ANIMAL REPRODUCTION

The biological process by which living organisms produce new individuals of the same species. It ensures the continuation and survival of species from one generation to the next.

Reproduction

 Involves only one parent and does not require the involvement of specialized reproductive cells known as gametes (sperm or egg cells). In this type of reproduction, the offspring are genetically identical to the parent, as there is no mixing of genetic material.

asexual reproduction

It involves the fusion of two gametes - a sperm cell from the male and an egg cell from the female. This union results in the formation of a fertilized egg, which develops into a new organism.

sexual reproductionb

 The act of mating between a male and a female animal.

copulation

Refers to the release of a mature egg cell (ovum) from the ovary of a female animal.

ovu;latipn

The period in the reproductive cycle when a female animal is sexually receptive and will accept the male for mating.

estrus (heat)

The process in which the male gamete (sperm) unites with the female gamete (egg) to form a single cell called a zygote

Fertilization

The length of time an animal is pregnant, starting from fertilization to the time of birth.

gestation period

The act of giving birth. It marks the final stage of the reproductive process, when the developed offspring is delivered from the mother's body

Parturition

The process in which the mammary glands of a female animal produce and secrete milk. This begins after parturition (giving birth) and continues until weaning.

Lactation

The process where young animals are gradually or suddenly separated from their mothers and begin to eat solid food on their own

Weaning

• A sac-like pouch that contains the testicles and epididymis, located outside the male body.

• It has muscle tissue that raises or lowers the testicles to maintain the ideal temperature for sperm production

Scrotum

•  Produce sperm cells and the male hormone testosterone, which is essential for reproduction.

• Testosterone is responsible for maintaining the animal's masculine appearance and male reproductive functions.

Testicles

• • A long, coiled tube attached to each testicle, responsible for transporting sperm.

• It stores sperm cells and allows them to mature before they are released during ejaculation.
  

Epididyms

A muscular tube that connects the epididymis to the urethra, carrying sperm during ejaculation.

• It runs inside a protective sheath known as the spermatic cord.

  Urethra

  • A tube that carries both urine and semen out through the penis

  
  

Vas deferens

• Produce seminal fluid that protects and transports sperm.

Seminal vesciles

Produces a fluid that mixes with seminal guid to nourish sperm

prostate gland

Produce a fluid that cleans and neutralises the urethra before ejaculation.

Cowper's Glands (Bulbourethral Glands)

A fluid mixture composed of sperm cells along with fluids from the seminal vesicles and the prostate gland.

plays a crucial role in ensuring sperm survive the journey to fertilize the egg.

semen

• The male reproductive organ responsible for delivering semen into the female reproductive tract during copulation.

• It acts as a conduit for sperm and semen, enabling fertilization to occur by depositing sperm closer to the female's eggs.

Penis

A hereditary condition where one or both testes fail to descend from the abdomen into the scrotum, often leading to infertility or behavioral issue

Cryptorchidism

 A male animal, typically a horse, in which one or both testicles remain undescended and are retained in the body cavity

Ridgling or Rig

Produce sperm and seminal fluid and are held within the body cavity

testicles (poultry)

Carries sperm and seminal fluid to the cloaca.

Vas deferens (poultry)

Enlarged part where the large intestine joins the end of the alimentary canal

Cloaca

Organ in the cloaca wall that deposits sperm into the hen's reproductive tract

Papilla

• Produce egg cells (ova) and secrete the female sex hormones estrogen and progesterone; after ovulation, they form the corpus luteum, which helps maintain early pregnancy by producing progesterone

Ovaries

Two narrow tubes that carry the ova from the ovaries to the uterus and serves as the site of fertilization

oviducts (fallopian tubes)

The funnel-shaped, open end of each oviduct located near the ovary, responsible for capturing the ovulated egg

infundibulum

A Y-shaped muscular organ made up of a central body, two uterine horns, and a cervix, where the embryo implants and develops

Uterus

Remains relaxed during estrus to allow sperm to enter the uterus, but stays tightly closed during pregnancy to protect the fetus

Cervix

The site where semen is deposited during mating; it becomes moist during estrus and dry when the animal is not in estrus

Vagina

 The external opening of both the reproductive and urinary systems in females

VUlva

A sensory, erectile organ located within the vulva, playing a role in sexual stimulation

clitoris

• is the first section of the oviduct, where it captures the yolk released from the ovary after ovulation.

• The yolk stays here for about 15 to 30 minutes, during which fertilization can occur if sperm is present, as sperm is stored in this region.

  
  

funnel (infundibulum,) chickens

•  secretes the thick albumen (egg white), which begins to surround the yolk.

• Thís stage lasts approximately 3 hours, contributing the majority of the egg white before the egg moves to the next section

magnum

•  the egg receives two shell membranes, which help protect the contents and shape the egg.

• This process takes about i hours before moving into the uterus for shell formation.

Isthmus

• it adds the thin albumen (watery white) and forms the hard outer shell of the egg

•  The egg remains in the uterus for around 20 hours, where most of the egg's structure is completed.

  
  

Uterus (shell gland)

• it temporarily stores the fully formed egg before it is laid.

  • The entire egg formation process takes approximately 25 to-27 hours, from yolk release to egg laying.

  
  

Vagina (cchicken)

Marks the onset of sexual maturity, when an animal becomes capable of reproduction for the first time.

puberty

• The repeating reproductive cycle in female animals, marked by periodic heat (estrus) and associated hormonal and physical changes.

