An evaluation of cocksfoot/lupin pasture as an alternative forage for summer-dry environments

Abstract

The aim of this study was to evaluate the animal and herbage productivity of a perennial lupin/cocksfoot pasture mix when compared with a lucerne pure sward positive control in a summer dry environment, at Lincoln University, Canterbury. The lupin/cocksfoot and lucerne pastures were sown on the 5th of December 2013. Only outcomes from the third growth season (1 July 2015 - 30 June 2016) of the trial are discussed within the current study. The pastures were rotationally grazed by mixed breed ewe hoggets in the early spring-summer (3 September - 11 March) and then swapped out for Coopworth stud ewe lambs in the autumn of 2016 (17 March - 20 May). The lupin/cocksfoot mix produced 50% as much sheep liveweight as the 1347 kg/ha from lucerne annually. This was due to fewer grazing days, a lower stocking rate and weak evidence of lower average annual daily liveweight gain. Lupin/cocksfoot relative to lucerne, grazing days were 75% of 5101 days, a stocking rate of 74% of the 20.2 head /ha, and 66% of the 264g of average annual daily liveweight gain that the lucerne provided. The cocksfoot/lupin total annual herbage yield was far lower, the mix provided only 34% of the 10,400 kg DM/ha that the lucerne produced. The lupin/cocksfoot had a lower annual average daily herbage dry matter allowance and daily apparent intake. The mix allowed 80% of the 2.5kg dry matter produced by the lucerne pasture per head per day. Of the dry matter produced, the sheep on the mix only grazed 69% of the 1.6kg dry matter that appeared to be grazed by the lucerne pasture per head per day. The higher proportion of pasture legume in the lucerne pasture gave overall higher pasture quality. Crude protein levels were on average 0.56 lower in the lupin/cocksfoot herbage mix than the 24% crude protein from the lucerne. The energy content of the pasture was very similar with both pastures having a metabolisable energy content around 10.6 MJ ME/kg DM. The pre-grazing pasture legume fraction in the lucerne was consistently 90%, while the lupin/cocksfoot mix had only around 10-12%. The proportion of pasture legume in the mix is the main point of interest and was a driver for both animal liveweight production and herbage production values. This study has shown that when put under a lucerne type grazing regime, perennial lupin in a pasture mix with cocksfoot produces similar outcomes to that of other cocksfoot clover mixtures.