犬胃扩张-肠扭转的风险因子和预防

胃扩张-肠扭转(Gastric Dilatation-Volvulus--GDV)又称为"臌"、"胃扭转"。GDV是一个极其严重,并应视为严重威胁犬生命的紧急事件,是仅次于癌症导致犬死亡的第二大杀手。24%的犬臌是由胃膨胀引起的。但是大多数的情况(75%)是由于胃扭转,弯曲和切断胃内容物的流入和流出。由于胃部膨胀,可旋转90°至360°,固定附着在食道和十二指肠之间缠绕。膨胀的胃妨碍腹部静脉、减少血液返回到心脏,丧失血液供应,导致低血压、胃缺血、休克、脏器损害,要在育种,饲养和管理上加强监管,有效的降低形成和促发GDV风险因子的条件,加强对GDV风险因子的预警和识别,以及发生后的及时发现和立即处理治疗。     

我国蛋鸡养殖成本收益及其影响因素分析

本文采用多元线性回归方法对2006～2008年中国小规模、中规模、大规模蛋鸡养殖者的成本收益进行了实证分析.研究发现:精饲料价格是影响蛋鸡养殖成本收益的关键,提高鸡蛋价格也是促进蛋农增收的重要因素,鸡蛋产量的稳定增长对蛋鸡成本收益的提高作用很大.     

规模化猪场疫病传入的外部风险因素指标体系的初探

据实际调查,运用层次分析法,将疫病传入的各外界风险因素指标划分为目标层、准则层和分准则层三个层次。采用EXCEL软件进行数据统计,依次编辑各层次结构模型,构建各层次的判断矩阵和一致性检验。结果表明：猪场的管理措施、生物安全、场址是疫病传入的主要风险因素。据此确立了I级指标和II级指标,从而构建疫病传入的风险因素指标体系。     

Timing and temperature thresholds of heat stress effects on fertility performance of different parity sows in Spanish herds

High temperature is an environmental factor that impairs sow fertility. In this study, we identified the critical weeks for heat stress effects on aspects of fertility performance, namely weaning-to-first-service interval (WSI) and farrowing rate (FR). We also examined the threshold temperatures above which the fertility performance deteriorated and whether there were any differences between parities regarding heat stress effects or thresholds. Performance data of sows in 142 herds from 2011 to 2016 were matched to appropriate weekly averaged daily maximum temperatures (T_max) from weather stations close to the herds. Two types of ratios (i.e., ratio for WSI and odds ratio for FR) were used to identify the critical weeks for heat stress by comparing the respective measures for two sow groups based on T_max in different weeks around weaning or service events. The ratios for WSI were calculated between groups of sows exposed to T_max ≥ 27 °C or <27 °C in each week before weaning, with the T_max cutoff value based on a recent review study. Similarly, the odds ratios for FR for the two groups were calculated in weeks around service. The weeks with the largest differences in the fertility measures between the two T_max groups (i.e., the highest ratio for WSI and the lowest odds ratio for FR) were considered to be the critical weeks for heat stress. Also, piecewise models with different breakpoints were constructed to identify the threshold T_max in the critical week. The breakpoint in the best-fit model was considered to be the threshold T_max. The highest ratios for WSI were obtained at 1 to 3 wk before weaning in parity 1 and 2 or higher sow groups. The threshold T_max leading to prolonged WSI was 17 °C for parity 1 sows and 25 °C for parity 2 or higher sows. Increasing T_max by 10 °C above these thresholds increased WSI by 0.65, and 0.33 to 0.35 d, respectively (P < 0.01). For FR, the lowest odds ratios were obtained at 2 to 3 wk before service in parity 0, 1, and 2 or higher sow groups. The threshold T_max leading to reductions in FR was 20, 21, and 24 to 25 °C for parity 0, 1, and 2 or higher sow groups, respectively. Increasing T_max by 10 °C above these thresholds decreased FR by 3.0%, 4.3%, and 1.9% to 2.8%, respectively (P < 0.01). These results indicate that the critical weeks for heat stress were 2 to 3 wk before service for FR and 1 to 3 wk before weaning for WSI. The decreases in fertility performance in parity 0 to 1 sows started at temperatures 3 to 8 °C lower than in parity 2 or higher sows.     

Regulation of fibroblast growth factor 9 on the differentiation of goat intramuscular adipocytes

It has been found that fibroblast growth factor receptor (FGF-FGFR) signaling can regulate the expression of adipocyte differentiation genes. FGF9 is one of the members of FGFs that mainly binds receptors FGFR2 and FGFR3. FGF9 is highly expressed in the adipose tissue of humans and mice, but there are few reports on the role of FGF9 in goat intramuscular adipocyte differentiation. Therefore, this study explored the effect of FGF9 on adipocyte differentiation through cell culture, interference, and overexpression. The expression of receptors FGFR1–FGFR4 in adipocyte differentiation and their effects on differentiation were detected to screen receptor gene of FGF9. Finally, the interaction between FGF9 and the receptor was tested by cotransfection. Our results showed that FGF9 interacts with FGFR2 to inhibit goat intramuscular adipocyte differentiation by regulating peroxisome proliferator-activated receptor gamma (PPARγ) and preadipocyte factor 1 (Pref1), which is a data support for subsequent pathway research.     

南极磷虾粉潜在危害因子分析及风险评价进展

南极磷虾粉是目前南极磷虾船载加工的主要产品之一,富含优质蛋白质、脂质、磷脂、虾青素和矿物质等物质,具有良好的开发利用前景。目前,南极磷虾粉主要用作水产动物饲料及提取油脂等的原料。然而,研究表明南极磷虾粉也存在潜在危害因子不明确等问题,严重限制了其应用领域和范围的拓展。因此,本文分析了南极磷虾粉潜在危害因子的来源、限量标准、检测方法等,介绍了南极磷虾粉风险评估进展,旨在为南极磷虾粉危害因子的减除和深度利用提供参考依据。     

影响注射剂澄明度因素的探讨

注射剂的澄明度是兽药生产中质量控制的主要指标,澄明度不合格的注射剂产品,不但影响药物疗效,伤害动物身体;也加大了企业生产的成本,影响了经济效益。从原辅材料、包装材料、净化系统、管道系统等方面对澄明度的影响因素进行了分析探讨,以寻求改进、提高产品质量的方法。     

Risk Indicators Associated with Subclinical Mastitis in Smallholder Dairy Cows in Tanzania

Smallholder dairy farmers in Tanzania appear to be unaware of the subclinical mastitis situation in their cows. A cross-sectional study was carried out between June and September 2002 on smallholder dairy herds in the Dar es Salaam region. The study objectives were to establish the prevalence of subclinical mastitis and related risk indicators, and to assess their contribution to the occurrence of subclinical mastitis. Three field procedures based on the principles of herd health and production management were followed: clinical, farm and data inspection. The California mastitis test (CMT) was carried out on quarter milk samples to determine the prevalence of subclinical mastitis. A total of 182 lactating cows from 62 herds were investigated. Clinical inspection indicated that 3.8% of the lactating cows had clinical mastitis. Subclinical mastitis was detected in 90.3% of lactating cows screened. Farm inspection revealed that water scarcity, barn size, residual suckling, single udder-towel and dairy labourers as the most substantial (p < 0.05) risk indicators. Although most of the risk indicators studied were not found to be statistically significantly associated with the occurrence of subclinical mastitis, possibly owing to sample size and the presence of confounders, the epidemiological need to address such risk indicators cannot be overemphasized.