Interstate Equine Semen and Embryo Shipment Regulations in the United States and Their Implications on Control of Disease Transmission

Outbreaks of both equine viral arteritis and contagious equine metritis (CEM) in the United States have occurred in recent years. Shipped semen has been implicated in disease transmission and rapid spread. A survey was performed of state regulations regarding testing for equine arteritis virus (EAV) and CEM before interstate semen or embryo shipment. Results demonstrated lack of any requirements in 31 states. Four states had regulations regarding EAV; 17 required a Certificate of Veterinary Inspection (CVI) to accompany a semen or embryo shipment. Ten states required a negative equine infectious anemia test, primarily as a requirement of a CVI versus because of risk of dissemination of disease. No states required CEM testing. A comparison of state department of agriculture or veterinary medical association Web sites and direct communication with state veterinarians or their offices demonstrated contradictory information in six states. The lack of uniform regulations concerning CEM and EAV testing for shipped semen and embryos, and the threat they pose to the equine breeding industry and horse health, should be alarming to veterinarians and horse owners. Routine testing of animals before shipment of semen or embryos and veterinary involvement in collection and breeding activities are appropriate and necessary to help prevent future outbreaks and protect equine health.     

Available (ileal digestible reactive) lysine in selected pet foods

A recently developed assay for determining available lysine (true ileal digestible reactive lysine) in foods and feedstuffs was applied to 20 commercially available cat foods. Semisynthetic diets, containing cat food as the sole protein source, were prepared. Titanium dioxide was included as an indigestible marker. The diets were fed to growing rats and digesta from the terminal ileum collected and analyzed, along with the diets, for reactive lysine. True reactive lysine digestibility was determined after correction for endogenous lysine loss at the terminal ileum of rats fed an enzyme-hydrolyzed casein-based diet. The amounts of digestible total lysine (conventional method) were also determined. Ileal total lysine digestibility significantly (P<0.05) underestimated (3.6-10.2%) lysine availability (ileal reactive lysine digestibility) for most of the cat foods tested. Ileal digestible total lysine significantly (P<0.05) overestimated the amount of dietary available lysine for all of the cat foods tested by between 38 and 143%. Total lysine digestibility determined using the conventional method of lysine analysis was inaccurate when applied to commercially available cat foods.     

Hydroelectric development and the disruption of migration in caribou

We investigated the effects of hydroelectric development on the movements and space-use of caribou (Rangifer tarandus caribou) in west-central Newfoundland, Canada. We compared patterns of range use, site fidelity, and timing of migration before, during, and after project construction. Coincidental with the first year of project construction, caribou were less likely to be found within 3 km of the site; this persisted at least 2 years after construction was completed. Relative timing of migration was individual-specific; the rank order of spring arrival on, and autumn departure from, the calving and summer grounds tended to be consistent year-to-year. This is the first report of such individual-specific consistency in migration for a non-avian species. This predictability disappeared during development: the year-to-year consistency of fall and spring migration among individuals was apparent before and after construction, but not during construction. Variation in calving site fidelity was correlated to year-to-year differences in snowfall. We conclude that the development caused a disruption of migrational timing during construction and longer-term diminished use of the range surrounding the project site. Long-term studies of individually marked animals can aid in environmental assessments for migratory animals.     

世界禽病研究进展

疾病是限制世界范围内家禽生产效益的主要因素。尽管分子生物学领域的基础性研究不断开发出新的疫苗 ,但由于新变异株的出现以及多种致病因子混合感染 ,仍制约着集约化生产。本文阐述了重大疾病对商业化蛋鸡群和肉仔鸡生产效益的潜在影响。1　鸡痘目前尚无法解释免疫过禽痘的鸡群仍有发病。澳大利亚、欧洲和美国的科学家们已从引发禽痘的 2株野毒和商业化禽痘疫苗的基因组中检测到网状内皮组织增殖病病毒 ( REV)的前病毒基因组。体液的抗体反应可作为一种衡量手段 ,用以评价现有疫苗在抵抗疫苗在抵抗致病性增强的禽痘病毒时的效力。现有的…