Cows should not be moved out of a dry cow pen and into an individual calving box during stage one of labour, according to a US animal health expert.
Jim Reynolds, professor of large animal medicine and welfare at the Western University of Health Sciences in California, said research had shown moving a cow later could ‘hinder progress and slow calving down’.
Speaking at an AHDB meeting hosted by strategic dairy farmers Tom and Karen Halton in Cheshire, Prof Reynolds said this ideal scenario was an achievable task on a farm with 24-hour calving surveillance, but flexibility needed to be allowed on farms where this was not possible.
He said on farms where cows calved in a group on a straw yard, it was important to beware of overcrowding, as this impeded behaviour in early calving and could result in not reliably knowing when the cow started calving.
He also said heifers required more space than cows to allow them to exhibit natural behaviours normally.
Prof Reynolds said the target of assisted calvings on dairy farms should be less than 10 per cent, with the target for stillborn between two and three per cent.
When choosing the optimum time to remove the calf from the cow, Mr Reynolds said there was no real right answer.
“There becomes ethical considerations, and the farming community as a whole has to match consumer and societal ethics.
“All consumers really want is it done as humanely as possible."
The bond between cow and calf was measured by cow and calf vocalisation as an indicator of anxiety or fear, as well as visible anxiety and movement behaviours, with the animals clearly looking for each other.
He said there seemed to be no significant difference in the strength of the bond between one and 12 hours, but a significant strengthening was seen after 24 hours.
“Some people find the best way to go about it is to take advantage of the cow’s natural behaviour and wait for the cow to hide the calf,” he said.
“Then calmly move the cow away. It thinks the calf is safe.”
Jenny Gibbons, from AHDB, added: “Cow and calf separation is moving up the agenda and it is something activists are campaigning about.
“It is a criticism we are facing from a small minority of the population, but we also have to recognise that 98 per cent of people in the UK eat dairy and trust the industry.
“We do have to be responsible and be ethical looking after the calves in the right way.”
TIMING was critical when it came to feeding colostrum, which Prof Reynolds said was important not only for its antibody content, but also for energy.
He said: “The value of antibodies in colostrum is extremely important, but research shows calves really need energy and colostrum provides the energy.
“Calves have a perfectly good immune system, but if they do not have energy, the immune cells cannot work.
“Calves should be getting transition milk. The first day is high quality colostrum, and the solids in the colostrum dilute slowly over time until about the fifth day when it becomes normal milk.”
Prof Reynolds said in the first three days of life, calves were not designed to drink lactose. Their digestive enzymes were not developed enough at this stage and needed milk with less than 30 per cent lactose.
“If there is too much lactose in an intestinal tract which does not have the enzyme lactase, the lactose sugars cannot be absorbed and stay in the stomach and intestine, providing a substrate for bacteria to grow on which increases the risk of enteritis and diarrhoea,” he said.
As well as the most well-known antibody, Immunoglobulin G (IgG) colostrum contains many other antibodies, including immunoglobulin A (IgA).
Prof Reynolds explained these antibodies were not time-sensitive, and rather than being absorbed into the bloodstream, they blocked receptors in the mucosal lining of
This mean pathogens were not able to bind with these receptor sites, which made the calf sick.
“The IgA for corona virus has a short half-life and are gone by day five,” he said.
“When we see calves with diarrhoea at day six, we should send a sample to the lab and feed colostrum again to calves on day four to block receptors again, irrespective of the calf’s inability to absorb IgG antibodies into the blood.
“If it is a corona virus problem, they will usually stop having diarrhoea before the results come back from the lab.”
He added that white blood cells were functional in a newborn calf, but if the calf went into a negative energy balance, the body ‘switched the off’, as the cells required glucose to work. In a period of negative energy, the body started to conserve glucose and energy sources for major organs and closed down non-essential systems which were not needed immediately to survive.
“Calves need the fat, the protein and the antibodies, probably in that order,” said Prof Reynolds
“This is also why cows get metritis after giving birth if they go into negative energy balance during transition.”
He also said, the rumen could take four to eight months to completely develop, as volatile fatty acids (VFAs) stimulated rumen development and roughage improved the mucosal carpet in the rumen.
“By day three to four, dry feed should be available, water drives feed intake from day one, more water, more feed intake,” said Mr Reynolds.
He explained dairy calves would be chewing cud between 24 and 25 days old and starting to absorb some VFAs between 15 and 20 days.
Prof Reynolds recommended providing roughage in the form of alfalfa, hay or haylage but not straw, to encourage calves to chew the cud. Silage was not suitable due to its acidic nature.