丁酸调控幼龄反刍动物瘤胃上皮发育研究进展

瘤胃是反刍动物营养物质消化吸收和代谢的重要器官,其发育状态直接影响反刍动物生产性能和健康。初生犊牛和羔羊,瘤胃功能尚未发育完全,不能够充分消化和吸收固体饲料。因此,在幼龄时期,通过营养调控手段促进反刍动物的瘤胃发育对维持动物健康及提高生产性能具有重要意义。丁酸是瘤胃微生物降解植物性饲料的主要产物,也是瘤胃上皮及宿主的重要能量来源。丁酸调控幼龄反刍动物瘤胃上皮发育是一个历久弥新的话题。主要介绍了幼龄反刍动物瘤胃上皮形态及功能的发育以及丁酸调控幼龄反刍动物瘤胃上皮发育的研究进展。     

江苏大丰麋鹿国家级自然保护区麋鹿死亡分析

From 2009 to 2020, we systematically investigated the population, mortality, and death factors of Père David’s deer (Elaphurus davidianus) in the Dafeng Milu National Nature Reserve, Jiangsu, China. The result showed the annual growth rate of the population was 13.09% ± 5.96%, which continuously increased in the 12 years. The annual mortality rate was 3.53% ± 2.27%, with an obvious fluctuation every 2 years. There was no significant difference in mortality of adults and sub-adults in different seasons, but significant in juveniles.Significant differences in mortality among different age groups were observed. The adults died most in summer and autumn, while the juveniles died most in winter and spring. 48.77% of subjects tend to choose the underbrush for dying. The death factors among different age groups were significantly different. The elders and the juveniles mainly died of epidemic diseases, including viral, bacterial, and parasitic. While the sub-adults died in accidents. We suggested that it is necessary to strengthen the daily monitoring and epidemic disease prevention in wildlife management. Our data provided important information for the protection of Père David’s deer in Dafeng Reserve.