Effect of feeding mechanically processed alfalfa silage on production performance of mid-lactation dairy cows

Improving the digestibility and utilization of feedstuffs through processing methods may result in improved production and efficiency of dairy cattle. Our objective was to determine the effect of an intensive mechanical processing technique applied to wilted alfalfa before ensiling on dairy cow performance when fed as part of a TMR. Thirty-six mid-lactation Holstein dairy cows (primiparous and multiparous) were fed diets of similar composition (28.5% alfalfa haylage, 31.2% corn silage and 40.3% concentrates) that differed by pre-ensiling processing technique of alfalfa silage over a 6-wk experimental period in a randomized complete block design. Treatments were alfalfa either conventionally chopped (CON) or mechanically processed (MPR). Neither BW, change in BW, BCS, nor change in BCS differed between diets. Apparent DM, NDF, ADF, and CP digestibility were greater in MPR compared with CON. The DMI was lesser in MPR compared with CON during wk 5. Furthermore, forage NDF intake was lesser in MPR compared with CON during wk 5. Milk yield did not differ between MPR and CON, but milk fat yield and content were higher in MPR compared with CON. Consequently, 4% FCM and ECM were 1.5 kg/d greater in MPR compared with CON. Gross feed efficiency (ECM/DMI) was greater in MPR compared with CON during wk 5 and 6. Our results suggest that feeding a mechanically processed alfalfa silage enhanced fiber digestibility and subsequently improved dairy cattle gross feed efficiency in mid-lactation dairy cattle by the end of the experimental period. Further research is needed to elucidate physiological responses and practicality of implementing this processing method in a typical production setting.