Even in well-managed dairy herds receiving regular vet visits, there is always some fine-tuning to be done. It is difficult to stay top of everything, says Cumbrian dairy farmer Robin Bell, Moorland Close, Cockermouth.
The Paddle herd, run by Mr Bell and his son Richard averages yields of 9600 litres a cow and receives regular vet input from Rod Welford of Millcroft Vet Group. Monthly fertility visits are routinely made and the herd is proactively protected against diseases common to cattle in Cumbria.
The high stocking density in the area means biosecurity can be difficult to maintain, says Mr Welford. “So although the herd was naïve to the key infectious diseases when it was bought to restock the farm in 2001, vaccination programmes are ongoing for BVD, leptospirosis and IBR. Heifers are also vaccinated before turn out to protect against lungworm.”
The Paddle herd was chosen as one of the dairy farms in the XLVets’ DEFRA-funded herd health planning initiatives. Three key areas were identified in which it was thought further improvements to health could still be made: Mastitis control, nutrition and identifying just what was behind the varied poor health seen in the farm’s autumn-calving heifer cohorts.
There had been a series of problems in autumn-calving heifers, says Mr Bell. “One year it was acute respiratory disease, the next it was metritis and then last autumn more trouble, animals with twisted stomachs.”
So the latest heifer cohort was blood tested in June and screened for trace element levels. It was found that despite receiving mineral boluses, animals were still lacking in selenium and vitamin E, so were given an extra injection of vitenium.
Providing extra nutritional advice on the project, working in conjunction with the farm’s nutritionist was Richard Vecqueray from Evidence-based Vet Consultancy. He recommended management changes to improve the social, environmental and nutritional integration of animals.
These heifers were already subjected to the stresses of a mineral shortfall and coming off poor quality autumn grass, says Mr Vecqueray. “Now as well as receiving the mineral injection, they are being brought inside and on to winter rations sooner and are mixed with dry cows before calving.”
Mr Bells says: “Already we are seeing positive results. Comparing this year’s heifer performance against last year’s there is a 5.5-litre increase in the 100-day average yields a heifer, with yields averaging 28.2 litres a day.”
Another aspect the Bells wanted to fine tune was nutritional health, says Mr Welford. “Cows can slip into a negative energy balance in early lactation when outputs exceed intakes.
“Conversely, too pokey a rumen loading can push cows to ruminal acidosis. As part of the project, the herd was actively monitored to avert either of these situations as they have an adverse impact on cow health and fertility.”
The first basic of health planning is to measure a given situation. So as a measure of sub-acute ruminal acidosis risk, the milk quality of freshly-calved cows is being monitored on a monthly basis. The signals for cows being at risk are when butterfat level drops below 3% or below protein percentage.
Dry and fresh-calved cows were routinely condition scored to track overt changes. Blood samples are also now taken monthly from 10 freshly-calved cows. These are analysed for beta-hydroxybutyrate (BHB), an indicator of energy balance, which can give warning of impending ketosis.
“The individual cow BHB results are categorised using a traffic light system – red for danger, amber as a warning and green for OK, and plotted on a graph. Any trend towards more cows being in the red than green are soon highlighted. Diet alterations can then be made to provide more energy,” says Mr Welford.
Clinical mastitis had been a problem in the past due to chronically infected cows and contagious mastitis pathogens. But the Bells and Mr Welford had already reduced this through focusing on parlour hygiene and culling problem cows.
Benchmarking against other herds within the Millcroft vet practice, showed the Paddle herd was just above the median figure for 2007. So the help of milking technologist Ian Ohnstad was enlisted.
Ventilation in cattle buildings can influence mastitis incidence, says Mr Ohhnstad. “Poor airflow leads to humid buildings and in moist, warm conditions bacteria can thrive and environmental mastitis can become a problem.”