A high yielding dairy enterprise no longer has to treat lactating cows with antibiotics since eradicating some of the most common bacteria that are targeted with these drugs.
Lloyd and Daphne Holterman only use antibiotics at drying off in their 1070-cow Rosy-Lane Holsteins herd in Wisconsin.
The Holtermans, who farms with two non-family partners, Tim Strobel and Jordan Matthews, say they have eradicated Staph aureus and Strep uberis - gram-positive bacteria which cause mastitis and require antibiotic treatment.
“To eliminate those you must have great staff skills to reduce the introduction of bacteria into the system,’’ says Mr Holterman.
“Train, train and train. You have to have good people, people who care. People who don’t like cows, your system or you should find a job they like better.’’
To reinforce this training, the farm uses written protocols designed by its vet.
The main mastitis bacteria the business now deals with in the milking herd are Ecoli and Klebsiella, gram-negative bacteria which have a much higher self-cure rate without antibiotics.
Cows are not treated with antibiotics for mastitis during lactation. “We catch it early and dehydrate then rehydrate,’’ Mr Holterman explains.
“We isolate the cow and administer an Intravenous therapy (IV) of hypertonic saline.
“We follow this immediately with an IV of four litres of electrolytes and pump 40 litres of water with yeast into the rumen. This has the effect of flushing toxins and rehydrating.’’
As soon as the cow has recovered she goes back to her social group so she doesn’t have to re-socialise.
By taking a holistic approach to herd health, Mr Holterman says milk yield has improved by 800 litres per cow and veterinary and medicine costs have reduced from 1.8 cents/litre to 0.6 cents.
But he advises farmers not to stop using antibiotics without consulting their vet.
“Pathogens on your farm will determine if you can go in this direction,’’ he says.
The farm treats every cow at drying off. A few years ago, it tried only treating cows with a cell count over 250,000 at drying off but as cows calved in, the herd’s overall cell count began to increase. This policy was quickly reversed and cows have since been treated at drying off.
Breeding for disease resistance has also played a major part in helping the Holtermans achieve their goals. They have bred for productive life instead of cow type since 1992.
“Instead of antibiotics we are using technology in the form of genomics, we have been breeding for disease resistance indirectly by breeding for productive life,’’ says Mr Holterman.
The enterprise also breeds for mastitis resistance, lameness, calving ease and calf pneumonia resistance.
“Healthier cows make more money and reduce vet costs, foot trimming costs and overall herd health costs,” says Mr Holterman. “This leads to better feed efficiency, and to environmental and food safety improvements for the consumer.”
The herd produces an average annual milk yield average per cow of 14,061 litres on a three times a day milking system. Cows are in the herd for an average of 4.6 lactations. Somatic cell count average is 113,000 cells/ml.
A long-term solution for reducing rates of lameness which require antibiotic treatment is genetics, Mr Holterman suggests. “We select for moderate heel depth, 0 – 0.5 linear and a slight spread toe.’’
He says his cows are healthier since he adopted a policy of less intervention at calving. “When a calf is half way out, we resist the temptation to assist straight away, we let nature take its course and as a result we get less tears, reduced metritis and fewer retained placentas and dead on arrivals.’’ His calf mortality rate at calving is 3.3%.
Although the Holtermans have reached a point where antibiotics are only used at drying off they are cautious about setting unrealistic ambitions for reducing antibiotic use.
“I think we should aim to reduce our use of antibiotics, not eliminate it altogether,’’ says Mr Holterman.
“To reduce antibiotic use, one practice has to complement another, you have to eradicate a disease first and then treat differently.’’
Guy Tomlinson of Wrexham-based Daleside Vets says in herds such as the Holtermans, with low levels of mastitis, and where the most common mastitis bacteria are gram negative, supportive therapy without antibiotics for mastitis cases can be appropriate, with regular monitoring of outcomes and cure rates.
“For most UK dairy farms, the most common mastitis bacteria are gram positive Strep Uberis and Staph aureus, which need prompt treatment with antibiotics to achieve good cure rates,’’ says Mr Tomlinson.
However, antibiotic use on UK farms can be significantly reduced with good management of the cows’ environment and parlour hygiene to reduce the overall number of mastitis cases, along with appropriate use of selective dry cow therapy, he added.