Measures to Improve the Artificial Insemination Rate of Cattle Breeding Chickens

To improve the fertilization rate of artificial insemination of cage-breeding chickens, the following major technical measures should be properly implemented during production:

The rooster stays

Body appearance options throughout. Picking cocks must come from the parents' healthy, high-yielding, offspring with good traits. Good appearance, strong physique, strong muscles, wide anterior chest, bright eyes and eyes, flexible and agile, clear and cry; legs and feet thick, strong and elastic foot pads; plump and shiny feathers, obvious secondary sexual characteristics, cockscomb and flesh Well-developed, bright red color, because of the positive correlation between the traits and semen quality.

Roosters go through 3 screens

The first choice should be from 45 days to 50 days. From the beginning of brooding, there are plans to choose healthy and lively, well-developed, and fast-growing chicks. The second time is from 120 days to 150 days, this age segment Is the key, growth and development and body important to meet the standard; the third in the 150 days to 160 days of age, sperm collection training according to sexual reflex and semen quality to choose.

Retaining a rooster depends not only on body appearance but also on growth and development.

The density of the spermatozoon of the rooster is reduced and the vigor is decreased; when it is too thin, the sexual reflex is not strong and the reproductive function is low. Any person who has a later sexual maturity, excessive weight, too little or no male characteristics, should be eliminated regardless of other indicators. The ratio between male and female can be reserved at 1:40.

Selection of initial reflections with sexual reflex

Sperm roosters have strong reflexes. When selected, the thumb and index finger are used to stimulate the tail of the rooster. It is easy to form a reflex, which can be lifted upwards, loose around the cloacal cavity, and full of milky valgus. Semen can be successful.

Semen quality is one of the key factors affecting the fertilization rate. When selecting the species, a comprehensive inspection and comprehensive assessment of semen quality should be performed.

The chicken's normal semen is a milky white thick liquid with an ejaculation amount of 0.4 ml to 1.0 ml. Sperm density varieties (strains) have large differences between individuals, generally 2.5 billion to 4 billion per milliliter, density and fertility rate are closely related, the correlation coefficient is 0.3 to 0.4. The greater the density, the greater the viability, and the more sperm that moves in a straight line, the higher the fertilization rate. The sperm density and fresh essence vitality of artificial insemination should be 300 million/ml and 0.95 or higher respectively.

The sperm morphology and fertilization rate were significantly correlated. The normal sperm abnormality rate in chickens was 5%-15%, and the correlation coefficient of survival r between the fertilization rate and the sperm deformity rate was -0.86 at 1 week after insemination. Fighting cock, the quality of semen is not necessarily good. The production should choose a large amount of ejaculate, sperm activity, high density, low deformity rate, no pollution, strong sexual desire cock species.

Rooster diet nutrition

The lack of energy in the diet can cause the cock to be in a state of negative energy balance, which causes the body weight to decrease, the testicle volume to become smaller, and the amount of seminal fluid to decrease. Conversely, excessive energy can cause fat deposition, weight gain, and difficulties in sperm collection. Cage breeding cockerel should limit feeding. Production practice has shown that metabolic energy is 11 megajoules to 12 megajoules per kilogram of diet, which can control weight gain and ensure that good quality semen is produced during breeding season.

During the brooding period of the roosters, the crude protein must reach 18% to 19%, the breeding period is 12% to 14%, and the breeding period is 14% to 16%. On the basis of ensuring protein levels, balancing methionine and lysine levels can ensure that the rooster has a high reproductive rate. Arginine and methionine are directly involved in spermatogenesis. The addition of 0.3% or 0.5% arginine to the diet can increase the total amount of ejaculate by 8.7% and 19%, respectively. The effect is extremely significant.

