The growth performance and histochemical characteristics of breast muscle fibers were used to estimate the standardized ileal digestible(SID)Lys requirements for 10-to 21-d-old male broilers.Three hundred and sixty 10...The growth performance and histochemical characteristics of breast muscle fibers were used to estimate the standardized ileal digestible(SID)Lys requirements for 10-to 21-d-old male broilers.Three hundred and sixty 10-d-old Ross 308 broilers(290±16.6 g)were allocated to 6 diets in a randomized complete block design with 6 replicate cages per treatment and 10 birds per cage.The 6 experimental diets were formulated to contain equally spaced increasing levels of SID Lys from 0.86%to 1.36%.The data were analyzed using the MIXED procedure of SAS.The Lys requirements were estimated by the NLIN procedure of SAS.An increase in dietary SID Lys from 0.86%to 1.36%resulted in a quadratic increase(P<0.05)in body weight gain(BWG),gain to feed ratio(G:F),breast weight,muscle cross-sectional area(MCSA),and fiber area.The SID Lys requirements based on the one-slope broken-line,quadratic line,the first intercept between the plateau of the one-slope broken-line and quadratic-line models and 95%of the upper asymptote of the quadratic-line model were estimated to be 1.01%,1.19%,1.08%,and 1.13%for BWG,1.06%,1.22%,1.11%,and 1.16%for G:F,1.10%,1.29%,1.19%,and 1.22%for breast weight,1.06%,1.22%,1.12%,and 1.16%for MCSA,and 1.14%,1.22%,1.16%,and 1.16%for breast muscle fiber area,respectively.It was concluded that the SID Lys requirements for broilers at the age of 10 to 21 d depended on the response variables used for estimation,and that histochemical characteristics of breast muscle fibers could be good indicators for estimating SID Lys requirements.展开更多
基金This work was carried out with the support of the “Cooperative Research Program for Agriculture Science and Technology Development (Project No. PJ013571)” Rural Development Administration, Republic of Korea.
文摘The growth performance and histochemical characteristics of breast muscle fibers were used to estimate the standardized ileal digestible(SID)Lys requirements for 10-to 21-d-old male broilers.Three hundred and sixty 10-d-old Ross 308 broilers(290±16.6 g)were allocated to 6 diets in a randomized complete block design with 6 replicate cages per treatment and 10 birds per cage.The 6 experimental diets were formulated to contain equally spaced increasing levels of SID Lys from 0.86%to 1.36%.The data were analyzed using the MIXED procedure of SAS.The Lys requirements were estimated by the NLIN procedure of SAS.An increase in dietary SID Lys from 0.86%to 1.36%resulted in a quadratic increase(P<0.05)in body weight gain(BWG),gain to feed ratio(G:F),breast weight,muscle cross-sectional area(MCSA),and fiber area.The SID Lys requirements based on the one-slope broken-line,quadratic line,the first intercept between the plateau of the one-slope broken-line and quadratic-line models and 95%of the upper asymptote of the quadratic-line model were estimated to be 1.01%,1.19%,1.08%,and 1.13%for BWG,1.06%,1.22%,1.11%,and 1.16%for G:F,1.10%,1.29%,1.19%,and 1.22%for breast weight,1.06%,1.22%,1.12%,and 1.16%for MCSA,and 1.14%,1.22%,1.16%,and 1.16%for breast muscle fiber area,respectively.It was concluded that the SID Lys requirements for broilers at the age of 10 to 21 d depended on the response variables used for estimation,and that histochemical characteristics of breast muscle fibers could be good indicators for estimating SID Lys requirements.
