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如何减少鸡群非疾病性死亡 被引量:1
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作者 张楚吾 《养殖技术顾问》 2003年第5期7-7,共1页
关键词 鸡群 非疾病性死亡 饲料配方 饮水 设施管理
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加强饲养管理,减少鸡群非疾病性死亡
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作者 张楚吾 《广东畜牧兽医科技》 2003年第1期45-45,44,共2页
疾病威胁养鸡生产,养禽场为减少鸡的病死率,使用各种药物来控制鸡群可能发生的疾病,由于片面理解"预防"的含义,往往只重视使用生物制剂和药物作预防,而忽视对鸡群自身素质的管理,未能从加强饲养管理,改善环境等方面提高鸡群... 疾病威胁养鸡生产,养禽场为减少鸡的病死率,使用各种药物来控制鸡群可能发生的疾病,由于片面理解"预防"的含义,往往只重视使用生物制剂和药物作预防,而忽视对鸡群自身素质的管理,未能从加强饲养管理,改善环境等方面提高鸡群的抵抗能力,频繁使用药物来预防疫病是目前养禽业的一大通病. 展开更多
关键词 饲养管理 非疾病性死亡 营养 饮水 饲养密度 转群
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TWO TYPES OF CONDITION FOR THE GLOBAL STABILITY OF DELAYED SIS EPIDEMIC MODELS WITH NONLINEAR BIRTH RATE AND DISEASE INDUCED DEATH RATE
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作者 YUKIHIKO NAKATA YOICHI ENATSU YOSHIAKI MUROYA 《International Journal of Biomathematics》 2012年第1期127-155,共29页
We study global asymptotic stability for an SIS epidemic model with maturation delay proposed by K. Cooke, P. van den Driessche and X. Zou, Interaction of maturation delay and nonlinear birth in population and epidemi... We study global asymptotic stability for an SIS epidemic model with maturation delay proposed by K. Cooke, P. van den Driessche and X. Zou, Interaction of maturation delay and nonlinear birth in population and epidemic models, J. Math. Biol. 39(4) (1999) 332-352. It is assumed that the population has a nonlinear birth term and disease causes death of infective individuals. By using a monotone iterative method, we establish sufficient conditions for the global stability of an endemic equilibrium when it exists dependently on the monotone property of the birth rate function. Based on the analysis, we further study the model with two specific birth rate functions BI(N) = be-aN and B3(N) = A/N + c, where N denotes the total population. For each model, we obtain the disease induced death rate which guarantees the global stability of the endemic equilibrium and this gives a positive answer for an open problem by X. Q. Zhao and X. Zou, Threshold dynamics in a delayed SIS epidemic model, J. Math. Anal. Appl. 257(2) (2001) 282-291. 展开更多
关键词 SIS epidemic models nonlinear birth rate function disease induced deathrate global asymptotic stability the basic reproduction number permanence.
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