South African Journal of Animal Science
versão On-line ISSN 2221-4062
versão impressa ISSN 0375-1589
MARIN, A.L. Martínez et al. Prediction of energy requirements of Murciano-Granadina preruminant female kids using the National Research Council. S. Afr. j. anim. sci. [online]. 2011, vol.41, n.4, pp.345-349. ISSN 2221-4062.
Data collected on metabolizable energy (ME) intake and growth performance of preruminant female kids of the Murciano-Granadina breed was used to assess the accuracy of the latest U. S. National Research Council (NRC) recommendations to predict their energy requirements. Female kids were fed a milk replacer individually, according to appetite three times a day from two to five weeks of age. The mean initial body weight and average daily weight gain (± SE) were 3.31 ± 0.08 kg/d and 120 ± 3 g/d. Daily ME intake, expressed relative to metabolic body weight (BW0.75), decreased linearly with age from 1085 to 970 kJ/kg BW0.75/d, and there was nearly a constant ratio of ME requirements for maintenance. The observed ME intake was 5.4% higher than the ME requirements, calculated according to NRC, probably due to the energy content of the weight gain. It was concluded that the energy system model of the NRC is accurate enough to calculate the ME requirements of preruminant female kids of the Murciano-Granadina breed.
Palavras-chave : Goats; pre-weaning period; suckling female kids; NRC.