26 September 1997

Monitor heifer growth with regular weighing

REPLACEMENT heifers must achieve average liveweight gains of at least 0.75kg/day if they are to successfully calve at two years old, and should be check weighedregularly.

That was the message from an RABDF joint venture with animal health company Merial, whose technical services director Andy Forbes warned that the modern dairy heifer had to grow steadily but rapidly if she was to calve at two years old.

"Modern dairy heifers are mainly Holsteins, and can reach 700-800kg mature weight. That means they have to weight 350-400kg at service, and then calve weighing at least 600kg at two years old. Achieving that means a daily liveweight gain of 0.75kg, which is not modest."

Will be less mature

He advised that producers check weigh heifers to ensure they achieved targets. "If they are not at a suitable weight, they will be less mature, delaying conception, which is a concern, particularly where herds block calve.

"With autumn born calves, some producers will weigh heifers at weaning, turnout and housing. However, there can be a six-month gap between turnout and housing, and you are leaving a lot to luckif you dont weigh while heifersare at grass. Id recommend weighing in July and again in Sep-tember."

Modern dairy heifers must grow steadily and rapidly to calve at two years old – check weighing will help ensure growth is on target, said Merial vet Andy Forbes.