22 July 2008 Some sheep are fussier eaters than others

Lincoln University honours students have shown some sheep are more fussy about what they eat than others.

Students, Rowan O’Connor, Sam Williams and Sam Bryan found fussier sheep leave more stem behind and choose to eat more leaf while others in the same mob eat stem along with the leaves. 

The difference in fussiness also carries over from one diet to another. When given the choice of eating clover or ryegrass, the more fussy ones selected more clover than the less fussy ones. The fussy sheep were identified by feeding them a diet of mixed stem and leaf and measuring the composition of what they didn’t eat.

After sorting out the more fussy and less fussy lambs, one of the students went back to the flock and picked out the full brothers and sisters of these animals, tested them, and found that they also split into more fussy and less fussy.  Impressed by this, he went back for their mothers and, sure enough, more fussy lambs had more fussy mothers and vice versa.

“At this stage it is difficult to say whether the lambs had learned to be more fussy from their mothers or whether they inherited genes for fussiness,” said Dr Alastair Nicol the students’ supervisor in the Agriculture and Life Sciences Division.

“The problem of sheep with strong dietary preferences is they select out the more nutritious components of the pasture, thus changing its composition. Clover content declines, seedheads and dead material accumulate so it’s hard to maintain pasture quality. Our hope is that by identifying and using sheep with less strong preferences, good pasture composition and high pasture quality will be more sustainable,” said Dr Nicol.

A paper on this work was recently presented at the joint New Zealand and Australian Societies of Animal Production Conference in Brisbane.

Dr Alastair Nicol, Agriculture and Life Sciences Division, Lincoln University