摘要
This research was to assess the dietary copper(Cu)requirement of broiler chickens fed a practical cornsoybean meal diet during 22—42 d of age.A total of 288 numbered Arbor Acres male broilers at 22 d of age were randomly allotted 6 treatments with 8 replicate cages(6 broilers per cage)per treatment.Broilers were fed a Cu-unsupplemented corn-soybean meal basal diet(control,containing 7.36 mg Cu/kg)or the basal diet added with 3,6,9,12,or 15 mg Cu/kg from CuSO_(4)·5H_(2)O for 21 d.Quadratic,asymptotic and broken-line models were fitted and the best fitted models were selected to determine dietary Cu requirements.The results revealed that the contents of Cu in serum and liver,m RNA expression levels of Cu-and zinc-containing superoxide dismutase(CuZnSOD)in liver and monoamine oxidase b(MAO B)in heart,as well as protein expression level of CuZnSOD in liver were affected(P<0.05)by supplemental Cu levels,and the above indices varied linearly and quadratically(P<0.05)with increasing Cu levels.Dietary Cu requirements assessed according to the best fitted broken-line models(P<0.05)of the above indexes were 10.45—13.81 mg/kg.It was concluded that mRNA expression levels of CuZnSOD in liver and MAO B in heart,as well as liver CuZnSOD protein expression level were new specific sensitive biomarkers for estimating dietary Cu requirements,and the dietary Cu requirement was recommended to be 14 mg/kg to support Cu metabolic needs related to key Cucontaining enzymes in broilers fed the corn-soybean meal diet during 22—42 d of age,which was higher than the dietary Cu requirement(8 mg/kg)for broilers at the corresponding stage suggested by the Chinese Feeding Standard of Chicken.
基金
supported by Jiangsu Shuang Chuang Tuan Dui program(JSSCTD202147)
Jiangsu Shuang Chuang Ren Cai program(JSSCRC2021541)
Young Elite Scientists Sponsorship Program by CAST(2022QNRC001)
the Initiation Funds of Yangzhou University for Distinguished Scientists
