Stylosanthes cv. Campo Grande silage and concentrate levels in diets for beef cattle

Abstract

The objective of this study was to evaluate the ruminal and intestinal digestion, the ruminal fermentation and the performance of beef cattle fed diets containing Stylosanthes silage (StS) and corn silage (CS). The treatments consisted of diets containing StS with different concentrate levels, based on dry matter (DM) (g/kg): 200 (StS-200), 400 (StS-400), 60 (StS-600), and a Control treatment with 600 g/kg CS and 400 g/kg concentrate (CS-400). In Experiment 1, 32 Nellore bulls, 364.28 ± 2.82 kg bodyweight, were distributed in a complete randomised design with eight replicates. Four Holstein × Zebu bulls (average bodyweight of 429 ± 15 kg) were used in Experiment 2, distributed in a 4 × 4 Latin square design. Nutrient intake was similar between StS-400 and CS-400 (P > 0.05), however, only StS-600 showed the same intake of total digestible nutrients as CS-400 (P < 0.05). Only the animals fed the StS-600 diet had similar (P > 0.05) average daily gain of carcass in comparison with those fed the Control diet. The StS-200 and StS-400 diets showed lower (P < 0.05) total tract digestibility of DM and crude protein than CS-400 (P < 0.05). Ruminal pH values of StS-200 and SE-400 were higher (P < 0.05) than in CS-400. The StS-600 diet showed a similar productive performance to CS in diets with 600 g/kg of concentrate, highlighting the potential use of this legume in diets for beef cattle in tropical conditions.