Productive performance of confined young bulls fed proportions of 'Mulato II' grass silage in the diet

Regis Luis Missio,José Messias De Rezende,Emerson Alexandrino,Darlene Pereira Da Silva,Joaquim José De Paula Neto,André Augusto Marinho Silva,Denise Vieira Da Silva

doi:10.1590/s0100-204x2017000800013

Regis Luis Missio, José Messias De Rezende + Show 5 more

Open Access

https://doi.org/10.1590/s0100-204x2017000800013

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Abstract

Abstract: The objective of this work was to evaluate the performance of young Nellore bulls and of young dual-purpose dairy bulls fed proportions of 'Mulato II' grass silage (400 and 100 g kg-1), in diets with high levels of concentrate, as well as to evaluate the cost of this feed. Sixteen young Nellore bulls and 16 young dairy crossbred bulls were used, with initial average weight of 380.69±10.45 and 376.94±17.16 kg, respectively, and average initial age of 24 months. A completely randomized experimental design was carried out in a 2x2 factorial arrangement. The highest silage proportion caused a 13% increase in dry matter intake (percentage of body weight) and a 19.7% decrease in dry matter digestibility of the diet, but it did not alter the intake of total digestible nutrients, nor the average daily gain or carcass characteristics. Nutrient intake and digestibility, average daily gain, and carcass characteristics (except conformation) did not change due to the genetic group of animals. Feed conversion was 18.3% better in young dairy bulls. In diets with high levels of concentrate, the proportion of 400 g kg-1 of 'Mulato II' grass silage, in comparison with that of 100 g kg-1, does not affect the productive performance, nor the main carcass characteristics of economic interest of confined young bulls, but reduces feeding costs.

Highlights

Brazil has the conditions needed to increase beef production, in order to meet the increased worldwide demand for animal protein (Anualpec, 2014)
The objective of this work was to evaluate the performance of young Nellore bulls and of young dualpurpose dairy bulls fed proportions of 'Mulato II' grass silage (400 and 100 g kg-1), in diets with high levels of concentrate, as well as to evaluate the cost of this feed
The increase in the proportion of 'Mulato II' grass silage in the diets resulted in an increase in dry matter intake (Table 3)

Summary

Introduction

Brazil has the conditions needed to increase beef production, in order to meet the increased worldwide demand for animal protein (Anualpec, 2014). In this context, the use of dairy males, which are usually sacrificed at birth or sold, is an alternative to increase both meat production and income generation. High feeding costs have made feedlot usage little attractive. These costs can be reduced by incorporating higher proportions of silage, preferably high-quality bulky ones, in the diets, but this is not always possible because of the agricultural potential of production systems. Tropical grass species are an alternative food source, but greater amounts of concentrate are required in the diet, which can affect the profit margin due to concentrate costs, leading to higher production costs in the feedlot when the cost of animal acquisition is not considered (Cruz et al, 2014; Silva et al, 2014)

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