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The Breed ► HERD BULL
SELECTION
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KLIEK
HIER VIR DIE AFRIKAANSE WEERGAWE
]
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When choosing a herd bull, the stud breeder must know the market
as well as the needs of the commercial beef farmer and strive to
satisfy these.
The commercial farmer, on the other hand, must inform the stud
breeder of his needs and then be willing to remunerate the
breeder in accordance with the quality of the product. He should
be willing to pay at least the price of four commercial cows for
one bull.
The farmer has two objectives when he chooses a herd bull,
namely to produce calves and to improve his herd genetically.
His choice is therefore vital for the success and economics of
his enterprise.
One reason why it is crucial for the farmer to choose correctly
is that many prominent, as well as less prominent abnormalities
of bulls are hereditary. The removal of undesirable genes that
have been brought into the herd by a bull is a difficult and
lengthy process. The following are examples of abnormalities:
ABNORMALITIES REGARDING FERTILITY
Fertility is five times more important economically than growth
and ten times more important than carcass traits. The following
abnormalities could occur:
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sheath too long or fleshy
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testes too small or abnormalities
such as hypoplasia of chryptorchidism
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scrotum excessively twisted
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semen abnormalities
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lack of libido
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venereal diseases
CONFORMATION AND SKELETON ABNORMALITIES
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weak on abnormal legs, on fetlocks and claws
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mouth and head abnormalities
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weak balance of fore- and hindquarters to depth
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weak muscles
POOR ADAPTATION TO THE ENVIRONMENT
Birth mass is highly hereditary and therefore a bull with too
high a mass at birth or one producing coarsely built calves
could cause calving problems. Fortunately, a number of aids are
available to help the farmer limit the above mentioned
abnormalities to a minimum. These are, for example:
PLANNING
The farmer must know what his cow's defects are as that will
determine the type of bull he needs. It might be necessary to
apply corrective mating in order to achieve his ultimate
objective. The farmer must find a bull well before the mating
season starts.
INFORMATION
The farmer needs information on the bull, e.g. regarding its
birth mass, weaning performance, post-weaning growth, feed
conversion efficiency and scrotum size.
He
also needs information on the performance of the bull’s parents
and progeny as well as on his BLUP breeding values.
GENERAL APPEARANCE
In
this regard the following is important: masculinity, colour
differentiation, robustness, alertness without being
temperamental, muscling. The characteristics mentioned before
must also be taken into account.
ENVIRONMENT
It
is preferable to buy a bull from an environment similar to the
new one. The bull must be allowed at least three months to adapt
to his new environment before mating starts. If his previous
environment differs substantially from the new one, this period
could be longer.
TESTS
Insist on a specified veterinary certificate which complies with
Veterinary Association Regulations. The bull must undergo a
proper clinical examination for fertility. A semen test is not
enough, as there could be semen abnormalities present that
cannot be detected by a general fertility test.
AGRICULTURAL NEWS -1998
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