Validation for use with coyotes (Canis latrans) of a commercially available enzyme-linked immunosorbent assay for Dirofilaria immitis

Serological tests offer a potentially powerful tool for monitoring parasites in wildlife populations. However, such tests must be validated before using them with target wildlife populations. We evaluated in coyotes (Canis latrans) the performance of a commercially available serological test used to detect canine heartworm (Dirofilaria immitis) in domestic dogs. We obtained 265 coyote carcasses and serological specimens from 54 additional coyotes from several regions of California, USA. We necropsied coyotes to determine the adult heartworm infection status. Blood was collected at necropsy on filter paper strips and allowed to dry; it was later eluted in a buffer solution, and the supernatant was tested for heartworm. Receiver operating characteristic (ROC) analysis was used to assess discriminatory power of the test and indicated a 93% probability that a randomly selected infected coyote would exhibit a higher enzyme-linked immunosorbent assay (ELISA) value than a randomly selected uninfected coyote. We estimated specificity at 96% (95% CI: 92-98%) for 165 uninfected coyotes and sensitivity at 85% (77-91%) for 100 infected coyotes, results similar to published values for the commercial serological test used with dog serum or plasma. Test performance was similar for filter paper specimens and supernatant of frozen whole blood collected in EDTA tubes (i.e. hemolyzed plasma). We found no difference in test performance among geographic or demographic coyote groups. Our findings support application of the test to filter paper or standard serological specimens for detection of heartworm in coyote populations.     

Genetic analysis of vesicular stomatitis virus-New Jersey from the 1995 outbreak in the western United States

OBJECTIVE: To compare molecular associations between the vesicular stomatitis virus (VSV)-New Jersey isolates of the 1995 outbreak with those from previous outbreaks between 1982 and 1985 in the western United States. SAMPLE POPULATION: 23 virus isolates considered representative of the 1995 outbreak of vesicular stomatitis. PROCEDURE: Viral gene coding for surface-envelope protein G was evaluated by use of nucleotide sequencing and phylogenetic analysis. RESULTS: Changes in up to 0.77% of the nucleotide bases and 1.35% of the amino acids were detected among the 1995 viral isolates, whereas changes in up to 3.2 and 2.9% of the nucleotides and amino acids, respectively, were found, compared with the 1982 to 1985 viruses. Insertions or deletions were not found in the entire gene, which spanned 1,554 nucleotide bases. CONCLUSIONS AND CLINICAL RELEVANCE: Phylogenetic analysis indicated that the 1995 VSV-New Jersey belongs to a lineage distinct from that of the 1982 to 1985 viruses that caused previous outbreaks in the western United States. Furthermore, it also is distinct from strains from Central America and from the Georgian Hazelhurst strain.     

Polysaccharide storage myopathy in Morgan, Arabian, and Standardbred related horses and Welsh-cross ponies

Polysaccharide storage myopathy is an equine neuromuscular disorder characterized by accumulation of glycogen-related polysaccharide inclusions within skeletal muscle fibers. The pathologic criteria for diagnosis of this disorder are somewhat controversial; however, periodic acid-Schiff-positive, amylase-resistant inclusions are considered pathognomonic. Although these inclusions are most often found in affected horses related to the Quarter Horse, draft horse, and Warmblood breeds, this report describes these characteristic inclusions in muscle of five horses from nonrelated breeds (two Morgans, one Arabian, one Arabian x Thoroughbred, and one Standardbred) and two Welsh cross ponies. Affected horses had histories of recurrent exertional rhabdomyolysis, and one developed progressive weakness leading to increased recumbency. The affected ponies were part of an unrelated research project and had no apparent clinical signs.     

Rapid separation of lysozyme from chicken egg white by reductants and thermal treatment

Reductants (0.1-2.0% ascorbic acid, cysteine, or cystine and 0.04-1. 0% beta-mercaptoethanol) were added to 5-fold diluted, salted duck egg whites (commercially and laboratory prepared) and fresh egg whites (chicken and duck), and subsequently the mixtures were heated at 70 degrees C for 1-10 min. The maximal recovery and purification fold of lysozyme obtained from fresh chicken egg whites added with 1. 0% ascorbic acid were 78% and 2.4, respectively. Storage tests showed that the obtained lyophilized lysozyme powder after dialysis was stable when refrigerated at 4 degrees C for 3 months.     

