Submitted to: Journal of Dairy Science
Publication Type: Abstract Only
Publication Acceptance Date: 2/25/2019
Publication Date: N/A
Technical Abstract: The production of baled silages is increasingly popular, particularly with small and mid-sized dairy and beef producers. There are several reasons this silage preservation technique is attractive to producers, but the primary advantage is a reduced risk of weather damage to valuable forage crops compared to preservation as dry hay. Most core principles for making high-quality baled silages are similar to those for precision-chopped silages; among these, maintaining anaerobiosis is a priority. However, there are some notable differences between silage types. Principal among these is the restriction of rate and extent of fermentation within baled silages, which often results in less production of desirable fermentation acids and a greater (less-acidic) final pH. For baled silages, fermentation restrictions occur in part because recommended moisture concentrations (45 to 55%) are drier, and particle-length is much longer. Preservation of baled silages is optimized by applying polyethylene (PE) film wraps promptly, using an appropriate number of film layers (6 to 8), selecting an appropriate storage site, and by close monitoring for evidence of puncture, particularly by birds or vermin. The heterogeneous nature of baled silages, coupled with a restricted rate and extent of fermentation, may increase clostridial activity relative to precision-chopped forages ensiled at comparable moisture concentrations. To date, research evaluating inoculants or other additives designed to improve the fermentation has been limited in scope. Embedding PE films with an oxygen-limiting barrier has been beneficial in some trials, but most differences between these novel plastic formulations and commercial PE films have been limited to decreased yeast and mold counts at the surface layer; whole-bale assessments of fermentation or nutritive value have been less conclusive. Recent evaluations of bale-cutting mechanisms have demonstrated modest improvements in fermentation, but bale-cutting is difficult to justify solely on that basis. Baled silages can be produced successfully by adhering to straightforward management principles, and is likely to remain popular in the well into the future.