Genotype effects on energy and protein requirements in growing male goats

Autor(es)

Almeida, A. K. ; Kebreab, E. ; Resende, K. T. ; Medeiros, A. N. ; Teixeira, I. A. M. A.

• Tipo de documento: Artigo Científico
• Fonte: ANIMAL; v. 14, p. 9-pg., 2020-08-01.

Resumo

Goat genotype may alter the net energy and protein requirements for maintenance (NE(m)andNP(m), respectively) and weight gain (NE(g)andNP(g)).This study was designed to investigate and quantify the effect of goat type on NEm, NPm, NE(g)and NPg, and quantify the net requirements for energy and protein for dairy, meat and indigenous growing male goats. For that, comparative slaughter studies were gathered and a meta-analytical approach was used. Two distinct databases were organized: one composed of 233 individual records from 11 studies of meat (n= 81), dairy (n= 97) and indigenous (n= 55) growing male goats weighing from 4.50 to 51.0 kg, to depict NE(m)and NPm; and another database composed of 239 individual records from nine studies of meat (n= 87), dairy (n= 97) and indigenous (n= 55) growing male goats weighing from 4.30 to 51.0 kg, to depict NE(g)and NPg. Our findings showed that NE(m)of meat goats was 8.5% greater (336 +/- 10.8 kJ/kg(0.75)of empty BW;EBW) than dairy and indigenous goats (310 +/- 8.20 kJ/kg(0.75)EBW;P< 0.05). Whereas, NP(m)was not affected by goat type (1.92 +/- 0.239 g/kg EBW;P= 0.91). The NP(g)was 185.1 +/- 1.82 g/kg of EBW gain for goats weighing 5 kg BW and 192.5 +/- 4.33 g/kg of EBW gain for goats weighing 45 kg BW, and thus did not change across goat type (P= 0.12). On the other hand, NE(g)increased from 7.29 +/- 0.191 to 11.9 +/- 0.386 MJ/kg of EBW in male dairy goats, and from 7.32 +/- 0.144 to 15.7 +/- 0.537 MJ/kg of EBW in meat and indigenous growing male goats weighing between 5 and 45 kg BW. When body protein was used as a predictor in the allometric equation instead of EBW seeking to account for the degree of maturity, goat type differences disappeared; however, this predictor showed a high variation among individuals. In conclusion, energy and protein requirements for gain in distinct goat types reflect on body composition differences. Future research should focus on better understanding the maturity degree and its consequences in the energy requirement of growing male goats and better depict the goat type effect on it, as well as on the efficiency of utilization. (AU)

• Processo FAPESP: 14/14734-9 - Desenvolvimento de modelos para predição das exigências nutricionais de cabritos em crescimento
• Beneficiário: Izabelle Auxiliadora Molina de Almeida Teixeira
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 15/50444-8 - Improving our understanding of nutritional requirements to reduce environmental impact of livestock
• Beneficiário: Izabelle Auxiliadora Molina de Almeida Teixeira
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 14/14939-0 - Desenvolvimento de modelos para predição das exigências de energia e proteína de cabritos em crescimento
• Beneficiário: Amélia Katiane de Almeida
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado