Farm Ireland

Wednesday 13 December 2017

Pinpoint lambing dates by raddling your rams

Tommy Boland

Tommy Boland

The recent good weather and high temperatures proved important on most farms and were invaluable for getting crops harvested, including silage in some cases.

Grass growth has also held up well, with 51kgDM/ha/day in the week to September 11, a bit ahead of what we would expect for this time of year. Our forage rape is also coming along well and received a bag of CAN per acre last Wednesday.

Lamb growth rate is running just under 200g/day and we had just drafted 30 lambs at 45kg liveweight at the time of writing.

Last week also coincided with the return of the agricultural science students to UCD.

This really confirmed the bad weather we have had this summer in two ways.

Firstly, we were fighting with the rain to get onto the hill to look at the sheep and, secondly, there are about twice as many lambs still to be sold as there usually would be when the students come back to Lyons.

Ewes are currently being flushed for mating in mid-October and are progressing as we would like.


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The good grass growth is ensuring a good grass supply for the ewes despite there being higher lamb numbers on the farm. Again this year we will be mating all the ewes, following synchronisation, using laproscopic AI.

We use a 12-day sponging procedure, with pregnant mare serum gonadotrophin (PMSG) administered on sponge withdrawal and mating occurring 36 hours later.

Great care needs to be taken by anybody using this system, that the PMSG is administered accurately, as an overdose can greatly increase the birth of large multiples. The ewes will then get two repeat services with the ram.

This ram will be raddled (with different colours for each service) to not only record which ewes repeat, but also to indicate the time of lambing.

I think this simple and cheap technique is incredibly useful and even more so in flocks which are not synchronised.

Frequently changing the colour of the raddle from light to dark, will allow farmers to estimate lambing date with a good degree of accuracy and, most importantly, plan the concentrate feeding programme accordingly.

This will lead to cost savings during the expensive pre-lambing feeding period. There are many options available for raddling rams, including harnesses and crayons.

What we have used at Lyons and on my home farm, are raddle powders mixed with oil and rubbed on the chest of the ram.

This is cheap and simple and works very well. Care should be taken when using harnesses.

The harness must be correctly fitted so as not to cause discomfort, irritation or restrict the mobility of the ram.

Practically all of our indoor fed lambs have been slaughtered at this stage, with just 5pc remaining. These will go to the factory in the next week.

These lambs have eaten on average 110kg of concentrates to slaughter, so there is a significant cost associated with the system.

On the other side of the equation there is no requirement for parasite control or cobalt dosing (contained in the concentrate) with these lambs and there has been a complete absence of lameness.

The animals were housed on timber slats. There are two main health concerns with this system, urinary calculi and acidosis.

We did not have an incidence of either this year. Both can largely be avoided through correct dietary formulation and correct feeding management.

Salt levels, magnesium levels and ammonium chloride all have a role to play in preventing urinary calculi, while ensuring a constant concentrate supply, gradual acclimatisation to the diet and the inclusion of slowly fermentable carbohydrates will all help to minimise the risk of acidosis.

Having spoken to some farmers with prolific flocks, they have followed similar systems this year, with their triplet lambs.

One lamb from each set of triplets was removed from the ewe at 24 hours of age, artificially reared to six weeks and fed on all concentrates until slaughter. Straw bedding would also be used in many instances and lambs frequently consume a portion of the bedding offered.

Dr Tommy Boland is a lecturer in sheep production and ruminant nutrition at UCD's research farm at Lyons, Newcastle, Co Dublin

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