Reproduction In Farm Animals | Oestrus Cycle, Ovulation, Heat Period, Mating, Fertilization, Gestation Period

Reproduction is the process that gives rise to young in farm animals; it is the ability of animals to birth young. This process starts when the animal is sexually matured. The time of sexual maturity varies between animals, in cattle, it takes up to 15 months, in goat and sheep about 6 months, in poultry […]

Reproduction is the process that gives rise to young in farm animals; it is the ability of animals to birth young. This process starts when the animal is sexually matured. The time of sexual maturity varies between animals, in cattle, it takes up to 15 months, in goat and sheep about 6 months, in poultry about 18 weeks etc. The following terms are associated with reproduction in farm animals.

 

Oestrus Cycle

This is the interval from the end of one heat period to the beginning of another. It is under the influence of a hormone called oestrogen. It is the sexual cycle that occurs in all female animals if the animal is not pregnant. The period varies among farm animals:

 

Cow is 20 – 21 days

Ewe is 17 – 21 days

Sow is 14 – 28 days

Doe (goat) is 17 – 21 days

Doe (rabbit) is spontaneous

 

Ovulation

This is the rupturing of the ovarian wall to release egg into the fallopian tube in farm animals; a process is controlled by luteinizing hormone (LH) and follicle-stimulating hormone (FSH). It varies among

 

Farm Animals

Cow is 10 – 14 hours

Ewe is 20 – 24 hours

Sow is 24 – 36 hours

Doe (goat) is 12 – 36 hours

Doe (rabbit) is spontaneous

 

Heat Period

This is the period in which female animals have the urge to copulate or accept the male animal. The female shows signs of readiness to mate. It is controlled by oestrogen. It varies among farm animals

Cow is 5 – 24 hours

Ewe is 35 – 36 hours

Sow is 40 – 48 hours

Doe (goat) is 40 – 50 hours

Doe (rabbit) is spontaneous

 

Signs Of Heat In Farm Animals

  1. Restlessness
  2. Mucus secretion by the cervix
  3. Swollen and reddened vulva
  4. Loss of appetite and frequent urination
  5. Viscous secretion comes from the vagina and these arouse and excite the males
  6. Abnormal body temperature
  7. Grunting
  8. Frequent urination
  9. Standing still to be mounted on

Ovulation (release of eggs) then heat period (receptivity to mating) then oestrus period (preparatory period for next ovulation)/pregnancy if there is successful mating that leads to fertilization.

 

Mating

This is also called coitus or copulation (sexual intercourse). This is the act in which the penis of the male animal is inserted into the vaginal of the female animal leading to introduction of sperm into the vagina. Mating could be natural or artificial.

 

Natural Mating

It occurs when a male after identifying a female on heat, mates with the female animal. Examples of natural mating include:

 

Flock Mating

This is a deliberate act in which the male and female animals are allowed to move together

 

Advantages Flock Mating

  1. All animals have freedom to participate in sexual intercourse
  2. The farmer is saved the labor and cost of monitoring breeding
  3. All female may be mated because the number of males are widely spread

 

Disadvantages Flock Mating

1. A female may be mated by more than one male thereby paternity become a difficult thing to determine

2. Two female may be on heat at the same time, thereby leading to the mating of only one of them.

 

Pen Mating

This form of mating occurs in pigs and poultry. A male is given a specific number of female depending on the strength of the breed. About 1 male to 20 females on heat

 

Advantages Pen Mating

1. In poultry female eggs can be produced

2. There is tendency of servicing female on heat

 

Disadvantages Pen Mating

1. The spread of venereal diseases may be rampant

2. Deformed male may not be able to mate

 

Stud Mating

A male (stud)with proven qualities is kept in a room in this type. Any female that is on heat is led to it for mating and thereafter the female is removed.

 

Advantages Stud Mating

  1. The paternity of the offspring can be identified
  2. It is a good system of upgrading the breed because only male with both proven quality is used.

 

Disadvantages Stud Mating

  1. The spread of venereal diseases may be rampant.
  2. It takes a lot of expertise to practice.

 

Artificial Mating

This is called artificial insemination, which involves the act of inserting the spermatozoa artificially into the vagina of female animals on heat. The sperm is collected from a male animal with desired characters with the aid of an artificial vagina, massage method, etc. Sperm collected is stored in liquid nitrogen at -196°C.

 

Advantages Artificial Mating

  1. The semen can be used over a long time even after the death of the male animal.
  2. It is more economical as it reduces the cost of feeding and managing male animals.

 

Disadvantages Artificial Mating

  1. It requires expertise which may not be readily available.
  2. Difficulty in detecting female animals on heat may limit success.

 

Fertilization

This is the fusion of the male and female sex cells spermatozoa and ovum respectively. This process occurs in the Fallopian tube or oviduct.

 

Implantation

This is the attachment of zygote (fertilized egg) to the wall of the uterus after fertilization. The zygote develops into a foetus and continues to grow till time of parturition.

 

Gestation Period

This is a period between fertilization of an ovum to the birth of young ones, conception and

birth. During gestation, female animals do not come on heat. It is under the control of a hormone called progesterone (Pregnancy hormone).

