Farm Ireland

Monday 11 December 2017

Lambs profiting from the weather but grazing still a problem in parts

Dr Tommy Boland

The lift in the weather conditions in the last week was very welcome and it has allowed for a vast improvement in conditions underfoot. The lambs certainly appreciated the improvement in temperature.

However, recent reports from west of the Shannon show that much of the country is still struggling with grazing conditions. Lambs were weighed at 11 weeks of age with an average live weight of 28kg. Growth rate from birth to 11 weeks stands at 310g/day. This leaves us online to achieve the target 32kg live weight at weaning at 14 weeks of age.

We plan to wean this year on June 19. This will represent a flurry of activity with the sheep flock as Sheep Ireland will be present to collect data as part of the Central Progeny Test scheme. The repeats will be weaned approximately two weeks later. At weaning we will body condition score all ewes and begin to think about the upcoming breeding season.

As part of our research activities all sheep pass through the handling unit every fortnight and are footbathed on each occasion. We have only three or four persistently lame ewes in the flock at this stage and we will cull these at weaning time. Currently formalin is used in the footbath, but this does rotate frequently.

We are tracking the performance of all lambs from our pre-lambing experiments. The progeny of ewes which were underfed during late pregnancy (20pc below requirements) are currently 3kg lighter than their well-fed counterparts. This is despite the fact that there were negligible differences in birth weight and all ewes have been treated the same since lambing. Again, this highlights the importance of correct pregnancy feeding.

Grass supply is reasonably strong at the moment, and we have closed up 10ac of ground on the back of the hill for silage. This is the first time in recent memory silage will be harvested off this portion of the farm.

Stocking rates are well back on this part of the farm in comparison to recent years. Grass growth rate at Lyons is 62kg DM/ha in the past couple of weeks, though this is well back on what you would expect for this time of year.

The ewes and lambs are turned into paddocks where pasture height is no greater than 8cm. These ewes are then removed at a post-grazing sward height of 5cm. A flock of dry ewes are then used to bring this post-grazing sward height down to about 4.25cm.

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As the year progresses this post-grazing sward height figure will increase to prevent animals having to graze the least digestible material at the base of the sward.

The main first cut silage was harvested on May 25 so there will be good after-grass available for lambs post-weaning.

Lambs received cobalt boluses last week.

This is our second year using these cobalt boluses as we were happy with the response we got last year. We blood-sampled lambs frequently last year after bolus administration for Vitamin B12 levels (the vitamin produced in response to cobalt supply) and were happy with the levels we were seeing into October.

We will do the same again this year. Lambs were dosed on 1 May with a benzimidazole drench, based on the results of faecal egg count, but at the time of writing signs of scouring are still evident.

We have taken further samples for a faecal egg count though it is evident another drench is needed.

Dr Tommy Boland; is a lecturer in Sheep Production, Lyons Research Farm, UCD.

Irish Independent