Trace minerals play a crucial role in late pregnancy and around lambing, so ensuring diets are balanced to meet ewe requirements should be a high priority.
This is according to Laura Drury from Trouw Nutrition GB who says: “Trace minerals are vital in and around lambing, contributing to improved ewe production as well as stronger, more vigorous lambs.”
Ms Drury says prior to birth lambs rely on maternal transfer for all their trace element supply.
They are then also born with limited supplies of certain essential trace elements such as selenium, so continue to rely on maternal supply from colostrum and milk.
Selenium plays an important role in energy production and building a healthy immune system.
“The better the ewe’s trace mineral status, the healthier and more productive she will be while also benefitting the mineral status of her lambs for optimal vigour, growth and survival.”
Ms Drury says a major issue is that the trace mineral supply of forages can be very variable.
Based on more than 700 grass silage samples analysed for their mineral content at the Trouw Nutrition laboratory in Ashbourne, she says that the average values for 2019 differ from the five-year average which indicates the importance of having this year’s forage analysed to ensure it is precisely balanced for minerals.
“For example, ewes require 0.3 mg/kg DM of selenium but this year’s grass silage contains around just 10 per cent of this on average.”
Ms Drury says there are numerous ways to cost effectively supplement ewes including compounds, buckets, powdered minerals, licks and boluses but stresses the importance of feeding a bioavailable source to improve efficiency while also considering all trace mineral sources in the diet.
“For example, feeding a good quality selenium yeast which is often up to 30 per cent more bioavailable than inorganic selenium, will be of particular benefit during the pre-lambing period.
Increased selenium levels in colostrum and milk reduce the risk of hypothermia in newborns through optimal brown fat mobilisation, while supporting the ewe’s immune system.
“To ensure ewes get the trace element supply they need for optimum performance alongside the correct energy supply, we would recommend getting forages analysed and then formulating a feed plan for the six weeks leading up to lambing.”