ARTIFICIAL INSEMINATION IN POULTRY

Artificial Insemination (AI) is an important tool to improve the reproductive performance of birds especially broiler breeders and turkey where fertility is low due to heavy body weight.  Eventhough AI is well developed technique in cattle, is not so well developed in poultry because no standard technique is available to store poultry semen for a long period.  The techniques available at present permits to collect semen and use it for insemination immediately with or without dilution using semen diluents at 1: 2 ratio.  Semen collected from one cock is sufficient for inseminating 5 to 10 hens depending upon the semen volume and sperm concentration.

At farms, where AI is practiced the males are kept separately in individual cages where sufficient space is available for movement of the birds.  There should be a particular team of workers to associate collection and insemination of semen.  Frequent changes of personnel in the team may affect the normal behaviour of birds.  Rough handling should be avoided, if not it may develop fear reaction, which affects the semen volume during ejaculation.

Characteristics of Poultry Semen

Semen consists of spermatozoa and seminal plasma.  Fowl semen is generally highly concentrated (3 to 8 billion spermatozoa per ml for broiler fowl).  This is due to the presence of limited amount of seminal plasma since the accessory reproductive organs are absent in avian species.  The seminal plasma is derived from the testes and excurrent ducts.  At the time of ejaculation a lymph-like fluid (also known as transparent fluid) of cloacal origin may be added to the semen in varying amounts.  The addition of transparent fluid to semen at the time of ejaculation act as an activating medium for the previously non-motile spermatozoa, thus ensuring their transport from the site of deposition to the sites of sperm storage tubules in the utero-vaginal junction of the hen's oviduct.

Usually cock start producing semen from the age of 16 weeks but the fertilizing capacity of the semen is low.  So the cocks from 22 or 24 weeks of age are used for semen collection. The natural colour of poultry semen is white or pearly white. Heavy breed male can produce 0.75  to 1 ml semen and light breed male can produce 0.4 to 0.6 ml of semen. A male can be used thrice in a week for semen collection with a gap of one day.  Although every day semen collection will not change the fertilizing capacity but the volume of semen will be low.

Equipment needed for A.I.

• Small glass funnel with stem plugged with wax.
• Inseminating syringe
• Wide mouthed glass vial.
• Small pyrex semen cup
• Large flask to hold water at 180 C to 200 C range for short time holding of semen.

Steps in AI

AI in poultry is a three-step procedure involving semen collection, semen dilution and insemination.  The second step may be omitted if 'neat' semen (undiluted) is to be used for inseminations within 30 minutes after collection.

Semen collection

The first step in AI program is manual collection (milking) of the semen.  For semen collection, a team of two members are generally involved, one for restraining the male and the other for collecting semen.

The bird is held in a horizontal position by a person at a height convenient to the operator who is attempting to collect the semen.  To collect semen the operator should place the thumb and index finger of the left hand on either side of the cloaca and massage gently.  By his right hand the operator should hold a collecting funnel and with the thumb and index finger massage the soft part of abdomen below the pelvic bones.  Massage should be rapid and continuous until the cock protrudes the papilla from the cloaca. Once the papilla is fully protruded, the previously positioned thumb and index finger of the left hand are used to squeeze out the semen in to the collecting funnel.  Avoid contamination of semen with faeces and  feather.
Semen evaluation at the time of collection

• Normal colour of the semen in pearly white or cream coloured.   Yellow semen and semen contaminated  with blood, urates, faeces or other debris should be avoided.
• Do not allow semen to contact water.
• If debris or contaminants are observed in pooled semen, carefully aspirate contaminates from the sample before mixing with additional diluent with the semen
• Place the diluted semen in a cooler or refrigerator (3 to 12 oC) to cool down.

Insemination:

All equipment used for insemination should be thoroughly cleaned and dry before Use. Insemination must be carried out when majority of the birds completed laying since a hard shelled egg in the lower end of the oviduct obstructs insemination and lowers fertility.  In practice, inseminating chicken after 3 pm obtained better results.  In turkey flocks much better results are obtained if insemination is done after 5 pm. It is difficult to inseminate non-laying hens.  Usually insemination is done when the flock reaches 25% egg production.  Hens are inseminated twice during first week.  Then at weekly intervals.

Procedure:

• Bird is held by the legs with the left hand down and tail tucked back and against the operator chest.
• The thumb of the right hand is placed against the upper lip of the vent then with a rounding motion press the abdomen muscle.
• Do not squeeze with fingers but apply pressure evenly with the palm of the hand. When the oviduct is everted, the second operator inserts the syringe into oviduct as far as it is going inside without exerting pressure.  The insemination apparatus is introduced into the vagina about 1 inch and semen is deposited at the junction of vagina and uterus.

Dose and frequency of insemination:
            Chicken : 0.05 ml, once in a week                 
            Turkey : 0.025 ml once in every 2 weeks
            Ducks : 0.03 ml once in every 5 days
            Goose : 0.05 ml for every 7 days.
            It has been observed that the males produce more semen of good quality during morning and females produce more fertile eggs when inseminated around 9 p.m.
Semen volume and sperm concentration in different species of poultry:

Source:

Dr. R. Mathivanan
Professor and Head,
Department of Animal Husbandry and Veterinary Science,
Tamil Nadu Agricultural University, Coimbatore - 3