Calves which are weak or ‘dopey’ after birth could be suffering from acidosis, says David Gibson, a veterinary investigation officer with SAC Consulting.
He explains calves can often suffer from acidosis following a prolonged calving, which can lead to oxygen deprivation, and ultimately weakness in the calf and an inability to stand.
“During an uncomplicated calving, the oxygen supply to the calf from the placenta stops when the calf is delivered. This results in a temporary increase in the concentration of carbon dioxide (CO2) in the bloodstream which acts as a trigger to make the calf start breathing.
“The act of breathing ‘blows off’ the CO2 and restores the normal levels of oxygen. Where calving is prolonged the oxygen supply becomes impaired and CO2 levels rise without the calf being able to blow off the CO2 by breathing. This forces the calf into a state of acidosis which can last a long period of time depending on the nature of the delay in calving.”
Mr Gibson explains human athletes can experience a similar problem following a hard-run race; once the running has stopped, the oxygen demand of the muscles decreases and they are able to breathe deeply, so oxygen supplementation is received and muscle cells return to their normal metabolic function.
“Calves which experience a prolonged calving have no way of addressing their acidosis, placing them at risk of longer-lasting and more severe effects of acidosis, including stupor, coma and death.
“Calving difficulties are almost inevitable in commercial cattle production and many producers will be familiar with the frustration of calves with no vigour which are unable to stand after an assisted or prolonged calving.
“The extended periods of recumbency in these calves often predispose them to other problems. A delay in suckling colostrum places the calf at risk of hypothermia and malnutrition as well as insufficient uptake of protective immunity from the dam. Lying down for long periods also places the calf at risk of navel infections and generalised septicaemia.”
However, he says there are ways of dealing with calves which are experiencing acidosis.
“The first and most simple action is to ensure the calf is breathing as soon after birth as possible. Commencement of regular breathing will help to blow off the CO2 in the bloodstream and start the process of recovery, however, often this is not enough.
“The second step is to reverse the acidosis by administering intravenous sodium bicarbonate. This will quickly elicit a marked improvement in demeanour and reduce the time it takes for the calf to stand.
“It is important to ensure the calf is breathing well before administering sodium bicarbonate as there may be a temporary increase in blood CO2 levels.
“However, a 2005 study did not encounter any side effects in acidotic calves following treatment with bicarbonate.
“Using bicarbonate to treat acidotic calves should be discussed with your vet in advance of the calving season and should form part of your herd health plan.
“Prompt action following prolonged calvings will improve survival rates in affected calves and should help to reduce the incidence of neonatal calf disease in these animals as well.”