Impacto da inclusão de taninos na dieta ou do turno de pastejo sobre parâmetros de fermentação ruminal em vacas leiteiras.

RAFAELA LEMOS; CLAUDIO A. POZO; CECILIA CAJARVILLE; GILBERTO V. KOZLOSKI

Goiânia

Congreso; 55ª Reunião Anual da Sociedade Brasileira de Zootecnia e 28º Congresso Brasileiro de Zootecnia; 2018

Sociedade Brasileira de Zootecnia

The aim of this study was to evaluate the impact of including Acacia mearnsii tannin extract (TA) in the diet or managing the grazing schedule on rumen fermentation variables of dairy cows grazing ryegrass combined with total mixedration (TMR). Nine lactating Holstein cows were arranged on a triplicate 3 x 3 Latin square study conducted through three experimental periods of 22 d. The three treatments consisted of: morning grazing and afternoon TMR without TA (AM), morning grazing and afternoon TMR added with 15 g TA kg-1 of dry matter (AMt), and morning TMR without TA and afternoon grazing (PM). The treatments did not affect the pH or the concentrations of volatile fatty acids (VFA), NH3-N or reducing sugars in the ruminal fluid. However, the acetate to propionate ratio was lower in AMt (P < 0.05). In conclusion, excepting a minor change on VFA proportion, neither thedietary TA nor the grazing schedule showed a significant impact on ruminal fermentation parameters of dairy cows fed with TMR combined with pasture.