THE EFFECT OF SPREADING SODIUM-BICARBONATE OVER THE SURFACE OF GRASS-SILAGE ON THE INTAKE OF GRASS SILAGES BY BEEF-CATTLE

Ten silages were obtained from farms in Northern Ireland. They were se lected on the basis of either low pH (< 3.7) or perceived low intakes on the farms. The silages were offered to 100 Charolais cross steers, either with or without the addition of sodium bicarbonate, in a two-pe riod changeover design experiment. The sodium bicarbonate was spread o ver the surface of the silage at a rate of 250 g per steer day(-1). Ea ch period was of a 2-week duration. Dry matter intakes (kg day(-1) and g kg(-1) liveweight (LW)(0.75)) were recorded daily, with intakes on the second week of each period being used in the statistical analysis. Silage dry matter intakes with (+) and without (-) dietary addition o f sodium bicarbonate were: 6.27 and 6.16 (SEM = 0.122) kg day(-1) 65.8 and 64.7 (SEM = 1.29) g kg(-1) LW0.75. The lack of a significant effe ct of dietary addition of sodium bicarbonate on the intake of low pH s ilages suggests that sodium bicarbonate spread over the surface of the silage has no beneficial effect, in terms of intake, with silages of this type. (C) 1997 Elsevier Science B.V.