Rotavirus vaccination: it's all in the timing
Timing, they say, is everything. Linda and Sean McGinty found to their cost that when it comes to protecting calves against the debilitating effects of rotavirus, this well-worn saying has special meaning. When they took over their Cheltenham dairy farm in 2004, they were told that rotavirus had been a problem on the farm, so took the precaution of vaccinating their pregnant cows each year with Rotavec® Corona.
The programme was working well, but in 2009, Linda says, the task was delayed. Cows were vaccinated only a few days before the planned start of calving and it wasn't long before rotavirus scours started to break out among the newborn calves.
In all, about 50 calves from the 650-cow spring-calving herd were affected (there are also 150 autumn calvers on the farm). Three calves had to be put down. The outbreak was a problem they could have done without during a typically busy spring calving.
"The later calvers weren't affected," Linda says. "These ones had more like the recommended interval between vaccination and calving. It just reinforced to us how well the vaccine works when it's administered at the right time."
The scours outbreak was a rare glitch for the couple, who take animal health planning very seriously. They came into the dairy industry in 1992 as ‘ex-townies' sharing a love of farming. Beginning as 50:50 sharemilkers, they set out a plan of what they wanted to achieve and have made big strides in a relatively short time.
Their 250ha Cheltenham farm is supported by a 250ha run-off at Kimbolton. It is set up as an equity partnership with a contract milker. The McGintys have another 170-ha farm with a lower order sharemilker at Bulls, running a 550-cow spring-calving herd and supported by a separate 170ha run-off at Kimbolton.
Linda says that until the 2009 outbreak, the only time they had experienced rotavirus was during their first season as sharemilkers. This happened before a rotavirus vaccine was available and, combined with an outbreak of salmonellosis, the disease had their calves "dropping like flies".
Rotavirus is not the only disease challenge on the Kimbolton farm, she adds. Bovine virus diarrhoea (BVD) is also present on the property, but a vaccination programme with Bovilis® BVD set up in consultation with vet Paul Wiseman "works a treat".
The couple have recently upgraded their calf-rearing sheds and have a carefully planned calf-rearing policy that applies to both farms. This includes close attention to colostrum management, an essential part of a rotavirus vaccination programme.
"It is my policy to feed the newborn calves with colostrum from the first milking from a cow," Linda notes. "This has the highest levels of antibodies and ‘goodness'. Antibodies drop markedly after subsequent milkings. When we bring in the calved cows, these get milked separately from the other colostrum cows and the milk gets stored separately for this reason. From talking to other farmers, I understand we are unusual in doing this - it isn't normal practice."
She says that notwithstanding the hiccup that occurred when the vaccination was left too late, their colostrum management is one reason why they have so few sick calves.
And after last year's experience, the "vaccination timing" aspect of the rearing policy will receive special attention, Linda concludes.
