Foraging Behavior of Alberes Cattle in a Mediterranean Forest Ecosystem

The dietary composition of the semiferal cattle population in the Alberes Natural Park in northeastern Spain was determined four times per year, from June 2002 to February 2004, by microhistological analysis of a total of 120 fecal samples. Woody species, mainly the Quercus and Erica genera, formed the bulk of the diet, reaching 89% of it in winter. However, in spring and summer, the proportion of woody and herbaceous species varied between samples, depending on the habitat where they were collected. The forest samples contained 67% woody species in summer, whereas grassland samples only contained 44%. The results showed that the Alberes cattle population grazed actively in Mediterranean forests and consumed a high proportion of the most combustible species, such as the Erica genus (39% of the epidermal fragments in winter samples). Even when grassland habitat was utilized, in spring and summer, one-third of the diet was from woody species. Some bovines, such as the Alberes cattle breed, can therefore survive year-round in a forest habitat with little forage supplementation, and the consumption of a predominantly woody diet would be expected to reduce forest fire hazards.     

Interspace/Undercanopy Foraging Patterns of Beef Cattle in Sagebrush Habitats

Forage selection patterns of cattle in sagebrush (Artemisia L.) communities are influenced by a variety of environmental and plant-associated factors. The relative preference of cattle for interspace versus under-sagebrush canopy bunchgrasses has not been documented. Potential preferences may indirectly affect habitat for sage-grouse and other ground-nesting birds. Our objectives were to investigate grazing patterns of cattle with respect to undercanopy (shrub) and interspace tussocks, determine the influence of cattle grazing on screening cover, and relate shrub morphology to undercanopy grazing occurrence. Eighteen-day replicated trials were conducted in the summers of 2003 and 2004. Findings suggest cattle initially concentrate grazing on tussocks between shrubs, and begin foraging on tussocks beneath shrubs as interspace plants are depleted. Grazing of undercanopy grass tussocks was negligible at light-to-moderate utilization levels (< 40% by weight). Grass tussocks under spreading, umbrella-shaped shrub canopies were less likely (P < 0.001) to be grazed than those beneath erect, narrow canopies. Horizontal screening cover decreased (P < 0.001) with pasture utilization. At the trial’s end, removal of 75% of the herbaceous standing crop induced about a 5% decrease in screening cover in all strata from ground level to 1 m with no differences among strata (P = 0.531). This implied that shrubs constituted the majority of screening vegetation. Our data suggest that conservative forage use, approaching 40% by weight, will affect a majority (about 70%) of interspace tussocks and a lesser proportion (about 15%) of potential nest-screening tussocks beneath sagebrush. Probability of grazing of tussocks beneath shrubs, however, is also affected by shrub morphology. These findings will help managers design grazing programs in locales where habitat for ground nesting birds is a concern.     

草地斑块面积对肉牛采食行为的影响(简报)

家畜采食行为和采食策略是放牧生态学的研究热点之一^[1]。目前有关放牧家畜采食行为、采食模型和采食理论的研究进展迅速,但大多数仅局限在对某个植物等级水平(个体、斑块)家畜采食特征的研究^[2~6],而对不同等级(个体、斑块、群落、景观)水平间的动物采食行为的整合研究不多见。本文通过测定放牧肉牛在草甸草原植物个体和斑块区域的采食方位和采食参数,分析家畜采食策略,以期进一步完善采食理论,并为制定合理的草地管理制度提供理论支持。     

利木赞和西门塔尔改良当地黄牛效果观察

为了了解利木赞和西门塔尔改良当地黄牛的效果,测量了62头繁殖母牛的体尺,利用肉用指数研究了牛群的经济类型。结果表明：利黄Fl和西黄Fl的繁殖母牛平均肉用指标分别达到3.40和3.42,比当地黄牛提高了12.21%和12.87%,改良效果显著（P〈0.05）,利黄F1,和西黄Fl改良效果无明显区别（P〉0.05）。     

奶牛良种扩繁:引种VS性控精液——SWOT分析

牛是单胎动物,如何实现奶牛良种的迅速扩繁是从事奶牛繁殖的科学家长期以来所思考和研究的问题。继人工授精和胚胎移植技术之后,奶牛性控精液的上市,带来了奶牛繁殖的第三次科技革命,为实现奶牛良种的迅速扩繁提供了一条新的途径。为此,本文根据国内外学者的研究结果,利用SWOT分析法对引种和性控精液的优势、劣势、机会和威胁进行比较分析。结果表明,对青年牛使用性控精液配种,可以实现奶牛良种的迅速扩繁,获取更大的经济效益。     

