Compared with other domestic animals, cats have unique reproductive physiological characteristics. Cats are estrous animals with mating, ovulation and seasonal reproduction.
1¡¢ Sexual maturity
Female cats reach sexual maturity 5-9 months after birth, but the sexual maturity period is not only related to the breed, but also different from the season of sexual maturity. Persian and Himalayan cats are late maturing and do not show oestrus before 1-1.5 years old. Generally, cats that reach sexual maturity in the spring show oestrus in the month of spring, while cats reaching sexual maturity in autumn will delay their estrus until the spring of the following year. The sexual maturity period of male cats is 9-12 months.
2¡¢ Breeding period
In the northern hemisphere, the breeding season is from late January to September. Cats usually mate in February, may and June, sometimes in September. Two to three times a year. Some of the cats kept indoors always showed estrus in one year, while most of them showed no estrus from late September to late January of the next year. This is due to the influence of sunlight. If the lighting time is artificially prolonged for more than 14 hours, the estrus free period can be shortened or completely disappeared. There is no specific breeding season for male cats.
3¡¢ Sexual cycle
The sexual cycle of cats is 13-15 days (sometimes 10-22 days). The estrus cycle of cats is very different from that of mating or pregnancy and from breeding to non estrus.
1. Pre estrus: no more than 3-5 days. The development and maturation of follicles, under the action of estrogen, genital and vaginal epithelial changes. Females usually do not have oestrus and males are not allowed to mate.
2. Estrus period: when mating is allowed, the cat will perform special estrus behavior, that is, making a unique Scream (called the female cat calls for spring, especially the Siamese cat), spinning on the ground, sometimes the owner thinks that the cat is sick; frequent urination; getting close to people; lying prone when touching the back and waist and making mating posture; showing uneasiness, sometimes not returning after several days out; vulva The swelling was not significant, different from dogs, blood was not discharged from the pudendum, and secretion was hardly seen (there was mucus in the vagina); the changes of vaginal epithelium were significant. The estrus period was 3-6 days when living with the male cat, and about 10 days when there was no male cat.
3. Estrus rest period: the copulation period of male cats is not allowed. Keratinocytes disappear in vaginal epithelium. When there is no mating, the follicles are atresia and degenerate. In the breeding season, after 7-12 days, follicles begin to develop, and at the same time enter the pre estrus (incomplete cycle). At the end of the breeding season, the ovaries are still and there is no oestrus for several months. Even if mating, there is no pregnancy (non pregnancy mating). After ovulation, corpus luteum is formed, which lasts for 30-45 days. Progesterone is secreted, which causes proliferative changes of uterine endometrium and induces pseudo pregnancy. In the breeding season, the corpus luteum degenerates and enters the early estrus immediately, and the estrus appears within a week. When pregnancy occurs after mating, delivery occurs after 63-65 days of gestation. After the lactation estrus free period, it enters into the next pre estrus or non reproductive period.
4. Estrus free period: from late September to late January of the next year, about 4 months are non reproductive period. During this period, the ovary is in a static state without estrus.
4¡¢ Diet during pregnancy
1. Feed high digestibility food. Including good quality protein and available calories, that is, low fiber, high protein, high calorie food.
2. Food conversion can be started at the beginning of estrus, from the original adult cat food to the young cat food, so that the maladjustment phenomenon (vomiting, pulling…) can be adjusted before actual pregnancy.
3. Increase calories at 5-6 weeks of pregnancy. (there is a saying that it is good for the older fetus at week 5 and for the smaller fetus at week 6.)
4. In the last three weeks, the system was changed to multiple meals (because the fetus became larger and the abdominal cavity became smaller, the mother could not eat a lot of food at a time.)
5. Gradually increase the food supply from the 5th to 6th week of pregnancy, until the time of giving birth, the amount of food eaten by the female cat is 1.25-1.5 times as much as usual.
6. When pregnant, the weight gain of female cat should not exceed 15-25% of usual.
7. Don’t add calcium. When the food is good quality feed, there is no need to supplement vitamins.
5¡¢ Diet after pregnancy
1. Continue to eat kitten feed until weaning (4 weeks old).
2. When the young cats are 2-4 weeks old, the food intake of female cats can be increased to 2-3 times of that of normal cats, so they can feed by eating freely.
3. When the kittens were 4 weeks old, their food intake was gradually reduced to normal. After weaning, the amount of milk can also be reduced by controlling food.
6¡¢ Estrus recovery after delivery
4-6 weeks from delivery to lactation is lactation estrus free period. After weaning, oestrus begins to recover after 2 weeks. However, in the absence of lactation (death of the kitten, etc.), after 7-10 days of delivery, oestrus will be restored, and mating and pregnancy can be carried out.
7¡¢ Mating and ovulation
They can mate on any day of estrus, but most of them mate on the third day of estrus. When mating, nerve impulses are formed due to genital stimulation, and they are transmitted to the anterior pituitary through nerves to promote the release of LH. Ovulation occurs about 27 hours after mating, with an average of 4 eggs. The eggs were fertilized in the upper 1 / 3 of the fallopian tube. The fertilized eggs (embryos) entered the uterus about 3-6 days and were implanted on the 11th to 14th days.
8¡¢ Vaginal smear (vaginal smear) examination
Vaginal smears vary with the sexual cycle of cats. In pre estrus and estrus, except for no red blood cells, it was similar to that of dogs. Because cats are mating and ovulating animals, the changes of vaginal smear can not be used to estimate the ovulation period, but it can be used to diagnose the estrus of cats without obvious estrus symptoms. In addition, the instruments inserted into the vagina during vaginal smear collection (cotton swab, glass tube, etc.) sometimes become mating like stimulation and induce ovulation. It is reported that the sexual cycles of cats raised in the laboratory 4-25 times a year (average 13 times) are confirmed by observing the changes of vaginal smears.
1. Pre estrus: in the early stage, most of them are nucleated epithelial cells, and the ratio of nucleus to cytoplasm is more than 1:1. With the approach of oestrus, the nucleus condensed and the cytoplasm enlarged.
2. Estrus phase: nuclear condensation occurs, and the number of keratinocytes with irregular edge appears. The ratio of nucleus to cytoplasm is 1:6 or 1:10.
3. Estrus resting period: keratinocytes are present in the first few days, and white blood cells, bacteria and nucleated epithelial cells appear soon after. After 3-4 days of mating, nucleated epithelial cells with large vacuoles appeared.
4. Anoestrus phase: obvious small oval, densely stained nuclear epithelial cells, as well as intangibles and white blood cells appeared.