Ensuring ewes are receiving sufficient trace elements will be essential if prolificacy and scanning percentages are to be optimised this year.

According to John Wilson, Agrimin Northern Sales manager, the better than average grazing season this year means many pastures have excellent covers meaning ewes may need little, if any supplementary feeds to meet their energy requirements. However, trace element supply could be an issue.

“The recent heavy rain in most parts of the country combined with high soil temperatures should keep grass growing for several weeks, ensuring a good supply of quality grazing through tupping and into early pregnancy,” he said.

He added that grazing can be expected to meet the energy requirements of ewes, especially as many are in good condition following the good grass supply throughout the spring and summer. He says a lowland ewe in appropriate condition will need 7.2-9.6MJ/day depending on bodyweight.

Mr Wilson said: “They can achieve this from 0.75-1.0kgDM of forage per day and in many cases the grazing will be there to support this. Given the huge uncertainty facing the sheep sector at present, it is understandable that producers will be keen to reduce costs. The grazing supply will mean they can cut back on supplementary feeds or blocks as the ewes will have sufficient energy.

“But grazed grass is generally low in essential trace elements, particularly cobalt, iodine and selenium. Reducing supplementation could put fertility and the future lamb crop at risk.”

The key trace elements affecting fertility are selenium, iodine, copper and cobalt. Ewes need the target daily levels every day so supplementation throughout pre-tupping and tupping is vital.

Lack of selenium can cause early embryonic death, resulting in poor scanning figures in sheep. Inadequate selenium also affects male fertility so rams may benefit from supplementation too.

If ewes have inadequate cobalt then ovulation rate and egg quality can both be affected while Iodine has a role in the production of the essential reproductive hormones influencing cycling and conception.

To minimise the consequences of trace element shortages, Mr Wilson recommends the use of a cost-effective and reliable trace element supplement throughout the tupping period.

“Supplementation must be started in advance of tupping as it is at this stage that the follicles that will develop into the eggs released at ovulation are forming.You want to ensure egg quality is as high as possible to maximise conception rate and scanning percentage.

“Supplementation should continue throughout the tupping and early pregnancy periods to help achieve low levels of inevitable early embryo loss. Ewes with adequate trace element also have more effective transfer of the elements to the lamb.”

Mr Wilson advises that bolusing with an eroding bolus is the only way to be sure every animal has an adequate intake, unlike methods such as free access minerals and blocks which rely on animals voluntarily consuming enough every day. Bolusing can be easily combined with other management activities to reduce the number of times cattle have to be handled, making it easier and more cost-effective.

“An Agrimin Smartrace bolus will provide cover for 180 days meaning ewes bolused pre-tupping will be covered right through to lambing,” he comments.