Postpartum Ovarian Activity in South Asian Zebu Cattle

Timely onset of postpartum ovarian activity is vital for optimal reproductive performance of dairy cows. Much depends upon genetic constitution of an animal although several factors interplay to govern the onset of postpartum ovarian activity. South Asian zebu cattle have much longer service period when compared with other exotic or crossbred cattle reared in the same Asian environment, which suggests differences in their genetic makeup. However, the cows with same genetic configuration expressed better reproductive potential when reared under different environment, such as in Brazil and Mexico, which suggests the role of extrinsic factors such as management, nutrition, environment and disease conditions. Better management of animals (provision of proper shade, water and housing, efficient oestrous detection and timely insemination), good quality nutrition supplemented with appropriate minerals and vitamins, prevention of diseases (vaccination, deworming, suitable therapeutic interventions) and application of biotechnology have helped in improving postpartum ovarian activity and, therefore, reproductive performance of zebu cattle in Asia. No comprehensive study appears to have been carried out on the various aspects of reproduction in zebu cattle reared under South Asian socio-agro-climatic conditions. This paper is a modest effort to collect what ever information available and to critically review the postpartum ovarian activity in zebu cattle with special reference to the effect of the various managemental practices and pharmacological interventions.     

Evaluation of Oestrous Detection in Dairy Cattle Comparing an Automated Activity Monitoring System to Visual Observation

The objective of the study was to evaluate an automated activity monitoring (AAM) system for oestrous detection in dairy cows. Specifically, we set out to determine the oestrous detection efficiency and accuracy of the AAM system and to compare reproductive performance of cows detected either by AAM, by visual observation (VO) or by at least 1 of the 2 methods (EOM). A total of 1004 potential cow‐periods from 348 cows were analysed. Oestrous detection rates (EDR) were calculated for 21 day (VWP+21), 42 day (VWP+42), and 63 day (VWP+63) after voluntary waiting period (VWP). Oestrous detection rate did not differ between AAM (42.1%) and VO (37.3%) during VWP+21 (p > 0.05) but was significantly higher in EOM (56.3%, p < 0.05). Oestrous detection by AAM achieved an efficiency (number of correctly detected oestruses/total number of cow‐periods*100) of 35.6% and an accuracy (number of correctly detected oestruses/(number of true+ false oestruses)*100) of 83.8%. Visual observation resulted in an efficiency of 34.3% and accuracy of 75.1%. Pregnancy rate at 200 DIM was higher in AAM (66.8%) and EOM (68.8%) than in VO (57.1%, p < 0.05). Cows detected by AAM (p < 0.05) showed a 1.37 times greater risk to conceive than cows detected by VO as the reference (p < 0.05). The results show that an automated activity monitoring system can support oestrous detection in dairy cattle. The exclusive use of such a system, however, cannot be recommended.     

Comparison of Breeding and Marketing Systems for Red Angus Cattle Using an Integrated Computer-Based Spreadsheet

An integrated computer-based spreadsheet was developed with data from 581 Red Angus-sired calves to compare synchronized AI and natural service breeding systems. This comparison was based on input costs, genetic merit of sires used for mating, and calf marketing system, using differences in net return. The spreadsheet integrated four elements into a decision summary: bull costs, AI costs, genetics merit, and marketing options. An economic sensitivity analysis was used to identify trends and key variables in the net return of each decision. Three prominent variables identified from economic analysis were bull purchase price, semen price, and percent genetic change. Bull purchase price was a primary factor in changes in net return; semen costs and genetic merit change explained rearrangements in ranking of net return. These two variables altered the ranking based on whether the estrous synchronization protocol used estrus detection or timed AI. The spreadsheet identified AI to be more cost effective than natural service when calves are marketed as finished cattle. Net revenue from AI calves was greater in all retained ownership scenarios; the weaned marketing scenario caused net return to vary by synchronization system for the combinations of costs and changes in genetic merit. However, there was a wide variance in identifying which breeding system provided the greatest benefit when calves were marketed as feeder cattle. Retaining ownership through finish and marketing either on the cash market or on a grid proved to be advantageous to AI in all of the estrous synchronization protocols provided. The economic advantage ranged from $142.98 to $214.16 per head compared with marketing at weaning. The spreadsheet developed provides a useful tool for evaluating the economic impacts of breeding system decisions.     

