|Coffey, Kenneth - University Of Arkansas|
|Chow, Edgard - Kuraray America, Inc|
Submitted to: Journal of Dairy Science
Publication Type: Abstract Only
Publication Acceptance Date: 4/22/2016
Publication Date: 7/19/2016
Citation: Coblentz, W.K., Coffey, K.P., Chow, E.A. 2016. Effects of wrapping time delays on fermentation characteristics of baled alfalfa silages. Journal of Dairy Science. ADSA/ASAS Joint Meeting, July 19-23, 2016. Salt Lake City, UT.
Technical Abstract: Baled silage is an attractive forage conservation approach for small and mid-sized dairy or beef producers, partly because it limits the risks associated with baling dry hay during wet or unstable weather conditions. Our objectives were to test the effects of delayed wrapping on silage fermentation, and the storage characteristics of baled alfalfa silages. A secondary objective was to evaluate a prototype bale wrap containing an O2-limiting barrier against an identical polyethylene wrap without the O2 barrier. Sixty-four 1.19 × 1.25-m round bales of alfalfa were made from 4 field blocks at a mean moisture concentration of 59.1 ± 4.3%, and a mean initial wet bale weight of 473 ± 26.4 kg. Large-round bales were wrapped in plastic film within 4 h of baling (d 0), or after delays of 1, 2, or 3 d, and then stored for 97 d. All bales were wrapped with 7 polyethylene layers. At wrapping, internal bale temperatures were greater for all bales with wrapping delays compared to bales wrapped on d 0 (54.9 vs. 34.9oC; P < 0.01), and increased linearly (P < 0.01) to a maximum of 63.9oC after a 3-d delay. No internal bale temperature for any treatment combination exceeded 30oC by 23 d post-baling. Concentrations of water soluble carbohydrates declined linearly with bale temperature at wrapping (Y = - 0.039 x + 6.5%; r2= 0.634); conversely, the buffering capacity of pre-ensiled forages increased linearly with bale temperature (Y = 2.98 x + 316 mEq/kg DM; r2 = 0.759). Total silage fermentation acids were greatest when bales were wrapped on d 0 compared to bales wrapped with 1, 2, or 3-d time delays (4.64 vs. 2.26%; P < 0.01), and declined with both linear (P < 0.01) and quadratic (P < 0.01) effects of time delay. Similar responses were observed for lactic acid, but without the quadratic effect of time (P = 0.18). Butyric acid also was detected, and was greatest within bales wrapped on d 0 compared to those wrapped after 1, 2, or 3 d (0.99 vs. 0.38%; P < 0.01), and a similar response (0.68 vs. 0.52%; P < 0.01) was observed for NH3-N (% of DM). Bale wrap had no effect on any silage fermentation response (P = 0.07), likely because of the conservative (7-layer) wrapping protocol. Silage fermentation characteristics deteriorated with time delays before wrapping, but responses were exacerbated when delays exceeded 1 d.