Seasonal influence on diet selection of sheep grazing a weedy dryland lucerne pasture

The experiment was conducted to determine the seasonal effects on the availability, chemical composition and digestibility of a grazing dry-land lucerne pasture, as measured on samples either collected by hand or with oesophageally fistulated (OF) sheep. The pasture was monitored monthly for a period of thirteen months. An overall mean amount of 647 kg DM ha^?1 of material was monitored during the experimental period. Lucerne, as a percentage of the total DM availability was relatively low (approximately 19%), probably due to the preference of sheep to select lucerne in spite of the other available material. Both the crude protein (CP) content and the organic matter (OM) digestibility of the samples showed a seasonal tendency with higher values during the winter and lower values during the summer. Mean OM, CP, organic matter digestibility (OMD), acid detergentfibre (ADF) and neutral detergent fibre (NDF) contents of 91.7%, 10.7%, 57.5%, 47.1% and 74.0%, respectively, were obtained with hand-clipped samples, while the corresponding composition of samples collected by OF sheep was 83.1%, 21.0%, 64.7%, 38.2% and 58.4%, respectively. The sheep were able to select forage samples with a higher CP content than those collected by hand throughout the year. This was, however, not the case with the organic matter digestibility of the samples during the growing season July to October. The CP content of fistula extrusion samples (f) could be predicted from hand-clipped samples (h) from the linear relationship, CP_f = 10.51 + 0.97CP_h (r = 0.59). The study provided figures on the chemical composition and digestibility of dryland lucerne pasture at grazing in a Mediterranean environment.     

凉山半细毛羊种质特性的研究

对凉山半细毛羊的产毛、产肉性能、繁殖性能、生长发育、生理生化性状、血液蛋白多态性和染色体核型作了全面的介绍。凉山半细毛羊成年公羊体重 85 2 5± 3 2 5kg、母羊 4 8 11± 4 13kg ;剪毛量分别为 6 5 5± 0 12kg和4 12± 0 32kg ;毛长分别为 18 12± 0 5 1cm和 15 74± 0 2 1cm ;羊毛主体细度 4 8～ 5 0支。 6月龄肥羔胴体重16 83± 0 76kg ,屠宰率为 5 0 79%。母羊初配年龄为 10～ 12月龄 ,平均产羔率为 111 36 %。染色体数目 2n =5 4。在长期的精心选育和当地生态条件的影响下 ,凉山半细毛羊的生理生化性状产生了不同程度的变化 ,以适应凉山地区的生态条件     

绵羊痒病在国内的首次报告

1982年7月四川省凉山彝族自治州从苏格兰购回2岁左右的边区莱塔特(简称边莱)种羊115只。1983年4～5月和12月,先后发现其中有2只母羊和3只一岁龄的纯种后代羔羊出现明显的搔痒与神经症状,经检查未见螨和虱等外寄生虫。一只母羊因迅速失重,后躯瘫痪,躺卧不起,于濒死期剖杀。尸体剖检无明显病变。病理组织学切片观察,在中枢神经系统的脑干(延髓、脑桥、丘脑和纹状体)呈两侧对称性的损害,出现特征的空泡性神经元(所谓“气球样细胞”)、灰质不同程度的海绵状变性和星形胶质细胞的肥大与增生等病变。取脑和脾作细菌培养为阴性,以病羊脑悬浮液接种家兔未发病。诊断是以呈现典型的痒病症状和脑内的组织损害为依据。     

凉山半细毛羊血液生化指标与生产性能的相关性研究

凉山半细毛羊的血液生化指标大多在正常范围内 ,生产性能达到较高水平。血清中无机磷含量、钙磷乘积与剪毛量、净毛率呈显著或极显著的正相关 ,而与羊毛的含脂率呈负相关 ( 0 0 1

0 0 5 )。因此可利用血清钾型、无机磷含量、钙磷乘积等生化指标作为凉山半细毛羊选育提高的辅助性状 ,在生产中适当参考应用。     

凉山48-50支半细毛羊母羊预期表型值综合选择指数的研究

本文利用凉山48－50支半细毛羊1990—1993年度的育种记录，用Harvey（1987）程序校正了出生年度和月份的固定效应，并估测了母羊三个体重性状及五个羊毛性状的遗传参数。利用表型通径分析方法建立了用初生和断奶性状的表型值，预测育成各性状表型值的“最优”回归方程，并制定了母羊预期表型值的综合选择指数。结果表明：预期表型值综合选择指数的预期遗传进展为独立淘汰法的1．230倍。     

绵羊血红蛋白基因对体重和剪毛量的影响

在对培育中凉山半细毛羊横交群研究发现，血红蛋白（ＨＢ）基因处于非遗传平衡状态。ＨＢ基因型间绵羊体重和产毛量存在显著或极显著差异，其中ＡＡ型或ＡＢ型绵羊比ＢＢ型绵羊的初生体重、断奶体重、育成体重、成年体重和成年剪毛量显著或极显著的高。     

四川凉山州羊寄生虫调查及防治研究

作者用完全蠕虫解剖法检查绵羊52只,山羊92只,收集虫体128万多条,虫体经分类鉴定共92种,隶属7纲、31科、48属;优势虫种16个;一只羊最多混合感染38种寄生虫,最大荷虫量142768条。经防治试验,认为用啤酒瓶稀释,按每公斤体重一次口服丙硫咪唑(Albendazole)5毫克对羊寄生蠕虫有良好驱治作用;用螨净(NEOCTDOL)按1∶1000浓度药浴,对驱治羊体表寄生虫也有很好疗效。     

凉山半细毛羊血清蛋白含量遗传力估测及其与经济性状相关分析

本研究用２７只公羊的后裔１２２只育成母羊估测了血清总蛋白、清蛋白和球蛋白含量的遗传力分别为０．３４３、０．５５５和０．２１１。这三种血清蛋白含量和育成体重的表型相关分别达到了显著或极显著水平（Ｐ＜０．０５或Ｐ＜０．０１），清蛋白含量和育成体重的遗传相关为０．３５０（Ｐ＜０．０１）。这提示血清清蛋白含量可作为一个指示性状，用于预测和选种。     

The use of trees,shrubs and herbs in livestock production by communal farmers in northern KwaZulu-Natal,South Africa

A survey of the use of trees, shrubs and herbs for livestock production was conducted through questionnaires among 90 farmers in the communal areas of northern KwaZulu-Natal in South Africa. The areas surveyed were located at Mtubatuba, Hluhluwe, Kwadlangezwa and Jozini. All the farmers questioned were found to own some form of livestock, mostly the Nguni breed. The commonly perceived sources of constraints on livestock production were external and internal parasites. The well known plants reported to be consumed by the animals were Vitellariopsis arginata and Rhus gueinzii. Most of the farmers (27.7%) used Cissus quadrangularis and Gnidia kraussiana for treating worm infestations and coughs in livestock. Plants used for increasing milk production were Crinum macowanii and Sarcostemma viminale. The well known plant species detrimental to livestock was Moraea spathulata, which causes diarrhoea and death.     

凉山半细毛羊遗传结构研究

本试验用血红蛋白（HB）、运铁蛋白（TF）、前白蛋白（PR）和后白蛋白（Po）等四个血液蛋白多态性座位，分析凉山半细毛羊横交群遗传结构。结果表明：除HB座位外，其余三个座位均处于Hardy－Weinberg平衡状态。各育种场间的遗传距离在0．9—2．0之间。用基因频率系统聚类，好谷场、州畜科所场和竹核场的横交群为一类，而螺吉山场自成一类。