Spring calving warning
After a summer of exceptional grass growth, beef cows across the country are generally in very good condition.
Beef farmers should consider delaying weaning over the winter months to ensure cows achieve optimal condition for spring calving.
Specialists at SAC Consulting, part of Scotland’s Rural College, say that, if cows are milking for longer, this will help fit mothers lose excess condition. It has the added benefit of reducing the risk of pneumonia in calves.
The advice comes after excellent summer grass growth led to many cows carrying a condition score of 3 or above. This, in turn, resulted in severe calving difficulties and increased levels of forced caesareans in autumn calving herds.
Farmers may be looking to restrict silage intakes and make up the rest of the ration with straw. But although energy levels of silage this year are extremely high – (over 65 per cent of all silages have analysed at 11 MJ of ME/kg dry matter) – protein levels have not shown a similar improvement, with many still below 10 per cent CP in the dry matter.
Mary Young, Nutritionist at SAC Consulting, said: “Restricting the intake of these silages and topping them up with straw will fail to meet the protein requirements of the microbes in the cows’ rumen. As a result, they become less active and take much longer to break down forage so the rumen becomes impacted. The silage and straw remains undigested so the cows can no longer eat.
“Adding a protein supplement, such as rapeseed meal, to the ration also supplies more energy so less silage can be fed, meaning that the cycle continues.
“It is therefore impossible to use these high-energy, low-protein silages for feeding dry spring calves and make them lose condition.
“Fortunately the solution is simple – a delay in weaning. Leaving calves on their mothers means that cows keep lactating so more protein can be fed to meet the cows’ requirement along with restricted energy, forcing the cow to milk off her back.”
Farmers are advised to get their silage analysed as soon as possible. If it has an ME value of 11 or more and protein content of 10 per cent CP or less, then farmers should consider delaying weaning calves. They should also get professional nutritional help in drawing up suitable rations.
Posted by SRUC on 30/10/2019