Grass tetany: Grass tetany was touched on last week but there have been numerous reports of ewes succumbing to grass tetany since.
The forecast over the next week is variable with high rainfall for all areas on Friday. Temperatures also remain variable with night time temperatures falling to a low level.
Where grass utilisation or intake is affected, it will limit a ewe’s ability to absorb nutrients and magnesium from the grass. Inclement weather can also act as a stress trigger increasing the risk of tetany. As ewes do not readily store magnesium in their system they need magnesium on a daily basis.
This is generally in the region of 1g to 2g but can be higher where absorption is impeded. It is also important to note that magnesium should be offered in advance of a heightened risk.
Offering access to high magnesium buckets or blocks will generally suffice to reduce the risk but where farmers have experienced significant issues or where ewes are grazing lush swards on high potassium soils, then additional measures may be warranted including offering concentrates on a short term basis.
Ensure that concentrates have sufficient magnesium levels or that sufficient volumes are fed to achieve the desired supplementation. Teagasc advise cal-mag inclusion / feeding to provide 10 grams per head per day.
Ewes typically succumb to grass tetany rapidly leaving little scope for treatment. But where ewes are identified then administering magnesium sulphate at body temperature under the skin in a number of locations will work with good success.
Kill-out percentage: Reports indicate that a high percentage of early born lambs are achieving an excellent kill-out averaging in the region of 49% to 50%.
This is allowing some producers to draft lambs at a lower liveweight while still utilising maximum weight limits. Performance of lambs offered creep feed has been higher than expected and as such it is advisable to weigh lambs regularly. Where lambs are being weighed for the first time this season and scales have not been used for a considerable period of time it is advisable to calibrate the scales to ensure it is weighing accurately.
Placing known weights in the weigh crate or a 50kg bag of fertiliser / 25kg bags of concentrates is a handy way of checking. It is important that weights are balanced across the weighing platform and comparable weights to lambs are used.
Nematodirus risk: A 2025 nematodirus warning was release by the Agri-food Biosciences Institute (AFBI) on Friday for Northern Ireland. The warning was similar to last week’s Department of Agriculture forecast and stated that current meteorological readings indicate that peak hatching would have taken place during 25 March to 3 April 2025.
It advised farmers to be alert for signs of scour in lambs (and possibly young calves at grass) from mid-April into May. It added that two practices are highlighted to avoid / reduce the disease in young lambs by:
“not grazing lambs on the same fields as those grazed by lambs of a similar age last year”.“using anthelmintic drenches every two to four weeks. The interval between doses depends on the particular anthelmintic used and the severity of infection. To date, only limited evidence has been found of drug resistance in Nematodirus to any of the available classes of anthelmintic”.
Grass tetany: Grass tetany was touched on last week but there have been numerous reports of ewes succumbing to grass tetany since.
The forecast over the next week is variable with high rainfall for all areas on Friday. Temperatures also remain variable with night time temperatures falling to a low level.
Where grass utilisation or intake is affected, it will limit a ewe’s ability to absorb nutrients and magnesium from the grass. Inclement weather can also act as a stress trigger increasing the risk of tetany. As ewes do not readily store magnesium in their system they need magnesium on a daily basis.
This is generally in the region of 1g to 2g but can be higher where absorption is impeded. It is also important to note that magnesium should be offered in advance of a heightened risk.
Offering access to high magnesium buckets or blocks will generally suffice to reduce the risk but where farmers have experienced significant issues or where ewes are grazing lush swards on high potassium soils, then additional measures may be warranted including offering concentrates on a short term basis.
Ensure that concentrates have sufficient magnesium levels or that sufficient volumes are fed to achieve the desired supplementation. Teagasc advise cal-mag inclusion / feeding to provide 10 grams per head per day.
Ewes typically succumb to grass tetany rapidly leaving little scope for treatment. But where ewes are identified then administering magnesium sulphate at body temperature under the skin in a number of locations will work with good success.
Kill-out percentage: Reports indicate that a high percentage of early born lambs are achieving an excellent kill-out averaging in the region of 49% to 50%.
This is allowing some producers to draft lambs at a lower liveweight while still utilising maximum weight limits. Performance of lambs offered creep feed has been higher than expected and as such it is advisable to weigh lambs regularly. Where lambs are being weighed for the first time this season and scales have not been used for a considerable period of time it is advisable to calibrate the scales to ensure it is weighing accurately.
Placing known weights in the weigh crate or a 50kg bag of fertiliser / 25kg bags of concentrates is a handy way of checking. It is important that weights are balanced across the weighing platform and comparable weights to lambs are used.
Nematodirus risk: A 2025 nematodirus warning was release by the Agri-food Biosciences Institute (AFBI) on Friday for Northern Ireland. The warning was similar to last week’s Department of Agriculture forecast and stated that current meteorological readings indicate that peak hatching would have taken place during 25 March to 3 April 2025.
It advised farmers to be alert for signs of scour in lambs (and possibly young calves at grass) from mid-April into May. It added that two practices are highlighted to avoid / reduce the disease in young lambs by:
“not grazing lambs on the same fields as those grazed by lambs of a similar age last year”.“using anthelmintic drenches every two to four weeks. The interval between doses depends on the particular anthelmintic used and the severity of infection. To date, only limited evidence has been found of drug resistance in Nematodirus to any of the available classes of anthelmintic”. 
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