HOW a bull is treated in the first year of joining will influence its performance for the rest of its life.
And it's why the Department of Primary Industries' Maria Crawford believes producers should manage any new sire carefully.
Ms Crawford, who is based in Hamilton, said the investment in a bull was not only financial.
"The financial investment, along with the contribution the bull will make to the herd's genetic improvement if bought well, is significant," she said.
"Management of the bull in its first working season will set it up for many productive years to come."
Ms Crawford said producers could do several things to make the most of any new sires.
"Ensure new bulls are transported home appropriately, including separating bulls bought from different vendors," she said.
Ms Crawford said bulls should be unloaded into yards that already held a small number of other cattle, but not other bulls.
"Give the bulls fresh water and hay overnight. Don't jump them off the truck into a paddock," she said.
Ms Crawford said management of the health of any bull was vital to both the productivity and the biosecurity of the herd.
"Particular attention should be given to vaccination of the bull, for clostridial diseases and vibriosis, along with a drench program for worms," she said.
"New bulls should be vaccinated twice - once on arrival and with a booster one month later, unless you are confident of the previous owner's vaccination program."
Other animal health treatments should include an annual drench and monitoring for lice. Also, bulls should be given a vibriosis vaccination twice a year.
When it is time to join the new bulls, Ms Crawford said they should not be mixed with older bulls to join the same group of cows.
"Use similar-age new bulls together or in single sire groups.
"Where a number of new bulls will be run together, ensure socialisation occurs before putting the bulls out with females."
Ms Crawford said new bulls should be inspected regularly during joining, monitoring to see they are working (joining the cows).
"Watch for difficulty with walking, swelling and body condition, as bulls will often develop problems, if they are going to occur, early in the mating season," she said.
"Particular attention to the management of bulls, new and old prior to and during mating, will ensure an effective, shorter joining period resulting in more calves born, a more fertile herd and a tighter aged progeny for marketing."
