Abstract

A trial was carried out to determine whether grass cultivar or water soluble carbohydrate (WSC) concentration would influence the partial preference of sheep for clover and ryegrass. Six mixed age Coopworth ewes were housed in individual pens and once a day offered swardlet monocultures of white clover adjacent to one of three perennial ryegrass cultivars. One swardlet of each grass cultivar was shaded and the other left un-shaded in order to create differences in WSC concentration. WSC concentration did not differ among ryegrass cultivars but was lower in shaded (210 g/kg dry matter (DM)) than non-shaded (230 g/kg DM) ryegrasses. Neutral detergent fibre was significantly higher in the un-shaded (439 g/kg DM) than non-shaded (422 g/kg DM) ryegrass (P <0.01). The total number of bites from clover swardlets fed adjacent to shaded grass swardlets was 21% greater (P = 0.026) than when fed adjacent to non-shaded grass swardlets. Sheep took a significantly lower proportion of bites from clover when paired with un-shaded (44%) than shaded (55%) ryegrass (P = 0.03). There were no significant effects of ryegrass cultivar on any aspect of the preference tests. The results of this work support the hypothesis that partial preference for clover can be manipulated by altering the WSC concentration of companion ryegrass by shading but not, in this case, by ryegrass cultivar.

ARC, Allsop, AM Nicol, and GR Edwards

Proceedings of the New Zealand Society of Animal Production, Volume 69, Christchurch, 20-23, 2009