Processes of Reproduction in Cattle
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Mating:
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The copulation process involves the union of male and female gametes, which can occur naturally or through artificial insemination (AI).
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(a) Natural Mating
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Description: Male mounts the female directly.
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Advantages:
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The male can detect when the female is in heat.
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Cost-effective, requiring no skilled personnel or expensive equipment.
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Can induce puberty and oestrus in some females.
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Disadvantages:
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Risk of inbreeding.
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Possible transmission of undesirable traits through flock mating.
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Higher risk of venereal diseases.
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(b) Artificial Insemination (AI)
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Description: Semen is injected into the female’s reproductive tract.
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Advantages:
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Improves herd genetics through access to quality semen.
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Controls inbreeding.
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More economical for smallholders compared to maintaining a bull.
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STDs can be checked and managed.
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Semen from desirable bulls can be preserved for future use.
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Disadvantages:
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Requires skilled personnel for administration.
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May fail if the heat period is not detected accurately.
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AI services may not be available in remote areas.
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Collecting and storing semen necessitates special equipment.
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2. Fertilization
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Definition: Occurs when viable sperm is deposited in the reproductive system of a cow after ovulation.
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Outcome: Results in the formation of a zygote (one-cell embryo).
3. Embryo Development
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Description: Early stage of development without distinct structures.
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Location: Takes place in the uterus.
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Process:
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Embryo undergoes differentiation.
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Cells (morula) begin to function as specialized structures.
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Morula refers to the group of cells formed through cell differentiation.
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4. Fetus Development
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Description: Advanced stage following embryo development.
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Nourishment: The fetus grows in the uterus, nourished through the umbilical cord attached to the placenta.
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Functions:
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Umbilical cord acts as a waste passage to the cow’s bloodstream.
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The fetus is cushioned in amniotic fluid, protecting it from shocks and maintaining temperature.
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5. Parturition (Birth)
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Definition: The process of giving birth.
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Hormonal Changes:
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Corpus luteum decreases progesterone and increases estrogen levels.
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High estrogen levels trigger uterine contractions.
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Signs of Parturition in a Cow
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Restlessness and nervousness.
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Enlargement of the udder filled with milk.
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Widening of muscles on either side of the pin bones.
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Swelling and enlargement of the vulva.
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Mucus discharge from the vulva.
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Isolation from the herd.
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Appearance of the water bag followed by labor.
Signs of Complications During Parturition
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Delay in calf appearance after the water bag breaks.
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Prolonged calving (more than 3 hours) after calf parts appear.
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Breech presentation (rear parts coming out first).
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Distress in the cow with no sign of the water bag after hours of straining.
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Only one limb appearing after the water bag bursts.
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Discharge of foul-smelling fluid indicating calf death.
Types of Calving Implications
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Breech Presentation: The rear of the calf emerges first instead of the forelegs.
Factors to Consider When Assisting a Cow During Parturition
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Hygiene:
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Wash hands and arms with warm soapy water mixed with antiseptic.
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Clean and disinfect materials or use sterilized equipment.
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If the vulva is dry, lubricate with clean, warm soapy water.
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Restraint and Position Check: Restrain the cow and check calf orientation.
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Immediate Assistance: Provide help promptly.
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Post-Procedure Care: If hands or ropes are inserted, treat the cow with antibiotic tablets to prevent infection.
Important Notes
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Correct calf presentation is that the front feet emerge first, followed by the head resting on the feet.
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Labor lasting more than 2-3 hours suggests possible mal-presentation.
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The afterbirth, consisting of the placenta, is the last stage of parturition.
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If the placenta remains in the uterus, it must be removed to avoid barrenness.