Extreme mechanical processing of corn and alfalfa silage: Effects on lactation and methane emissions in mid-lactation cows

Authors: MONTES CASTILLO, KATHERINE - University Of Wisconsin; OLLERTZ-MERRTENS, BERND - Norwegian University Of Life Sciences; Kalscheur, Kenneth; French, Elizabeth; FERRARETTO, LUIZ - University Of Wisconsin; DIGMAN, MATTHEW - University Of Wisconsin; SHINNERS, KEVIN - University Of Wisconsin

Submitted to: American Dairy Science Association Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 3/26/2025
Publication Date: 6/22/2025
Citation: Montes Castillo, K., Ollertz-Merrtens, B., Kalscheur, K., French, E.A., Ferraretto, L.F., Digman, M.F., Shinners, K.J. 2025. Extreme mechanical processing of corn and alfalfa silage: Effects on lactation and methane emissions in mid-lactation cows. American Dairy Science Association Abstracts. 06/22/2025.

Interpretive Summary: ABSTRACT ONLY

Technical Abstract: Techniques that enhance forage fiber utilization are needed to increase the availability of nutrients in dairy cows, resulting in improved lactation performance. Extreme mechanical processing (ExMP) increases the surface area of plant cell walls potentially improving fiber utilization of forages. We assessed the effect of ExMP technique on corn and alfalfa silages separately, and in combination, on lactation performance and methane emissions of dairy cows. Sixty-four mid-lactation multiparous dairy cows (mean ± SD; 106±29 DIM) were assigned to one of four diets in a randomized complete block design with a 2-wk covariate period followed by an 8-wk experimental period. Experimental diets were arranged as a 2×2 factorial evaluating two types of corn silage (conventional corn silage and ExMP corn silage) and two types of alfalfa silage (conventional alfalfa silage and ExMP alfalfa silage). Methane emissions were measured using GreenFeed. Data were analyzed using the MIXED procedure of SAS. Dry matter intake (DMI) averaged 29.7 kg/d and was not affected by the type of corn silage nor by the type of alfalfa silage; however, there was a treatment × week interaction (P<0.001). Milk production averaged 47.9 kg/d and was not affected by treatment, however, there was a treatment × week interaction (P=0.04). No treatment effect was observed for energy-corrected milk (ECM) (51.6 kg/d; P=0.69), however there tended to be an interaction of corn silage and alfalfa silage on feed efficiency (ECM/DMI; P=0.06). An interaction of type of silage processed, corn and alfalfa, occurred for fat % (P=0.03) and total solids % (P=0.02). Milk protein % was not affected by treatment (P>0.10). In addition, treatment did not affect milk component yields (kg/d) and milk urea nitrogen. Processing did not affect BW, BCS, CH4 production, CH4 yield or CH4 intensity (P>0.10) for either silage. These results indicate that processing of corn and alfalfa silages did not increase lactation performance or methane emissions of mid-lactation dairy cows.