 

Features Of The Gestation Period

  1. There is swelling of the abdomen
  2. There is swelling of adder
  3. There is an increase in body weight

 

ANIMAL SPECIES   FEMALE NAME       GESTATION PERIOD

Horse,                                    Mare                          336 days

Cattle,                                    Cow                            283 days

Goat,                                      Doe                            150 days

Sheep,                                   Ewe                            150 days

Pig,                                         Sow                            114 days

Rabbit,                                   Doe                            31 days

Chicken,                                Hen                            21 days

 

 

Parturition

This is the act of giving birth in farm animals. It marks the end of pregnancy and the beginning of lactation. The act of parturition for each animal is unique.

 

Cow is Calving

Sow is Farrowing

Ewe is Lambing

Goat (Doe) is Kidding

Rabbit (Doe) is Kindling

Poultry is hatching

 

Signs Of Approaching Parturition

  1. Mammary glands enlarge and begin to secrete milk substance
  2. The vulva swells and becomes soft
  3. There may be thick mucus discharge
  4. The animal becomes restless lies down and gets up frequently
  5. The animal urinates frequently
  6. Loss of appetite
  7. The animal tries to build a nest and beds e.g. in rabbit

 

Lactation

This is the period during which the female releases milk from its udder immediately after parturition and thereafter. Lactation is under the control of a hormone called oxytocin, it can be increased by injecting animals with oxytocin.

 

Lactation is also stimulated by the presence of the young ones, the presence of a milker, the use of hand to rub the udder and the use of machine to milk the cow. The milk from goat is the best and richest of all the animals. Milk collected from animals is made fit for consumption via a process known as pasteurization.

 

Colostrum

This is the milk produced immediately after parturition within the first five days of milk production is essentially colostrum. It is yellowish-white milk. It is important for the new born animals to take colostrum because

  1. It contains some anti-biotic against diseases to which the mother has been exposed.
  2. It enables the new born to get immunity against diseases
  3. It is rich in protein especially albumin and globulins
  4. It is rich in vitamins.
  5. It is highly digestible and has a laxative effect which helps the young ones to expel the feaces.

 

Processes Of Egg Formation In Poultry

The egg in poultry is partly formed in the ovary and the oviduct. At ovulation, the ovum carrying the yolk is released by the ovary into the oviduct through the funnel called the infundibulum. Fertilization takes place in the infundibulum where the egg spends 15 minutes and moves into the magnum. In the magnum, part of the egg white (albumen) and the chalaza are secreted around the yolk. The egg stays for 3 hours in the magnum and moves into the isthmus where the two shell membranes are formed. The egg stays for 1 hour and 15 minutes in the isthmus and moves into the uterus where it remains for 18 – 21 hours and the egg shell is formed from calcium carbonate. Mineral solutions are also added to the egg before it moves into the vagina where it remains for 1 – 15 minutes before it is laid through the cloaca. A complete formation of eggs takes almost 26 hours.

 

Male And Female Reproductive Hormones

Hormones, which are organic chemical substances produced by endocrine (ductless) glands, play a crucial role in influencing the growth, development, and metabolic activities in farm animals. These hormones can be categorized as follows:

 

Testosterone/Androgen (Male)

Source: Testes

Functions:

  1. Stimulation of secondary sexual characteristics in males.
  2. Promotion of sperm production through spermatogenesis.

 

Oestrogen (Female)

Source: Ovary

Functions:

  1. Stimulation of secondary sexual characteristics in female animals.
  2. Promotion of ova or egg production through oogenesis.
  3. Stimulation of mammary gland development.

 

Progesterone (Female)

Source: Corpus luteum

Functions:

  1. Ensuring uterus development and implantation of the fertilized ovum.
  2. Inhibition of estrus, preventing ovulation.
  3. Stimulation of mammary gland development.
  4. Ensuring the continuance of pregnancy.

 

Oxytocin (Female)

Source: Pituitary

Functions:

  1. Aiding the contraction of the uterine wall during parturition.
  2. Promoting milk let-down after parturition.
  3. Aiding sperm transportation in the vagina.

 

Relaxin (Female)

Source: Pituitary

Function: Aiding the relaxation of pelvic ligaments during parturition.

 

Follicle Stimulating Hormone (FSH) (Female)

Source: Pituitary

Function: Stimulation of the growth of ovarian follicles.

 

Luteinizing Hormone (Female)

Source: Pituitary

Functions:

  1. Stimulation of the secretion of estrogen and progesterone.
  2. Induction of the rupture of the follicle and release of the ova.

Related Posts:

Respiratory System | Meaning, Organs, Breathing, Importance

Anatomy And Physiology Of Farm Animals | Ruminant & Non-Ruminant

Farm Mechanization | Meaning, Goals, Advantages, Disadvantages & Limitations

Farm Power | Meaning, Sources, Human, Animal, Mechanical, Electrical, Solar, Wind, Water, Biogas

Simple Farm Tools

Leave a Comment

Your email address will not be published. Required fields are marked *

Scroll to Top