Honors students at Lincoln University in New Zealand found that some sheep are more fussy about what they eat than others.
The fussy sheep leave more stem behind and choose to eat more leaf, while the less fussy ones eat stem along with leaf. Fussy sheep select more clover than ryegrass.
When full brothers and sisters to the fussy lambs were tested, they were also found to be fussy eaters, as were the mothers of the fussy lambs. It is not known whether lambs learn to be more fussy from their mothers or whether they inherit genes for fussiness.
Sheep with less strong preferences are preferred because they will be less likely to alter the composition of a pasture.
Source: Lincoln University