Can the body composition of crossbred dairy cattle be predicted by equations for beef cattle?

Abstract

ObjectiveThe aim of the study was to evaluate the efficiency of the Hankins and Howe (HH46), Valadares Filho (V06), and Marcondes (M12) equations for predicting the physical and chemical composition of dairy crossbred bulls carcasses, as well as the chemical composition of their empty bodies.MethodsThis study was conducted using 30 dairy crossbred bulls. One group of five animals was slaughtered at the beginning of the experiment, and the remaining were slaughtered 112 days later. Animals were distributed in a completely randomized design into treatments consisting different levels of concentrate (0%, 17%, 34%, 51%, and 68%). The physical and chemical compositions of the cattle were obtained from the right half of the carcass and using samples taken between the 9th and 11th ribs of the left half of the carcass. The estimated and experimentally determined values were compared using the correlation and concordance coefficient, as well as the mean square error of prediction (MSEP) and its components.ResultsThe HH46 equations were better at estimating the amount of muscle plus fat in the carcass. The amount of bone in the carcasses could not be well estimated by the HH46 and M12 models. The M12, HH46, and V06 equations were worst at estimating the amounts of protein, ether extract, and water in the carcass, respectively. In the empty body, the amounts of protein and water were well estimated by the HH46 equations. Protein, ether extract, and water were accurately estimated by the V06 equations, and ether extract by the M12 equations.ConclusionThe physical and chemical composition of dairy crossbred bull carcasses, as well as the chemical composition of their empty bodies, can be predicted using the equations tested here. The amount of bone in these carcasses could not be accurately predicted.

Empty body chemical composition of Nellore steers estimated by indirect methods

“…The methods applied considered that determining amounts of water in ribs cut and body water by deuterium was sufficient to estimate other body components, using equations available for Nellore steers (NEVES et al, 2018).…”

“…Biological responses of each animal to feed restriction vary according to the level of sub-nutrition and posterior re-alimentation as well as the stage of animal development (CUNNINGHAM et al, 2018). In these cases, indirect methods that use carcass composition or subcutaneous fat may not identify these changes in fat deposition, explaining the divergence in literature data (NEVES et al, 2018;CASTILHOS et al, 2018).…”

“…The most traditional indirect method is the use of 9-10-11 th ribs, recommended by Hankins and Howes (1946). Many studies have investigated this method and some errors in the estimates were found, although the method has been validated in several circumstances (SILVA et al, 2017;NEVES et al, 2018).…”

“…Knowing the concentration of main components in the empty body through body water concentration is possible due to relationships between water and other body constituents (NEVES et al, 2018).…”