Intake, digestibility and feeding behaviour of grazing dairy cows supplemented with common bean (Phaseolus vulgaris L.) residue

Abstract

Context In Brazil, dairy cattle pasture-based systems use grass pasture as the main feed source, with little or no supplementation. However, it is necessary to invest in nutritional technologies that allow dairy cattle systems to produce milk with a high protein and energy content, and better total bacterial counts at low costs. Aims This study aimed to evaluate the effect of adding a common bean residue (CBR) to cattle diets on feed intake, digestibility and feeding behaviour of lactating dairy cows. Methods Eight lactating Holstein × Zebu crossbred cows, with an average bodyweight of 500 ± 30 kg (mean ± s.d.) and a mean daily milk yield of 13 ± 2 kg/cow were randomly assigned in a double 4 × 4 Latin square. The treatments consisted of four increasing levels of CBR (134, 240, 348 and 449 g/kg) in the concentrate. Key results The inclusion of CBR linearly decreased (P ≤ 0.034) the DM intake and neutral detergent fibre intake of pasture, sugarcane and the total diet. The inclusion of CBR did not affect (P ≥ 0.111) grazing, rumination or idle time. The feeding efficiency in kg DM/h and kg neutral detergent fibre corrected for ash and protein/h linearly decreased (P < 0.001), with an estimated decrease of 39.1 and 23.4 g/h respectively for every 10 g/kg of CBR added to the concentrate. The number of boluses per day and the time spent per ruminated bolus were not affected (P ≥ 0.086) by CBR inclusion. Conclusions The results obtained in this study indicate that the inclusion of up to 240 g/kg of CBR to the diets of lactating dairy cows with a mean daily milk yield of 13 kg, managed on pastures, is recommended. Implications The use of CBR, which has high availability in several countries, may be an alternative to supplying small ruminants.