• Factors influencing the conservation characteristics of baled and precision-chop grass silages

      McEniry, Joseph; Forristal, P.D.; O'Kiely, Padraig (Teagasc (Agriculture and Food Development Authority), Ireland, 2011)
      The composition of baled silage on Irish farms frequently differs from that of comparable precision-chop silage. This paper concerns a field-scale study designed to investigate: (a) the effects of number of layers (2, 4, 6 or 8) of polyethylene stretch film and the duration of storage (7 vs. 18 months) on the conservation characteristics of baled silage, and (b) the conservation characteristics of baled (4 layers of stretch film) and precision-chop silages. All silages were made following three durations of wilting (0, 24 or 48 h). Wilting restricted silage fermentation, with silage pH being highest (P<0.001) and the concentration of fermentation products lowest (P<0.001) for the 48 h wilt treatment. Wrapping bales in only 2 layers of polyethylene stretch film resulted in extensive visible mould growth, but mould growth was practically eliminated by the application of 4 or more layers of film. Silage fermentation characteristics were generally improved by wilting, and by 4 compared to 2 layers of stretch film. Extending the storage duration of baled silage from 7 to 18 months reduced (P<0.001) the concentration of fermentation products and increased in-silo fresh weight losses (P<0.001) and visible mould growth. Whereas 4 layers of conventional stretch film are normally sufficient, 6 layers may be necessary to prevent mould growth when bales of unwilted silage are stored for a second season. Under good farm-management conditions differences observed between baled and precision-chop silages probably result mainly from differences in the concentration of dry matter in herbage at ensiling.
    • Manipulating the ensilage of wilted, unchopped grass through the use of additive treatments

      McEniry, Joseph; O'Kiely, Padraig; Clipson, Nicholas J.W.; Forristal, P.D.; Doyle, Evelyn M.; Teagasc Walsh Fellowship Programme (Teagasc, Oak Park, Carlow, Ireland, 2007)
      Baled silage composition frequently differs from that of comparable conventional precision-chop silage. The lower final concentration of fermentation products in baled silage makes it more conducive to the activities of undesirable microorganisms. Silage additives can be used to encourage beneficial microbial activity and/or inhibit detrimental microbial activity. The experiment was organised in a 2 (chop treatments) × 6 (additive treatments) × 2 (stages of ensilage) factorial arrangement of treatments (n = 3 silos/treatment) to suggest additive treatments for use in baled silage production that would help create conditions more inhibitory to the activities of undesirable microorganisms and realise an outcome comparable to precision-chop silage. Chopping the herbage prior to ensiling, in the absence of an additive treatment, improved the silage fermentation. In the unchopped herbage, where the fermentation was poorer, the lactic acid bacterial inoculant resulted in an immediate increase (P < 0.001) in lactic acid concentration and a faster decline (P < 0.001) in pH with a subsequent reduction in butyric acid (P < 0.001) and ammonia-N (P < 0.01) concentrations. When sucrose was added in addition to the lactic acid bacterial inoculant, the combined treatment had a more pronounced effect on pH, butyric acid and ammonia-N values at the end of ensilage. The formic acid based additive and the antimicrobial mixture restricted the activities of undesirable microorganisms resulting in reduced concentrations of butyric acid (P < 0.001) and ammonia-N (P < 0.01). These additives offer a potential to create conditions in baled silage more inhibitory to the activities of undesirable microorganisms.
    • The microbiological and chemical composition of baled and precision-chop silages on a sample of farms in County Meath

      McEniry, Joseph; O'Kiely, Padraig; Clipson, Nicholas J.W.; Forristal, P.D.; Doyle, Evelyn M.; Teagasc Walsh Fellowship Programme; (Teagasc, Oak Park, Carlow, Ireland, 2006)
      Baled and precision-chop silages were examined on a sample of farms in the Irish midlands to determine microbiological and chemical composition at feedout. Silage making practices and chemical composition were similar to those in national surveys. Wilting was an integral part of baled silage production and was reflected in a more restricted fermentation (higher pH and water-soluble carbohydrates, with lower fermentation acids and buffering capacity) compared to precision-chop silage. Yeast numbers were higher in baled silage, suggesting a more aerobic environment within the bale. Although the fermentation appeared similar in the outer and inner horizons of baled silage, yeast, lactic acid bacteria and Enterobacteria numbers were higher in the outer horizon suggesting less exacting anaerobiosis adjacent to the surface of the bale.
    • Technologies for restricting mould growth on baled silage

      O'Kiely, Padraig; Forristal, Dermot; O'Brien, Martin; McEniry, Joseph; Laffin, Christopher; Fuller, Hubert T.; Egan, Damian; Doohan, Fiona; Doyle, Evelyn M.; Clipson, Nicholas J.W.; et al. (Teagasc, 01/12/2007)
      Silage is made on approximately 86% of Irish farms, and 85% of these make some baled silage. Baled silage is particularly important as the primary silage making, storage and feeding system on many beef and smaller sized farms, but is also employed as a secondary system (often associated with facilitating grazing management during mid-summer) on many dairy and larger sized farms (O’Kiely et al., 2002). Previous surveys on farms indicated that the extent of visible fungal growth on baled silage was sometimes quite large, and could be a cause for concern. Whereas some improvements could come from applying existing knowledge and technologies, the circumstances surrounding the making and storage of baled silage suggested that environmental conditions within the bale differed from those in conventional silos, and that further knowledge was required in order to arrive at a secure set of recommendations for baled silage systems. This report deals with the final in a series (O’Kiely et al., 1999; O’Kiely et al., 2002) of three consecutive research projects investigating numerous aspect of the science and technology of baled silage. The success of each depended on extensive, integrated collaboration between the Teagasc research centres at Grange and Oak Park, and with University College Dublin. As the series progressed the multidisciplinary team needed to underpin the programme expanded, and this greatly improved the amount and detail of the research undertaken. The major objective of the project recorded in this report was to develop technologies to improve the “hygienic value” of baled silage.