Decisions made at drying off and during the dry period directly affect the calving period and fertility in the following service period as vet Helen Rogers told Laura Bowyer.
While outcomes such as the number of assisted calvings or stillborn calves are a reflection of dry period management, Helen Rogers, of Friars Moor Vets, says it must not be forgotten that eggs take three to four months to develop in the cow.
She says: “The eggs must be present in order to be fertilised which, in turn, will keep calving intervals tight. These eggs develop in the dry period and/or around the time of calving.
"Dry period management therefore influences the success of the following service period and, ultimately, a herd’s profitability before even thinking about letting the bulls out.”
Ms Rogers offers some tips which have been discussed within her practice’s suckler cow discussion group...
All cows should be condition scored before drying off, with a target of 2.5, she says. If herd numbers and facilities allow, they should subsequently be sorted into two management groups.
“Those cows with a BCS of 2 or less should be managed as a ‘priority group’ along with first calvers. Cows with a BCS greater than 3 should be managed as a ‘fat group’.”
One of the simplest ways to control cow BCS is to change the age at which their calves are weaned, she explains and once the calf is 200 days old, only 25 per cent of its nutrient requirements will come from milk.
Thin cows should have calves removed one month earlier than your typical weaning date she advises, while fat cows can keep calves for an extra month to encourage the loss of condition.
“Maiden heifers need to be at 85 per cent of adult mature weight by the start of their second breeding season so they need to grow at 0.5kg/day during the latter stages of pregnancy and early lactation.
"Retaining them in the ‘priority group’ should achieve this,” says Ms Rogers.
Ms Rogers says it is important to analyse silage, which should include a mineral analysis, prior to the start of the dry period.
“This will allow much more accurate and effective rationing. Ask your vet or nutritionist for advice on ration formulation once analysis results have been received.”
Straw-based diets are a very effective means of managing the BCS of dry cows, she says. To ensure palatability, the straw needs to be good quality and the water supply plentiful and these diets need to include a high quality protein source, to maximise rumen function.
“Remember straw contains very low levels of minerals, so supplementation is essential.”
Ms Rogers advises pregnancy detecting cows around the time of weaning to identify any which are barren.
“This is particularly important for maiden heifers which if not in-calf can enter the food chain while still relatively young.
"It also allows the retention of heifers from the current year’s calf crop to be accurately planned before they are weaned and sold.”
Ms Rogers says it is important to treat effectively and efficiently during the dry period for conditions such as fluke and mineral deficiencies.
Calf growth rates of 1kg per day should be achieved and if most calves are averaging this growth rate then lighter, healthy individuals will have been influenced by poor maternal milk production.
Ms Rogers says dams whose calves are not achieving these growth rates should be identified and their next calf’s growth closely monitored before the breeding season starts.
Those cows identified with repeated low milk production should not be bred from again.
Observe cows closely during the dry period to check for signs of abortion as cows carrying twins are most likely to abort at this time.
She advises: “Give your calving jack an MOT and find your calving ropes. Purchase fresh iodine navel dip, good quality artificial colostrum and anti-inflammatory for difficult calvings.”