Composition of herbage consumed in mixed sequential grazing of cows with ewes as followers

The aim of this study was to evaluate whether botanical, morphological and nutritional compositions of the herbage ingested by the cows are affected by age of pastures and grazing system. Mixed sequential grazing of dairy Holstein cows with Pelibuey breeding ewes as followers (MixG) and single species cow grazing (CowG) were the systems evaluated. Animals grazed on pastures of alfalfa (Medicago sativa L.) and orchard grass (Dactylis glomerata L.) in their first and second year (young) or third to fifth year (mature). During spring-summer, the proportion of alfalfa in herbage ingested by the cows was 20% higher (P<0.01) in young than in mature pastures. Conversely, that of orchard grass was 43% higher (P<0.05) in mature pastures. The NDF and ADF contents were 9 and 13% lower (P<0.05) under MixG than CowG. During autumn-winter, CP content was not affected by grazing system or age of pastures. During spring-summer, CP content was 8% higher in MixG than CowG. Sequential mixed grazing of dairy cows and breeding ewes improved the composition of herbage ingested by the cows.Abbreviations: ADF, acid detergent fiber; CowG, cow grazing; CP, crude protein; DM, dry matter; LW, live weight; MixG, mixed sequential grazing; NDF, neutral detergent fiber