Pasture allocation time and tannins in partial mixed ration: intake and performance of dairy cows

CLAUDIO A. POZO; CECILIA CAJARVILLE; JOSE LUIS REPETTO ; GILBERTO V. KOZLOSKI

Belfast

Congreso; 67th Annual Meeting of the European Association for Animal Production; 2016

European Association for Animal Production

The aim of this study was to evaluate the effect of Acacia mearnsii tannin extract (TE) inclusion in a partial mixed ration (PMR) and the time of pasture allocation on intake (DMI) and performance of grazing dairy cows. Nine Holstein cows averaging 197±12 days in milk were arranged on a triplicate 3x3 Latin square design, conducted through three experimental periods of 21 days. The three treatments consisted of: morning pasture allocation and afternoon PMR supply (AM), morning pasture allocation and afternoon PMR supply with 15 g/kg of TE (AMt) and morning PMR supply and afternoon pasture allocation (PM). Individual DMI was measured during 5 days of each period. Pasture DMI was determined in individual paddocks as the difference in herbage mass before and after grazing. Individual milk production was recorded daily during 5 days, and milk samples were collected during 2 days of each period for composition analysis. Statistical analysis was carried out using the MIXED procedure of SAS. Although DMI was similar for all treatments (19.9±1.2 kg/d), the proportion of pasture in the diet was higher in PM than AM and AMt (0.43 vs. 0.41, P