The hygienic threshold limit values for ammonia （25 ppm） for animal welfare but also for occupational safety and health is often exceeded in floor housing systems for laying hens with long time storage of manure in ...The hygienic threshold limit values for ammonia （25 ppm） for animal welfare but also for occupational safety and health is often exceeded in floor housing systems for laying hens with long time storage of manure in bins below draining floors. The major reason for high ammonia concentrations is the large amounts of stored and exposed manure. The possibility to reduce ammonia release by reducing the amount of stored manure in bins in floor housing systems for laying hens has therefore been investigated. Investigations were carried out in a climate chamber equipped with a floor housing system with a manure removal system with two parallel motor driven conveyors placed below an elevated draining floor. The conditions when manure is stored in bins below draining floors were simulated by storing manure on the conveyors for several days at constant ventilation rates and temperatures. The investigations clearly showed that storage of manure in the bin caused a rapid increase in ammonia concentrations. After about 7 days storage of manure in the bin the ammonia concentration exceeded the hygienic threshold limit values. It can be concluded that long time storage of manure in storage bins below draining floors should not be recommended. It was possible to maintain the ammonia concentration below the hygienic threshold limit values when manure was removed frequently with conveyors. Floor housing systems for laying hens with elevated draining floors should therefore be equipped with manure removal systems that enable frequent removal of manure in the bins.展开更多
This study investigated the putative protective effects of supplemental 2-aminoethane sulfonic acid（taurine） and reduced housing density on renal function in laying hens. We randomly assigned fifteen thousand green-...This study investigated the putative protective effects of supplemental 2-aminoethane sulfonic acid（taurine） and reduced housing density on renal function in laying hens. We randomly assigned fifteen thousand green-shell laying hens into three groups： a free range group, a low-density caged group, and a high-density caged group. Each group was further divided equally into a control group（C） and a taurine treatment group（T）. After 15 d, we analyzed histological changes in kidney cells, inflammatory mediator levels, oxidation and anti-oxidation levels. Experimental data revealed taurine supplementation, and rearing free range or in low-density housing can lessen morphological renal damage, inflammatory mediator levels, and oxidation levels and increase anti-oxidation levels. Our data demonstrate that taurine supplementation and a reduction in housing density can ameliorate renal impairment, increase productivity, enhance health, and promote welfare in laying hens.展开更多
文摘The hygienic threshold limit values for ammonia （25 ppm） for animal welfare but also for occupational safety and health is often exceeded in floor housing systems for laying hens with long time storage of manure in bins below draining floors. The major reason for high ammonia concentrations is the large amounts of stored and exposed manure. The possibility to reduce ammonia release by reducing the amount of stored manure in bins in floor housing systems for laying hens has therefore been investigated. Investigations were carried out in a climate chamber equipped with a floor housing system with a manure removal system with two parallel motor driven conveyors placed below an elevated draining floor. The conditions when manure is stored in bins below draining floors were simulated by storing manure on the conveyors for several days at constant ventilation rates and temperatures. The investigations clearly showed that storage of manure in the bin caused a rapid increase in ammonia concentrations. After about 7 days storage of manure in the bin the ammonia concentration exceeded the hygienic threshold limit values. It can be concluded that long time storage of manure in storage bins below draining floors should not be recommended. It was possible to maintain the ammonia concentration below the hygienic threshold limit values when manure was removed frequently with conveyors. Floor housing systems for laying hens with elevated draining floors should therefore be equipped with manure removal systems that enable frequent removal of manure in the bins.
基金supported by the National Natural Science Foundation of China(Nos.31372421,31530074,and 31672515)the Fundamental Research Funds for the Central Universities(No.KYZ201415)the Priority Academic Program Development of Jiangsu Higher Education Institutions,China
文摘This study investigated the putative protective effects of supplemental 2-aminoethane sulfonic acid（taurine） and reduced housing density on renal function in laying hens. We randomly assigned fifteen thousand green-shell laying hens into three groups： a free range group, a low-density caged group, and a high-density caged group. Each group was further divided equally into a control group（C） and a taurine treatment group（T）. After 15 d, we analyzed histological changes in kidney cells, inflammatory mediator levels, oxidation and anti-oxidation levels. Experimental data revealed taurine supplementation, and rearing free range or in low-density housing can lessen morphological renal damage, inflammatory mediator levels, and oxidation levels and increase anti-oxidation levels. Our data demonstrate that taurine supplementation and a reduction in housing density can ameliorate renal impairment, increase productivity, enhance health, and promote welfare in laying hens.
