A new treatment for trichophytosis of cattle]

A new way to treat ringworm in calves and young cattle giving 1 ml formaldehyde solution (10%) per kg BW intravenously is described.     

A new heat load index for feedlot cattle

The ability to predict the effects of extreme climatic variables on livestock is important in terms of welfare and performance. An index combining temperature and humidity (THI) has been used for more than 4 decades to assess heat stress in cattle. However, the THI does not include important climatic variables such as solar load and wind speed (WS, m/s). Likewise, it does not include management factors (the effect of shade) or animal factors (genotype differences). Over 8 summers, a total of 11,669 Bos taurus steers, 2,344 B. taurus crossbred steers, 2,142 B. taurus x Bos indicus steers, and 1,595 B. indicus steers were used to develop and test a heat load index (HLI) for feedlot cattle. A new HLI incorporating black globe (BG) temperature ( degrees C), relative humidity (RH, decimal form), and WS was initially developed by using the panting score (PS) of 2,490 Angus steers. The HLI consists of 2 parts based on a BG temperature threshold of 25 degrees C: HLI(BG>25) = 8.62 + (0.38 x RH) + (1.55 x BG) - (0.5 x WS) + e((2.4-WS)), and HLI(BG<25) = 10.66 + (0.28 x RH) + (1.3 x BG) - WS, where e is the base of the natural logarithm. A threshold HLI above which cattle of different genotypes gain body heat was developed for 7 genotypes. The threshold for unshaded black B. taurus steers was 86, and for unshaded B. indicus (100%) the threshold was 96. Threshold adjustments were developed for factors such as coat color, health status, access to shade, drinking water temperature, and manure management. Upward and downward adjustments are possible; upward adjustments occur when cattle have access to shade (+3 to +7) and downward adjustments occur when cattle are showing clinical signs of disease (-5). A related measure, the accumulated heat load (AHL) model, also was developed after the development of the HLI. The AHL is a measure of the animal's heat load balance and is determined by the duration of exposure above the threshold HLI. The THI and THI-hours (hours above a THI threshold) were compared with the HLI and AHL. The relationships between tympanic temperature and the average HLI and THI for the previous 24 h were R(2) = 0.67, P < 0.001, and R(2) = 0.26, P < 0.001, respectively. The R(2) for the relationships between HLI or AHL and PS were positive (0.93 and 0.92 for HLI and AHL, respectively, P < 0.001). The R(2) for the relationship between THI and PS was 0.61 (P < 0.001), and for THI-hours was 0.37 (P < 0.001). The HLI and the AHL were successful in predicting PS responses of different cattle genotypes during periods of high heat load.     

乳铁蛋白肽的研究现状及进展

<正>近年来抗菌肽由于自身的优点成为抗生素的替代品,已成为学术界研究与开发的热点,其中乳铁蛋白肽(Lactoferricin,Lfcin)因其强大的生物学功能而备受关注。最初是由Bellamy等从乳铁蛋白水解物中分离到一种乳铁蛋白多肽,即牛乳铁蛋白肽(LfcinB),此     

新型饲料添加剂--二甲酸钾

随着人们对安全食品或绿色食品的青睐,抗生素类促生长添加剂广泛使用所带来的药物残留和耐药性问题也越来越受到人们的关注.目前,FAO等组织及发达国家对食品中抗生素的限制越来越严格.饲料安全是食品安全的基本保障,为了保障食品安全,2006年开始,欧盟将全面禁止在饲料中使用生长素类抗生素作为饲料促生长添加剂.近年来,替代传统抗生素添加剂的研究正在不断深入,在欧洲,二甲酸钾作为一种新的饲料添加剂由BASF公司研制开发并已被欧共体、瑞士、挪威批准在仔猪和育肥猪饲料中作为促生长剂使用.二甲酸钾于2001年被欧盟批准使用,是欧盟批准的第一种用于替代抗生素促生长剂的非抗生素饲料添加剂,应用前景广阔.在国内,北京挑战农业科技有限公司与中国农业科学院饲料研究所联合研制开发了二甲酸钾产品,并于2005年3月22日获得农业部颁发的新饲料添加剂证书.     

