Premium
Evaluation studies in the development of a commercial bacterial inoculant as an additive for grass silage
Author(s) -
KENNEDY S. J.,
GRACEY H. I.,
UNSWORTH E. F.,
STEEN R. W. J.,
ANDERSON R.
Publication year - 1989
Publication title -
grass and forage science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.716
H-Index - 56
eISSN - 1365-2494
pISSN - 0142-5242
DOI - 10.1111/j.1365-2494.1989.tb01935.x
Subject(s) - microbial inoculant , silage , formic acid , lactic acid , zoology , fermentation , agronomy , factorial experiment , chemistry , ammonia , biology , food science , horticulture , mathematics , bacteria , biochemistry , inoculation , genetics , statistics
Two 2×3 factorial design experiments were conducted during 1985 to compare the effect of treating grass at ensiling with a silage inoculant (Imperial Chemical Industries plc) or formic acid with an untreated control, on fermentation, in‐silo losses, intake and performance of finishing cattle. In experiment 1, three covered concrete‐walled silos were each filled with approximately 70 t of primary growth, unwilted herbage at each of two cutting dates, 20–21 May (early harvest) and 3 June 1985 (late harvest). In experiment 2, the above procedure was repeated for second regrowth grass with two cutting dates, 30 September‐1 October (early harvest) and 16–21 October 1985 (late harvest). The water‐soluble carbohydrate (WSC) contents of the herbage were low in both, being 130–160 and 121–137 g kg −1 DM for the first and second experiments respectively. In both experiments the formic acid‐treated silages attained lower temperatures than the inoculant‐treated and untreated silages. At both harvests in experiment 1 the pH, ammonia nitrogen (NH 3 N) and volatile fatty acid (VFA) contents of the inoculant‐treated and formic acid‐treated silages were significantly lower than those in the untreated silage. However, at the early harvest in experiment 2 the pH and NH 3 N contents of the inoculant‐treated silage were significantly higher than those in the two other silages. At the late harvest in experiment 2 the inoculant‐treated and the formic acid‐treated silages had significantly lower pH and VFA contents than the untreated silage. After 126 d and 98 d storage periods in experiments 1 and 2 respectively, each of the six silages was offered to twelve 475 kg steers throughout a 70‐d period (experiment I) and a 63‐d period (experiment 2). In experiment 1 there were no significant effects of additive on silage DM intake, liveweight gain or carcass gain with the mean carcass gains being 0·49, 0·51 and 0·52±0·024 kg d −1 for the untreated, formic acid‐treated and inoculant‐treated silages respectively. In experiment 2 the mean silage DM intakes were 6·34, 7·33 and 6·60±0·151 kg d −1 and carcass gains were 0·27, 0·35 and 0·26±0·026 kg d −1 for the untreated, formic acid‐treated and inoculant‐treated silages respectively, formic acid treatment thus gave the most consistent results.