Back to: Animal Husbandry SS 2
MEANING OF REPRODUCTION
Reproduction is the ability in animals to give birth to young ones. The purpose of reproduction is to ensure continuity of life.
The reproductive system includes all the organs and tissues concerned with reproduction in animals.
Farm animals reproduce sexually and are mostly viviparous because they bear their young ones alive. Poultry birds on the other hand are oviparous because they produce their young ones by hatching eggs after an incubation period.
DEFINITION OF SOME TERMS IN LIVESTOCK REPRODUCTION
OVULATION
Ovulation is the rupturing of the ovary wal (Graafian follicle) to release mature eggs (ova or ovum) into the fallopian tube in animals.
(ii) It is under the control of pituitary gland Sihormones (luteinising hormones).
(iii) It occurs in-between or midway of th oestrus cycle. Bone
(iv) It occurs when female animals are o (heat or show desire to be mated.
(v) Time of ovulation varies among farm animals, for examples, in cow, it occurs 10-14 hours after oestrus.
In Sow, it occurs 24 – 36 hours after oestrus.
In ewe, it occurs 20 – 24 hours after oestrus.
In rabbit, it occurs immediately after or during mating.
OESTRUS CYCLE
The oestrus cycle is the interval from the end of one heat period to the beginning of another.
It is also the period of “heat” or “oestrus” for coitus or mating.
It is followed by a long period in which female animals will not show desire to mate.
It is under the influence of the hormone called oestrogen.
The oestrus cycle varies among farm
Animals, e.g.:
Cow – 20-21 days
Ewe – 17-21 days
Sow – 14-28 days
Doe (Goat) 17 – 21 days
Doe (Rabbit) – Spontaneous
Reasons Why Oestrus Detection is Important in Farm Animals
It enables the farmer to know when best his animals can be serviced.
It enables the farmer to properly managethe animals.
It also helps the farmer to start Preparation for the impending Pregnancy.
3.5 HEAT PERIOD
(i) The heat or oestrus period is the time when the female animal shows signs of its readiness to mate.
(ii) It is the period of sexual receptivity in female animals, when the ovum or ova are released. It is, the period when ovulation takes place.
(iii) It occurs within the oestrus cycle and controlled by oestrogen.
(iv) The heat period varies from one animal to another. e.g.:
Cow = 5-24 hours
Ewe = 35-36 hours
Sow = 40-48 hours
Doe (Goat) = 40-50 hours
Signs of Heat in Farm Animals
(ii) The vulva becomes large, red and swollen.
(ii) There is undue noise making or grunting.
(iii) A clear viscous secretion comes from the vagina and this arouses and excites the malesmounted
(iv) The animal becomes restless.
(v) It shows tendency to be ridden or mounted by other animals. w There is loss of appetite.
(vi) vii) The animal has abnormal high body temperature.
(viii) Frequent urination.
(ix) Standing still to be mounted.
(x) Frequent tail shaking as in goat.
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