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

Gustavo Chamon De Castro Menezes,Luciana Navajas Rennó,Sebastião De Campos Valadares Filho,Lays Débora Silva Mariz,José Reinaldo Mendes Ruas,Edenio Detmann,Arismar De Castro Menezes,Jarbas Miguel Da Silva Junior,Diego Zanett

doi:10.1155/2014/371968

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, (3/4) Zebu × (1/4) 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 (P < 0.05) of dry matter in grams per kg of body weight. Steers presented with a greater (P < 0.05) final empty body weight, carcass gain, cold carcass weight, and meat proportion in the carcass; however, heifers presented with a greater subcutaneous fat thickness (P < 0.05) and, consequently, a greater (P < 0.05) 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: NEg(Mcal/d) = 0.067 × EBW0.75 × EBG1.095 and NPg = 162 × EBG − 5.62 × RE for the two sexes.

Highlights

IntroductionDairy farmers have sought to diversify production, through integration with the meat chain
To increase profitability, dairy farmers have sought to diversify production, through integration with the meat chain
When the intake was expressed in grams per kg of body weight (BW), an effect was observed (P < 0.05) for sex and period on the intake of dry matter (DM), organic matter (OM), and apNDF, with greater values for the heifers (P < 0.05) (Table 2)

Summary

Introduction

Dairy farmers have sought to diversify production, through integration with the meat chain. The reason for using beef bulls to breed dairy cattle is the increased productivity, along with improvements in the carcass and meat quality of the progeny, which result in a greater acceptance and value of calves on the market. Strategies to define the proportion of beef bulls in dairy herd [1] and the use of specialized breed in meat production [2] are observed. Zebu and Holstein cattle, and a lot of questions are raised regarding the productive and biological efficiency when Zebu animals crossbred with Holstein cattle are utilized for meat production in a feedlot system. In Brazil, the use of ration formulation systems that utilize net and metabolizable nutritional units is limited by the lack of information regarding the nutritional value of feedstuff and the nutritional requirements of Zebu cattle crossbred with Holstein cattle.

Objectives

Methods

Results

Conclusion