Can fish oil benefit lamb vigour and growth?
FISH oil in ewe diets boosts lamb vigour, but depresses ewe milk fat content and lamb growth, according to a recent study conducted at Harper Adams.
But more work is being carried out to see whether fish oils beneficial effect on vigour can be retained without an adverse effect on growth, says researcher Judith Capper.
"We are looking at the effect of feeding fish oil in late pregnancy, but switching to protected fat in early lactation diets to maximise milk fat."
In her initial study, lambs from ewes fed fish oil in their diets for the final six weeks of pregnancy got to their feet within 16 minutes of birth, compared with 20 minutes for those from ewes fed protected fat.
However, lambs from ewes fed protected fat for the first four weeks of lactation grew at 0.27kg/day.
This compares with 0.24kg/day for lambs from ewes fed fish oil during this period -because they had a 3% lower milk fat content. *