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The Scientific World Journal
Volume 2014, Article ID 371968, 7 pages
http://dx.doi.org/10.1155/2014/371968
Research Article

Meat Production in a Feedlot System of Zebu—Holstein Steers and Heifers with Dairy Genetics: Productive and Biological Analyses

1Animal Science Department, Federal University of Viçosa, 36570-000 Viçosa, MG, Brazil
2Agricultural Research Company of Minas Gerais (EPAMIG), Brazil

Received 30 September 2014; Accepted 18 November 2014; Published 10 December 2014

Academic Editor: Daiji Endoh

Copyright © 2014 Gustavo Chamon de Castro Menezes et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The aim of this study was to evaluate the productive and biological efficiency of steers and heifers from dairy genetics in a feedlot system in terms of meat production. Twenty-four steers and 24 heifers at 10 monthes of age, () Zebu × () Holstein were utilized. They were distributed over four feedlot times, 30, 60, 90, and 120 days with four replications for each sex, and were slaughtered at the end of each period. The productive and biological analyses were performed through comparative slaughter to determine the body composition. Heifers presented with greater intakes () of dry matter in grams per kg of body weight. Steers presented with a greater () final empty body weight, carcass gain, cold carcass weight, and meat proportion in the carcass; however, heifers presented with a greater subcutaneous fat thickness () and, consequently, a greater () fat proportion in the carcass. We conclude that steers are more efficient in their productive performance than heifers in a feedlot. For the finishing carcass fat cover, heifers need 90 days in the feedlot. The net energy requirements for maintenance are 67 kcal/EBW0.75/d, and the net requirements of energy (NEg) and protein (NPg) for gain can be estimated by the following equations: and for the two sexes.