In his overhead value assessment and setting of a breeding
goal, the Simmentaler breeder must always bear in mind the
following relative economic values pertaining to extensive
beef production: REPRODUCTION/FERTILITY = 10; PRODUCTION
(WEIGHT GROWTH) = 2 and PRODUCT (CARCASS) = 1.
Only cows that are adapted to their environment calve
regularly, and they can only be adapted if they have the
desired correct legs, hair coating, size, length, rump, etc.
as dictated by nature. BY SELECTING FOR REPRODUCTION, YOU
IN FACT ALSO INDIRECTLY SELECTING FOR STRUCTURAL SOUNDNESS.
“Select for fertility and the rest will follow.
Unbelievable! Yes, but accountable.” (Reini Rusch).
The Fertile Heifer / Cow
No judge can “see” the reproduction rate – therefore we
make use of the annual Simpro herd analysis and indicate the
Simdex on the show cards. Breeders must nevertheless be
aware of the following (from a lecture by Cas Maré):
and high fertility are associated with a wedge-shaped body
with the deepest point through the body, the belly, being
close to the udder, with a wedge-shaped narrowing to the
front, starting at the first rib. The fertile cow has an
inconspicuous brisket and large belly girth and shows no
heavy muscle development in fore- or hindquarters. This is
in direct contrast with the bull where a well-developed
forequarter and a narrow, but well- muscled hindquarter are
typical masculine characteristics.
that are too fat have lower fertility and infertile cattle
get fat. The actual producers are never fat. The low
fertile heifer is usually big, heavy and fat and appears
masculine. Fertile cows are not big and beefy in
conformation and cows should therefore never be judged for
beef or carcass characteristics.
� Size: Extremes in size, both small and big, should be avoided,
although the reasons for doing so could differ. The low
fertile heifer is usually big and heavy.
Shoulder blades hump: In the fertile cow the hump and neck are lean in
appearance. The highest point of the shoulder blade bones is
slightly muscled and moves alongside and protrudes above the
dorsal vertebrae when the animal moves. In the description
of excellence of many breeds one does, however, find that
“looseness of shoulder” is considered an undesirable
property. There is, however, no evidence that a loose
shoulder has ever been detrimental. In fact – a
well-muscled firm shoulder or a rising dorsal vertebra in a
cow is an indication of low fertility.
signs of infertility that are normally treated with a good
measure of suspicion are: shrunken teats sunk into the
udder, long hair and underdevelopment of the udder. By the
way, visual appraisal of the udder is of no value in
determining milk production, but sustained milk production
is at least dependent on the functional effectiveness and
conformation of the udder.
Sex organs: A
sign of questionable fertility (even if the animal is
presently in calf) is underdevelopment of the external
genital orifice with fat deposit around the tail head.
The Fertile Bull
In a bull there are some visually assessed properties which
are a prerequisite for high fertility. According to C.
Maré positive signs of male hormone excretion are normally
associated with the following:
Muscle definition and heavy forequarter development.
A well-developed and heavy and muscular hump.
behaviour, traction and retraction of testicles.
Movement of the sheath and coarse hair growth on sheath and
Coarse hair growth on head and neck.
Concerning the latter, the opinion of Drayson, who studied
15 537 bulls from 19 breeds, is as follows: “Look first at
the coarseness of hair on a bull’s head and face. The most
fertile bulls generally have quite coarse and curly hair,
with the hair most tightly curled when the bull is at his
peak of sperm production between three to seven years of
age. How curly is “curly”? If you take a curl of hair
strand between your thumb and index finger and pull it
straight, it immediately returns to its curly position when
you release it.
Coarse, straight hair is a step down the fertility ladder,
although the bull should still have good fertility. But, be
careful of a bull with fine, straight hair.
The same principles apply to neck hair as to head and poll
hair. Coarse and curly hair suggests the bull is highly
Bulls should be fit and not fat
Coetzer sums up his research regarding the
above as follows: “Excessive fatness in bulls can lead to
fat deposit in the scrotum which can hamper thermo
regulation, leading to possible semen deformities.
