Listeriosis in sheep. Listeria monocytogenes excretion and immunological state in sheep in flocks with clinical listeriosis.

The excretion of Listeria monocytogenes (Lm) in the faeces and milk, and humoral immunity against Lm, were examined in a sheep flock with outbreaks of listeric encephalitis and in a flock with outbreaks of listeric abortion. The encephalitis flock consisted of 86 ewes and 20 hoggs, the abortion flock of 45 ewes and 3 hoggs, all of them pregnant. Faecal excretion rate in the encephalitis flock varied from about 25 % in the first part of the indoor season to nearly zero 1 month later, to about 30 % 1 month before lambing and about 15 % at lambing. About 15 % of the animals also excreted Lm in the milk. Lm 4 was the dominating serotype.In the abortion flock about 2/3 of the animals excreted Lm in the faeces and 1/3 in the milk at lambing. All the isolates belonged to serotype 1, which also was isolated from grass silage and strawbedding samples.In the encephalitis flock ewes with ≥ 3 foetuses had a higher excretion rate than the remainder, while no such differences were found in the abortion flock.Antibody titres against Lm in sera and whey in the encephalitis flock were of the same order as in the healthy flock described in an earlier publication (Grønstøl 1979), except that the highest titres were found in the hoggs. Serum titres from the abortion flock after lambing were significantly higher than in the encephalitis flock, while whey titres were of the same order.Treatment with 2-mercapto-ethanol reduced the titres substantially in sera from the abortion flock, indicating that the antibodies belonged to the IgM-fraction, while only a slight reduction was seen after similar treatment of the whey.     

A Study on the Productivity and Diseases of Camels in Eastern Ethiopia

A study concerning performance traits of the Ethiopian camel indicated that, in the camel herds examined, there was one active bull camel for 25 females. The bull camel was 5 years old at puberty; it reached rutting vigour at the age of 9 years, the number of mountings per day was 8 during the breeding season, and the reproduction span was 10 years. The female camel reached puberty at 4 years of age; the age at first calving was 5 years, and the lactation period was one year; the calving interval was 2 years, the calving rate was 50%, and the reproduction span was 10–15 years. The survival rate of the newborn calves was 50%. The average milk yield was 2.5 L per day; the price of camel's milk was higher than that of cow's milk at US$0.5. Adult camels weighed around 500 kg; the dressing-out percentage was 52%. Mutton was preferred to camel meat, which came second in popularity, costing US$2/kg. Owing to their poor reproductive performance, camels are not efficient for producing meat. The camels worked for 16 h per day, covering 60 km. Animal health problems encountered were trypanosomosis, camel pox, camel pustular dermatitis, camel cephalopsis, dermatomycosis, mange mite, tick infestation and balantidiosis, most of which mainly affected the young animals.     

Protein and Energy Requirements of Pre-weaned West African Dwarf Goats Fed Soyabean Diet as a Replacement for Milk in a Tropical Environment

Twenty-one early-weaned West African dwarf goats weighing between 1.0 and 1.5 kg at birth were used to assess the protein and energy requirement of pre-weaned West African Dwarf (WAD) goats fed soyabean diet. Three isonitrogenous diets (24%) were prepared such that dried whole-milk protein was replaced by corn starch and soyabean concentrate protein at 0.0%, 25.0% and 50.0% levels such that a 14.5% total solid solution was obtained for each diet. Results indicated that a daily digestible energy (expressed as kcal/day/W0.75 kg) intake of 58.2, 63.7, 98.5 and 114.6 kcal was required for maintenance, while a corresponding value of 7.37, 4.50, 2.18 and 1.91 kcal was required per day per gram live weight gain by the kids at 4, 6, 9 and 13weeks old, respectively. Similarly, a digestible crude protein (DCP) intake of 3.59 g/day/W0.75 kg) appeared to be adequate for maintenance of the kids between 0 and 13 weeks, while 0.34 g/day/W0.75 kg of DCP intake was required per day per gram live weight.     

关中奶山羊体尺指标和产奶量研究分析

通过对关中奶山羊的体尺指标和产奶量的调查研究分析,发现当前的关中奶山羊的年龄结构分布合理,但主要体尺指标均表现为显著性差异,其中体高、体长、腰角宽、胸围差异高度显著,管围差异不显著;各项指标和产奶性能均有退化现象,且有明显的地域性差异。     

复合微量元素缓释丸对奶牛产奶量及奶品质影响的研究

以产奶的黑白花奶牛２０头,分为两组,每组１０头。在同一日粮和饲养管理条件下,一组投丸,为试验组;另一组不投丸,为对照组。预试期１０ｄ,正试期３２ｄ。试验结果,试验组日平均产奶量１７．７６ｋｇ,对照为１６．３０ｋｇ。试验组比对照组提高８．９５％;校正为４％乳脂率的标准乳的日产奶量,试验组为１５．９９ｋｇ,对照组为１３．９４ｋｇ,试验组比对照组提高１４．７１％;     

