Sheep farmers are being urged to review ewe and ram nutrition ahead of tupping, as heat stress and dry conditions could put pressure on fertility.
While the impact of hot weather is often associated with immediate effects such as reduced feed intake and poorer performance, the consequences can extend much further, potentially affecting reproductive performance months later.
“Heat stress is not just an immediate challenge; it can have lasting consequences for fertility,” said Nia Williams, Nettex technical manager.
“In rams, sperm production takes around two months, while in ewes, follicle development takes around six months. This means the effects of heat stress may not become apparent until the autumn breeding season.”
As grass growth slows, forage quality can change, increasing the risk of trace element shortfalls at a time when nutritional demands are rising ahead of tupping.
“Pre-tupping is a critical period for getting nutrition right. Ovulation rate, conception and ultimately lambing performance all depend on having the right balance of energy, protein, vitamins and trace elements,” explained Mrs Williams.
“Trace elements including cobalt, selenium, zinc, manganese and iodine all play important roles in fertility, immunity and lamb development. However, farmers should always first understand what their flock requires.”
Assess before supplementing
Every flock and farm is different, with trace element availability influenced by soil type, forage quality, weather conditions and previous supplementation strategies.
“Testing and working with your vet or nutritional adviser is the best way to understand the current status of your flock and identify any potential gaps,” said Mrs Williams.
“Over-supplementing can be costly and, in the case of some trace elements such as copper, can create a risk of toxicity. The aim should always be targeted supplementation based on need.”
Cobalt is particularly important during the summer months as pasture cobalt levels can decline. It is required by rumen microbes to produce vitamin B12, which supports energy metabolism, growth and fertility.
“Because vitamin B12 production is a continuous process in the rumen, a continuous supply of cobalt is important where deficiencies have been identified,” added Mrs Williams.
“Farmers should consider supplementation strategies that provide the right nutrients in the right way for their system. A long-term supply, such as a bolus, can help provide a consistent source of trace elements and vitamins over time and give certainty that all animals are covered.”
EnduraBol Sheep provides up to 180 days’ supplementation of six key trace elements and three essential vitamins, supporting ewes and rams in the run-up to tupping.
For weaned lambs, Nettex Cobalt, Selenium and B12 Drench can support trace element status and help maintain growth, keeping lambs on track to reach finishing weight. This is particularly important in situations of forage shortage where producers will want to get lambs away to free-up the best available grazing for ewes in the run-up to tupping.
“Good fertility incorporates all aspects of a farm’s system, and starts well before the rams are turned out,” added Mrs Williams.
“By reviewing ewe and ram body condition, forage availability and trace element status now, farmers can help maximise the chances of strong conception rates and healthy lambs next spring.”
Alongside nutrition, farmers should not overlook other factors that influence reproductive performance, including lameness management and ensuring ewes are fit and mobile enough to maintain feed intake.
“Early preparation this year could make a significant difference to fertility outcomes when tupping begins,” she added.

