Abstract

In New Zealand, growth rates of dairy heifers can be restricted during late summer/early autumn due to inadequate pasture production and quality, which may delay puberty and compromise lactational performance, and, ultimately reduce their longevity in the herd and overall farm profits. The aim of this experiment was to determine the effect of feeding leafy turnip as an alternative summer forage to ryegrass-based pasture on the growth rate of heifers. Forty-five heifer calves aged six months were assigned to one of two treatment groups: (1) ryegrass-based pasture and (2) leafy turnip and were fed a combination of these feeds during summer/early autumn. Calves fed a greater proportion of leafy turnip were heavier (235.6 ± 3.8kg, P<0.05) and had greater average daily gain (0.74 ± 0.01 kg/day, P<0.05) than calves fed a greater proportion of pasture (218 ± 3.9 kg and 0.59 ± 0.01 kg/day), primarily due to pasture supply being restricted during the latter part of the experiment. The greater liveweight advantage from feeding leafy turnip remained for two months. Leafy turnip could be considered as an option to maintain growth rates of dairy heifers when pasture supply is restricted.

Fan, YC, GS Purchas, RE Hickson, and PJ Back

New Zealand Journal of Animal Science and Production, Volume 79, Palmerston North, 108-111, 2019