Background: Reports of doxycycline‐induced toxicity are limited despite common use of this antibiotic to treat infectious respiratory disorders in calves. Objective: To describe previously unreported kidney lesions and diagnostic test results in doxycycline‐overdosed calves and to compare these results with other findings reported previously. Animals: Thirty‐two calves that presented with adverse effects after receiving high doses of doxycycline as a treatment for mild respiratory disorders. Method: Retrospective review of medical records. Results: Clinical examination identified mainly lethargy, dyspnea, cough, tongue paresia or paralysis associated with dysphagia and sialorrhea, tachycardia, tachypnea, and signs of myopathy. Blood analysis indicated increases in creatine kinase, lactate dehydrogenase, aspartate aminotransferase, and sorbitol dehydrogenase activities and increased serum creatinine and urea concentrations. ECG recordings and Doppler echocardiography examination identified ventricular premature beats and a decrease in left ventricular global and systolic function, respectively. Necropsy and histopathology disclosed necrosis of the myocardium, tongue, and some striated muscles, acute renal tubular necrosis, and fatty degeneration or congestion of the liver. Conclusions: Most of these findings corroborate previous observations made in doxycycline‐overdosed calves, and further suggest myocardial and striated muscular toxicity as well as renal toxicity in doxycycline‐overdosed calves.     

规模化奶牛场粪污危害、处理及循环利用模式

随着我国奶牛养殖业发展规模的壮大,规模化奶牛场数量持续增加,但奶牛场粪污污染问题也日益凸显。本文结合自身工作经验,首先分析了规模化奶牛场粪污的危害性,然后从雨污分离、固液分离和干清粪工艺对规模化奶牛场粪污处理方式进行概述,最后从厌气（厌氧）发酵获得沼气、微生物发酵用作饲料和生产生物有机肥三种不同模式介绍模化奶牛场粪污的循环利用操作,以期为规模化奶牛场粪污高效利用提供借鉴。     

绿肥影响农田土传病害的研究进展

土传病害是制约我国农业可持续发展的因素之一.绿肥作为高效清洁的有机肥源,与主作物合理搭配,可有效降低主作物土传病害的发生和危害,是减少化学药剂使用的重要措施.因此,综述绿肥对土传病害的防控效果与机制,对于绿肥推广应用和土传病害绿色防控具有重要意义.绿肥影响作物土传病害的研究主要集中于土传真菌病害和线虫病害,且大多数研究...