Breeding Management

General breeding management practices in Sheep and Goat

• The male female ratio is 1:20.
• Young males can be put in to experienced older ewes and older rams to younger ewes will help in better mating.
• Inbreeding should be avoided.
• The males should be replaced or exchanged once in two years to avoid inbreeding.
• Breeding ewe of indigenous breeds should be 18 to 24 months depending upon their body condition.
• Breeding too young ewes result in more weakling and thus results in higher lamb loss.
• Body weight of ewe at breeding should normally less than the adult body weight of that breed.
• Oestrous detection of all female goats above 1 year should be done either with approned or vasectomized buck both in morning or evening during breeding season.
• The normal breeding season is Sept to Oct, Feb to march and may to June.
• In order to synchronize them improved hormonal technology may be used or buck may be in a partitioned corral of woven-wire net so that the does and the buck may have full view of each other. This may be done a week or two before or during the breeding season.
• A 90% conception rate in does may be ensured if one buck with one doe or more does (not exceeding 2 to 3) in heat are allowed to remain together for a whole day or whole night provided it is followed over period of 3 cycles.
• If 2 services at an interval of 8 to 12 hrs is practised improvement in conception may be achieved.
• Goats which do not return to oestrus after 2 cycles are considered as pregnant and should be separated from the dry, non pregnant flock. They should be kept in a group of not more than 15 to 20 does to avoid infighting.
• If they have no kidding for complete one year they should be removed from flock.
• Efforts should always be made to avoid kidding during the peak winter season which can be practically achieved by a planned breeding summer season within a specified period between 15^th may to 15^th June. This will save the kids from cold susceptibility and resultant pneumonic death during winter.
• Avoid starvation of goat since even two days starvation period early in pregnancy can cause a high percentage of shed embryos to be absorbed.

Reproductive parameters

• Breeding age - 6-8 months
• Comes to heat after lambing – 21 days after
• Length of pregnancy - 147 days (ranges between 144 and 152 days)
• Male female ratio - 1:20
• Estrous period is repeated every 16-17 days on average in ewes (range 14-19 days)
• Estrous period is 19-21 days in does (range 17-24 days).
• The estrous period lasts for about 24-36 hours in ewes and 34-38 hours in does.

Estrous signs

The estrous signs normally exhibited by female animals in estrus period are

• Redding of the vulva and discharge from vulva
• Tail wagging
• Mounting other animal
• Seeking male
• Frequent bleating
• Push her back
• Standing for mating (standing reflex)

Identification of sheep and goat in heat

1. Using an intact male

• The male is allowed in the flock to identify the oestrous animals.
• There is a chance the buck or ram will mate the doe or ewe if is not controlled properly.

2. Use of intact male fitted with aprons

• An apron is tied on the abdomen of the male to cover the penis.
• The apron is made of a soft piece of cloth measuring 60x45 cm with strings on four sides to tie it properly. This prevents mating.
• The apron should be washed daily and checked for holes or tears to avoid unwanted mating.
• The first there is a risk of fertile mating if the apron is not securely fastened and checked frequently.
• Inflammation, irritation and infection of penis and prepuce area can occur, resulting in inhibited sexual desire and mounting behaviour.
• The ram/buck are apronized and allowed in to the flock for identification of animals in the morning and evening for about 15 to 20minutes.
• Teasure ram/buck detects the females in heat, which are marked and separated out for breeding with desired ram.

3. Vasactamised ram

• Vasactamised rams can be prepared by doing surgical intervention.
• An intact buck or ram is let in to the flock. The buck or ram follows the doe/ewe in estrous.

Methods of mating

1. Hand mating

• In this system the females are allowed to mate one by one.
• In this system a ram or buck not allowed to mate more than three ewes/does in a day.

Merits

• This method ensured the expected time of lambing.
• This system allows the farmer to know that the animal has actually bred.
• This system reduces the risk of injuries to the animals.
• It is beneficial when mating older male with a younger female.
• It also improved the breeding efficiency of male, resulting in an increased number of females that can be bred in shorter period of time.

2. Pen mating

• In this mating system the ewes/does are divided into batches varying from 20 to 25 ewes/does.
• Males are turned in to the flock only during the night time and separated during day time.

Merits

• This system of mating prevents the disturbances to the ewes/does by the male during grazing hours.
• Males also given with enough rest and they can be fed properly.

3. Flock mating/pasture mating

• In this system males are allowed to run along with the females throughout the day and     night.
• The ram may lose its most of its body reserves in chasing the ewes and they may lose their body conditions.

Demerits

• The ram or buck sometimes may develop attraction for particular ewe or doe in heat and serve it a number of times while other remains unattended resulting in empty ewes/does and low fertility rate.
• The ram/buck some time  exhaust  itself overnight by serving more than a dozen times and the last served ewes or does not receive optimum number of spermatozoa and remain unconceived.

4. Artificial insemination

• Artificial insemination offer the best means of distributing germplasm from nucleus breeding flock to many small flocks within each eco system.
• Fresh as well as frozen semen is used.
• The speculum method of insemination is used for ewes and does.
• Generally artificial insemination leads to lower reproductive rate than natural service and frozen semen  gives even much low pregnancy rate that is around 40%.
• Cervical insemination is generally followed for better conception rate.

Source: Expert System for Sheep & Goat, ICAR-TANUVAS-TNAU