Body chemical composition of Nellore bulls with different residual feed intakes1
- 1 July 2013
- journal article
- research article
- Published by Oxford University Press (OUP) in Journal of Animal Science
- Vol. 91 (7), 3457-3464
- https://doi.org/10.2527/jas.2012-5437
Abstract
Empty body and carcass chemical compositions, expressed as content of water, ether extract, protein, minerals, and energy, were evaluated in Nellore bulls with different residual feed intakes (RFI). Forty-nine not castrated males, with 343 kg of average initial BW and 398 kg of average slaughter BW, were studied. Animals were divided in two subgroups: reference group (RG) and ad libitum feeding group. At the end of the adaptation period, animals of subgroup RG were slaughtered and the other animals were finished in individual pens for approximately 100 d, until they reached a subcutaneous fat thickness over the LM of 4 mm, and were slaughtered at an average age of 540 d. Body composition was obtained after grinding, homogenizing, sampling, analyzing, and combining blood, hide, head + feet, viscera, and carcass. Tissue deposition rates and chemical composition of gain were also measured based on gains estimated by comparative slaughter technique. No significant differences in slaughter BW (P = 0.8639), empty BW (P = 0.7288), HCW (P = 0.6563), or empty body and carcass rates of gain were observed between RFI groups, demonstrating that the low (–0.331 kg DM/d) and high (+0.325 kg DM/d) RFI animals presented similar body sizes and growth rates. No significant differences in empty body or carcass content of water, ether extract, protein, minerals, and energy were observed between the low and high RFI animals. And also there were no significant differences in empty BW or carcass gain, demonstrating that low and high RFI animals had a similar growth potential. More efficient animals (low RFI) consumed less feed than less efficient animals (high RFI) but presented similar body sizes, growth rates, and empty body and carcass chemical composition. Copyright © 2013. American Society of Animal Science .Keywords
This publication has 14 references indexed in Scilit:
- Physiological basis for residual feed intake1Journal of Animal Science, 2009
- Residual feed intake in beef cattleRevista Brasileira de Zootecnia, 2008
- Efeito da seleção para peso pós-desmame sobre a composição corporal de bovinosRevista Brasileira de Zootecnia, 2007
- Growth, carcass quality, and protein and energy metabolism in beef cattle with different growth potentials and residual feed intakes1,2Journal of Animal Science, 2007
- Residual feed intake of purebred Angus steers: Effects on meat quality and palatabilityJournal of Animal Science, 2006
- Residual feed intake and body composition in young growing cattleCanadian Journal of Animal Science, 2003
- Exigências líquidas de proteína e energia para crescimento de tourinhos santa gertrudis em dietas de alto teor de concentradoRevista Brasileira de Zootecnia, 2002
- Genetic and phenotypic variance and covariance components for feed intake, feed efficiency, and other postweaning traits in Angus cattle.Journal of Animal Science, 2001
- Potential for selection to improve efficiency of feed use in beef cattle: a reviewAustralian Journal of Agricultural Research, 1999
- Efficiency of Feed Use in Beef CattleJournal of Animal Science, 1963