Developing model equation to subdivide methionine + cystine requirements into requirement for growth and maintenance in pigs

Yang, C. J.; Lee, D. W.; Chung, I. B.; Cho, Y. M.; Shin, I. S.; Chae, B. J.; Kim, J. H.; Han, In K.

doi:1997.10.1.86

Article

Swine Nutrition and Feed Technology

Asian-Australasian Journal of Animal Sciences 1997;10(1): 86-97.
https://doi.org/10.5713/ajas.1997.86 Published online February 1, 1997.

Developing model equation to subdivide methionine + cystine requirements into requirement for growth and maintenance in pigs

C. J. Yang, D. W. Lee, I. B. Chung, Y. M. Cho, I. S. Shin, B. J. Chae, J. H. Kim, In K. Han

Abstract

Purified diets containing 5 graded levels of methionine + cystine were fed to young, growing and finishing pigs to determine the methionine + cystine requirement for growth and maintenance. A model was developed to subdivide the methionine + cystine requirement for maintenance from requirement for growth. From this model, the methionine + cystine requirement for growth was 8.633, 10.260 and 9.293 g/kg live weight gain and the maintenance requirement was 0.049, 0.016 and 0.019 g per unit of metabolic body size at each stage of growth, respectively. In the young pigs, the methionine + cystine requirement for growth was 0.491 g/g N gain and the maintenance requirement was 0.059 g per unit of metabolic body size. The breakpoint of plasma methionine + cystine concentrations was 3.888, 6.935 and 8.116 g/d, respectively. Expected requirements obtained from these formulae were in general agreement with previous estimates. Based on the weight gain vs N gain equation, about 4.44% of the retained protein was comprised of methionine + cystine and compared to 3.31%, the mean methionine + cystine content of pig muscle CP.

Keywords: Methionine + Cystine; Requirement; Maintenance; Growth; Body Composition; Plasma Concentration