Two key control chains must be grasped in pig artificial insemination
In recent years, pig artificial insemination technology has developed rapidly. Large-scale pig farms have basically carried out artificial insemination work, and some large boar studs (companies) mainly selling boar semen have emerged, mainly including the SPF Boar Stud of the Northern Region of the Ministry of Agriculture under the Beijing @#@227@#@ Pig Breeding Center and Beijing Haobang Pig Artificial Insemination Service Co., Ltd. At the same time, in areas where rural backyard pig farming is relatively concentrated, small boar studs with 3 to 5 boars built by individual farmers with their own investment have sprung up like bamboo shoots after rain. Based on the author's work experience at the SPF Boar Stud of the Beijing Pig Breeding Center, the author summarized two key control chains in the pig artificial insemination process. The two key control chains are now described below.
The two key control chains in the artificial insemination process are the cleanliness chain and the temperature chain, and these two chains run through every link of artificial insemination. The cleanliness chain mainly includes the management of the boar stud, the management of the semen collection room and semen collection personnel, the management of semen dilution in the laboratory, and the insemination procedure. The temperature chain mainly includes preparation before semen collection, semen dilution, semen packaging, and semen preservation and transport.
Cleanliness chain
Feeding and management of breeding boars
Clean the pig house regularly every day, and train the breeding boars to eat, sleep and excrete in three fixed locations, so that the breeding boars maintain a good living environment. Keep the trough clean; clean the trough with a high-pressure washer at least once a week; check the quality of the feed before each feeding, and destroy any moldy or spoiled feed; it must not be fed to breeding boars; clean feces and urine in the pig pen in a timely manner to reduce opportunities for contamination of the boar's body and prepuce; regularly brush the boar's body to remove dust and dander from the breeding boar; disinfect the pig house with pigs present 2 times per week, using broad-spectrum high-efficiency disinfectants such as Baijunxiao-30, Mieduwei, Xiaoduwei, peracetic acid, etc., prepared according to the disinfection concentration specified in the instructions, mixed evenly before disinfection, with the amount of disinfectant guaranteed to be 0.3L/m2, and replace the disinfectant regularly.
Management of the semen collection room and semen collection personnel
The semen collection room must be clean, dry, and free of foreign matter on the floor. The ceiling of the semen collection room uses aluminum gusset panels or plastic steel panels to reduce dust falling, and it is cleaned once a week. Semen collection personnel wear sanitary caps to prevent hair and dander from falling off and contaminating the semen. Before semen collection, promptly squeeze out the accumulated urine in the prepuce, rinse the prepuce with clean water, and then wipe the prepuce thoroughly clean with toilet paper. Semen collectors must wear gloves during semen collection to prevent cross-contamination of semen. At the same time, semen collectors must regularly trim their nails to prevent overly long nails from tearing the gloves and contaminating the semen. During semen collection, the first portion and the last portion of semen should not be collected. The first portion may be mixed with a small amount of urine, and the last portion contains more gelatinous material and fewer sperm, so it is not suitable for collection. After semen collection, tie the semen collection bag securely and immediately cover the thermos cup lid.
Management of semen dilution in the laboratory
Clean the laboratory regularly every day to minimize dust on the floor, bench, walls and ceiling of the laboratory. Personnel diluting semen must change into work clothes, shoes and hats before entering the laboratory. After each use, thoroughly clean the semen collection cup, dilution cup, glass rod and dilution powder bottle; after cleaning, rinse twice with double-distilled water, then disinfect by autoclaving or dry heating (depending on the nature of the equipment). Semen dilution must use double-distilled water or deionized water, and the storage period of double-distilled water and deionized water must not exceed 1 month.
Insemination procedure
Pay attention to cleanliness during the insemination process to reduce the occurrence of uterine inflammation. Place a teaser boar in front of the estrous sow to stimulate the sow. Clean the sow's vulva, tail base and surrounding rump with 0.1% potassium permanganate aqueous solution, and wipe the sow's vulva clean with clean toilet paper. Gently mix the semen so that the semen is evenly distributed in the insemination bottle, and insert the insemination catheter into the sow's vagina. Paying attention to the above details is one of the reliable guarantees for keeping the sow's uterus free from contamination.
Temperature chain
Preparation before semen collection
Before semen collection, all items that come into contact with semen, including gloves, semen collection cups, semen packaging bottles, etc., must be preheated in an incubator at 37°C to ensure that during semen collection the temperature difference between the semen and the items it contacts is no higher than 2°C. Semen diluent must also be preheated in a 37°C water bath at least 1 hour in advance to ensure the diluent is mixed evenly. The most suitable setting for the laboratory air conditioner is 25°C.
Semen dilution
Immediately after semen collection, perform a semen quality check, including sperm color, odor, motility and density, etc., and finally dilute the semen at an appropriate ratio according to the test results. The temperature difference between the diluent and the raw semen must not be higher than 2°C; otherwise, it will seriously affect sperm motility after semen dilution.
Semen packaging, preservation and transport
After semen dilution, packaging must be carried out immediately. Take the semen packaging bottle out of the incubator so that the temperature difference between the diluted semen and the semen packaging bottle is no higher than 2°C. After semen packaging, the semen should not be immediately placed in a 17°C insulated box for preservation. Let the semen cool slowly at room temperature of 25°C, and then place it in the insulated box. During semen transport, an insulated box must also be used to ensure that sperm motility is not affected in any way.