NO NEED TO RESTRICT MEAL SIZE TO TWO LITRES
5 June 2018
Research confirms that calves can safely be fed higher volumes of milk without the risk of nutritional upsets and so achieve higher milk replacer intakes.
Georgina Thomas, Ruminant Technical Manager with Trouw Nutrition GB says that restricting milk volume is based on the premise that larger meal sizes can lead to abomasal overload and the risk of milk replacer entering the rumen. However, this presumption is based on little scientific evidence.
“Naturally calves would feed 10-15 times per day consuming up to 1.5 kg of dry matter from milk,” she explains. “Research has shown when given the option to drink ad lib, dairy calves will drink up to five litres per day at one week old, doubling daily intakes at week 10.
“Meal size has traditionally been restricted by management due to concerns about abomasal overload; this is where milk can spill out of the abomasum and into the rumen. This is a problem as milk in the rumen can cause nutritional scours and therefore reduced growth rates.”
She says that calves are essentially born monogastric and that as the rumen develops it is important to prevent lactose-rich milk from entering as it can change the rumen pH and disrupt the microbial populations.
However, the volume of a calves’ abomasum is flexible and expansive. New research shows calves can actually drink larger volumes per feed safely without risk of abomasal overflow.
Researchers in Norway gave six calves, aged 3-4 weeks, adlib access to milk and x-rayed their stomachs before, during and after feeding. Four of the six calves voluntarily drank more than five litres and one calf drank nearly seven litres in one feed.
“When calves were allowed to drink their fill, they were content to drink 2-3 times the recommended amounts without any milk overflowing into the rumen and with no symptoms of bloat or digestive problems.
“This means it is possible to feed larger meals which can help achieve higher daily intakes of milk replacer from even twice a day feeding systems. This in turn will optimise growth rates at the time when the calves feed conversion efficiency is at its highest, improving preweaning growth rates and the development of key organs including the udder.”
Ms Thomas emphasises that the method of feeding is important if larger meals are to be fed. She advises that bucket feeding is not advisable for higher intakes because calves on bucket systems drink quickly which can lead to milk overflowing into the rumen.
“Teat feeding limits the speed of intake and reduces the risk of abomasal overflow as the stomach is able to stretch slowly according to the volume of milk.
“Calves fed larger meals of high quality milk replacer through a hygienic teat feeder will achieve higher intakes and improved growth rates pre-weaning, setting them up for more profitable milk production.”