JPH072067B2 - Artificial sex selection method - Google Patents

Description

[Detailed Description of the Invention] With the progress of science, research on the chronatality has reached the scope of day-to-day elucidation, and recently, the Percoll method using the Hy antigen has been announced. It is the current situation that has been announced as a way to do.

All of these are based on the idea that the male is the main subject.It has been clarified genetically that males have the right to determine sex in mammals, but once the spermatozoa released from the male body are In the female body, it must be controlled by the physiological, nutritional and internal environment of the female body. That is, it is considered that the influence of the type of feed given to females, the amount of feeding period, feeding management, etc., becomes a factor in the selection of spermatozoa in females. It is considered that the male has the decision right and the female has the choice right. Therefore, it is thought that the sex can be deviated to one side by artificially changing the internal environment of the female body.
The evidence for this is that there are many cases in which male calves have been delivered due to resale of cows that produce only female calves and changes in the barn and breeders. For breeding cattle with the purpose of artificially selecting sex using Japanese Black cattle, roughage and arginine less than about 10 g, digestible energy amount less than about 3500 kcal, digestible protein mass less than about 150 g concentrated feed almost daily As a result of artificial fertilization by shocking feeding from 10 to 14 days before ovulation, the results shown in Appendix 1 were obtained. When each test group was aggregated, 52 out of 64 became male and accounted for 81, 25% of the total. It was demonstrated that sex is selected with a higher probability than the probability of a sex ratio of 1: 1 in the natural world. Among them, the selection rates in test areas 1 and 2 are 85 and 71, respectively.
% And 80, 71%, showing a large deviation from the natural sex ratio. This method is considered to be within the economical range of salary, without judging from an economic or veterinary nutritional point of view, that the livestock do not become fertilized and become unfertilized.

Explaining the feeding method with reference to Fig. 1 and Fig. 2, inexperienced cows are fed with roughage necessary for maintenance for about 7-10 days immediately after estrus (H ₁ ) before mating, and then about 10-14 Fertilize (F ₁ ) for a day and fertilize after estrus (H ₂ ). Feeding of concentrated feed is stopped immediately after fertilization, feeding is continued for about 7 to 10 days, and the next estrus (H ₃ ) is predicted, and flushing of concentrated feed (F ₂ ) is performed again. Move to rearing. If the person is in estrus, repeat the above-mentioned feeding method, but if it is overfertilized or pathological, stop this method and take appropriate measures.
For multiparous cows, immediately after calving (Fig. 2A), they are fed with a roughage necessary for maintenance for about 30 days, and then flushed (F ₃ ) until estrus (about 10 to 20 days). If there are individual differences but estrus does not develop even after 20 days, the feeding of concentrated feed is temporarily stopped, and the animals are kept for about 7 to 10 days without being fed with roughage necessary for maintenance. When the concentrated feed is increased (F ₄ ) by the same method as in ( ₄ ), estrus is prominent and the conception rate is good. By feeding with a postpartum roughage, the uterine contraction is accelerated, metabolism is enhanced, uterine mucus and mucous membranes are normalized, and the effect of the next sex selection is enhanced, and it is useful for preventing diarrhea of dairy calves.

If there is estrus within 30 days, raise the cow by the same method as heifers (Fig. 1) based on that day. Concentrate feed should be normal nutrition or slightly lean.

The shocking feeding of concentrated feed by this method further enhances the effect of sex selection, further improves the environment in the reproductive organs, improves the hormone balance, and feeds with unprecedentedly high energy and amino acids stimulates the ovaries and follicles. It has the effect of promoting the development and ovulation of chicks and improving the conception rate. Although there are individual differences, as shown in Fig. 3, a concentrated feed is shocked when the luteal body (E) degenerates and the follicle (O) increases immediately after ovulation, about 20 days after the estrous cycle (C) for about 20 days. By repeating this method, an artificial synergistic effect occurs.

According to this method, the farmer can easily carry out the method, and more male calves can be systematically produced, which has many advantages for securing the meat amount.

[Brief description of drawings]

Fig. 1 shows the method of feeding heifers. Fig. 2 shows the method of heifers. H ₁ Estrus of heifers before mating scheduled H ₂ Estrus of mating of heifers H ₃ Estrus of next heifers H ₄ estrus schedule of cows H ₅ Economy, Trade and Industry next estrous F ₁ the first time flushing F ₄ of the second times flushing F ₃ cows of the first time flushing F ₂ heifers of heifers of cattle Second flushing of heifers A Scheduled calving date G Roughage feeding period Roughing period (about 7-10 days) Concentrated feeding period (about 10-14 days) Roughing period for heifers (about 30 days) For heifers 1st concentrated feed period (about 10-20 days) Figure 3 is a schematic diagram of estrus cycle B concentrated feed feeding period C estrus cycle C'estrus D ovulation E luteal O follicle G rough feed feeding period

Claims (1)

[Claims] 1. A concentrated feed containing digestible energy of 3,500 kcal or less and digestible protein of 150 g or less containing 11 g or less of arginine for a breeding cow from 10 to 14 days before ovulation, and the period until conception A method for selecting male and female offspring, which is characterized by performing flushing salary.