Impacts Of Biological Stress Factors In House Environment On Duel Performance, Immune Function And Welfare Condition

With the development of intensive and large-scale livestock&poultry productionsystems, animal health and welfare have attracted extensive attention. It has been estimatedthat the major factors affecting animal production benefits include genetic performance,nutritional condition, and environmental quality, they have contribution rates of45%,30%,and25%, respectively. Air quality is an important index of the environmental quality, whilemicrobial aerosols are the main indications of the environmental quality. Under the modernintensive livestock, the living environment of poultry lives much to be desired, makingchickens being stringent state, which broke their health and welfare seriously. Taking animalwelfare as the point of view, the article synthesized the animal welfare level reliable indicatorof both domestic and overseas, combining animal welfare and production, in order toinvestigate the effects of different house on ducks’ performance and welfare condition.To better understand the effect of different breeding environments on ducks’performance and immune function, in this study,320one-day-old healthy ducks wererandomly divided into two groups, i.e., Experimental Group(EG) and Control Group(CG),and bred in the duck houses of different sanitary environmental management conditions inseven weeks. The concentrations of aerobic bacteria, fungi, endotoxins and NH3in the air ofthe ducks’ houses were determined periodically, measuring ducks’ productionperformance， and meanwhile, avian influenza antibody(AI-Ab) levels、 immune organindexes organ indexes of ducks、serum lysozyme content、WBC and peripheral blood Tlymphocyte conversion ratio were detected.The results indicated that in the whole growth cycle of ducks, increasing tendency ofconcentration of airborne aerobic and airborne fungal in different environmental groups wasobviously different, which was significiantly differently in growth later period （P＜0.05）.The concentration of airborn endotoxin was not significiantly differently（P＞0.05）; Therewas significiantly differently for the average body weight, slaughter rate, breast muscle rate,abdominal fat rate and whole net carcass rate of broilers between the two groups（P＜0.05）while slaughter rate were not significiantly differently（P＞0.05）; Better house environmentcan obviously increase cecal lactobacillus counts of ducks （P＜0.05）; Results ofmeasurement of AI-Ab levels showed, in the prophase, there was no significant differencebetween the two groups（P＞0.05）. But, significant difference was shown in later period （P＜0.05）；The results of measurement of immune organ indexes showed that, the spleenindexes, BF indexes, and thymus indexes of the test group were higher than the controlgroup’s all the time. The BF had no-significant difference（P＞0.05）while the thymusindexes had significant difference（P＜0.05）.Before21days，the spleen indexes has no-significant difference （P＞0.05）, and after that，it had significant difference（P＜0.05）;The results of measurement of serum lysozyme content showed that, before35days, the testgroup was higher and they had no-significant difference（P＞0.05）. After that, the controlgroup was higher and they had significant difference （P＜0.05）; The results ofmeasurement of WBC showed, only in the prophase, the test was higher than the controlgroup, and the14days and49days had significant difference（P＜0.05）; The peripheralblood T lymphocyte conversion ratio of the experimental group was lower than the controlgroup.The total conclusion of the article are as follows: the better house environment tosome degree can improve health and welfare of ducks, which can increase average bodyweight of ducks, reduce mortality. In addition, immunity can be well improved in betterenvironment which can be manifested by cecal lactobacillus counts of ducks. It is a key pointfor healthy breeding to do well breeding sanitary management of animal houses.