Intake and feeding behaviour of dairy cows grazing kale and grass at low and high allowances during winter

Abstract

Intake and foraging behaviour of dairy cows grazing kale offered at 11 (K-11) or 14 (K-14) kg DM/cow/day, and grass offered at 11 (G-11) kg DM/cow/day were measured during week 2 and 5 of a 7-week winter feeding period. The % dry matter (DM) utilisation of K-11 (96%) and K-14 (88%) were higher than G11 (70%). Apparent DM intake (kg DM/day) was higher for K-14 (12.3) than K-11 (10.6). Apparent DM intake of G-11 was low (7.8 kg DM/day) due to the lower % DM utilisation. Grazing behaviour was altered by both forage type and allowance. Within 6 hours of being offered a fresh break, cows had consumed over 86% of their apparent daily intake with DM consumptions of 10.4, 10.5 and 7.3 kg DM/cow for the K-11, K-14 and G-11 treatments, respectively. Cows on the K-14 treatment grazed for longer over the day and consumed a further 1.6 kg DM. Based on these results, monitoring kale grazing residuals mid afternoon following a morning allocation of forage, and modifying break widths may be a useful management tool to manage intake and diet quality of cows with different nutritional requirements.