Core Tip: Commercial swine semen thinners are widely used in countries with developed swine industry. Commercially available diluents have stable quality, exact effect, and ease of use, which can increase labor productivity and reduce labor costs for commercial pig farms. The preparation of pig semen diluent requires certain equipment and testing equipment, so most pig farms rarely make semen thinner themselves.
1. Semen Dilution - Expanding Available Semen Volume
One of the purposes of dilution of semen is to increase the number of breeding sows. In natural mating, boars can only be bred for one sow at a time. Once boar semen is used, dilution treatment can normally be used to breed 20-30 sows, and the pregnancy rate of sows will not be reduced. Scientific research has proven that every time a gild sow is inseminated, the input semen contains 2-3 billion mobilized sperm, which can guarantee the pregnancy rate of the sow. According to the latest scientific research, boar semen quality checks, the number of spermatozoa in straight-line exercise is between 60% and 95%, and there is no significant difference in the pregnancy rate of sows that received artificial insemination. Some people worry that the small number of imported sperm will affect the pregnancy rate of sows. In past teaching materials, 80-100 billion active sperm were required for each artificial insemination. According to the common methods used to evaluate the motility of spermatozoa in the world, it can be divided into four grades. Grade A spermatozoa are fast-moving, B-grade sperm is slow-moving, C-grade sperm is non-directional, and D-grade sperm is not. Using the computer sperm image analysis technique, in a spermatozoa with a high total vitality of up to 90% of the fresh semen, the A-grade spermatozoa generally do not exceed 50%, and the B-grade spermatozoa does not exceed 40%. In the implementation of 2 artificial insemination, as long as the A-grade spermatozoa account for 25% of the total number of spermatozoa, the B-grade spermatozoa account for 35%, there are approximately 4-5 billion A spermatozoa and 506 million B-grade spermatozoa, the sow’s The pregnancy rate can reach the ideal target. When a sperm volume (1) is 300 ml, sperm density (2) is 280 million/ml, semen is diluted and stored for 2-4 days, viability (3) is 65%, and once insemination reaches more than 2.5 billion active sperm ( 4). Then multiply (1)(2)(3) and divide by (4) to obtain the dilution factor. Divide the semen by 22 parts.
2, the quality of diluted powder indicators
The main components of commercialized diluted powders contain nutrients that supply sperm, such as glucose, inorganic salts and organic acids that maintain pH and osmotic pressure, and antibiotics that inhibit microbial growth and activity. It is required that all components in the diluent be of analytically pure grade. Water-insoluble substances do not exceed 10 PPM. Does not contain or detect heavy metal ions. The short-term preservation of the diluent, the preservation of semen for 2-4 days, the medium-term preservation of the diluent can save the sperm 4-5 days, the long-term preservation of the diluent can save sperm for 5-7 days. After storage, an insemination dose contains more than 60% of motile spermatozoa, and the sum of A- and B-grade spermatozoa amounts to 10-15 million.
3, the dilution of water requirements
Distilled water that has been distilled twice using a glass distiller is the standard water for the preparation of dilutions. Water quality can be measured using a conductivity meter, and the water quality is acceptable when the conductivity is below 0.1 millisiemens/cm2. Freshly distilled fresh distilled water with a pH of 7.0 and no microorganisms. In production practice, many people do not understand the importance of diluting water. Some people use mineral water, purified water, or drinking distilled water to make semen dilution water. So there are many problems with semen preservation. Distilled water requires storage in glass bottles. The use period of each batch is about 3 days. After a long time, the CO2 in the air dissolves, and the distilled water will become acid, and the pH value will drop. When the pH value drops below pH 6.6, redistillation is required. Distilled water storage for a long time, the more microorganisms invade, it should not be used.
4, the preparation of diluted liquid
Semen dilutions should be prepared 1 hour before the dilution of the semen. After complete dissolution of the seminal diluent powder, it is required to stand for 40-50 minutes, so that the pH and osmotic pressure of the diluent are stable, and it exerts a good protective effect on the sperm. The temperature of the water when the diluted powder is dissolved is required to be controlled at 25°C-35°C and the maximum temperature is not to exceed 40°C. Excessive temperatures will invalidate antibiotics.
5, choose the principle of seminal dilution powder
To select the principle of pig semen dilution powder, first of all, it is necessary to clarify the period for which the pig semen is to be preserved. If you save about 3 days, and you choose the short-term type to achieve the goal, there is no need to use the long-term preservation type. Many people get from the practice, when choosing semen dilution powder: "The same type than the quality, the same quality than the price" method chooses the type of semen dilution powder, brand and manufacturer. This is a good choice. Regardless of the type of diluted powder, after 4 days of preservation of the semen, although the sperm motility decreased, the energy was reduced. Long-term preservation of diluted powder imported from Germany's famous brands, the test proved that the pregnancy rate of semen sows kept for 3-4 days was 85%-90%, and the pregnancy rate of semen kept 5 days after semen preservation was reduced to 70%-75%. The pregnancy rate of the insemination sows was 60%-65% by 6 days.
6, the advantages of commercial dilution
The advantages of commercialized diluted powders are that the quality is stable and the batch-to-batch variation is small, which facilitates the standardized operation and management in artificial insemination. The disadvantage is slightly higher than the cost of self-made diluent
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