Condition scoring twice a year, with the second in late lactation, can help identify thin or fat cows so bodyweight can change before drying off.
Condition scoring spring calvers in the last third of lactation gives a better opportunity to manipulate cow condition because feed conversion is more efficient before drying off.
In addition, dietary changes during the dry period can affect follicle development, which then has an impact on post-calving fertility. So the aim should be to correct condition in late lactation, says vet Kate Burnby of Stock1st in Sussex. This allows cows to be dried off in the correct condition, about score 3, then maintained during the dry period.
“Cows require less dry matter in late lactation to gain weight compared with during the dry period. When a cow has to eat 10kg DM to gain 1kg in body tissue, you could feed her 8kg in lactation, but would need 11kg DM when dry to achieve the same gain,” she explains.
“Also, there isn’t enough time when a cow is dry to reduce her weight – one month pre-calving. You shouldn’t be altering condition, but feeding adequately, or you risk a difficult calving, ketosis and other metabolic problems. Similarly, it takes three months to grow a dominant follicle that can be affected by changes in the diet during the dry period.
“But it is a balance point: When feed is tight, it makes sense to dry cows off early, as it decreases feed demand and is more economic.”
Miss Burnby says cows dried off early benefit from a teat seal, as protection from intramammary antibiotics will not last for an extended dry period.
Once cows have been condition scored, they can be split into groups and managed accordingly. For fat cows, the aim is to reduce the diet energy density by cutting down on starchy products, such as concentrates or maize silage. “Don’t feed poor-quality silage, as there are risks associated with nutritional stress and abortion,” she warns.
Thin cows still at grass can graze paddocks closer to the parlour, so they don’t burn up energy walking. Extra concentrate feeding, or milking once a day, are other tactics to gain condition. “This is also the time to address lameness, as this could be why cows are thin.”
For those who find condition scoring a chore, Miss Burnby suggests incorporating it into a routine vet visit to gain a comprehensive herd health check or, for the brave, inviting your discussion group to do it. “It is crucial that it’s someone objective and results are written down. Cows starting their lactation at the optimum body condition score produce to their potential. They also have fewer metabolic diseases, better uterine involution and they cycle better.”
JOHN ARCHER, CHESHIRE
John Archer of Bolesworth Hill Farm, Cheshire, says condition scoring cows at least four to six weeks before drying off is an essential part of managing a block-calving herd.
He has condition scored his two herds, one calving in spring the other in autumn, for four years and says it’s all part of getting cows back in calf. “It’s the key reason we do it and it has to be built into management.”
The herdsmen condition score each other’s herds to get a fresh pair of eyes and an independent view, says Mr Archer. “We condition score the whole herd twice a year so we can gauge whether the herd has lost or gained weight and respond. We adjust rations and check cows again after two to three weeks to see whether they have improved.”
The second score in late lactation is to pick out any fat or thin cows so they can be split off from the main herd and either given extra food, dried off early, or slimmed down.
This year, he found no thin cows and only a handful of fat cows before drying off.
“We averaged a score of 2.9 this year. Our objective is to calve at score 3 and get cows as a whole about right. The few fat cows this year have been dried off and are running in and outside on a diet of baled silage and straw for long fibre.”
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