BCS 2 is “too low” for post-calving cows

New insights into the digital cushion’s role in cattle lameness suggest current post-calving condition targets need revising.

That’s the conclusion reached by Dr Georgios Oikonomou, lecturer in livestock health and welfare at the University of Liverpool, who warns that targeting a minimum body condition score (BCS) of 2, as AHDB Dairy suggests, could increase the risk of claw horn lesions.

Dairy units and herd managers should lift BCS targets to hit “ideal and not minimal” condition targets, he told the Cattle Lameness Conference in Worcester on Wednesday (20 April).

See also: Condition scoring app helps reduce lameness in herds

Dr Oikonomou recommended feeding for a 2.25-2.5 BCS at 60 days post-calving to reduce the risk of fat mobilisation from the digital cushion in early lactation and the potential loss of the dampening effect on foot compression.

“If they calve at 2.5 BCS, they will probably then drop down to 2 BCS, which is too low,” he told Farmers Weekly.

However, he admitted that more research was needed to fully understand the relationship between the digital cushion and nutrition.

“We are studying what appears to be a complicated relationship,” said Dr Oikonomou. “We are unsure as to whether a cow loses condition as a precursor to lameness or gets lame and then has dry matter intakes reduced and loses condition.

“I am suggesting targeting ideal scores, which means cows being closer to 3 through the year. There is perhaps a tendency for farms to see a cow at BCS 2 and accept it.”

He admitted that balancing thin and fat cows was a challenge, trading off the risk of ketosis and compromised livers against the risk of increased lameness and claw horn lesions.

Dr Oikonomou’s recommended BCS targets

Dr Stephen Whelan, AHDB Dairy R&D manager, told Farmers Weekly it was important that farms were noting body condition scores regularly. He said consistent scoring could be provided by allocating the role to one person on the farm.

“We advise transition-period scoring to be done fortnightly, and then monthly after cows leave the transition period,” said Dr Whelan.

He stressed that AHDB Dairy targets were based on a wide consultation with academics in the UK and AHDB would still advocate a post-calving loss of 0.5 BCS as a maximum, agreeing that reaching a 2.25-2.5 is “more ideal”.

He added: “Adding condition, as many farmers know, is far easier in the last 100 days of lactation that in the dry period. This is the time to add condition to lift a cow to 2.5-3 BCS and ideally 2.75-3 BCS at calving.

“We are still advocating a loss of 0.5 BCS post-calving up until the 60-day point, although this is a maximum loss. Losing weight during lactation is a perfectly natural thing for cows to do.”

As well as the risk of lameness, Dr Whelan stressed the reproductive challenge thin cows brought.