一种新型饲料添加剂-卵黄免疫球蛋白IgY

对卵黄色疫球蛋白IgY分子结构功能性质、提纯方法、作为饲料添加剂的应用及作用机制 4个方面进行了讨论 ,旨在说明卵黄免疫球蛋白作为一种新型饲料添加剂的可行性、优越性。     

A new approach in the prevention of gastrointestinal parasitic infections in cattle

The efficacy of a morantel long-acting device in preventing parasitic gastroenteric infections throughout a whole year was evaluated in heifers and steer calves in south central Québec. Thirty-two calves, comprising nine Hereford steers, one Hereford heifer, fourteen Holstein crossbred steers and eight Holstein crossbred heifers, were allotted into two treatment groups and maintained throughout the grazing season on adjacent pastures resulting from equivalently dividing one original pasture. One morantel long-acting device was administered to each animal in one group at the time of turnout onto the pasture in the spring while the calves in the other group remained as nonmedicated controls. The parasitic infections incurred during the pasture season were primarily Ostertagia, Trichostrongylus, Cooperia and Nematodirus.

The following fall, after twelve calves were necropsied for worm counts, the twenty remaining ones were brought into the barn where they were kept throughout the winter with access to an outside yard. They received good quality hay and rolled barley (1 kg/head/day) up until the following May, at which time they were weighed and had fecal samples taken for egg counts. In contrast to the results observed among controls, the morantel long-acting device treatment group had an 87% reduction in fecal worm egg excretion and a 67.3 kg per calf increased weight gain after one year.

     

A new aid to the diagnosis of Vibrio foetus infection in cattle

This paper describes poisonings that occurred when two cows were fed, small quantities of minced white clover per rumen fistulam over a two-hour period. One animal died; the other survived following treatment with a specific antidote. The level of cyanide found in the leaf material was 200 /g greentissue. It seemsclear from calculations based on this result that the intake of glucosides was sufficient to account for the results observed. Aspects of these cases are discussed in relation to findings of other workers. These cases demonstrate the potential dangers of the high levels of cyanogenetic glucosides in N.Z. white clovers.     

新型防霉剂富马酸酯类

1新型防霉剂的优点长期以来,广泛应用的化学防霉防腐剂主要是有机酸及其盐类,如苯甲酸及其钠盐,山梨酸及其钠、钾盐,丙酸及其钠、钙盐,脱氢醋酸及其钾盐等。它们都对细菌和霉菌有很强的抑制作用,但其毒性都较高,有些品种如苯甲酸钠、脱氢醋酸钠等被世界卫生组织禁止使用;即使使用,其使用条件和使用范围也受到很大限制。20世纪80年代以后,新开发的有机酸酯作为防霉防腐剂已被广泛采用,原因主要有以下几大特点:1)毒性较低,使用安全。有机酸酯类与有机酸盐作为防霉防腐剂的毒性比较,见表1。2)杀菌力极强,且具有广谱性,对霉菌有特殊抑制效果,特…     

新型人畜共患病——附红细胞体病

附红细胞体病 (Ｅｐｅｒｙｔｈｒｏｚｏｏｎｏｓｉｓ :简称附红体病 )是由附红细胞体 (Ｅｐｅｒｙｔｈｒｏｚｏｏｎ ;简称附红体 )引起的一种人畜共患传染病 ,以贫血、黄疸和发热为特征。本病最早发现于 1 92 8年 ,但过去因其对非摘脾动物很少有致病性而长期被人们所忽视 ,直到 1 950年确定猪的黄疸性贫血是由附红体所引起 ,才逐渐被重视起来。目前本病已广泛分布于世界许多国家和地区。我国于 1 981年首先在家兔中发现附红体 ,相继在牛、羊、猪等家畜中查到附红体 ,以后在人群中也证实了附红体感染的存在。近年来 ,特别是 1 993年以来 ,随…