~Dr. Nekibuddin Ahmed and Dr Sharmita Doley
In recent India, poultry industry is growing tremendously as it is one of the major income sources among the unemployed people. According to Aisha and Zain (2010), artificial insemination (AI) in poultry is the process by which semen from male birds is collected and then introduced to females for the purpose of fertilizing eggs. In modern poultry industry, AI has been considered as a valuable technique as it allows a wider utilization of genetically superior cockerels with a high productive performance. AI is a crucial assisted reproductive technique to improve the reproductive performance of poultry such as broiler breeders and turkey where fertility is poor due to heavy body weight. Unlike in cattle, AI is not so well developed in poultry and mostly farmers do not even aware the feasibility of AI in poultry.
First successful AI in poultry was carried out in the year 1899, when a Russian scientist named Ivanov produced fertile chicken eggs using semen recovered from the ductus deferens after killing a cock.
Advantages of AI in poultry industry
i. It helps in rapid dissemination of genetic material of superior sires to a large number of females.
ii. It controls the transmission of fatal venereal diseases.
iii. It eliminates the risk and cost of rearing of breeder sires where usually one male sire mates with six to ten hens.
iv. Valuable male sires that have been injured in the legs and unable to mate naturally can be utilized in an AI programme.
v. Transportation of poultry from one region to another is very difficult but semen can be transported easily and at a large proportion.
vi. AI can serve as a good means for conservation of endangered avian species.
vii. It helps in regular evaluation of sires to be kept for breeding programme.
Semen collection methods
The goal of semen collection is to get maximum volume of clear and superior quality semen with minimum handling. The best time for semen collection is early morning as it leads to get maximum time for semen processing and utilization. The donor sire prior to the semen collection should be properly cleaned. The region around the cloaca should be properly washed and dried before commencement of the semen collection process.
In poultry, generally three methods are used for successful collection of semen viz. Abdominal massage method, Electro-ejaculation method and Co-operative approach method (Dharma et al. 2014).
Abdominal massage method: This method was described by Burrows and Quinn in 1937 for collection of semen from the donor sires. This method involves restraining of the donor sire on a table or the sitting collector’s knee by holding the breast down. The bird is held by another assistant or alternatively held in some type of mechanical leg clamp. The cloacal region is then massaged to achieve phallic tumescence. The collector then quickly places his hand around the cloaca and the cloaca is gently massaged from top to bottom using thumb and fore finger which allows the vent to evert out. Then the semen is collected from the surface of the phallus directly into the collection tube. Average volume of ejaculated semen by using this method is 0.25 ml.
Electro-ejaculation method: This method of semen collection can also be employed in poultry species like duck, geese, psittacines and pigeons. In this method, semen is collected under anaesthesia by using an electric probe. The major disadvantage of this method is semen contamination with urine.
Co-operative approach method: This method of semen collection needs co-operation from the donor sire which can be achieved by an external stimulus like voice, nest and food. The major advantage of this technique is that the collected semen is of good quality without any contamination because there is no stress or pain to the donor sire as it does not involve any manual handing. However, the volume of the collected semen will be comparatively less. In this method, there is requirement of dummy or teaser females and artificial vagina for semen collection.
For a successful AI programme, the collected semen should be regularly evaluated for determination of its quality. Generally, semen of poultry is creamy which indicates a high sperm concentration. Cockerel produces 0.1 to 1.5 ml per ejaculate (average 0.6 ml). The optimum pH of semen ranges between 7.0 and 7.4 (slightly alkaline). The collected semen of domestic cockerel contains 3000 to 7000 × 106 sperm per ml.
Semen extension and preservation
Collected poultry semen can be extended to inseminate 5 to 20 hens depending on different semen parameter. The level of semen extension is mostly depending upon sperm concentration. Like other species, poultry semen can be preserved at -196ºC in liquid nitrogen for long term preservation. The fertility rate, after AI with frozen thawed semen in poultry was ranges between 69 to 90% depending on various conditions.
AI should be carried out when majority of the birds completed laying since a hard shelled egg in the lower end of the oviduct obstructs the insemination process which results in lower fertility. AI after egg laying (after 3 pm) results in better fertility rate. Generally, AI should be performed in poultry when the flock reaches 25% egg production. Usually, hens are inseminated twice during the first weeks followed by weekly interval when the fertile eggs are required.
Procedure: Generally, AI process in poultry requires two operators. First the hen is restrained by holding the legs with the left hand down and tail tucked back against the operator chest. Then the thumb of the right hand is placed against the upper lip of the vent and with a rounding motion press the abdominal muscle. This causes the cloaca to evert and the oviduct to protrude so that the second operator insert a plastic straw or insemination tube into the oviduct as far as possible without exerting any pressure. Then deposit the semen at the junction of vaginal and uterus; and release the pressure on the cloaca at the same time which helps the hen in retaining semen in the vagina or the oviduct.
Dose and frequency of insemination in domestic poultry species:
|Species||Dose||Concentration of sperm||Frequency of AI|
|Chicken||0.05 ml||150-200 million||Once in a week|
|Turkey||0.025 ml||2 billion||Once in every 2 weeks|
|Duck||0.03 ml||300 million||Once in every 5 days|
AI in poultry is a common practice in captive breeding system in developed countries. However, it is not so popular in developing countries like India due to lack of knowledge and skilled personnel. Adoption of AI in poultry industry can help in better production of fertile eggs without maintaining the normal sex ratio for natural mating. Better awareness among progressive farmers on this sector may help in upliftment of the poultry production in India.
AUTHORS: Dr. Nekibuddin Ahmed1 and Dr Sharmita Doley2
1Assistant Professor, Lakhimpur College of Veterinary Science, Assam Agricultural University, Joyhing, North Lakhimpur, Assam, India
2Veterinary Officer, Animal Husbandry and Veterinary Department, Govt. of Assam, India