IN VITRO NUTRITIONAL VALUE OF BLACK OAT (Avena strigosa) IN GRAZING OR SILAGE FOR SMALL SCALE DAIRY SYSTEMS

Abstract

Background. Evaluate the nutritional quality of forages is fundamental and to do different techniques are used including in vitro gas production. Objetive. In this paper, gas production technique was used to estimate in vitro digestibility and fermentation kinetics in Avena strigosa.  Methodology. The work consisted of two experiments, in experiment 1, forage composed of black oat regrowth (AN) and black oat regrowth associated with red clover (ANT) was compared with a multi-species of temperate pastures (PME). In experiment 2, black oat silage (EAN) was evaluated in comparison to two multi-species grasslands composed of temperate climate grasses (PME-1 and PME-2). Results. In experiment 1 the PC content was different (P <0.05). The estimated digestibility and metabolizable energy of gas production were not different (P> 0.05). In vitro gas production was not different (P> 0.05) for any of the variables. In experiment 2, differences (P <0.05) were observed in the contents of CP, NDF, ADF, however, the digestibilities and metabolizable energy were not different (P> 0.05). Regarding in vitro gas production, there were no differences (P> 0.05) in any of the evaluated parameters (soluble fraction (A), fermentation rate of fraction A (C1); slow fermentation fraction (B); rate fermentation time of fraction B (C2) and fermentation time of fraction B (lag). Implications. The results of this study allow us to know the best way the nutritional assessment of black oats. Conclusions. It is concluded that the forage of the oat regrowth has a different behaviour since it has more slowly fermentable carbohydrates compared to the forage composed of temperate grasses (experiment 1). In experiment 2, the compound temperate forage grasses and oats silage similar nutritional value was similar.