Effect of Corn Shredlage on lactation performance and total tract starch digestibility by dairy cows

The objective of this trial was to determine the effect of feeding a TMR containing Corn Shredlage (SHRD; Shredlage LLC, Tea, SD) or conventionally processed corn silage (KPCS) on lactation performance by dairy cows. The KPCS was harvested using conventional rolls (3-mm gap) and set at a 19-mm theoretical length of cut. The SHRD was harvested using novel cross-grooved rolls (2.5-mm gap) and set at a 30-mm length of cut. One hundred twelve cows stratified by DIM, milk yield, breed, and parity were randomly assigned to 14 pens with 8 cows. Pens were randomly assigned to 2 treatment TMR in a completely randomized design. A 2-wk covariate period with cows fed a 50:50 mixture of treatment diets was followed by an 8-wk treatment period with cows fed their assigned treatment diet. The TMR contained (DM basis) KPCS or SHRD (50%), alfalfa silage (10%), and concentrate mixture (40%). Data were analyzed using Proc Mixed in SAS with covariate, treatment, week, and the treatment × week interaction as fixed effects and pen within treatment as a random effect. Cows fed SHRD tended to consume 0.7 kg/d more DM. Milk yield and composition were similar between treatments. The 3.5% FCM yield tended to be 1.0 kg/d greater for cows fed SHRD. A treatment × week interaction was detected for 3.5% FCM yield; as during wk 2, a tendency was observed for SHRD to be greater during wk 4 and 6 and greater for SHRD at wk 8. Ruminal in situ digestibility of starch was greater for SHRD than for KPCS. Feeding SHRD tended to increase DMI and 3.5% FCM yield.