The threat of tetracycline residues ending up in the bulk tank is one for dairy producers to take seriously. While the legal limit for the drug in milk is 300 ppb in the U.S. and 100 ppb in Canada, there are processors running tests that can detect as little as 10 to 30 ppb – and by some of their standards, that could mean rejecting a load of milk.
According to Dr. Nigel Cook, achieving a high level of herd performance and controlling lameness go hand-in-hand.
“You cannot manage your herd successfully unless you manage lameness,” he said. “It undermines everything you try to do. It impacts the way the cow behaves, the way she walks, the way she eats, the way she rests. It impacts reproduction and increases the risk for early removal.”
In a survey of 22 intensively managed, high-producing commercial dairies in Wisconsin, Cook compared lameness prevalence to that of cows kept primarily on pasture.
Three new factsheets address the causes, prevention and treatment of each of the 3 most common dairy cattle claw lesions: digital dermatitis, sole ulcer and white line lesion. The factsheets are written in plain language, designed to help producers deal with these lesions.
To estimate the accuracy of subjective locomotion scoring, 7 experienced observers were asked to score video recordings of the locomotion of 58 cows on two different occasions. Agreement between scores for each cow assigned by individual observers on the 2 occasions averaged 67.4%. Agreement between observers scoring the same cows averaged only 58.2%
Hoof blocks, fixed under one claw to allow the other claw to recover from corrective trimming, are used to reduce pain during the healing process. A German trial compared the used of uniform thickness wood and flexible synthetic hoof blocks with wedge-shaped blocks of the same materials.
There are 2 main causes of thin soles in dairy cattle:
1. an abrasive floor, particularly a new one in a barn cows have recently moved into;
2. excessive hoof trimming.
Without immediate intervention, some cows will completely lose the sole horn and the underlying corium, which is especially thin at the tip of the toe, will be uncovered. Therefore this area is very vulnerable for ascending infections. An alternative treatment for cattle with thin soles was presented at the recent Lameness Conference in Bristol UK.
Users of Hoof Supervisor® (HS) lesion recording software have an excellent pictorial, touch-screen based system for selecting hoof lesions, based on the claw zone where they appear. For others wanting to identify and deal with a lesion they see on inspection of a hoof, a web-based lesion selector similar to that used in the HS system will be helpful.
To assist trimmers to more consistently score lesion severity, Alberta hoof trimmers have created a Lesion Severity Scoring Guide containing example photos of each of 3 severity scores for 14 lesions.
The greater the manure contamination of the lower leg, the more frequently cows should be foot bathed. While some farms with excellent leg hygiene may use a footbath only once a week, others must footbath 5-7 days per week.
Researchers at the University of Wisconsin conducted a study using a custom-designed footbath to test four different bath dimensions with two different step-in heights. Optimum dimensions to maximize foot immersions while limiting solution volume are recommended.