秦川牛改良延安本地黄牛效果分析

在陕西省延安市延长和志丹两县,对农村散养模式下的秦川牛改良延安本地黄牛杂交F1代,公母牛各80头分3日龄、6月龄、12月龄、24月龄四个年龄段的体高、体斜长、胸围、髋宽体尺指标和体重进行测量和计算,通过与同龄延安本地黄牛的体尺和体重比较分析发现,秦川牛改良延安本地黄牛杂交F1代在体重上有显著提高,增长幅度在22.15%~71.19%,在4项体尺指标上也有明显的提高,增长幅度在6.49%~63.53%之间。在毛色、适应性、繁殖力等方面也表现出良好的杂交优势。调查分析表明改良方向正确,改良效果显著。     

Artificial Insemination Using Local Cattle Breeds in Niger

Tropical Animal Health and Production -     

肉用型西门塔尔与安格斯不同杂交方式杂交效果研究

[目的]为检验肉用型西门塔尔牛云南本地黄牛的改良效果.[方法]云南省种畜繁育推广中心肉牛纯繁场分别利用XM♂×本地西门塔尔高代杂交黄牛♀（Ⅰ组）;XM♀×AG♂（Ⅱ组）;AG♂×本地西门塔尔高代杂交黄牛♀（Ⅲ组）.[结果]在相同的饲养管理条件下,Ⅱ组初生、6月龄、12月龄、18月龄、24月龄平均体重明显高于I组和Ⅲ组,工组结果明显高于Ⅲ组;6月龄、18月龄日增重Ⅰ组和Ⅲ组差异不显著,Ⅰ组12月龄、24月龄日增重明显高于和Ⅲ组,而Ⅱ组6月龄、12月龄、18月龄、24月龄日增重明显高于Ⅰ组和Ⅲ组.[结论]通过实验结果可以看出,肉用型西门塔尔牛与安格斯种公牛杂交效果优势明显,而肉用型西门塔尔种公牛与本地黄牛杂交效果又明显高于安格斯种公牛.     

牛胸膜肽的提取及活性检测

为了探讨一种简便、快速、收获率高，适于大量提取的胸腺肽制备方法，在分析国内外报道的方法的基础上，确定了4种提取流程，对其收获率，所获提取物的活性进行鉴定和比较，同时对FA组分在鸡的新城疫病毒（NDV）和传染性喉气管炎（简称传喉）病毒（ILTV）混合感染中的防治作用进行了初步试验。为其在兽医临床的应用提供了试验依据。     

牛胸腺肽的提取及活性检测

为了探求一种简便、快速、收获率高、适于大量提取的胸腺肽制备方法,在分析国内外报道的方法的基础上,确定了4种提取流程,对其收获率、所获提取物的活性进行鉴定和比较,同时对FA组分在鸡的新城疫病毒(NDV)和传染性喉气管炎(简称传喉)病毒(ILTV)混合感染中的防治作用进行了初步试验.为其在兽医临床的应用提供了试验依据.     

青海本地黄牛唾液淀粉酶活性测定

采用碘比色法对１０６头青海本地黄牛的唾液淀粉酶活性进行测定。结果表明：青海本地黄牛的唾液淀粉酶活性为１０８．０９ＩＵ／Ｌ,不同地区、性别、年龄黄牛之间均无显著差异。     

利用甘蔗副产品饲养肉牛试验研究

为开发甘蔗副产品作为肉牛养殖的饲料资源,应用氨化、微贮的方法处理甘蔗副产品,测定氨化、微贮处理后甘蔗副产品的营养成分,试验牛日采食甘蔗副产品数量及试验牛增重效果。结果:经氨化、微贮处理后,甘蔗副产品的粗纤维(CF)、中性洗涤纤维(NDF)含量降低,粗蛋白(CP)含量增加;氨化组、微贮组比对照组显著提高了采食量(P﹤0.05);氨化组日增重最高,与对照组相比差异极显著(P﹤0.01),微贮组比对照组显著提高了日增重(P﹤0.05)。结果表明,甘蔗副产品经氨化、微贮后是一种优良的饲料资源,以氨化方法处理效果最佳。     

利用SCS进行抗奶牛乳房炎育种概述

本文介绍了奶牛乳房炎的危害。并简述了奶牛SCS性状与奶牛抗乳房炎性状之间关系的研究现状，认为利用SCS可对奶牛抗乳房炎性状进行间接选择，可降低牛群乳房炎的发病率；给出对SCS进行遗传估计的动物模型，并提出存在的相关问题。     

微贮秸秆和未经处理秸秆育肥肉牛对比试验

本试验利用经秸秆发酵活干菌处理的农作物秸秆和未经处理的秸秆对１６头１２月龄西杂黄牛进行育肥对比试验。结果表明：试验组牛的日增重比对照组牛日增重多０．２４４ｋｇ，提高２７．９％，差异显著（Ｐ〈０．０５）。     

多种方法诊疗牛前胃弛缓的体会

前胃弛缓是牛最常见的内科疾病之一,本病虽然死亡率不高,但对牛的健康影响极大。笔者通过临床实践摸索,对该病采取中医、西医及中西医结合等多种方法,先后治愈了多数患牛,取得了很好的治疗效果。现将该病发生的原因、症状及治疗措施介绍如下,望对同行及养殖户有所帮助。