• Beef production from feedstuffs conserved using new technologies to reduce negative environmental impacts

      O'Kiely, Padraig; Crosson, Paul; Hamilton, William J.; Little, Enda; Stacey, Pamela; Walsh, Karl; Black, Alistair D; Crowley, James C.; Drennan, Michael J; Forristal, Dermot; et al. (Teagasc, 2007-12-01)
      Most (ca. 86%) Irish farms make some silage. Besides directly providing feed for livestock, the provision of grass silage within integrated grassland systems makes an important positive contribution to effective grazing management and improved forage utilisation by grazing animals, and to effective feed budgeting by farmers. It can also contribute to maintaining the content of desirable species in pastures, and to livestock not succumbing to parasites at sensitive times of the year. Furthermore, the optimal recycling of nutrients collected from housed livestock can often be best achieved by spreading the manures on the land used for producing the conserved feed. On most Irish farms, grass silage will remain the main conserved forage for feeding to livestock during winter for the foreseeable future. However, on some farms high yields of whole-crop (i.e. grain + straw) cereals such as wheat, barley and triticale, and of forage maize, will be an alternative option provided that losses during harvesting, storage and feedout are minimised and that input costs are restrained. These alternative forages have the potential to reliably support high levels of animal performance while avoiding the production of effluent. Their production and use however will need to advantageously integrate into ruminant production systems. A range of technologies can be employed for crop production and conservation, and for beef production, and the optimal options need to be identified. Beef cattle being finished indoors are offered concentrate feedstuffs at rates that range from modest inputs through to ad libitum access. Such concentrates frequently contain high levels of cereals such as barley or wheat. These cereals are generally between 14% to 18% moisture content and tend to be rolled shortly before being included in coarse rations or are more finely processed prior to pelleting. Farmers thinking of using ‘high-moisture grain’ techniques for preserving and processing cereal grains destined for feeding to beef cattle need to know how the yield, conservation efficiency and feeding value of such grains compares with grains conserved using more conventional techniques. European Union policy strongly encourages a sustainable and multifunctional agriculture. Therefore, in addition to providing European consumers with quality food produced within approved systems, agriculture must also contribute positively to the conservation of natural resources and the upkeep of the rural landscape. Plastics are widely used in agriculture and their post-use fate on farms must not harm the environment - they must be managed to support the enduring sustainability of farming systems. There is an absence of information on the efficacy of some new options for covering and sealing silage with plastic sheeting and tyres, and an absence of an inventory of the use, re-use and post-use fate of plastic film on farms. Irish cattle farmers operate a large number of beef production systems, half of which use dairy bred calves. In the current, continuously changing production and market conditions, new beef systems must be considered. A computer package is required that will allow the rapid, repeatable simulation and assessment of alternate beef production systems using appropriate, standardised procedures. There is thus a need to construct, evaluate and utilise computer models of components of beef production systems and to develop mathematical relationships to link system components into a network that would support their integration into an optimal system model. This will provide a framework to integrate physical and financial on-farm conditions with models for estimating feed supply and animal growth patterns. Cash flow and profit/loss results will be developed. This will help identify optimal systems, indicate the cause of failure of imperfect systems and identify areas where applied research data are currently lacking, or more basic research is required.
    • Changes in yield and composition of barley, wheat and triticale grains harvested during advancing stages of ripening

      Stacey, Pamela; O'Kiely, Padraig; Hackett, Richard; Rice, B.; O'Mara, Frank P.; Teagasc Walsh Fellowship Programme (Teagasc, Oak Park, Carlow, Ireland, 2006)
      This study involved an evaluation of the changes in grain yield, nutritive value, ensilability and harvesting losses of intensively managed winter cereals harvested during the advancing stages of ripening. Five cereal crops (barley cv. Regina and wheat cv. Madrigal in 2001; barley cv. Regina, wheat cv. Falstaff and triticale cv. Fidelio in 2002) were assessed. Twenty plots per crop were arranged in a randomised complete block design, with five times of harvest (four for barley in 2002) and four replicate blocks per harvest. Dry matter (DM) yields changed relatively little between harvest dates, but fresh yields declined (P < 0.001) over time due to the moisture loss associated with ripening. Time-course changes in indices of nutritive value, such as concentrations of crude protein, starch and ash, and organic matter digestibility, were relatively small and did not follow a consistent pattern. Ensilability indices, such as DM and watersoluble carbohydrate concentrations and buffering capacity, indicated that satisfactory fermentations were likely if such crops were ensiled; buffering capacity, generally declining with advancing maturity. Harvesting losses were not clearly related to growth stage at harvest. It is concluded that winter cereal grain (barley, wheat and triticale) DM yields and quality were relatively constant as ripening progressed from DM concentrations of around 550 to >800 g/kg.
    • Conservation characteristics of baled grass silages differing in duration of wilting, bale density and number of layers of plastic stretch-film

      Keles, G.; O'Kiely, Padraig; Lenehan, J.J.; Forristal, P.D. (Teagasc, Oak Park, Carlow, Ireland, 2009)
      The effects of duration of wilting, bale density and number of layers of plastic stretchfilm used to wrap bales on the conservation characteristics of baled grass silage was investigated. Grass from the primary growth of a Lolium perenne dominant sward was wilted for 24, 48 or 72 h. For each duration of wilting, 54 cylindrical bales (1.2 m nominal diameter) were made with the baler at a high or low density setting for alternate bales. Bales were wrapped with 2, 4 or 6 layers of plastic stretch-film and stored outdoors for 295 days. Two layers of plastic stretch-film resulted in inferior preservation, lower digestibility and extensive mould growth and deteriorated silage. Substantial improvement occurred to each of these characteristics from applying four layers of stretch-film (P<0.05), while six layers of stretch-film brought little further improvement. When four or six layers of stretch-film were used, extensive wilting restricted fermentation and improved the standard of preservation with the apparently difficult-to-preserve herbage used in this experiment. However, under the anaerobic conditions provided by four or six layers of stretch-film neither progressive wilting nor bale density had a major effect on digestibility, or the extent of surface mould growth or deteriorated silage. It can be concluded that a minimum of four layers of conventional black plastic stretch-film were required to achieve suitably anaerobic conditions, and that the additional benefits from six layers were small. Once anaerobic conditions were achieved, extensive wilting improved the conservation characteristics of baled grass silage made from a difficult-to-preserve crop, whereas bale density had little impact.
    • 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.
    • A note on the conservation characteristics of baled grass silages ensiled with different additives.

      Keles, G.; O'Kiely, Padraig; Forristal, P.D. (Teagasc, Oak Park, Carlow, Ireland, 2010)
      The effects of contrasting conventional silage additives on chemical composition, aerobic stability and deterioration, and mould development in baled silage were investigated. Herbage from a grassland sward was wilted for 24 h and treated with acid (formic or sulphuric), sugar (molasses), bacterial (Lactobacillus plantarum, L. plantarum + Serratia rubidaea + Bacillus subtilis, or L. buchneri) or sugar + bacterial (molasses + L. plantarum) additives prior to baling and wrapping. Silage made without an additive preserved well and had a low incidence of mould growth, and the effects of additives were minor or absent. It is concluded that little practical benefit was realised when conventional additives were applied to wilted, leafy, easy-to-ensile grass prior to baling and ensilage.
    • 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.