The value of maize silage in replacing grass silage and concentrates in beef cattle

01 Jun 2015

Take home message: Maize silage in beef cattle diets can reduce finishing period and maintain animal performance providing inclusion rate and stage of maturity are optimal. During beef production, costs could be reduced if the level of concentrate supplementation can be reduced while maintaining animal performance. A study carried out in Northern Ireland has investigated the effects of maturity of maize at harvest, level of inclusion and potential interactions on the performance, carcass composition, meat quality and potential concentrate-sparing effect when offered to finishing beef cattle. Six diets were offered to 72 steers for 146 days with the forages offered ad libitum. Grass silage, representative of average grass silage produced in Ireland on the basis of its fermentation and feed value characteristics, was offered as the sole forage supplemented with either 4 or 8 kg concentrate/steer daily. The levels of concentration supplementation, was representative of the range used by many commercial beef finishers in the UK and Ireland, and accounted for 40% and 67% of the total dry matter (DM) intake. Two maize silages were also offered as the sole forage supplemented with 4 kg concentrate/steer daily, or in addition with one of the supplemented grass silages at a 1:1 ratio. The researchers from the Department of Agriculture and Rural Development for Northern Ireland, reported that fat yellowness was reduced by increasing the level of concentrate offered with grass silage, maize maturity and level of maize inclusion. There were significant interactions between maize maturity and inclusion level for food intake, fibre digestibility and daily gain. Maize silage with a high DM offered as the sole forage produced carcasses with whiter fat and resulted in 31% increased carcass gain, because of a combination of increased metabolizable energy (ME) intake and improved efficiency of utilisation of ME. Maturity of maize silage had no impact on animal performance when offered as 50% of the forage but has a daily concentrate-sparing effect per steer of up to 2.4 kg. Lead author Tim Keady concluded that increasing the inclusion of maize, harvested at the optimum stage of maturity, in the diet of beef cattle either reduces the finishing period or maintains animal performance at a lower concentrate feed level relative to medium feed value grass silage. Effects of replacing grass silage with maize silages differing in inclusion level and maturity on the performance, meat quality and concentrate-sparing effect of beef cattle  T. W. J. Keady, A. W. Gordon and B. W. Moss By Joanne Stocks, University of Nottingham