Agriculture Victoria is advising north-east Victorian cattle producers to be aware of a calf deformity known by a variety of names, including crooked calves and acorn calves.
Agriculture Victoria District Veterinary Officer Jeff Cave said the condition was detected a number years ago on spring calving properties situated on the south-western slopes of the Great Dividing Range of New South Wales and Victoria and has been seen again recently.
“The deformities have been most noticeable in the limbs, and included shortening and rotation, also the calves have been undersized. The cows of these calves were clinically normal,” Dr Cave said.
“In the past, the outbreak has primarily affected beef producers, with all beef breeds commonly found in these districts affected.
“Deformed calves have been born to cows of all age groups, and there was no known genetic link between affected properties.
“A fluctuating percentage of calves with a varying severity of deformities were reported on affected properties.
“One constant in the outbreaks, has been that they have followed adverse seasonal conditions early in the year.
“It is understood the deformity occurs from day 45 to day 245 of pregnancy.
“Affected property owners have consistently reported their pregnant cattle were on undulating or hilly, granitic country during this critical stage of pregnancy.”
Several potential causes have been ruled out, including genetic defects, plant toxins, farm chemicals and a number of viruses.
Dr Cave said the cause of the deformity is most likely a trace element deficiency.
“If manganese or zinc deficiency is the cause of the deformity, it is unlikely this disease is caused by one factor such as a simple lack of supply. It is more likely to be a complex interaction of nutritional imbalances.
“We are urging owners of affected properties to report any abortions, stillbirths or births of deformed calves.
“Previously affected producers are also asked to keep sound records, particularly of the conditions during the critical stage of their cattle’s pregnancy, as accurate information will help the validity of any future questionnaires.
“In the meantime, our advice to producers is to be aware and avoid the known risk factors of the condition, particularly during their cattle’s critical stage of pregnancy.”
Further research will help determine the cause and establish risk factors.
For further information or advice contact your local veterinarian or Agriculture Victoria Veterinary or Animal Health Officer, or in NSW your Local Land Services office.
- Contributed by Agriculture Victoria