Effect of a silage inoculant on the fermentation and aerobic stability of maize silage, and effect on production results when fed to high yielding cows

Abstract

The high nutritional value of corn silage is nutrient to development of opportunist microorganisms responsible by aerobic spoilage. For improve the fermentation and aerobic stability these silages, the utilization of inoculants with heterofermentatives bacterias obligate and facultative has been studied. Thus, the aim of this study is to evaluate the effect of an inoculant on silage quality in big scale silos and to document the effect on production results (especially milk production) when the inoculated silage is fed to high yielding cows compared to untreated corn silage. The following three treatments will be applied:T1: Control sample (no inoculant) Ag bags for feeding trial, T2: As T1 with added test product microbial inoculant 1 (experimental) at an inclusion of 150.000 CFU/g fresh crop (minimum 5 replicate Ag bags) and T3: As T1 with the test product microbial inoculant 2 (experimental) at an inclusion of 150.000 CFU/g fresh crop Ag bags for feeding trial. Five, 45-ton bags of forage will be prepared for each treatment and ensiled for 90 days. Representative samples of forage destined for each bag will be taken for lactic acid bacteria counts and stored (-20oC) stored for chemical analysis. Temperature sensors will be strategically placed at approximately the same locations within each bag to monitor temperature changes during ensiling and the feedout period. After 90 days of ensiling, bags will be opened and approximately 0.5 ton of silage per day will be taken from each bag every day for feeding to the cows, good and spoiled silage from each bag will be weighed daily and subsampled for DM analysis and storage (-20oC). Stored daily samples will be composited every three weeks and analyzed for chemical composition to allow estimation of losses of nutrients in good and spoiled silage over time. Dry matter, pH, crude protein, NDF, ADF, WSC, VFA, lactate, acetate, butyrate, propionate, ammonia-N, aerobic stability, in vitro DM digestibility, DM losses, yeasts and molds and total lactic acid bacteria, visual scoring of fungal growth (photo documentation), area of fungal growth, quantities of good and spoiled (darkened, heating or moldy) silage. The zootechnical effect of the inoculant will be tested by feeding inoculant treated or untreated silage as the only forage source to lactating dairy cows for a 3 month period with measurements of the following end points: individual silage intake, individual milk production and milk composition (protein, fat, lactose, urea content measured on pooled samples) as well as standard hygiene analyses (somatic cells, bacterial contamination, inhibitors) and content of Clostridium perfringens. (AU)