Follow experts guidance to get good fertility…
Follow experts guidance to get good fertility…
Managing autumn calving
cows appropriately ensures
good fertility and maintain a
tight calving block.
Jessica Buss reports
BODY condition losses of more than a half a score from calving to service must be avoided to prevent poor fertility results.
ADAS senior dairy consultant Cate Barrow says that some weight loss must be accepted and built into a ration. But it is important to control that loss by ensuring cows achieve predicted dry matter intakes and positive energy balance when trying to keep cows calving in a block.
Welsh milk producer Jonathan Bird is keen to continue calving 90% of his 150-cow herd from August to the end of December for ease of management. His 200ha (500-acre) Home Farm, Duffryn, Cardiff, grows arable crops, so calving cows are not wanted in spring and summer.
There is also little grass near the buildings, making it more difficult to manage fresh calvers at grass. Mr Bird feels a more consistent diet can be fed though winter to increase yields above 7000 litres. Fresh calvers and cows giving over 30 litres were housed in mid-September. Later lactation cows are still grazing.
Miss Barrow adds that autumn calvers can receive some of their nutrient requirement from grass at this time of year. But they will need some supplements.
Mr Bird prefers to have cows housed when looking for bullers. "The herdsman can then spend more time with the cows and see them closely at any time of day," he says.
"Heifers can then be given extra care. They are kept in the higher yielding group even though the ration supplies supports five litres more than their average yield."
The cow ration is based on a dry matter intake of 20kg a cow a day for fresh calvers averaging 35 litres. Mr Bird monitors cow intakes of the mixed ration to ensure they are adequate, says Miss Barrow.
"The crude protein of a ration is a balance between supplying enough for milk production while avoiding excessive protein levels which are thought to reduce embryo survival," she says. A ration should not exceed 18.5-19% crude protein.
Minerals also need to be well balanced and fed at the correct rate. "Many minerals are fed inappropriately and some can be toxic when fed in excess.
"Mr Bird must include adequate selenimum and vitamin E because maize is fed as 45% of cows forage in winter supplemented with caustic treated wheat. But minerals for 7000-litre cows need not be expensive."
Mr Bird takes blood profiles to ensure mineral status of cows and plans to check some cows again in mid-winter.
Dry cows are also supplemented with high magnesium minerals for three weeks before calving and fed a proportion of the milkers ration with some straw to minimise stress of diet changes and prime cows for milk production. This should also help ensure good fertility, adds Miss Barrow.
FERTILITYSUCCESS
• Check dry matter intake.
• Ensure cows are healthy.
• Discus infertility causes with vet.