• It begins when a follicle starts developing on the ovary and continues through ovulation, ending with the next ovulation

Estrous cycle

This phase is marked by the growth and maturation of the follicle and oocyte, leading up to ovulation.

Follicular phase

In F phase, as the follicle develops, _______ levels rise, preparing the reproductive tract for possible fertilization and signaling the onset of estrus (heat)

estrogen

Follows ovulation and is characterized by the formation of the corpus luteum (“yellow body”) from the ruptured follicle.

Luteal phase

The corpus luteum secretes ____________, a hormone essential for maintaining pregnancy and preparing the uterus for embryo implantation.

progesterone

This is the early stage of the follicular phase, during which the hormones estrogen and follicle stimulating hormone (FSH) increase to prepare the ovary and uterus for estrus.

Small pulses of luteinizing hormone (LH) begin to be released, signaling the body to get ready for ovulation

Proestrus (Days 17-21)

• The oocyte (egg) reaches full maturity during this peak stage of the follicular phase.

• Levels of estrogen, FSH, and LH peak, triggering the rupture of the follicle and ovulation (release of the egg).

Estrus (Days 0 to 1)

• levels of estrogen, LH, and FSH decline,

• the female is no longer sexually receptive

Metestrus (Days 2 to 4)

In Metestrus, The ovarian follicles undergo luteinization, forming the _______________, which then develops into the corpus luteum (CL) that begins secreting progesterone

corpus hemorrhagicum

• This is the longest phase of the estrous cycle, during which pregnancy recognition occurs.

Diestrus (Days 5 to 18)

Progesterone secretion increases (around _____) to maintain pregnancy

day 12

if no viable embryos are detected by day 15, __________________ causes the corpus luteum to regress, lowering progesterone and restarting the cycle

prostaglandin F2 alpha (PGF2α)

Common Signs of Estrus

• _______ and __________ of the vulva

• Thick ______________ from the vagina

• _______behavior

• Restlessness and __________

• swelling and reddening

• mucous discharge

• Mounting

• vocalization

Signs of Estrus in Swine

• Reduced ________

• Frequent attempts to urinate with little or no urine •

• Reluctance to move or be transferred when near a boar •

• Response to boar’s mating sounds •

• _________or “popping”

• appetite

• Ear stiffening

Signs of Estrus in Cattle

• Standing to be mounted by another cow •

• Nervousness and mating calls (_______) •

• Swelling of the vulva •

• Inflamed appearance around the ___________ •

• Frequent urination •

• Mucus discharge from the vulva •

• _________ other cattle

• bellowing

• lips of the vulva

• Trying to mount

Signs of Estrus in Goats

• _________ and frequent urination

• ____________and increased vocalization

• Swelling and reddening of the vulva

• ____________

• Standing to be mounted

• _______and playful behavior

• Tail wagging

• Restlessness

• Seeking the buck

• Bleating

Signs of estrus in Horse

• _______of the vulva

• Frequent urination and _______

• __________ and squatting

• Seeking the _______

• Standing to be mounted (_________)

• Increased vocalization and restlessness

• _________and swelling of the vulva

• Winking

• squatting

• Tail raising

• stallion

• standing heat

• Softening

The surest indication of a sow in heat is her _______of the boar—she allows mating

acceptance

In group-reared sows, it’s best to bring the female to the________ or bring both to a ______________ for effective detection.

1. boar’s pen

2. designated mating pen

____________ is critical for successful breeding, especially due to the increased use of artificial insemination (AI)

Estrus detection

• General restlessness

• Vulva turns red and is swollen

• White mucus discharge

First Stage: Early heat signs

Real estrrus lasts for

40-60 hours

• Vulva becomes less red and swollen •

• Slimy mucus discharge •

• Tendency to mount and be mounted by others •

• The sow or gilt will stand still when pressure is applied to her back

Second Stage: Service period signs

• The sow/gilt will not stand still when pressure is applied to her back. •

The swelling of the vulva disappears

Third Stage: Post estrus period signs

• The animal stops showing heat or estrus behaviors.

Cessation of the estrous cycle

The pregnant animal often eats well and gains noticeable weight

Increased appetite AND WEIGHT GAIN

The belly becomes visibly larger, especially in the later stages of pregnancy

enlargement of the abdomen

Signs of Advanced Pregnancy in Swine (Near Farrowing)

• ________, swelling, and _________of external genitalia

• __________and restlessness

• Fully distended _______________

• Presence of ____

• __________ behavior

• Abdominal __________

• Expulsion of _____________

• enlargement, reddening'

• Nervousness

• mammary glands

• milk

• Nest building

• contractions

• blood-stained fluids

Ultrasoung

• __________ __________ _____________ ________

• __________

• ___________

• Amplitude Depth Ultrasound Mchines

• Doppler tests

• Scanner

Advantages of Detecting Early Pregnancy

1. Allows easy identification of non-pregnant animals for ______ or _______reducing feed wastage.

2. Provides early warning of breeding issues, such as ________ or _________ in females.

3. Helps producers efficiently utilize ____________ and plan for parturition, nursing, and finishing

4. Prevents the _________ of pregnant animals

1. culling or rebreeding

2. infertile males, cystic ovaries’

3. breeding facilities

4. accidental sale