南非Borakalalo国家公园二斑沙鸡(Pterocles bicinctus)的迁移(英文)

本文旨在描述可能引起南非Borakalalo国家公园内二斑沙鸡(Pterocles bicinctus)迁移行为的内在(繁殖)及外在因素(降雨量及植被情况)。该公园位于西北省比勒陀利亚以北80km,Jericho以北30km处。2010年,采取乘车辆沿固定路线穿越该保护区的方式搜集数据。车速为每小时10km,固定路线长为32km,调查强度为每月2天。二斑沙鸡平均每群2.47个个体。种群内雄性与雌性的比例为1:0.87。该鸟常出现在路边、遭踩踏过的矮草丛中或经焚烧但长出新叶的金合欢丛中。二斑沙鸡在该保护区主要出现在两个相对干燥的季节,即2–3月及7–9月。早晨在该公园的腹地能更多地观察到该鸟,而下午晚些时候,在Klipvoor河坝的水体边则可多见该鸟。讨论了可能影响二斑沙鸡迁移的5个因素,包括年降雨量、雨季中短时雨量大小、2–4km的日间饮水飞行、繁殖及草原植被情况。     

越南水产品出口的可持续发展分析

近年来,越南水产品(越南主要出口产品)的出口趋于稳定增长。经过20多年的发展,水产部门在提高增长质量、保护环境和满足其他重要的可持续性标准方面取得了重大进展。     

A comparative efficacy test of 1 versus 2 doses of CIRCOQ PCV2 subunit vaccine against naturally occurring PCV2-type d in piglets with high maternally derived antibodies (MDAs) on a Vietnamese swine farm

The aim of this study was to evaluate the protective efficacy of the CIRCOQ porcine circovirus type 2 (PCV2) subunit vaccine in piglets with high maternally derived antibodies (MDAs) against disease caused by natural infection with PCV2d. A total of 130 weaned, 21-day-old healthy pigs was allocated into 3 trial groups. The signs of respiratory disorder were higher in unvaccinated pigs than in vaccinated pigs at 13 to 17 weeks old (P < 0.05), 18 to 22 weeks old (P < 0.001), and 23 to 27 weeks old (P < 0.01). The unvaccinated pigs had an early rate of dermatitis at 8 to 12 weeks old (10.0%), 13 to 17 weeks old (30.0%), 18 to 22 weeks old (46.7%), and 23 to 27 weeks old (33.3%), while there were no cases of dermatitis in vaccinated pigs. There was a significant difference (P < 0.05) in the mortality of pigs in the unvaccinated group and the 2-dosed vaccinated group. PCV2 viremia was detected in the blood and peaked at 105 days old in both unvaccinated pigs (Ct-adj = 8.40) and pigs vaccinated with 1 dose (Ct-adj = 6.37), while no detectable PCV2 virus was found in the blood of pigs vaccinated with 2 doses. At 77 and 105 days old, the PCV2 viremia load (Ct-adj) of unvaccinated pigs and those vaccinated with 1 dose was significantly higher (P < 0.05) than that of the 2-dosed vaccinated pigs. The body weight (BW), average weight gain (AWG), and average daily gain (ADG) in both groups of vaccinated pigs were significantly higher (P < 0.05) than those of unvaccinated pigs. The study vaccine was significantly efficacious in protecting vaccinated pigs against clinical symptoms, blood viral load, and mortality, as well as improving productivity, compared with unvaccinated pigs.