John Large: Why sowing some multi-species swards this year might be worth a go

Multi species sward

John Large

July 07 2022 08:56 AM

The big job of weighing and weaning the March-born lambs is complete. Our average weaning weight was 33kg, with a big variation from a few lambs over 50kg down to small ones of 15kg. This is what happens when you weigh all the lambs, but to get the correct result you must weigh them all, no point in just weighing top performers.

Our average daily gain since last weighing was 260g per day, which is a bit disappointing, but with grass tight and quality not good, we expected gain to be back. By being ahead at the 40-day weight we still hit our target at weaning of over 32kg. When we had the lambs in the weighing scales, we also checked for dag score with 70pc of the lambs clean and 30pc showing some signs of being dirty.

On the same day all the ewes were weighed. Our average was 75kg with a body condition score of just three. They were checked for signs of mastitis, with 4.2pc showing a positive result.

We sold any lambs that were over 42kg live weight with a good covering of fat. They did well, almost 20kg, and the price was good for this time of year. But there is a lot of them to be sold yet and it will be later in the year before we see where our average price will rest.

The weaned lambs are on after-grass which has grown OK for the last few weeks. We will divide the lambs into three groups. The best will get a small amount of meal, 250g/day, for three weeks before being sold. The next group will just get grass, as will the ewe-lambs we are keeping for replacements.

Looking forward, the question is what should we be growing to finish these lambs both from a environmental point and also providing a financial return for the farmer.

Multi-species seems to be the buzzword at the moment. What are multi-species swards? They are swards which have a variety of plants from various families of plants including grasses, clovers, brassicas and herbs. When combined in a sward, the various species root at varying depths, allowing them to access more nutrients and moisture from the soil.

The advantages of multi-species swards are to maintain a steady growth rate at reduced fertiliser application. A well-managed clover content in the sward (20pc to 25pc) can allow you to cut chemical fertiliser application by more than half in summer at a time when it is critical for green house grass emissions.

The multi species have the ability to our perform monoculture perennial swards by around two tonne of dry matter per HA. But there are a lot of unanswered questions, most of the trials have been done by cutting trial plots, but how will these mixtures perform in a grazing situation? Will they suit a 21-day rotation, will they be taken over by other weed species, will they last in the mixture or will they all disappear in a few years?

The persistency of multi-grass swards in a grazing situation is the area we know least about at this stage, but even if the chicory and plantain were to die out after a few years and you are left with a field of perennial rye grass with good levels of clover, then that may not be such a bad outcome.

The ability of these mixtures to grow large quantities of herbage with little or no chemical nitrogen cannot be ignored and yes, there are still some questions to be answered. Sometimes the best way to find out these answers is to find out for yourself.

If you are re-seeding a paddock this year, perhaps sowing a few acres of multi-species mixture might be worth a go.

I know we will try some.

John Large farms at Gortnahoe, Co Tipperary