Making changes to the rearing system and introducing a milk replacer formulated to develop a baby calf’s immune and digestive systems has helped a Leicestershire dairy farm prevent outbreaks of cryptosporidium in their heifer replacements.
Brian and Rob Sercombe run a herd of 200 Holstein Fresian cows in an all-year round calving system with milk averaging 9,500L/cow/year and sold to Muller on a liquid milk contract.
For breeding, 80% of the semen used is sexed and the remainder of cows are inseminated to a British Blue or Aberdeen Angus. Heifer replacements calve at 26 months of age, from July to October.
Cryptosporidium
The father and son had on-going battle with cryptosporidium – although regular monitoring of the calves’ immune status recorded antibody levels above 5.2g/l of IgG, the disease was a concern.
The cause was identified in the management of calves in their first days of life. After receiving colostrum they were removed from the calving shed to join the youngest batch of calves on a machine feeder, a group ranging in age from one day to 30 days and older.
The issue with cryptosporidium in calves was seen at around seven days old, said Mollie Phipps of Bonanza Calf Nutrition.
“A common issue seen on farms that introduce machines to their rearing system is higher disease outbreaks if there is mixing and housing calves of variable age ranges and more calves sharing the same teat,’’ she said.
Mollie suggested changing the system, to allow baby calves to be reared in an environment slightly away from the older calves and from areas with higher disease burdens, in smaller groups on teat feeders.
The calves are now reared in this group until they are two weeks old, at a point when they have started to develop their own active immunity. Having the addition of an area to rear the baby calves results in a “domino effect of positives’’, Mollie said.
“Stressors and bullying within the group are reduced and so too is the disease burden and spread, feed refusals and assistance required when feeder training,” she added.
Less stress, more success
With stronger calves entering the machine-fed group there is less bullying between older and younger calves; this in turn reduces stress among the calves with fewer being pushed down the pecking order.
“Reduced stressors and a reduced number of mixed age group calves on the feeder at once will in turn reduce the disease burden and spread within the pen,’’ Mollie advises.
The most common period for a calf to succumb to cryptosporidium and rotavirus is a week old, but it can be from 3-14 days.
At that point, calves that haven’t received adequate colostrum followed by transition milk and are housed under stressed situations, are more likely to contract disease.
Calves that are introduced to the machine at a younger age are more likely to need guidance onto the teat multiple times compared to older calves.
A Danish study on 90 calves looking at the effect of age of introduction to feeders found that calves introduced at six days old were more likely to require assistance and had not consumed their full allocation of milk compared to calves introduced to the feeder at 14 days old.
Transition milk
In the Sercombes’ system, calves are fed 5L at 140g/L/day of Transformula – a transition milk replacer designed for use after colostrum feeding. Fed from two days old until they leave the smaller groups at 10 days old to go onto the machine feeder.
Transition milk is produced by the cow from day two to five and is key to encouraging the production of acid and enzymes in the calf and the full closure of the gut wall.
But unlike cows milk, Transformula is dried under low temperatures and ensures the baby calf is not exposed to high bacterial counts that can be found in stored raw cow’s milk and which can remove antibodies from the milk and have pathogenic effects, said Mollie.
“Transformula is made with low heat skim milk and buttermilk along with fi ve plant oils and is easily digested by the baby calf,’’ she said.
It contains a range of oligosaccharides that are key to developing a baby calf’s digestive and immune system – these can be found in other calf milks but only at low levels.
“The levels included in Transformula are comparable to the calf tubes and pastes available in the market,’’ Mollie points out.
In 2020, the Sercombes built a new calf shed and installed a new Forster Technic machine for calf rearing, using Compumate, the only milk replacer designed for machine feeding.
Compumate is formulated to provide calves with a range of feed ingredients and additives including skim milk, buttermilk, plant oils and polyphenols, omega 3 oil, egg protein, vitamin C and vitamin E, to help keep calves healthy during the feeding period.
Compumate is sweetened and contains milk flavours to aid training on the teat while the plant oils encourage dry feed intake, an important consideration as calves get older.
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