The quality of silage from crops fertilized with

The influence of adding clostridial spores to silage was studied in 2 successive years. Direct

The influence of adding small aggregates (5 g) of farmyard manure (FYM) and/or a bacteria suspension (BS), containing Escherichia coli, and spores of Bacillus cereus and Clostridium tyrobutyricum, to silage was studied in two successive years. Direct cut (approximately 200 g DM kg−1), precision‐chopped grass herbage was ensiled in 1·6 l experimental silos. At ensiling the BS was either well distributed in the crop or added directly to 5 g of grass or FYM, which was placed in the centre of the green material when the silos were filled. Silage was further treated with formic acid (4 kg t−1 FM), or an inoculant of lactic acid bacteria (106 cfu g−1 FM), and compared with no additive. Only minor influences on silage quality resulted from the addition of BS, although the number of clostridial spores increased slightly. Silages given additions of small aggregates of FYM were of poor quality. The inferior silage with a high number of clostridial spores (⩾3·9 cfu g−1) and a high concentration of butyric acid (⩾2·8 g kg−1) was found in the immediate vicinity of the addition. Application of silage additives did not improve silage quality. The poor quality of ‘FYM‐silages’ could not solely be explained by the high number of organisms, but other factors in the manure and/or crops may contribute to the poor silage fermentation. © 1997 SCI.

: The inÑuence of cattle slurry applied to a silage crop was studied in three successive years. Each year, 40 t slurry ha~1 were applied in two equal applications. Unfertilised and mineral-fertilised Ðeld plots were used as controls. Before spreading, the slurry was contaminated with spores of Clostridium tyrobutyricum (103È104 g~1 FM). The Ðelds were harvested two times a year, the yields were measured and the chemical composition and bacterial content of the crop were determined. The fresh material was chopped, ensiled without additives, and stored for 100 days before opening. The bacterial content of the soil surface and available N, P and K in soil were measured. Slurry did not seem to have any signiÐcance in a short-term perspective. Yield increase as an e †ect of slurry application was slight and inconsistent in comparison with the yield from unfertilised plots. The number of Clostridium or Bacillus spores in the soil surface was not signiÐcantly a †ected by the slurry application, nor was the number of deterimental organisms in harvested crop at ensiling. Nonetheless, in three of the four silages in which clostridial spores were estimated, numbers were higher in silage made from slurry-treated crops.

No abstract