Storage Method Effects on Dry Matter and Quality Losses of Tall Fescue Round Bales

Outside storage with no protection from the weather contriutes to the frequent large storage losses for round-baled hay compared with small rectangular bales stored inside. We evaluated losses in dry matter (DM) yield and forage quality of round bales bound with solid or woven-mesh plastic instead of sisal twince. Round bales of tall fescue (Festuca arundinacea Schreb.) averaging 706 ± 19 lb and 18.2 ± 1.4% moisture were wrapped with two layers of plastic mesh or solid self-adhesive plastic wrap and placed on grass sod for storage. Twine-tied bales were stored on sod or indoors for comparison. Trials were conducted in 1990 and 1991, each with four replicates of each treatment. Dry matter losses and changes in crude protein (CP), neutral detergent fiber (NDF), and in vitro dry matter disappearance (IVDMD) were measured after 1 yr of storage. Weathering affected layers 0, 0.6, 2.1, and 4.4 in. deep for indoor, solid plastic, plastic mesh, and twine-tied bales stored outside, respectively. Storage DM losses of 18.2% for twine-tied bales stored outside were reduced to 10.6% by plastic mesh wrap but were lowest for solid-plastic-wrapped (3.6%) and inside-stored bales (5.7%). Weathered hay from twine and plastic mesh-wrapped bales fell approximately 20 percentage units in IVDMD during storage. Weathering and storage treatment effects on CP and NDF were small. Using solid plastic wrap or plastic mesh wrap as binding materials for bales stored outside saved DM and solid plastic wrap improved hay quality over twine-tied bales. Research QuestionStorage losses of round bales are usually greater than those of rectangular bales but routine storage of round bales outside without protection from moisture is largely responsible for the difference. Plastic mesh wrap and solid plastic wrap have been developed as binding materials to replace twine with the proposed advantage of reducing losses for round bales that are stored outside. The objective of this study was to evaluate the utility of some recent developments in round bale binding materials for reducing losses in DM yield and forage quality during hay storage. Literature SummaryLarge round bales and other larger hay packages minimize labor required for hay baling and transport. In the humid regions of the US, however, storage losses of round bales are frequently much greater than for similar hay in rectangular bales. It is clear from previous research that round bales of dry hay stored indoors lose similar amounts of DM during storage as rectangular bales, indicating that storage conditions account for most of the additional losses experienced with large round bales. Losses in forage quality may be very great for round bales stored outside with no protection from the weather. Labor for covering bales and bale tying time can be reduced by applying self-adhesive solid wrap or porous plastic wrap (net wrap) materials instead of twine during the baling process. Both materials are also hypothesized to reduce weathering losses by shedding precipitation during outside storage of round bales. Research with alfalfa and mixed hay indicates variable success of these alternative bale binding materials in reducing DM and quality loss during storage. These recent developments in bale binding materials have not been evaluated under Kentucky weather conditions and more information is needed to assess their usefulness with mature grass hay. Study DescriptionFirst-cutting hay was harvested during early June in 1990 and 1991 using a fixed chamber type round baler (M&W Gear Company, Gibson City, IL). Bales were bound with two wraps of plastic mesh (polyethylene mesh with about 0.8 in. [2 cm] spacing between strands) or solid self-adhesive plastic wrap or by using sisal twine spaced at 4-in. intervals. These bales, for outside storage, as well as twine-tied bales for indoor storage were weighed and sampled at the beginning and end of the 1-yr storage period. Applied QuestionDoes inside storage or the use of plastic mesh wrap or solid plastic wrap during outside storage result in less loss of tall fescue hay yield and quality than twice-tied bales stored outside? Indoor storage of round bales essentially eliminated weathering, although there was some discoloration of one or two layers of shoots at the surface. Solid plastic wrapped bales showed the least weathering of the outside-storage treatments, and were as good as hay stored indoors (Fig. 1). Twine-tied bales showed the most weathering and bales wrapped with plastic mesh wrap were intermediate. Storage losses ranged from 3.6 to 18.2% of the initial bale dry unless weathered hay was considered as part of the loss, which increased losses from 5.7 to 34.1% (Fig. 1). We feel that the high levels of precipitation experienced during storage and the coarse surface presented by mature grass hay contributed to the large losses measured in this study. Fig. 1Depth of the weathered layer and DM losses during storage of tall fescue round bales bound using twine, plastic mesh netting, or solid plastic wrap. The impact of weathering during hay storage on forage quality was seen mainly in IVDMD, which decreased from levels in the mid 40s to below 30% digestibility (Fig. 2). Storage treatment did not influence post-storage CP concentration. Previous research suggests that increases in CP during storage result not from any real production of protein but rather from the loss of less CP than other constituents during storage. Fiber levels tended to icnrease during storage but changes were generally small. Fig. 2In vitro dry matter disappearance of tall fescue from round bales bound using twine, plastic mesh netting, or solid plastic wrap. Assuming a value of $45/ton of hay at 14% moisture, the substitution of solid plastic wrap for twine would save $4.19/bale if the weathered hay is considered lost. Indoor storage completely prevented weathering and thus would save slightly more, $4.52/bale. Plastic mesh wrap saved $1.72/bale over time. Net savings over twine-tied bales stored outside were $3.09 for solid plastic wrap, $2.49 for inside storage and $0.59/bale for plastic mesh wrap. Based upon these data, all three storage treatments appear to be feasible substitutes for outside storage of twine-tied tall fescue round bales.