Sampling and chemical composition of silage from a farm stack: Variation in moisture content and in degree of fermentation

摘要

Abstract A freshly exposed face of a stack containing wilted pasture silage from a Manawatu dairy farm was randomly sampled to assess the variation in chemical composition and moisture content within the silage. Total and soluble nitrogen, predicted in vivo digestibility, and silage pH were uniform within the sampled profile but dry matter (DM) (% of fresh material), soluble sugars, lactic and volatile fatty acids, and ammoniacal N were much more variable. DM was significantly correlated with soluble sugars (r 2 = 0.96) and inversely correlated with total volatile fatty acids (r 2 = -0.96), ammoniacal N (r 2 = -0.74) and lactic acid (r 2 = -0.65) in the sampled sites. Changes in the extent of lactate and clostridial fermentation were related to the moisture content of the different samples taken from the profile. Minimum sample numbers required for representative sampling of this silage were estimated from the analytical data; the predicted sample numbers varied from 4 to 61 depending on the individual si...