Ivan Zamorano

Acupunture Treatment

Part 3: Factors fertility

Part 3: Factors fertility

Hi, my name is Heather Schlesser with the
Marathon County UW-Extension office. Today, we are going to talk about the third
part in our four part series on Bull Health and Fertility. Today’s topic is factors affecting bull health There are five different factors that affect
bull health and fertility: The first is structural soundness; the second is the capability of
the reproductive organs; the third is the semen quality; fourth, level of libido, and
fifth, plane of nutrition. We will discuss each one of these in more
detail. Structural soundness: you want to make sure
that your bull has functional feet, legs, and associated joints. If he does not, he is not able to walk the
breeding pasture, and unable to access all of the cows that may be available to him. You also want to make sure that the rear legs
are not extremely straight. Having a moderate angle to the legs is necessary,
in order for the bull to mount and to thrust. The reproductive organs can be affected. If the testis is surrounded by lots of fat
tissue, than the pampiniform plexus in the scrotum are not able to function effectively,
and allow for cooling. Scar tissue also affects cooling. Having a small scrotum also affects the bull’s
ability to lower his testis and to get his testicles away from the body. Soft testicles are a sign of degeneration,
meaning that inadequate spermatogenesis may be occurring. Having small testicles is also a sign of unsatisfactory
development of the testicles, indicating small, or low sperm supply. Some common penile problems that occur in
bulls are spiral deviation, persistent frenulum, and penile hair rings. Spiral deviation is where the penis is twisted
instead of straight. A persistent frenulum is where the tip of
the penis remains attached to the sheath, and cannot be extended. A persistent frenulum is a genetic disorder
that can be corrected by surgery. Penile hair rings are where a band of hair
encircles the penis. This can cause scarring and infection if left
untreated. Some other issues that can affect the penis
are fractures, warts, and then scarring from previous injuries. Semen quality is also important to evaluate. When we look at semen quality we are looking
at both sperm morphology and sperm motility. Morphology refers to the structure of the
sperm, while motility refers to the progressive forward travel of the sperm. It is not uncommon for poor sperm tests to
occur in bulls less than 15 months of age. So, you want to make sure that if you are
testing a young bull, and they fail the reproductive exam, that you continue to repeat tests for
up to 4 months after puberty. This slide shows some common abnormalities
in Bovine sperm. You can see the defects usually occur in the
head or in the tail. Affects of high temperature also effects sperm
quality. After 8 hours or more of heat exposure, sperm
motility is significantly reduced. It has also been shown that after 16 hours
of heat being applied to the scrotum, that DNA damage within the sperm has occurred. This was shown by a test that used normal
eggs, or eggs from females that had not been exposed to heat, and sperm from males that
had been exposed to heat. The result was significant embryo death caused
by the DNA damage. Cold weather also has an effect on sperm quality. Cold weather decreases spermatogenesis, creates
bulls that are sub-fertile, and then also allows for frost bite to occur on the scrotum. Frost bite on the scrotum causes scar tissue,
which will hinder the cooling ability of the testis. Libido is the animal’s sex drive. An animal that has low libido, or low sex
drive, is not going to mate as many females as an animal with higher sex drive. You can measure the animal’s sex drive, or
his libido, based on his measure serving capacity. Measure serving capacity is the number of
animals the bull will breed in a given period of time. Social interactions and social dominance also
affect an animal’s libido. Often, if you have more than one male, the
dominant male will breed his select choice of females, leaving the other females for
the other male to breed. The plane of nutrition of the bull is also
important. During the breeding season, the bull will
tend to eat less, since his mind is predominately focused on breeding. Because the bull is not eating as much, he
can use up his body stores of fat, and lose up to 150 pounds of weight. It is important that our bulls come into the
breeding season with a little extra conditioning, so that by the end of the season, they are
not under-conditioned. When we look at our bulls’ ability to breed,
we want to make sure we are not over-taxing our bulls by giving them more females than
they can handle. This chart is showing the number of cows a
bull of average fertility can be expected to impregnant in a 60 day breeding season
on pasture. So, a yearling bull can be expected to breed
15-20 cows, a 2 year old can breed 20-30 cows, and a 3 year old and greater can breed 30-40
animals. Thank you for watching this video, and we
hope you learned something!

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