Whole-crop maturity trials
Whole-crop maturity trials
WHOLE-CROP wheat tends to increase cow yields with stage of maturity, although the differences are not big enough to be statistically significant.
That is according to Axient consultant Diana Allen, co-ordinator of this MDC funded project.
The latest 16-week study at CEDAR compared four whole-crops, at 30% DM, 50% DM without additive, 50% DM with additive and 60% DM with 40kg/t of urea. Cows were offered whole-crop and grass silage at a 2:1 ratio, and 10kg of a 26% crude protein concentrate.
The most mature 60% DM urea treated whole-crop showed the greatest improvement in cow performance. It increased DM intakes by 2.8kg to 13.7kg and yield by 1.3kg to 29.2kg a day, compared with the 30% DM fermented whole-crop forage.
The difference in milk protein yield between the two crops was significant at 0.91kg a day and 0.99kg a day, respectively.
Ms Allen points out that the results contrast with previous work, which showed no improvement in performance, despite the higher intakes, when high DM urea-treated whole-crop was fed.
She suggests, therefore, that fermented whole-crop is the better feed, but advises aiming for 45% DM because starch content will be higher at this DM and milk yields better.
"Previous MDC trial work has shown that high DM urea-treated whole-crop wheat can be low in digestibility, especially when DM goes over 60%," says Ms Allen, who also highlights that there are potential environmental concerns when using urea. *