不同鸡品种维持净能的需要量测定

Determination to Net Energy Requirements for Maintenance for Different Chicken Breeds

本研究使用新型12室并联禽用开放回流式呼吸测热装置测定不同鸡品种维持净能的需要量,以期探究不同鸡品种能量代谢的差异。试验共选用35周龄海兰褐蛋鸡、32周龄吉林芦花鸡、25~28日龄罗斯(Ross)308肉鸡各24只,采用完全随机试验设计,每个品种试验鸡12个重复,每个重复2只鸡。每种试验鸡在不同鸡舍内饲养,饲喂满足各自营养需要的全价饲粮,预试期7 d,正试期27 d。正式试验分3期完成,每期9 d,每期从每种试验鸡中随机选择8只,称重后每2只放入1个呼吸测热装置的代谢室内,每4个代谢室对应1种鸡。代谢室内测定气体交换9 d,其中适应期3 d、呼吸测热3 d、绝食测热3 d。结果表明:海兰褐蛋鸡和吉林芦花鸡的代谢体重产热量显著低于Ross 308肉鸡(P<0.05)。吉林芦花鸡和Ross 308肉鸡的代谢体重绝食产热量显著高于海兰褐蛋鸡(P<0.05)。3种鸡之间代谢体重热增耗、采食呼吸熵、绝食呼吸熵差异均不显著(P>0.05)。本研究中,35周龄海兰褐蛋鸡、32周龄吉林芦花鸡、25~28日龄Ross 308肉鸡的维持净能需要量分别为368.79、449.24、450.75 kJ/(kg BW^0.75·d)。

A new open circuit respiratory calorimetry apparatus with 12 chambers in parallel for poultry was used to determine the net energy requirement for maintenance for different chicken breeds,in order to explore the differences in energy metabolism among them.Thirty five week old Hy Line brown laying hens,32 week old Jilin Luhua hens and 25 to 28 day old Ross 308 broilers were chosen,and 24 chickens per breed were nee ded.A completely random trial was designed.Twelve replicates were set for each breed of test chickens,with 2 chickens per replicate.Each kind of test chickens were raised in a separate house and individually fed com plete feed that met their nutritional needs.The pre feeding period was 7 days,and formal trial period was 21 days which included 3 phases,with 9 days each phase.In each phrase,8 chickens from each breed were ran domly selected.After weighing,each 2 chickens were placed in the metabolic chamber of the respiratory calo rimeter apparatus,and each 4 metabolic chambers corresponded to one kind of chickens.Then the gas ex change was measured in the metabolic chamber for 9 days of formal trial period,including 3 days of dietary ad aptation period,3 days of respiratory calorimetry and 3 days of fasting heat production.The results showed that the metabolic body weight of Hy Line brown laying hens and Jilin Luhua hens was significantly lower than that of Ross 308 broilers(P<0.05).The fasting heat productions under the metabolic weight of Jilin Luhua laying hens and Ross 308 broilers was significantly higher than that of Hy Line brown laying hens(P<0.05).For heat increase consumption(HI)under metabolic body weight,feed intake respiratory quotient(RQ),and fasting RQ,the differences among the three kinds of chickens were not significant(P>0.05).The maintenance net energy requirements of the 34 week old Hy Line brown laying hens,31 week old Jilin Luhua hens,and 25 to 28 day old Ross 308 broilers are 368.79,449.24 and 450.75 kJ/(kg BW0.75·d),respectively.