Physical activity and energy expenditure of dairy cows grazing canola

摘要

Forage canola. has a high nutritional value, good biomass production, and may reduce energy loss as methane. We aimed to evaluate heat production and physical activity of lactating dairy cows with access to canola pasture. Eighteen mid-lactating Jersey cows (12 multiparous and 6 primiparous) were used. Cows were blocked by parity and randomly assigned to 1 of 2 treatments: CTRL, cows fed indoors with no access to pasture; or CAN, cows fed in the bam during the day and grazing canola during the night.Physical activity and gas production were measured. CAN cows had reduced methane emission but also greater physical activity resulting in similar heat production than CRTL cows.