Furthermore, bulls that are too fat are more inclined to
develop leg and hoof problems which decrease libido.
Another problem with such bulls bought at an auction is that
the new owner often tries to slim down the bull by
drastically reducing the energy intake and sometimes also
immediately starts with mating. The metabolic challenge
that fat catabolism poses to the bull, in addition to the
novel experience of an unfit bull having to defend himself
against a new group of bulls, more often than not leads to
failure of such a bull to produce progeny for several
months. While overfeeding is more detrimental, underfeeding
can negatively influence semen production and libido.”
In his studies on fat Coulter found that “the fat bulls in
our tests showed a reduction of 50% sperm reserves, half as
many mobile sperm, one third as many normal sperm and eleven
times less services.”
Richardson also studied fat bulls and summarises his
findings as follows: “High energy rations fed to young
bulls in order to achieve rapid growth rates or fatten the
bull for a show does adversely affect reproductive
characteristics of the bull.”
Pruitt reports as follows: “Bulls fed high gaining rations
often lay down fat in the scrotum, and this results in lower
fertility. The testes normally maintain a temperature four
to six degrees cooler than body temperature. If fat
deposits develop in the neck of the scrotum, the
countercurrent heat exchange, where warm blood from the body
is cooled by the blood in the testes, is disrupted. Sperm
production is not normal at higher temperatures and results
in impaired reproductive traits. “
The business end of a bull
“When I buy a bull, I always start by looking
at the back end of the bull. That’s where the business end
is. I want to see large testicles and a well shaped
scrotum. That’s the most important part of a bull. No
matter how good he is otherwise, if he can’t sire calves,
he’s no good to me. It doesn’t matter if he’s the best
walking bull in the world if he hasn’t got the equipment to
do the job.” (Anonymous).
Lusby; Hunlun; Curtis; Bosman and Morrow all found that the
reproduction potential of a bull depends largely on the
appearance and size of its scrotum. The high correlation
with semen production, semen quality and puberty of
daughters stresses the importance of scrotal circumference.
Of the discriminatory scrotal deviations that judges should
take heed of are portrayed in our basic principles of
judging. From a genetic point of view, it is mainly
hypoplasia (underdevelopment of one or both testes) that is
Our Society has, from as early as 1985, been prescribing
minimum testicle circumference per weight requirements,
since scrotal circumference is, according to above-mentioned
researchers, positively correlated with semen production,
semen quality, puberty of bull and puberty of daughters.
The correlations below were found in British beef breeds:
% good semen
On our Breedplan 400-days’ weighing lists there is space
for scrotal circumference and this important BLUP breeding
values will be provided to breeders that are already
measuring all their bulls (between age 350 – 550 days).
Scrotal sticks are available from inspectors.
The effect of scrotal twisting on the fertility of a bull
has been debated in many judges’ circles. In a subjective
evaluation of 15 beef breeds at 15 phase C bull testing
centres, Van Rooyen found that 54% of the bulls had
displayed scrotal twisting (87% to the left). According to
him semen tests had proved beyond doubt that scrotal
twisting has no negative effect on normal testicular
development or functions. It was also found that scrotal
twisting is indeed moderately to highly heritable in male
progeny. The stud industry should look with cautious
seriousness at scrotal twisting. Testicular torsi is the
twisting of testes within the scrotum and must not be
confused with scrotal twisting (twisting of the entire
scrotum). T. torsi is a painful condition with direct
detrimental influence on the function of the testes.
This you cannot see
An important but visually not observable
problem is a lack of libido with resulting low conception.
Causes I have come across in the literature are, amongst
Heritability (Johansson en Rendel).
Too heavily used at too early an age (Neumann).
The well known too much or too little: overworked, overfed, underfed,
used too soon in a new environment (buying) and of
course any condition of ill health (several
Since infertile and poor quality semen is not visible in
the bull, we make testing compulsory for sales under our