Survey of management practices of dairy cows grazing kale in Canterbury

Abstract

Many dairy cows, particularly in southern New Zealand have kale (Brassica olercaea) as a major component of their winter diet. Anecdotal evidence suggests variable results in cow body condition are achieved when kale is used as a component of the winter diet. A survey of crop yield, nutritive value and grazing management practices of kale crops was undertaken in Canterbury during winter 2007 to investigate possible causes of these variable results. Kale utilisation ranged from less than 40% to greater than 90% on kale yields that ranged from 5-17 t DM. Nutritive value of kale was generally high (12 MJ ME/kg DM) but diet ME declined as grazing residuals decreased due to the poorer quality of the lower stem. Two thirds of the herds consumed less than the targeted DM intake by more than 1 kg DM/cow/day. Inaccurate crop allocation was the likely cause of cows not achieving their targeted kale intakes.