New milk test will highlight negative energy balance
Farmers and vets will very shortly be able to get an indication of cow metabolic status through milk records thanks to a joint initiative between EBVC, NMR and SRUC.
EBVC have been providing technical support to NMR on the practicalities of using milk samples as a way of highlighting fat metabolism in fresh calvers. Their work, coupled with that of SRUC - who have been building the equation to interpret data - means the service will be available to milk recorded herds this autumn.
The service will dovetail with a recently-launched service by SRUC and NMR to provide two readings from cows in the first 60 days in milk to answer the questions; Is the cow in negative energy balance and is she mobilising too much fat?
All cows go into negative energy balance after calving as the energy requirements for milk production exceed energy intakes from feed. However the key is to minimise this defecit as much as possible to avoid the cow developing metabolic diseases such as ketosis, and experiencing general depression in health and performance. Most animals in severe negative energy balance will have high plasma nonesterified fatty acids (NEFA) caused by mobilisation of body fat reserves.
Up until now, NEFAs have only been able to be tested by taking bloods and sending them to the lab, which is invasive and expensive. Richard Cooper from EBVC, says the new simple milk test will hopefully encourage NEFA testing.
"NEFAs are a very good predictor of whether a cow is likely to get in calf or get metabolic diseases such as displaced abomasa. It's a valuable tool to indicate how much fat is being mobilised through the liver," he explains.
As part of the new testing service, a milk 'finger print' will give an idea of whether a cow has mild or severe negative energy balance and whether she is mobilising fat. Farmers and vets can then make management decisions based on the results.
Richard adds: "It tells us how well the cow is performing and it can help detect problems with energy supply and metabolic health, allowing us to react and make changes to the dry and milking cow rations. Ultimately it will enable us to have healthier cows, less treatments and less antibiotic use, so less drug costs and more milk in the tank."
Having the two parameters is also helpful, considering a small proportion of cows can have mild negative energy balance, but still have high levels of NEFAs. This could be due to cows being managed sub optimally in the dry period; for example gaining weight or receiving too much starch.
Richard has also done further work on testing strategies for ketones as part of his diploma in Cattle Health and Production. Ketones are synthesised by the liver from NEFAs.
Richard's work showed that using milk fat and protein to look for ketones was ineffective and inaccurate. He says this highlights that cow side blood ketone testing is by far the most accurate way to monitor levels.
"Many of my clients incorporate regular ketone testing of fresh calves cows 5-15 days in milk or any time under 60 days in milk if a smaller herd. If they find high ketone levels, they can then use this as prompt for treatment with propylene glycol for example," he says.
Ketone meters and testing strips are available to farmers and vets through the EBVC office. To find out more, contact us.