利用TB_PCR试剂盒对牛结核病的检测

应用聚合酶链式反应（ＰＣＲ）技术制备的ＴＢ－ＰＣＲ试剂盒对来自新疆６个牛场的２３８份血样、奶样、口腔分泌物标本中结核分枝杆菌进行检测,结果显示：ＴＢ－ＰＣＲ试剂盒对４０份奶样样本进行检测,７头为阳性,阳性检出率１７．５％。ＴＢ－ＰＣＲ试剂盒对１７８份血样标本的检测,２３头牛为阳性,阳性检出率为１２．９２％。ＴＢ－ＰＣＲ试剂盒对２０份口腔分泌物标本中结核分歧杆菌检测结果均为阴性。本试验中共计检测６个牛场的２３８份不同标本的ＰＣＲ阳性牛共计２７头,阳性检出率为３．０２％。将ＰＣＲ和传统的ＰＰＤ检测方法的结果比较显示ＰＰＤ检出阳性率高于ＰＣＲ,ＰＰＤ检出阳性牛３９头,检出阳性率６．７％。本试验对口腔分泌物标本的检测结果不理想。总之,ＴＢ－ＰＣＲ试剂盒在检测牛结核病不同标本中显示出快速、特异等优点。为今后牛结核病的检测     

棚式牛舍的温热环境及其对乳牛产奶量的影响

以一栋棚舍和其中所饲养的奶牛为对象,系统地测定了舍内、外的气温、湿度、风速、辐射强度、黑体温度及屋顶热流量,并计算了奶牛产奶量的环境影响系数。结果表明:夏季舍内旬均THI值全超过了荷斯坦牛热应激的临界值,舍内热辐射强烈,黑体温度高;环境影响系数以7～9月为较大的负值,对奶牛产奶最不利。冬季舍内寒冷,同时受舍外气流的影响;但环境影响系数仍然为正值,对奶牛产奶量影响相对较小。这在一定程度上还提示,中原地区可以采用棚式乳牛舍,增加棚舍高度和选用高热阻屋顶材料利于夏季防暑     

麦洼牦牛初乳和常乳中超氧化物歧化酶活力的研究

研究了麦洼牦牛脱脂乳中超氧化物歧化酶 (SOD)的活力。结果显示 :牦牛初乳 (泌乳第 1～ 7天 )中SOD活力(Nu/mL)分别为 31 4 6 3± 39 5 1、35 5 73± 39 1、36 4 4 9±2 2 1 7、32 4 73± 30 6、31 3 96± 1 8 0 0、31 6 6 5± 1 9 5 1、31 7 5 2± 1 0 6 8,常乳中的活力为 2 92 4 9± 6 96Nu/mL。与常乳相比 ,泌乳第 3天的初乳中SOD活力显著高于常乳 ,其余各天差异不显著。半奶牦牛和犏牛乳中SOD活力分别为 1 89 75± 1 1 71和 1 2 5 6 5± 2 2 9,均极显著低于常乳     

二花脸猪乳中生长因子的动态分析及其与大约克猪的比较

通过 2个系列实验 ,分析了二花脸猪乳中生长因子 (IGF Ⅰ、EGF和胰岛素 )在泌乳早期 (1～ 2 1d)的含量及其变化规律 ,并与大约克猪进行了比较研究。结果表明 ,二花脸和大约克猪乳中IGF Ⅰ在初乳中浓度很高 ,分娩 1周后迅速下降 ,泌乳第 7～ 2 1天变化不大。在泌乳第 1～ 7天 ,二花脸猪乳中IGF Ⅰ低于大约克猪 ,泌乳第 7天以后又高于大约克 ,但 2种猪的差别不显著 (P >0 0 5)。猪乳中的EGF变化规律基本上和IGF Ⅰ相同。在泌乳第 1天 ,二花脸猪乳中的EGF显著低于大约克猪 (P <0 0 5) ,第 1天以后 2种猪没有明显差异。二花脸和大约克猪乳中的胰岛素在初乳很高 ,产后 4d迅速下降 ,4d以后变化幅度不大。二花脸猪乳中的胰岛素在泌乳早期 (1～ 2 1d)全都低于大约克猪 ,其中在泌乳第 1天、第 6～ 7天、第 8～10天和第 11～ 14天这 4个阶段显著低于大约克猪 (P <0 0 5)。     

奶牛各胎次产乳量相关性研究与终生产乳量的早期预测

本文通过对荷斯坦奶牛１～７胎各胎次产乳量相关性的研究,分析了各胎次之间产乳量的相互关系,泌乳的规律性,并通过早期产乳量 生产乳量,筛选最佳预测终生产乳量的回归方程,预测的终生产乳量的相关系数达到０．７８１９。