Resumo Este trabalho teve como objetivo avaliar as características produtivas e nutricionais de diferentes cultivares de aveia (Avena spp.),visando à produção de silagem. Os tratamentos foram constituídos dos cultivares de aveia branca IPR 126 (Avena sativa), Agrocoxilha, e IPR Cabocla (Avena strigosa), bem como das cultivares BRS Madrugada e BRS Centauro (Avena vertis). As forragens foram colhidas e ensiladas quando atingiram o estádio fenológico de grão pastoso/farináceo. O delineamento experimental foi em blocos casualizados, com cinco tratamentos e três repetições por tratamento. O cultivar Cabocla apresentou os maiores teores de matéria seca (antes e após a abertura dos silos) e maior digestibilidade in vitro da matéria seca no momento de ensilagem. Após a ensilagem não foram observadas diferenças para a digestibilidade in vitro e perdas de matéria seca entre os tratamentos. Contudo, após correção dos respectivos valores para perdas de matéria seca na ensilagem e digestibilidade in vitro da matéria seca, observou-se maior produção de matéria seca digestível (kg ha-1) para o cultivar Centauro.

Abstract This study evaluated dry matter yield and nutritional characteristics of different oat genotypes (Avena spp.) for ensiling. Treatments consisted of genotypes of white oat IPR 126 (Avena sativa), black oat Cabocla IPR and Agrocoxilha (Avena strigosa), and BRS Madrugada and BRS Centauro (Avena vertis). Oats were harvested at the phenological stage of milk/dough grain. The design was a completely randomized block scheme, with five treatments and three replications per treatment. The IPR Cabocla genotype showed the highest dry matter content (before and after silo opening) and in vitro dry matter digestibility of fresh forage. No differences were observed for in vitro dry matter digestibility and dry matter losses among silages. The highest silage digestible dry matter yield (kg ha-1) was observed for the BRS Centauro genotype. Thus, despite the better nutritional quality presented by the IPR Cabocla genotype before ensiling, BRS Centauro genotype presented a higher yield of digestible dry matter per hectare.

ABSTRACT Our objective was to determine the effects of maturity and storage length on the fermentation pattern, ruminal disappearance of nutrients, and recovery of digestible nutrients in flint corn (Zea mays L.) silage harvested with a pull-type machine without a kernel processor. Corn plants were harvested at 300 g kg−1 DM (low dry matter, LDM) or 400 g kg−1 DM (high dry matter, HDM) and stored for 0, 7, 14, 30, 60, 90, 120, and 180 d in laboratory silos. Corn harvested at HDM had a higher proportion of long particles (>19 mm), more intact kernels, and lower kernel processing score. There was an interaction between maturity and storage length for several fermentation end-products, DM recovery, ruminal disappearance of nutrients, and recovery of digestible DM. Overall, the concentrations of fermentation end-products were higher in LDM than in HDM silage. The DM recovery decreased over time, mainly for LDM silage. Ruminal disappearance of nutrients (starch, CP, and DM) increased with storage length, with greater values for LDM silage at shorter storage, but closer values among LDM and HDM at longer storage periods. The recovery of digestible DM (DM recovery × ruminal disappearance) slightly increased in LDM silage up to 26 d of fermentation, but it markedly increased in HDM silage, mainly up to 60 d of storage. Storing for longer periods is a strategy to partially offset the negative impact of maturity on the digestibility of flint corn silage harvested with pull-type machines without kernel processor.