The effect of winter fodder beet or kale

Fodder beet (FB) and kale are commonly used to address winter feed deficits in New Zealand’s southern regions. However, the impact of feeding high rates of these crops on metabolic diseases and cow behaviour is uncertain. This study aimed to determine the animal health and wellbeing status of cows fed FB or kale at two allocations by testing blood and activity measures. In winter 2017, 328 mixed-aged, multiparous, pregnant non-lactating Friesian x Jersey cows were allocated to feeding treatments of either FB or kale, offered at two allocation rates: ‘target’ (to achieve 0.5 BCS gain) or ‘high’ (ad libitum) supplemented with pasture baleage. In each treatment, 20 cows had blood metabolites monitored, and 15 cows had an activity sensor fitted for 8 days in early July. Cows fed FB had higher plasma magnesium and lower sodium, phosphate, total protein and urea levels than cows fed kale. Allocation had no effect on blood metabolites. Cows fed FB spent less time lying down (9.4 vs. 11.1 h/d), walked more (2113 vs. 1737 steps/d) and had fewer, but longer, lying bouts than those offered kale. Results indicate differences between winter crops in blood indicators of metabolic disease and behaviour which require further investigation.