Microscopic examination of pig semen

Application purpose: Through microscopic examination of collected boar semen, the mirror condition of semen can be effectively determined to estimate the success rate of fertilization and the reproductive ability of boars

Application method: Semen should be checked immediately after sperm collection. It is not necessary to perform morphological examination on sperm every time, but morphological examination should be performed on the first few ejaculations of new boars. From now on, check the morphology once a month.

　1. Volume of semen

The usual ejaculation volume of a boar is 150-250 milliliters, but the range can be between 50-500 milliliters. It is generally recommended to weigh semen using an electronic scale. As the specific gravity of pig semen is 1.03, which is close to 1, the volume of 1 gram of semen is approximately equal to 1 milliliter.

Put the beaker into a food bag and place it on the electronic scale to zero

After removing the food bag, put it into the bag containing semen, and the reading will be displayed as the grams of semen

2. Odor

Normal and pure semen only has a slight fishy smell. Semen with abnormal odor includes: (1) semen with a strong odor, which may be contaminated by foreskin fluid; (2) If semen has a foul odor, it may be mixed with pus. Semen with abnormal odor must be discarded.

3. Color

The semen of pigs is light gray white to thick milky white, while the concentrated semen just ejaculated by boars is creamy in color (slightly yellowish). Abnormal semen, including bloody semen (red in color) and purulent semen (green in color), should be discarded.

4. Vitality

Vitality is the percentage of forward moving sperm in semen that accounts for the total number of sperm.

The evaluation of sperm motility can usually only be estimated, so it requires some experiencetechnologyPersonnel conduct evaluations. The microscope stage should be preheated to 37-39 ℃ before vitality testing, and the glass slide and cover slide should be preheated together. Take 10 or 15ul of semen using a sampler (note that the sampler's nozzle is disposable and wiped clean with a disinfectant tissue before sampling to prevent contamination of the semen), and inject it into the middle of a preheated glass slide. And cover it with a glass slide. Cover the glass slidemethodYes, first place the cover glass on the left side of the semen droplet to form an angle with the slide, forming an acute angle, and move the cover glass to the right. When the cover glass comes into contact with the semen, then lower it down to avoid the formation of bubbles that may affect the examination results. By covering the glass slide, a thin layer of sperm can be seen in the microscope's field of view, with a clear view, avoiding human errors in judgment due to the different vitality of sperm in different layers.

Use a microscope at 100x or 400x magnification to detect the vitality of sperm, that is, to determine the proportion of forward moving sperm in the field of view.

The rating method for vitality level 5 is:

There are obvious large motion waves in the entire field of view, very good 5 points

There are some movement waves and groups of sperm moving well. 4 points

Good group movement 3 points

No group movement, some show forward movement, generally 2 points

Only 1 point difference in peristalsis

No sperm activity score 0

Note: Motion wave refers to the cloud like rolling phenomenon formed by the movement of liquid when sperm move in groups.

Drip semen onto a preheated glass slide

After covering with a glass slide, observe the movement of semen. Sperm motility is active and can form movement waves

100x visual observation effect diagram 400x visual observation effect diagram

When evaluating sperm motility in diluted and preserved semen, a ten point scoring system is generally used. Estimate the percentage of forward moving sperm in the field of view, as diluted semen makes it easier to see the movement of sperm, and can be estimated based on the approximate ratio of forward moving sperm to non forward moving sperm. For example, if 70% of the sperm are in forward motion, the vitality is 0.7, and so on.

Whether it is original semen or diluted and stored semen, if the vitality of sperm is poor during the examination, each step should be carefully checked and a second examination should be conducted. Attention should be paid to the cleanliness of the suction nozzle, glass slide, and cover glass, which are non-toxic to sperm, and the temperature of the glass slide should be appropriate. If the second examination is still poor, the semen must be discarded.

After years of understanding the user's usage process, Weiyu Company has found that pig semen has the characteristics of large quantity, large size, and simple specimen preparation. Therefore, the detection of pig semen does not require very high requirements for microscopes. Generally, 100x and 400x observations are sufficient, and monocular observations can be selected according to budget and requirements（WSB100 monocular biological microscope）, both eyes（WSB300 binocular biological microscope）Digital microscope（WSB300T+imaging system）.