Maintenance Energy Requirements of Double-Muscled Belgian Blue Beef Cows.

José Vanacker,Leo Fiems,Johan De Boever,Sam De Campeneere

doi:10.3390/ani5010089

Abstract

Simple SummaryDouble-muscled Belgian Blue animals are extremely lean, characterized by a deviant muscle fiber type with more fast-glycolytic fibers, compared to non-double-muscled animals. This fiber type may result in lower maintenance energy requirements. On the other hand, lean meat animals mostly have a higher rate of protein turnover, which requires more energy for maintenance. Therefore, maintenance requirements of Belgian Blue cows were investigated based on a zero body weight gain. This technique showed that maintenance energy requirements of double-muscled Belgian Blue beef cows were close to the mean requirements of cows of other beef genotypes.Sixty non-pregnant, non-lactating double-muscled Belgian Blue (DMBB) cows were used to estimate the energy required to maintain body weight (BW). They were fed one of three energy levels for 112 or 140 days, corresponding to approximately 100%, 80% or 70% of their total energy requirements. The relationship between daily energy intake and BW and daily BW change was developed using regression analysis. Maintenance energy requirements were estimated from the regression equation by setting BW gain to zero. Metabolizable and net energy for maintenance amounted to 0.569 ± 0.001 and 0.332 ± 0.001 MJ per kg BW0.75/d, respectively. Maintenance energy requirements were not dependent on energy level (p > 0.10). Parity affected maintenance energy requirements (p < 0.001), although the small numerical differences between parities may hardly be nutritionally relevant. Maintenance energy requirements of DMBB beef cows were close to the mean energy requirements of other beef genotypes reported in the literature.

Highlights

Improving the efficiency of energy utilization is of paramount importance from several points of view.First, a higher efficiency means a reduction of feed costs for livestock production
Derno et al [5] reported a variation in energy requirements for maintenance of 10% to 30% because of genetic differences, so that it is not excluded that double-muscled Belgian Blue (DMBB) and non-DMBB animals have divergent requirements
Increasing the level of feed restriction resulted in a decrease of body weight (BW) and body condition score (BCS) (p < 0.001) and an increased daily BW loss (p < 0.001)

Summary

Introduction

Improving the efficiency of energy utilization is of paramount importance from several points of view. A higher efficiency means a reduction of feed costs for livestock production. This may result in an increased income for the farmer. A higher efficiency means that nutrients are better utilized by the animal, resulting in a lower excretion into the environment and lower costs for manure management. Derno et al [5] reported a variation in energy requirements for maintenance of 10% to 30% because of genetic differences, so that it is not excluded that DMBB and non-DMBB animals have divergent requirements. Energy and protein requirements for growing-finishing beef bulls have been derived [9], but maintenance requirements of DMBB cows are lacking. Maintenance energy requirements can be defined as the daily energy intake that will balance heat production, resulting in no loss or gain of body energy reserves [10]

Animals and Management

Analytical Procedures

Statistical Analysis

Effect of Energy Level on Animal Performance

Energy Requirements for Maintenance

Conclusions