Grass dry-matter content has a big impact on performance

With the recent rainfall, grass growth at UCD Lyons Farm has improved dramatically, with growth rates ranging from 63 to 92kgDM/ ha/day.

Rainfall in June was 33pc ahead of average, and this is going some way to alleviating the soil moisture deficits which built up in April and May.

With this rainfall we will continue to be vigilant for an increase in intestinal parasites in the lambs. The wet conditions will support the development of larvae in the faeces and their migration on to grass plants, increasing the challenge faced by the lambs.

Our Redstart crop has benefited greatly from the rainfall, and triplet-reared lambs were turned out to this crop three weeks ago.

This grazing area is split in four divisions and will be rotationally grazed for the rest of the year. We will be hoping to get four grazings off the crop in total.

Lambs are going to the factory; the dry conditions earlier in the year, while challenging from a grass production point of view, were very beneficial for animal performance.

Kill-out percentages are approaching 50pc for these early-slaughtered lambs.

Work conducted by Frank Campion as part of his PhD at Lyons a few years ago showed just how much feed intake, and subsequently animal performance, can be influenced by grass drymatter content.

While Frank’s work was conducted with spring grass, there was a 33pc lower daily dry-matter intake between the ‘wettest’ and ‘driest’ grass.

It is easy to see how long periods of consuming high dry-matter grass will drive improved lamb performance, especially when it is coupled with lambs being dry and constantly subject to wet weather conditions.

Culling

Ewes will be checked this week for udder faults, and any animals displaying such signs will be earmarked for culling.

We will also check mouths for any signs of defects such as broken mouth or molar abscess etc. As the flock is relatively young, following our restructuring a few years ago, we are not having to cull many animals due to lost teeth/broken mouth yet.

The focus of the new flock is to compare different prolific breed types across a range of metrics. As we are less than half-way through he project at this stage, it is too early to be drawing any conclusions.

While stocking rate is not the focus of our study, there is plenty of research data to show how stocking rate can influence performance and profitability of sheep production systems.

When we talk about stocking rate, we talk in ewes per hectare. While a hectare is a clearly defined unit of area, is a ewe so clearly defined?

What size is this ewe? Is she 65kg or 95kg? It’s easy to see how a 95kg ewe will have a much higher feed demand than a 65kg ewe.

How many lambs do they produce? One lamb per ewe or two lambs per ewe? On the surface of it you would expect that two lambs will require more feed to finish than one lamb, but data from Dr Philip Creighton and Dr Elizabeth Earle in Teagasc show that the quantity of feed required to produce a kilogram of carcass is lower at higher litter size.

How quickly do the lambs finish? Do they take 180 days or 240 days? The longer lambs are on the farm, the more feed they will consume!

So the issue of stocking rate is much more complex than the number of mouths in the field.

We will be aiming to add new information to this discussion with the findings from Jonathan Higgins’ PhD, and early indications show that the breed of ewe you use can influence the efficiency with which feed is converted into meat.