Serological tests as indicators of immunity against Pasteurella multocida infection in sheep.

Five serological tests, i.e. single tube agglutination, doubling dilution tube agglutination, agar agglutination, passive hemagglutination and passive mouse protection tests were evaluated for their efficacy in predicting the fate of vaccinated and unvaccinated sheep on challenge with an ovine strain of Pasteurella multocida. The passive hemagglutination test predicted the fate of unvaccinated sheep while the agar agglutination test indicated the immune status of vaccinated sheep.     

从近日豆粕价格小幅走高看后市行情

由于世界范围内大豆供应充足,而国内养殖业陷入低谷,导致下游豆粕需求始终未见明显提升,2006年以来的国内豆粕市场持续振荡走低,市场纷纷看空。进入8月份后,豆粕现货价格表现出了明显的抗跌特征,整体振荡,涨跌幅度均不大。尽管日前美国农业部8月份的供需报告中将全球大豆库存由     

Free Flying Sparrows as Carriers of Salmonellosis

Salmonella typhimurium was isolated from nine of 60 wild sparrows trapped in the Guelph area. While this organism was isolated from birds trapped at several different locations, the highest prevalence was in sparrows trapped in close proximity to an animal clinic. The significance of these findings in relation to human and animal salmonellosis is discussed.     

Serine-to-glycine ratios in low-protein diets regulate intramuscular fat by affecting lipid metabolism and myofiber type transition in the skeletal muscle of growing-finishing pigs

Serine and glycine are 2 of the first-affected nonessential amino acids in low crude protein (CP) diets for pigs. Therefore, we explored the effects of different dietary serine-to-glycine ratios on growth performance and lipid metabolism in growing-finishing pigs. A total of 160 crossbred healthy barrows, with a similar body weight of around 59.50 kg, were randomly allotted into 1 of 5 treatments (8 pens per treatment and 4 pigs per pen). The serine-to-glycine ratios of the 5 dietary treatments were as follows: diet A (NORMAL group), 1.18:1 (16% CP); diet B (LOW group), 1.2:1 (12% CP); diet C (S2G1 group), 2:1 (12% CP); diet D (S1G2 group), 1:2 (12% CP); and diet E (S1G1 group), 1:1 (12% CP).We found that the pigs fed a low CP diet (12% CP), when maintaining serine-to-glycine ratio at 1:2 and a total amount of 1.44%, had the same average daily gain as the pigs fed a normal CP diet (16% CP) (P > 0.05), but they had increased intramuscular fat (P < 0.05). Furthermore, they exhibited higher expression of genes involved in lipid oxidation (P < 0.05), which was regulated by modulating methylation levels in the promoters of acyl-CoA oxidase 1 (ACOX1) and acyl-CoA dehydrogenase medium chain (ACADM). When compared with the pigs fed a normal CP diet, these pigs had more oxidative myofibers (P < 0.05), which were regulated by AMPK-PGC-1α and Calcineurin-MEF2/NFAT pathways in a coordinated manner. Our findings suggested that a dietary serine-to-glycine ratio of 1:2 is beneficial for improving meat quality in pigs fed a low CP diet.     

桑尺蠖和丝棉木金星尺蠖的微孢子虫对家蚕病原性和胚种传染性研究

从桑尺蠖（ＨｅｍｅｒｏｐｈｉｌａａｔｒｉｌｉｎｅａｔａＢｕｔｌｅｒ）中分离的微孢子虫（简称桑尺蠖微孢子虫），形态为长卵圆形，大小为３．５～４．１×１．６～１．９μｍ。从丝棉木金星尺蠖（ＣａｌｏｓｐｉｌｏｓｓｕｓｐｅｃｔａＷａｒｒｅｎ）中分离的微孢子虫（简称丝棉木金星尺蠖微孢子虫），形状为卵圆形，大小为３．２～３．７×１．６～２．１μｍ。两种微孢子虫均能感染寄生家蚕的主要组织器官，引起蚕儿发病，但致病力要比家蚕微孢子虫（Ｎｏｓｅｍａｂｏｍｂｙｃｉｓ）弱，且能经卵传染给下一代，其胚种传染率要比家蚕微孢子虫低。     

鸡对粉浆蛋白粉的氨基酸利用率测定

用排空强饲法对粉浆蛋白粉的常规成分、代谢能及氨基酸利用率进行了测定。结果表明:粉浆蛋白粉干物质中含有粗蛋白质78.4％;代谢能为15.86MJ/kg;赖氨酸5.03％;蛋氨酸0.39％;胱氨酸1.30％;异亮氨酸3.25％;亮氨酸6.92％;精氨酸6.68％:酪氨酸2.34％;苯丙氨酸3.78％:组氨酸1.75％。这些必需氨基酸利用率分别为:92.0％、81.7％、85.2％、90.2％、92.9％、92.4％、90.5％、90.5％和92.1％。其氨基酸利用率介于豆饼与鱼粉之间,是一种值得开发的蛋白质饲料资源。     

The Prevention and Control of Epidemics of Acute Undifferentiated Diarrhea of Beef Calves in Western Canada

It is frequently evident that outbreaks of diarrhea occur in spite of apparent “good management” and “good calving conditions”. This observation underlies the fact that we still do not understand many of the epidemiological factors which contribute to calf diarrhea outbreaks. For example, we still lack biological criteria by which to judge the degree of crowding and the degree of stress. Nevertheless, application of the principles described above will prevent or decrease the severity of many annual epidemics. To be successful, a program of prevention and control should be discussed with producers long before the calving season, preferably during the preceding summer or fall. Implementation of a complete program may take several calving seasons and producers should be made aware that prevention by improved management is an on-going, evolutionary process. More and improved vaccines are becoming available; however, as is the case with most biologicals, their impact cannot be determined until after they have been used for several years. They should be recognized as only one of several managent tools at the disposal of the veterinarian and livestock producer.     

Experimental Hemorrhagic Septicemia: Gross and Microscopic Lesions Resulting from Acute Infections and from Endotoxin Administration

Gross and microscopic lesions observed in bovine and porcine hemorrhagic septicemia, and in bovine Pasteurella multocida endotoxemia are described. Widely distributed hemorrhages, edema, and general hyperemia were the most obvious tissue changes observed in the infected calves. Pneumonia was a constant lesion. Aerosol exposure produced a multiple focal fibrinosuppurative pneumonia, while intranasal and intramuscular inoculation resulted in generalized interstitial pneumonia. A slight lymphadenitis and degenerative changes in hepatic and renal parenchymal cells were also observed.

The predominant lesions observed in infected pigs were a diffuse, extensive, fibrinous pneumonia and fibrinous polyserositis. Edema and general hyperemia were observed, but the widespread hemorrhages which occurred in the calves were not present. Acute lymphadenitis and renal tubule vacuolar degeneration were observed. A slight amount of cloudy swelling and focal areas of necrosis were found in the liver.

Lesions in a calf that died following administration of Past. multocida endotoxin were widely distributed hemorrhages, edema, and general hyperemia. These lesions were especially evident in the lungs, and indicated widespread vascular alteration.