Insufficient vitamins in the diet can reduce the cock's viability, reduce sexual reflexes, and reduce semen volume. Cage breeder chickens are not exposed to sunlight or restricted, and vitamin D must be added to the diet. Production practice shows that adding 200 million units of vitamin A, 3.3 million units of vitamin D, vitamin E4 grams of vitamin B20.8 grams, and vitamin C6 grams per 100 kilograms of rooster diets can obtain excellent quality semen.

The addition of 0.1 g to 0.2 g of zinc sulfate and manganese sulfate and 0.3 to 0.5 mg/kg of sodium selenite per kilogram to the diet of the roosters had a significant effect on improving semen quality and fertility.

Dietary calcium and phosphorus contents of 1.5%-2.0% and 0.4% were suitable. Production practice shows that when the calcium and phosphorus in the diet are 28 grams per kilogram and 7 grams per kilogram respectively, the libido reflex and sperm harvest of the breeder rooster have great influence.

Collection interval

Reasonable sperm collection interval is an important measure to obtain high-quality semen and improve the fertilization rate. It has been reported that semen can be obtained once a day and good quality semen can be obtained and the mating task within the breeding period can be successfully completed. In order to give full play to the utilization rate of the excellent breeding rooster, in order to infuse more hens, a system of 2 days to 3 days of weekly sperm recovery and 2 days of rest is adopted. The results showed that the amount and density of semen could recover to the best level after 2 days of rest, and had no adverse effect on semen quality.

Semen preservation

For sperm metabolism, undiluted fresh semen at 20 °C ~ 25 °C, 30 minutes will reduce the fertilization rate. The fresh semen should be immediately stored at 30°C to 35°C and should be used within 25 minutes to 30 minutes. The faster the insemination rate, the shorter the sperm stays in the outside world, the better the live rate, and the higher the fertilization rate.

When the hen population is large, dilute semen may be stored at low temperature with a simple diluent or with BPSE or BPSE-2 (1.8 g fructose, 2.8 g sodium glutamate, 100 ml distilled water) and stored at 5°C to 10°C. It can be stored for 24 hours to 48 hours.

Best insemination time

The best insemination time for hens should be better when no hard shell eggs are in the uterus or after 3 hours of egg production. The author has observed the egg laying time of 2187 hens. The results showed that 95.02% (2078/2187) of the hens had finished egg production at 16 o'clock. It can be seen that the genital tract has been in the “open and unobstructed” state. Therefore, at 16:00: 00 to 18:30 insemination is conducive to the improvement of fertility rate.

The appropriate amount of insemination

The amount of insemination is closely related to the fertilization rate. When 100 million and 1 billion sperm were input once, the fertilization rate was 95% and 97% respectively.

When 10 million sperm were entered, the fertilization rate dropped to 38%. Production is now using the original semen insemination, each input 0.03 ml ~ 0.05 ml, effective sperm of 80 million to 100 million or more is appropriate. To ensure the number of sperm required for fertilization, the first insemination should be increased by 2 to 3 times the amount of semen. In addition, it should be noted that while the hen's fertility is declining, the cock's fertility is also decreasing. From the middle to the end of the breeding period, the amount of insemination should be increased appropriately with the age of the male cockerel, so as to maintain a higher fertilization rate of the breeding eggs.

After mating, most of the sperm quickly enter the "preserved sperm follicle" of the utero-vaginal junction, and thereafter "release" to the fallopian tube in a slow continuous manner.

Because of the testicular temperature of the rooster and the special structure of the reproductive tract of the hen, the survival time of chicken sperm in the fallopian tube can reach 35 days, which is much longer than that of livestock sperm. The fertilization ability of chicken sperm declines after mating for 3 days to 5 days. In order to keep the egg fertilization rate high, it is necessary to supplement the input of high quality semen at certain intervals. A short interval will not only increase the workload, but also increase the stress response to flocking when catching chickens; if it is too long, it will reduce the fertility rate. According to the emergence time of fertilization, after many years of production practice, it is most appropriate to inseminate once every 5 days, and the fertilization rate can be kept above 94%.