Acute phase protein changes in calves during an outbreak of respiratory disease caused by bovine respiratory syncytial virus

Bovine acute phase proteins (APPs), lipopolysaccharide binding protein (LBP), serum amyloid A (SAA), haptoglobin (Hp) and alpha₁-acid glycoprotein (AGP) were evaluated as inflammatory markers during an outbreak of bovine respiratory disease (BRD) caused by bovine respiratory syncytial virus (BRSV). Calves (n = 10) presented mild to moderate signs of respiratory disease. Secondary bacterial infections, Pasteurella multocida and Mycoplasma dispar as major species, were detected in tracheobronchial lavage samples. Concentrations of SAA and LBP increased at week 1 had the highest values at week 3 and decreased at week 4 of outbreak. Some calves had high Hp concentrations at week 3, but AGP concentrations did not rise during respiratory disease. Higher SAA, LBP and Hp concentrations at a later stage of BRD (week 3) were associated with the low BRSV-specific IgG₁ production, suggesting that these calves had enhanced inflammatory response to the secondary bacterial infection. In conclusion, APPs (especially SAA and LBP) are sensitive markers of respiratory infection, and they may be useful to explore host response to the respiratory infections in clinical research.     

Virulence factors in Escherichia coli isolated from calves with diarrhea in Vietnam

This study was conducted to determine the prevalence and characteristics of pathogenic Escherichia (E.) coli strains from diarrheic calves in Vietnam. A total of 345 E. coli isolates obtained from 322 diarrheic calves were subjected to PCR and multiplex PCR for detection of the f5, f41, f17, eae, sta, lt, stx1, and stx2 genes. Of the 345 isolates, 108 (31.3%) carried at least one fimbrial gene. Of these 108 isolates, 50 carried genes for Shiga toxin and one possessed genes for both enterotoxin and Shiga toxin. The eae gene was found in 34 isolates (9.8%), 23 of which also carried stx genes. The Shiga toxin genes were detected in 177 isolates (51.3%) and the number of strains that carried stx1, stx2 and stx1/stx2 were 46, 73 and 58, respectively. Among 177 Shiga toxin-producing E. coli isolates, 89 carried the ehxA gene and 87 possessed the saa gene. Further characterization of the stx subtypes showed that among 104 stx1-positive isolates, 58 were the stx1c variant and 46 were the stx1 variant. Of the 131 stx2-positive strains, 48 were stx2, 48 were stx2c, 11 were stx2d, 17 were stx2g, and seven were stx2c/stx2g subtypes. The serogroups most prevalent among the 345 isolates were O15, O20, O103 and O157.     

Effects of haul distance and stocking density on young suckling calves transported in Japan

We conducted applicability evaluation of recommendations of the European Union (EU) and the Royal Society for Prevention of Cruelty to Animals (RSPCA) for suckling calves. Nineteen calves (14 Holstein aged 11–26 days and five cross‐bred aged 13–45 days) were divided into six groups. Three groups were allocated into the stocking densities of 0.25, 0.35, 0.45 m²/head and were weekly transported 50, 100, 150 km in this order. Another three groups were allocated and transported in reverse order. Observation was conducted during and after transportation. Blood sampling was performed before and after transportation. The occurrences of lying and turning round on the truck were significantly associated with stocking density (P < 0.05), but not with haul distance. Scratching was observed only in one calf. Incidence of watery feces was not associated with both factors. There were significant effects of haul distance on the concentrations of plasma cortisol and noradrenaline, and serum aspartate aminotranserase (AST) and IgM (P < 0.05). These concentrations, except cortisol, were higher after transportation at 150 km compared to the pre‐transportation value (AST and IgM P < 0.05; noradrenaline P < 0.10). Results suggest that haul distances greater than 100 km should not be recommended even for suckling calves transported in Japan.     

雄性梅花鹿仔鹿越冬期配合日粮适宜蛋白质水平的研究

为探讨不同蛋白质水平配合日粮对雄性梅花鹿仔鹿越冬期蛋白质消化率及生产性能的影响,试验选用18头雄性梅花鹿仔鹿随机分成4组,分别饲喂4种不同蛋白质水平的配合日粮（平均粗蛋白质水平分别为8.71%、11.88%、15.66%和17.95%）,进行饲养试验及消化试验。结果表明,仔鹿越冬期配合日粮适宜蛋白质水平为15.66%。     

一起肉犊牛大肠杆菌性急性腹泻的诊治

2020年春,内蒙古赤峰和通辽发生新生犊牛腹泻甚至死亡情况。随即进行临床初步诊断并采集新鲜粪便样品进行实验室检测,结果显示为大肠杆菌为主引起的腹泻。根据药敏试验结果选用抗生素,同时采用支持疗法。一周后回访,腹泻情况得到有效防控。     

不同诱食剂对乳肉兼用犊牛采食偏好的影响

对于乳肉兼用犊牛而言,能更早的采食犊牛料并提高采食量是实现犊牛早期断奶和提升日增重的关键手段。本试验结合常用的三种犊牛颗粒料饲料添加产品(S1:0.03%乳香味诱食剂;S2:0.015%糖精钠;S3:0.3%包被丁酸钠)从诱食效果方面进行评估,选取效果最好的诱食产品在犊牛颗粒料生产中推广使用。试验结果表明：3种不同诱食剂对乳肉兼用犊牛诱食效果为：0.03%乳香味诱食剂>0.015%糖精钠>0.3%包被丁酸钠。     

新生犊牛的生理特点及饲养管理措施

新生犊牛由于组织器官发育不完善,胃肠消化功能弱,体温调节能力差,抵抗力免疫力低下,代谢旺盛生长发育快等生理特点,若管理不善,极易造成犊牛免疫力低,死亡率高等不良后果,因此科学化、精细化的饲养管理非常重要。本文通过对新生犊牛生理特点的分析,介绍了新生犊牛饲养管理关键技术,为培育健康状况良好,有生长潜力的牛群提供借鉴。     

引起犊牛腹泻的Nebovirus

Newbury-1 virus目前是杯状病毒科（Caliciviridae）纽布病毒属（Nebovirus）的唯一成员,常用Nebovirus（NeV）表述。NeV为单股正链RNA病毒,基因组全长为7 453~7 460 bp,是致犊牛腹泻的重要病毒。NeV的病原检测主要依靠RT-PCR和Real-time RT-PCR方法。迄今为止,NeV已经在美国、英国、巴西、土耳其等13个国家检出,具有广泛的地域分布。最近,本实验室的研究表明该病毒在我国奶牛和牦牛中广泛流行,具有独特的进化趋势,并且有新基因型毒株的出现。本文就NeV的生物学特性、流行概况、所致疾病的临床症状与病理变化、检测方法和防控措施等研究进展进行综述,以期为NeV的研究提供参考。     

不同粗饲料来源对荷斯坦公犊生长性能、血清生化指标及营养物质表观消化率的影响

试验旨在研究桑枝、花生藤和燕麦草3种粗饲料对断奶荷斯坦公犊生长性能、血清生化指标和营养物质表观消化率的影响.选取8周龄、健康的体重(64±5)kg断奶荷斯坦奶公犊27头,随机分成A、B、C3组,每组9个重复,分别饲喂桑枝、花生藤和燕麦草3种粗饲料.试验期24 d.结果 显示,C组犊牛的末重和平均日增重均极显著高于A组和...