Colorado Agriscience Curriculum

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Colorado Agriscience Curriculum

• Animal Science
• Unit 4 Reproduction and Genetics
• Lesson 2 - Male Reproductive Anatomy

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Diagram 1
(A.S.Repro.1.TM.A)
Taylor, Robert E., Scientific Farm Animal
Production, 4th ed.
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Diagram 2
(A.S.Repro.1.TM.B)
Taylor, Robert E., Scientific Farm Animal
Production, 4th ed.
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Labels
(A.S.Repro.1.TM.C)

• Vesicular Gland
• Glandular Part of Vas Deferens
• Prostate Gland
• Rectum
• Bulbourethral Gland
• Bulbospongiosus
• Ischiocavernosus Muscle
• Retractor Penis Muscle
• Epididymis
• Testis

Penis Ureter Urinary Bladder VasDeferens Sigmi
od Flexure Prepuital Divirticulum Testicles Kid
neys Vas Deferens Ureters Cloaca
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Male Reproductive Parts of a Boar
(A.S.Repro.1.TM.D)
Taylor, Robert E., Scientific Farm Animal
Production, 4th ed.
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Male Reproductive Parts of a Rooster
(A.S.Repro.1.TM.E)
Taylor, Robert E., Scientific Farm Animal
Production, 4th ed
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(A.S.Repro.1.TM.F)
Levels of Organization Within an Organism

• Cells Building block of both unicellular and
  multicellular organisms.
• Tissues- A group of cells functioning together to
  perform an activity.
• Organs- Groups of two or more tissues that
  function together.
• Organ Systems- Cooperation among organs makes
  life function within an organism efficient.

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(A.S.Repro.1.TM.G)
Male Organs of Reproduction and Their Functions

• The testicles The testicles produce the sperm
  cells that fertilize the females egg. The sperm
  are produced in the seminiferous tubules within
  the testicles. Testosterone is produced here.
  Testosterone is the hormone that makes the
  appearance and behavior of a male masculine.
• The epididymis This is where the sperm are
  stored from the testicle to mature.
• The scrotum The scrotum is a sac that contains
  and protects the testicles. It regulates the
  temperature to be a few degrees lower than body
  temperature since sperm like this lower
  temperature.
• The vas deferens The vas deferens transports
  the sperm from the epididymis to the urethra.
• The urethra A large muscular canal extending
  from the urinary bladder. This is the pathway
  through with urine and semen are excreted.
• Accessory sex glands The seminal vesicles,
  prostate, and bulbourethral glands are a part of
  this category. They primarily add to the semen
  fluid to provide health and nutrition to the
  sperm.
• The penis The organ of copulation. It is
  characterized by its spongy, erectile tissue. It
  provides the passage way for urine and semen.

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(A.S.Repro.1.TM.H)
Differences in the Poultry Male Reproductive
Organs

• The testes are contained in the body cavity.
• Each vas deferens opens into small papillae,
  which are located in the cloacal wall.
• Male fowl have no penis but have a copulatory
  organ.

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How long do chickens live?

1. Answer  Chickens in small flocks live several
   years if conditions are correct. A life span of
   6-8 years may not be unreasonable.   Most
   commercial layers are kept for 2-3 years.

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2. How old are chickens when they begin to lay
eggs?

1. Answer  Under optimum conditions good
   nutrition, ideal day length, adequate housing and
   good management practices, most layers should
   begin egg production at about 20-22 weeks of age.

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3. What should chickens be fed?

1. Answer  Commercial rations will usually produce
   the best results from all types of poultry.  A
   ration designed specifically for a particular
   type of bird should always be used (ie. layer
   ration for layers, broiler ration for broilers,
   etc.).  The commercial ration should not be
   supplemented with scratch, corn or table scraps
   because the birds will not be eating a balanced
   diet.

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4.  How can the sex of baby chicks be determined?

1. Answer  Vent sexing by an experienced chick
   sexer can be done at one day of age.  This
   technique is difficult and requires a great deal
   of experience.  If a fast feathering gene has
   been introduced into the breeding flock, chicks
   can be sexed by observing the differences in the
   appearance of the primary wing feathers.  The
   feathers on the wings of the female will be a
   little longer and in a different pattern than
   those on the males.  Most chickens can not be
   sexed in this manner.

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5.  Can eggs be produced without a male being
present?

1. Answer  Yes, most eggs produced for human
   consumption are produced this way and are
   non-fertile.

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6.  How do chickens reproduce?

1. Answer  Chickens reproduce in a manner similar
   to some other animals.  The female produces an
   egg which if fertilized can result in a baby
   chick.  The true egg, the part that develops into
   the embryo, is located on the egg yolk.  The yolk
   begins to develop in the ovary and after 10-12
   days of development, ovulation occurs.  If the
   female has been mating with a male, sperm will be
   present and fertilization can occur.  The male
   chicken does not have a penis and therefore there
   is no penetration of the female reproductive
   tract at the time of mating.  Instead the female
   inverts the cloaca (site of the common junction
   of the reproductive and digestive systems) which
   comes in contact with the males inverted cloaca
   and receives the sperm.  The cloaca is then drawn
   back into the hens body and the sperm are
   captured. They then begin the journey up the
   length of the reproductive system.  The sperm
   live inside the female reproductive system and
   each time an ovulation occurs (every 24-26 hours
   in good egg producers) the egg can become
   fertile.  This process continues and matings at 7
   - 10 day intervals are necessary to maintain
   fertility.  After fertilization occurs the egg
   albumen, shell membranes, and shell are added to
   complete the egg formation process.  The chicken
   usually lays the egg about 24 hours after
   ovulation.

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7.  What are certified egg production flocks?

1. Answer  Certified egg production flocks are
   those flocks that comply with the guidelines
   established by the United Egg Producers
   organization.  To be certified, flocks must meet
   requirements in housing and cage space allowance,
   beak trimming, molting, transportation and
   handling.