Grazing provides an important opportunity to rebuild margins following the past wet winter which has seen dairy cattle housed for longer than normal.

However, it is still important to keep a close eye on the health and welfare of those grazing cows to maximise the benefits according to Brett Finch, area sales manager of HerdVision in Scotland.

“Grazed grass remains the cheapest feed for dairy cows and with purchased feed prices remaining high it will be essential to maximise the contribution from grazing,” he comments.

“Key to this is optimising grazing dry matter intakes. Anything that affects intakes will compromise performance.”

Cows will typically consume 1kgDM from grazing per hour so it is important to maximise grazing times.

“We expect grazing cows to often walk long distances to get to grazing and to then stand and feed for several hours before lying down to ruminate. As soon as cows begin to suffer reduced mobility all these factors will be compromised meaning intakes and performance will fall.

“A one-hour reduction in grazing time can reduce intakes by 1kgDM, worth more than two litres of milk in terms of energy. In addition, milk protein may be reduced further hitting margins.”

Mr Finch added that the risk of reduced mobility can be higher with grazing cows due to ground conditions. Wet ground can lead to softer horn which can lead to more physical damage and bruising.

If intakes are reduced, cows are also at risk of losing condition. For spring-calved cows this could have a direct impact on fertility. For late lactation cows, the risk is that they will go dry in poor condition which will have consequences for calving related conditions as well as fertility in the next lactation.

The issue with grazing cows is that they are not as closely monitored as housed cows and the changes in milk yield, milk composition and body condition may often be subtle. By the time a cow is identified as showing poor mobility she will often be at mobility score 2 meaning losses will already have occurred and treatment costs and recovery time will be greater.

The average cost of a case of lameness is £330. Early intervention and trimming cows at the right time will prevent cows becoming a score 2 or 3. Tracking mobility regularly means trimming can become proactive rather than reactive, improving efficiency and reducing costs.

“Changes in condition will be even harder to pick up manually meaning problems may go unnoticed until it is too late. Cows losing condition due to poor intakes at grass will struggle to get back in calf, pushing up calving to conception interval. Each missed service will cost over £100 in lost productivity.

“However, automated systems will allow daily assessment of both mobility and condition scores with problems flagged up as soon as they are detected, allowing earlier intervention to reduce the financial consequences.”

The HerdVision system is a fully automated mobility and body condition scoring technology using 3D imagery. The system streamlines the collection of individual cow mobility and body condition data, through a robust camera set up that is easily installed above any race.

The camera captures data for every cow that passes beneath it, every time they do so meaning cows can be scored every day. The camera is unobtrusive meaning cows don’t notice it, meaning their behaviour is unaffected. The system utilises existing EID tags for cow identification, eliminating the need for additional wearable devices.

The combination of more frequent and more consistent monitoring and greater precision means it is possible to identify changes in mobility and condition score sooner, allowing earlier intervention and management to be altered as required to reduce the consequences of poor mobility or excessive condition loss.