Experimental animals of different sexes have different responses to many experimental methods, drug sensitivity, and responsiveness to various stimuli. Therefore, animal sex is usually an important part of animal selection. The determination of animal sex is mainly based on reproduction and secondary traits.
1. Sex determination of mice, rats and hamsters
By observing the shape and position of the external organs of the genitals, sexually mature animals can be easily identified. In male animals, the distance between the genitalia and the anus is relatively large, so if you gently pinch the external genitalia with your fingers, you will see the penis and penis protruding. The distance between the female genitalia and anus is very small, the vaginal opening is visible, and the nipples are clearly visible. The sex of pups can be determined by the distance between the perineum genitalia and the anus. The longer distance between the two is male. The women are close to each other and there are small grooves without hair.
2, the sex of the guinea pig
The sex of the guinea pig can be judged by the shape of the external reproductive organs. Use your thumb and index finger to peel off the fur near the genitals to expose the genitals. Guinea female pigs have small protrusions on the external genitalia and clitoris, which can be pushed to pull out wrinkles and check the vaginal opening. The external reproductive organs of Guinea male pigs have large protrusions, and the small protrusions of the penis can be seen covered by the front skin and protruding particles.
3. Determine the gender of domestic rabbits
It is difficult to determine the sex of a newborn rabbit. According to the distance between the anus and the urethra opening and the shape of the urethra opening to judge men and women. ①The distance from the anus to the urethral opening is 1.5 to 2 times that of women, and the finger presses the lower abdomen near the urethral opening. The distance between the anus of the female rabbit and the urethral opening did not increase significantly, and the urethral opening still exists. It points in the direction of the anus. The male rabbit is obviously elongated, and the urethra opens on the other side of the anus. (2) The shape of the urinary tract opening The shape of the urinary tract opening of the female rabbit is elongated like a slit, and the shape of the urinary tract opening of the male rabbit is cylindrical.
Adult female rabbits can see vaginal openings and obvious nipples. Adult male rabbits can see the inside of the penis and testicles with prominent external reproductive organs.
4. The gender of dogs, monkeys and pigs
The genitals of this large animal have obvious gender differences. You can distinguish between men and women after birth, the penis and penis of male animals are prominent, and the vaginal opening of female animals is clear.