Exigências nutricionais e desempenho de fêmeas Nelore, F1 Nelore x Angus e F1 Nelore x Simental

• Autor(a) principal: SOUZA, Evaristo Jorge Oliveira de
• Data de Publicação: 2010
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFRPE
• Texto Completo: http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/6762
• topic: Novilha Mestiça; Composição de ganho; Energia líquida; Energia metabolizável; Gain composition; Heifer; Net energy; Metabolizable energy; CIENCIAS AGRARIAS::ZOOTECNIA

The objective of this work was to evaluate of carcass traits, deposition pattems of body tissues, energy and protein requirements of Nellore (NE), Nellore x Angus (NA) and Nellore x Simental (NS), fed with two levels concentrate (30 and 50% of dry matter diet in concentrate). Sixty nine heifers (23 NE, 23 NA and 23 NS) were used, being 12 heifers (four in each genetic group) slaughtered before the beginning of the experiment as the baseline group. Twelve heifers (four in each genetic group) were fed the level maintenance and thirty six (twelve in each genetic group) were ad libitun fed with 30 (six in each group) and 50% (six in each group) of dry matter diet in concentrate. Nine remaining animals were to digestibility trial. At the end of the experiment all these animals were slaughtered and its corporal composition and empty body weight (EBW) determined. The net energy requirements for gain were estimate as a retained energy (RE) as a function of EBW0,75 and empty body gain (EBG). The net energy requirements for maintenance were obtained as a function of heat production (HP) on metabolizable energy intake (MEI). The metabolizable energy requirements for maintenance were obtained as a function of RE and MEI. The net protein requirements for gain were estimate as retained protein (RP) as RE and EBG. The requirements of metabolizable protein for maintenance were estimate as metabolizable protein intake (MPI) as function of empty body gain (EBG). The net protein requirements for maintenance as RP as a function MPI. Chemical constituents of EBW and EBG there were not effects of genetic group (P>0.05). There were not effects of genetic group in energy and protein requirements so it’s proposed the model RE = 0.0703 * EBW0.75 * EBG1.128 for net energy requirements for gain and NPg = 197.40 * EBG – 11.14 * RE for net protein requirements for gain. The net and metabolizable energy requirements for maintenance for all group were 70.55 and 106.53 kcal/EBW0.75/day, respectively. The net protein requirements for maintenance was 1.07 g/ EBW0.75/day and the metabolizable protein requirements for maintenance were 3.88 g/EBW0.75/day for all group.