Page 131 - 2020 NZ Hereford Magazine

Industry Focus
Selecting your bulls

this season

WORDS RUSSELL PRIEST PHOTOGRAPHS SUPPLIED

WITH THE BULL-SELLING SEASON fast approaching, buyers’ veterinary inspection of the reproductive tract is a wise move, as
thoughts should be starting to focus on what bull(s) should be more obscure conditions like corkscrew penis may be detected.
purchased for the 2020 season’s mating. Have a close look at the eyes. If they are inflamed, it may
Touching base with clients to see whether they have been mean the poor fella has developed eye cancer. Check the
happy with the performance of their previous purchases (this general ravages of time and work have not rendered him
applies both to commercial and stud breeders) is a good start. incapable or even partially incapable of performing his role.
They will soon tell you whether there is a need to refine your Having satisfied yourself that all is OK and all or most of the
breeding programme to meet their needs. Don’t automatically team is up to the rigours of another breeding season, sit down
accept that all is well simply because you haven’t heard from and list how many new bulls are needed and what traits you need
them. Clients always appreciate a call and it shows them you to target to satisfy your clients’ needs. This may be something as
are interested in what they are doing as well as giving you simple as genetically increasing the amount of fat on your cattle,
important feedback. to improving the grading or increasing the growth rate, to achieve
Next, a roundup of the residents of the bull paddock and a heavier carcasses at slaughter. Whatever the trait is, select the
close inspection, particularly of their legs/hips and reproductive EBV (estimated breeding value) that is going to enable you to
system, will indicate how many need replacing. Survey information achieve this change and place it on a wish list. This list may end
has shown that up to 25% of breeding bulls in New Zealand up including a number of different EBVs, so the next challenge
achieve poor reproductive performance for one reason or another. involves placing these in order of priority, so that the ones that
Make sure your herd’s reproductive rate is not going to be affected are going to have the greatest financial impact are placed at the
by poor bull performance. top of the list. During this ranking process, remember that some
Check particularly how each animal walks – is he placing the traits are not inherited very strongly, meaning you have very little
back foot in the imprint left by the front foot, or thereabouts? influence over them through EBV selection. For this reason, these
If not, is he showing stiffness when he walks (often a sign of traits should be placed further down the list. Generally, growth
arthritis) or has he developed swollen fluid sacks on either side and carcass traits are moderately to highly inherited, and fertility,
of the hock joint (an early sign of arthritis)? What are his feet calving ease and milk are poorly inherited.
like? Is there excessive claw growth or is he lame? If there is Armed with this information, you can now get hold of a
any sign of swelling at the base of the sheath this generally sale catalogue and work your way through it, genetically
indicates an infection. Are his testicles of a reasonable size and selecting bulls with the appropriate combination of EBVs to
tone? Imagine a pair of beer cans in a sack – this is roughly satisfy your needs.
an acceptable scrotal size for a two-year-old bull. Check the Alternatively, bulls can be genetically selected using the
scrotum does not hang too low (below the hock joints) on a index system that ranks bulls on their ability to generate profit
warm day. If it does, this can lead to damage of the testicles in a particular production system. Examples of two production
when they become entangled in his legs as he walks. A full systems are: one in which a bull is used as a terminal sire or

EBV PERCENTILES FOR A EBV PERCENTILES FOR A
GENETICALLY GOOD BULL LESSER BULL, GENETICALLY.

129