有机铬对热应激蛋鸡生产性能和血液生化指标的影响

试验选用91周龄新罗曼商品蛋鸡480只,按2×2双因子试验设计随机分为5组,对照组饲喂不添加铬的玉米-豆粕型基础日粮,4个试验组饲喂在基础日粮中分别添加了以吡啶羧酸铬或酵母铬来源的0.2mg/kg或0.4mg/kg的日粮,试验30d,以研究有机铬对热应激蛋鸡生产性能和血液生化指标的影响。试验结果显示:①有机铬能在一定程度上促进热应激蛋鸡的蛋白质利用,提高热应激蛋鸡的生产性能;②铬水平对血清尿素氮有极显著的影响(P<0.01),添加0.4mg/kg铬组均极显著地低于对照组(P<0.01),说明了补铬能够抑制由高温引起的蛋白质分解过程,从而起到缓解高温应激的作用;③吡啶羧酸铬和酵母铬在作用效果上无显著的差异;从经济效益方面考虑,0.4mg/kg铬水平的酵母铬和吡啶羧酸铬经济效益较高。     

在西南大学开展双语教学的思考

从双语教学概念的界定、模式以及我国双语教学的现状入手，结合西南大学的实际情况，讨论了在西南大学开展双语教学的必要性和可行性，并在此基础上提出了几点建议。     

Effects of chilled drinking water on the performance of lactating sows and their litters during high ambient temperatures under farm conditions

Heat stress has detrimental effects on lactating sows and their litters, including decreased feed intake and milk production in sows and decreased weight gain in their offspring. It also increases respiration rate, rectal temperature, and weaning to estrus interval in sows. This study was conducted to investigate the effects of chilled water (CW) on the performance of lactating sows and their litters exposed to high ambient temperatures for 21 days. Ninety multiparous sows (Yorkshire × Landrace; parity range: 2 to 5) and their litters (Yorkshire × Landrace × Duroc) were divided into 3 blocks (30 each). Sows and their litters within each block were randomly assigned to one of the three treatment groups (n = 10 each). Each group was provided with drinking water at 10, 15, or 22 °C (control) under farm conditions where ambient temperature above 25 °C was consistent during the experimental period. Sows on CW (both 10 and 15 °C) consumed more feed and water than did control (P < 0.01) and higher estimated milk production compared with control (P < 0.01), but had lower rectal temperature and respiration rate compared with control (P < 0.01). Mean weaning weight (P < 0.01) and average daily gain (P < 0.01) of litters in CW groups were higher than those in control group. There were no differences in the measured variables, with the exception of the respiration rates, between the two CW treatment groups. These results suggest that CW may improve the performance of sows and their litters exposed to high ambient temperatures and the 15 °C water, from an energy viewpoint, may be more effective.     

万州区农业产业化、农村工业化、农村城镇化发展不协调的表现研究

通过大量调查，分析了万州区农业产业化、农村工业化、农村城镇化发展不协调的表现。具体表现在：农业产业化与农村工业化发展不协调，工业化程度偏低，农业产业化程度不高，没有形成规模经济和产业链；农业产业化与农村城镇化发展不协调，影响市场容量的扩大，制约农业自身的发展，制约第三产业发展和农民进入城镇就业步伐，城镇化辐射带动能力弱；农村工业化与农村城镇化发展不协调，城镇对生产要素的集聚功能差，农村工业布局较分散且技术落后，“空城现象”明显；农业产业化、农村工业化、农村城镇化与区域经济发展不协调，区域经济发展水平不高，区域经济结构运行质量不高，区域经济的市场竞争力不强，区域经济的发展环境不优。     

Evaluation of association between polymorphism within the thyroglobulin gene and milk production traits in dairy cattle

In dairy cattle, many studies have reported quantitative trait loci (QTL) on the centromeric end of chromosome 14 that affect milk production traits. One of the candidate genes in this QTL region – thyroglobulin (TG) – was previously found to be significantly associated with marbling in beef cattle. Thus, based on QTL studies in dairy cattle and because of possible effects of this gene on fat metabolism, we investigated the association of TG with milk yield and composition in Holstein dairy cattle. A total of 1279 bulls from the Cooperative Dairy DNA Repository Holstein population were genotyped for a single nucleotide polymorphism in TG used previously in beef cattle studies. Analysis of 29 sire families showed no significant association between TG variants and milk production traits. Within‐sire family analysis suggests that TG is neither the responsible gene nor a genetic marker in association with milk production traits.     

兽用常温耐热型弱毒活疫苗的研究进展

常温耐热型弱毒活疫苗对预防畜禽疾病具有重要作用，对它的研究越来越多，尤其是耐热冻干保护剂。作者对耐热冻干保护剂的组成、作用机制、效能及畜禽疫病中的应用进行了介绍。