Healthy start essential to calve at two years
By Jessica Buss
DAIRY heifers calving at two years old must have a healthy start to reach target calving weight.
Speaking at a Midland Shires Farmers heifer rearing meeting in Oxfordshire, Bicester vet Peter Ferens said that calving at two years old is most profitable.
Holstein heifers must reach 500-600kg by calving. To do that, and calve at two years old, growth rates must average 0.75kg a day, which requires a high standard of stockmanship, he said.
He advised reducing infection risk at calving by ensuring bedding or ground is dry and clean. He also warned that the calfs navel can become infected when wet, and so recommended trimming the navel cord to 10cm (4in) and dipping in an alcohol-based tincture of iodine to dry it.
"Calves are born lacking immunity. Colostrum from fit cows in good condition gives immunity against most bugs on your farm."
However, for rotavirus, which causes 47% of scours, calves need milk from vaccinated cows for an extended period to provide immunity, he said.
"A milk fed calf has huge potential for growth, and this is the fastest it grows in its life." But once calves are away from the cow, overfeeding was the biggest cause of diarrhoea – reducing growth rate, said Mr Ferens.
To prevent bacterial challenge, feed at a standard temperature and at regular times. And when using milk powder the strength must be consistent.
He also advised against diluting milk for scouring calves because it prevented the milk clotting in the calfs stomach.
"Reduce the amount of milk fed but not the quality. Feed one pint at normal strength, then give fluid replacement therapy, and avoid using antibiotics which are often not needed."
Heifer growth rates must average 0.75kg/day for a Holstein to calve at two years old, said Peter Ferens.
• Clean calving area needed.
• Colostrum provides immunity.
• Consistency needed when milk feeding.