Technical Measures to Improve Reproduction of Rex Rabbits
1. Improved mating methods using repeated mating or double mating can significantly increase female fertility rates and litter size. Repeated breeding refers to the interval of 4-6 hours after the first breeding, and mating with a rabbit. Double breeding means that a female rabbit is mated with 2 male rabbits continuously, and the interval between them is no more than 20-30 minutes. Double mating can increase female fertility by 10%-20% and increase litter size by 1-3. It is worth noting that when using double mating, the female rabbit should be returned to the original cage in time after mating with the first male rabbit. After the male rabbit's odor disappears, the second male rabbit should be bred. Otherwise, due to the scent of other male rabbits on the female rabbit, the fight will not only fail to be successful, but may also bite the female rabbit. 2. Raising the breeding density Generally, most rabbits in rabbit farms are weaned at 40-45 days of age, and then the female rabbits are reared again. Therefore, only 3-4 births can be propagated in one year, and the reproduction rate is very slow. If the feeding and management conditions are better, frequent breeding or semi-frequent breeding may be carried out to increase its breeding density. Frequency breeding due to breeding time is shorter than the farrowing period of childbirth, so this breed is commonly known as "blood allocation", that is, mating in the female rabbit within 1-3 days after childbirth, can shorten the breeding interval 20-30 days, each year can breed 8 to 10 tires; semi-frequent breeding means that the female rabbit is mated within 12 to 15 days after childbirth, which can shorten the breeding interval by 8-10 days, and increase the number of fetuses by 3-4 births per year. It should be pointed out that after maternal blood mating, because of breast-feeding and pregnancy at the same time, the demand for nutrient substances is very large, and the quantity and quality of feed must meet the needs of female rabbit itself and lactation and fetus growth and development. In addition, the female rabbit must be weighed regularly, and if it is found that the weight is significantly reduced, the next blood allocation must be stopped. Due to the frequent breeding, the breeding year of rabbits is shortened, generally not exceeding 1.5-2 years, and the natural elimination rate is higher. Therefore, we must update the reproduction of female rabbits in time, and we must strengthen the breeding and management of the young rabbits that are kept. 3, the use of artificial aphrodisiac Some female rabbits due to long-term estrus or refuse to affect mating, especially in autumn and winter. In order to make female rabbits estrus, in addition to improving the husbandry and management, artificial aphrodisiac can also be used. 3.1 hormone aphrodisiac to promote ovulation hormones in female rabbits, mainly in the anterior pituitary follicle-stimulating hormone (FSH), luteinizing hormone (LH) and placenta secretion of human chorionic gonadotropin (HCG), pregnancy Horse serum gonadotropin (PMSG) and so on. According to the trial, intramuscular follicle stimulating hormone (2 times daily, 0.6 mg each), intravenous luteinizing hormone (10 units/bomb/time), and intramuscular injection of chorionic gonadotropin (each time 50- 100 units/body) or pregnant horse serum gonadotropin (40 units/increment per intramuscular injection) generally allows the ovulation rate of the female rabbit to reach 70% to 90% and the conception rate to 65% to 70%. The number of births is 4-6. 3.2 Sex-induced aphrodisiac Sex-induced aphrodisiac can be used for female rabbits that do not have heat for a long time or refuse to mate. The female rabbit is released into a cage of male rabbits, and after being stimulated by chasing or climbing, the female rabbit is still sent back to the original cage. After 2-3 times, the female rabbit can be induced to secrete sex hormones and promote estrus and ovulation. Usually aphrodisiac in the morning, and breeding in the evening.