The recent Teagasc Beef Conference was held online over three evenings, in a one-hour webinar style event.

The first evening concentrated on the winter period for weanlings. Getting the growth rate correct in this period has been identified as a particular issue on many beef farms. The diet over the winter period will have a massive effect on the overall performance of the animal. As outlined by Dr Mark McGee of Teagasc Grange, optimising the first winter growth rate can only be done if the feed value of the silage being fed is known.

It is therefore a worthy exercise for farmers to get silage tested, even at this stage of the winter period.

Mark outlined that where silage quality is not known, it is likely that animals will either be under-supplemented with concentrates and growth rates will be sub-optimal, or in some instances, cattle may be over-supplemented, resulting in good growth rates but at a high cost in the shed through the use of concentrates.

Compensatory growth

Mark outlined numerous studies carried out at Teagasc Grange looking at the effect of the first winter growth rate on the subsequent performance at grass. In all cases, with dairy-beef animals, suckler steers and young bulls, there was no benefit in growing in excess of 0.5kg/day – 0.6kg/day over the winter period.

Where animals grew faster than this, performance at grass was poorer the following season, while where cattle grew below this level, animals that performed well at grass the following season, the growth rate at grass was not good enough to make up for the poor winter performance.

Ration formulation

In terms of concentrate type, Mark outlined studies that looked at different energy and protein sources in weanling rations. However, the main finding from the trial was that once a ration is formulated to the same net energy and protein level on a /kg DM basis, the ingredient composition was not important.

Where there was potential issues was with the energy and protein values that are assigned to individual feed ingredients – some ingredients are overestimated while others underestimated.

Key points:

•Know the feed value of your silage and supplement with concentrates accordingly.

•Once a ration is formulated to same net energy and protein levels/kgDM, ingredient composition not important.

•Where animals are destined to return to pasture, there is no economic benefit of growing above 0.5 – 0.6kg/day over the first winter period.

In the next article, we will outline the key messages from Martina Harrington, Teagasc Beef specialist from her talk on steps to improve the performance of beef weanlings over the first winter period.