Reducing antibiotic use in the dairy herd should be a target for all vets and farmers. Now a presentation at a principal European conference has shown that using monensin in dairy cows at high risk of developing subclinical ketosis reduces curative antibiotic use by 25%.
This work by the University of Toulouse has shown that using a monensin bolus in cows at high risk of getting subclinical ketosis led to a 25% reduction in antibiotics to treat and cure conditions associated with the metabolic condition. The results were presented to leading cattle vets, academics and representatives of the pharmaceutical industry at the European Buiatrics Forum in Rome last month.
“There is much global concern and debate over the threats to human and livestock health from antibiotic resistance and the use of antibiotics for livestock,” says Fiona Anderson MRCVS of Elanco. “Vets and livestock owners all have a part to play in ensuring we safeguard veterinary medicines and use antibiotics responsibly. This study shows that using monensin in the form of a bolus could be a powerful way to cut antibiotic use in the dairy herd.
“Farmers should work with their vets to improve their husbandry and farm management techniques to reduce the risk of ketosis and subclinical ketosis, and the subsequent need to treat associated diseases with antibiotics. Subclinical ketosis in particular is more common than people think and is very costly for a dairy herd,” she says.
Ketosis and subclinical ketosis usually occur in early lactation when energy demands to produce high quantities of milk exceed energy intake. This results in an excessive negative energy balance. Fat is mobilised to fill the energy gap, but if too much fat is mobilised it leads to the production of high levels of ketones which cause clinical and subclinical disease. Clinical ketosis is rare with symptoms including nervous cows with reduced yield. Subclinical ketosis often goes unnoticed as it has no visible symptoms yet it is very common. It can affect up to 30% of cows in early lactation with a large variation between herds.
Cows affected by subclinical ketosis are at a higher risk of getting infectious diseases which require antibiotics to treat and cure. They are also at higher risk of developing displaced abomasum, retained placenta and cystic ovaries. They consequently face a higher early culling risk. Subclinical ketosis also lowers milk production, reduces conception rates and lengthens calving intervals. A study from 2015 found that for a 100-cow herd with 30% ketosis, the direct and indirect costs can be around £10,416 or around £347 per affected cow.
Fiona urges any farm where subclinical ketosis could be an issue to discuss control and testing strategies with their vet. “Developing an effective strategy to highlight cows at risk of subclinical ketosis and to prevent the condition occurring could make a big impact on the productivity and profitability of dairy farms and reduce antibiotic use,” she says. “If ketosis is an issue targeted administration of monensin in a Kexxtone bolus to cows at high risk of developing ketosis reduces the incidences of ketosis by 74%. The bolus is given three weeks before calving and provides coverage during the main risk period for the condition. Kexxtone uses monensin to improve rumen function and increase glucose delivery. This ultimately increases the energy available and buffers the dairy cow against the tendency to drop into negative energy balance.
