LIC: Faster Bull Team Change Reflects Genetic Progress
In the past, a bull could sit comfortably in a breeding team for several years with little change, but today, that’s no longer the case.
No matter what the payout is, the fundamental principles remain the same.
Heifers must reach puberty to cycle and get in calf. Puberty is driven by liveweight in cattle (about 47% of mature liveweight on average); check their weights, enter weights into Minda to see how they are tracking, check growth rates and check to see if they are all cycling.
Heifers take about 10 days longer to cycle once they calve down as 2-year-olds. Mate yearling heifers 7 -10 days ahead of the main herd to help them next year.
Service bulls need to be sound and suitable. A difficult calving or a slow calving pattern as 2-year-olds can set heifers back badly.
Sufficient numbers of high quality healthy bulls is a must for natural mating of heifers.
- Select bulls carefully to be easy calving and fertile
- Reject aggressive bulls and monitor bull performance in the heifer mob
- Yearling bulls: use 1:20 heifers; 2-year-olds 1:30
- Ensure they are fully BVD tested and vaccinated. Sight the vet certificate.
Underground heifers
There may still be time to flush them up, as a group or as poor individuals. Very small heifers are a poor investment. It may be more economic to cut your losses now on the poor performing tail-enders.
Check the feed plan with your grazier
Some synchrony programmes can advance reaching puberty, if the line is undergrown. Talk to your vet.
Keep them growing. They need to catch up before they are 22 months if they are to survive and thrive in the herd
Don’t let animal health disasters rob you of pregnancies; create a sound heifer health plan to keep them growing and pregnant.
Replacement heifers
Replacement heifers are a big investment, in most cases costing over $1200 to rear through to a milking cow.
It costs the same to rear a high BW animal as a low BW one.
Review your replacement rate and replacement quality; invest the money in the best genetic merit animals.
Rear the number that suits your business needs and future plans. If grazing is limited, it may pay to put the money into fewer higher quality animals.
