Outlook For Long Bone Deformity

It is likely that cases of Long Bone Deformity in calves next spring will be more common. While we still don’t know the exact cause of this deformity it does appear to be associated with –

• High quality grass silage taken from a flush of grass growth. For many this is what occurred this spring with the very early drought being followed by a rapid flush of grass.
• That the danger period is the fourth month of pregnancy. With the wet weather forcing spring calving cows to be fed silage earlier than normal more cows will be at the critical four month stage of pregnancy when silage feeding starts.

Recommendations

1. Avoid feeding more the 75% of the cows’ daily dry matter intake from silage. Bulk out rations with straw and other low quality forages.
2. Feed a mineral containing higher levels of manganese. The target would be a mineral containing 7,000 ppm of manganese, fed at 150 g per cow per day.

Basil Lowman, val.angus@sac.co.uk