Farm Ireland

Sunday 19 November 2017

Sheep: Getting the flock ready for breeding to improve genetic gain

Getting ewes and rams ready for mating.
Getting ewes and rams ready for mating.
Tommy Boland

Tommy Boland

Grass growth on the sheep block at Lyons was running at 50kg DM per ha per day last week and is following a similar pattern to last year when we saw grass growth pushing on into October.

The site we are grazing is dry so utilisation is not proving difficult, though this is in contrast to a lot of regions of the country where rainfall is making grazing more difficult.

We will begin to close paddocks for spring grazing in the next two weeks. We will need an average farm cover for turnout in Mid-March of 820 kg DM per ha.

With moderate spring growth on this site, we are looking at a closing farm cover of approximately 580 kg DM per ha.

Yesterday saw one of the busiest days of the year at Lyons with approximately 450 ewes and ewe lambs sponged was part of the Sheep Ireland Central Progeny Test program.

This is a project we have been involved in for the last seven years and the overall aim of the program is to improve the rate of genetic gain in the national flock through the generation of breeding values and hence indices for use when farmers are purchasing rams.

Ewe Condition

Ewes are in good condition with an average BCS of 3.5. The sponges remain in place for 12 days and ewes will be mated approximately 36 to 48 hours after sponge withdrawal.

Also Read

The sponge delivers a continual dose of progestogen (a progesterone proxy) to the blood stream of the ewe and this serves to suppress heat and ovulation.

When the sponge is withdrawn the ewe ovulates. We also administer another compound (PMSG) at sponge withdrawal which helps to increase the number of eggs which are ovulated, hopefully leading to a larger litter size.

The University is also back in teaching term now and I had 50 students from 4th year B.Agr.Sc out on the farm for sheep practical classes yesterday.

It gave these students a good opportunity to see the process involved in the synchronisation program, but also made for a very busy yard.

Progeny rams are onsite for the Central Progeny Test program also as Lyons hosts the ram test centre.

This involves ram intake, quarantine, training for semen collection and then ultimately collection of semen for use in the A.I. program. This aspect is obviously co-ordinated by Sheep Ireland and bio-security is of the highest priority with these high value animals.

Lamb drafting is behind 2015

Lamb drafting continues apace, but is clearly running behind 2015.

We have about 30 pc of lambs remaining on farm at the moment, compared to about 12 pc at the same time last year. Grass supply is not an issue, but the lower grass dry matter (DM) content does appear to be reducing performance.

Work carried out by Frank Campion in Lyons would show low DM grass reduces daily DM intake and work by Brian Garry in Moorepark shows that low grass DM reduces grass digestibility, and combined these two reduce the daily energy intake of the lamb.

At the ploughing two weeks ago plenty of farmers and processors alike were commenting on the poor kill out performance of lambs off grass, which is likely linked to the above issue.

The lambs not involved in the SMARTGRASS trial are now grazing Redstart (a kale and forage rape hybrid) which was planted after a winter cereal crop.

While there was strong competition from volunteer cereal plants the Redstart has grown very well and we are hoping to finish lambs off this without supplementation and to also carry the ewes into December on this crop.

It's our first year growing it at Lyons having traditionally used forage rape, but there are plenty of positive reports from growers around the country.

Dr Tommy Boland, lecturer in sheep production, Lyons Research Farm, UCD. Twitter @Pallastb

Indo Farming