Keeping lamb thrive post weaning is a challenge
Type Media Article
By Michael Conroy, Beef & Sheep Adviser, Roscommon Town
The recipe for good lamb thrive after weaning is plenty of leafy grass. What have we got on a lot of farms at present is stemming pastures that got out of control in early June due to the exceptional growth and dare I say the word drought situation at present. Forcing lambs to eat stemmy pastures will stall lamb growth. Wean lambs at 12-14 weeks. There is no benefit from keeping lambs on ewes longer and have ewes competing with them for any leafy grass on the farm. Fields that are a bit strong lightly graze with lambs as these will pick the leafiest grass and clean out the fields with the ewes and top anything left down to 5 cms (2 inches). After grass would be ideal and would maintain growth rates of 1.6 to 1.9 kgs per week so lambs should be grazed on any after grass. Apply 25 units of Nitrogen per acre to topped fields and after grass to promote leafy growth but not in present conditions as it is too dry. You will have to wait until we get some rain.
A plentiful supply of clean water is vital for lambs to thrive and it must be easily accessible and also have shaded areas to reduce heat stress.
Cobalt is not directly required by lambs. It is needed by the rumen microbes to produce vitamin B12. B12 deficiency will result in loss of condition and the wool will dry out. Lambs cannot store cobalt in the body so they need a constant supply.
- Drench lambs at 2 week intervals with cobalt. Longer intervals give poor response.
- Treat lambs with boluses where the release of cobalt varies depending on the product used and the results can be variable.
The main parasites at this time of year are roundworms, coccidiosis and to a lesser degree liver fluke due to the dry weather. Doing a faecal count on lambs will determine the level of infection present and is there a requirement to dose and what you need to dose for. Dirty lambs don’t always mean worms are a problem and you may have a problem even with clean lambs. There are 3 classes of wormer readily available to treat lambs for roundworm, white, yellow and clear wormer. Results from the previous STAP Scheme show that there is a very high worm resistance to white wormers, high resistance to yellow wormer and some resistance to clear wormer on farms. What this means is some wormers will not kill the roundworms present on particular farms. The results vary from farm to farm. You can do a faecal egg count reduction test to see if the wormer is working on your farm. This entails marking 15 lambs and do faecal sample, dose the lambs and depending on the product used do faecal sample on the same 15 lambs 7 – 14 days later and you should get the reduction in the egg count. This will determine if you have resistance or not on your farm and the level of resistance. For effective dosing
- Dose to the heaviest lamb. Split lambs if there is a big variation in weights.
- Make sure the dosing gun is giving the correct amount of dose.
- Make sure the product you are using is killing the worms present on your farm.
Creep feeding should be a benefit to good grassland management not a substitute for poor grassland management. Feeding up to 300g/lamb daily will ;
- Increase lamb performance.
- Reduce age at slaughter by 28 days so having more grass for ewes.
- Give higher kill out % and slightly better carcase information.
The conversion rate is 7 kg of concentrates to 1 Kg of liveweight and this is approximately 0.45 kgs carcase. The profitability is dependent on lamb price and the cost of concentrates but other factors such as getting lambs away quicker and have more grass for ewes has to be taken into consideration.