RU2189743C1 - Method for sex regulation in animals, for example, in cattle - Google Patents

Abstract

FIELD: animal science. SUBSTANCE: for sex regulation in animals one should use physiological alterations associated with age. Moreover, to obtain increased number of calves age selection of couples is performed so that first-calf heifers and bulls are older than 7 years, or cows should be older than 7 years and bulls older than 3 years, or cows - older than 7 years and bulls - older than 7 years, for predominance of heifers one should select couples of cows and bulls aged 5 years. The method is simple in application and safe for animals. It enables to obtain more calves or heifers in the offspring depending on the necessity to exclude specific impact upon animal body and, as a result, development of stresses and allergic reactions, exclude additional material and labor expenditures for preparing and injecting the preparation. EFFECT: higher efficiency of sex regulation. 3 ex, 1 tbl

Description

 The invention relates to animal husbandry, in particular, to methods for regulating sex in animals, for example, in cattle.

 Known methods for regulating the sex of animals, for example, by identifying sex and selective transplantation of embryos, exposing females to physiologically active drugs [1].

 In addition, there are methods of sex regulation based on the influence of natural factors on the body, in particular, the creation of certain nutritional conditions for males and females [2].

The disadvantages of these methods include
- high price;
- the need to use sophisticated machinery and equipment;
- the complexity of molecular genetic methods;
- slight deviations of the sex ratio in the offspring from genetically determined (1: 1);
- the need to create certain conditions for feeding and keeping animals.

 There is also known a method of regulating the sex of animals by immunizing females with male tissue homogenates, based on the suppression in the body of females of living cells giving rise to males by treating them with antiserum against male tissues [3].

The disadvantages of this method are
- the possibility of shifting the sex ratio in the offspring only in the direction of increasing the number of females;
- high material costs for the preparation and administration of the drug;
- the need for subcutaneous administration of the drug, which increases the complexity of the procedure and requires the involvement of additional veterinary specialists;
- the possibility of stress and allergic reactions in animals.

 The objective of the invention is to increase the number of individuals of the desired sex in the offspring of animals in a natural way (without specific effects on the body).

 To accomplish the task in a known method of regulating the sex of animals, which consists in using physiological changes occurring in the body of animals, according to the invention, physiological changes associated with age are used, while in order to obtain more bulls in the offspring, the age selection of pairs is carried out in such a way that first-born cows and bulls older than 7 years old, or cows older than 7 years old and bulls 3 years old, or cows older than 7 years old and bulls older than 7 years old, and for predominance in offspring heifers are picked up by pairs of cows and bulls of five years of age.

 The initial theoretical principle is the assumption that a more vital zygote should tend to develop in the direction of the female sex, and less vital in the direction of the male sex. Based on this, with a certain age combination of parents, coinciding with the "flowering" of the functional systems of their body, when the most viable gametes are produced, females predominate in their offspring. In other age combinations, more males are born.

 Thus, a certain orientation of metabolic processes in the body, which changes with age, affects the physiological state of gamete parents before fertilization and further on the formation of the sex of the embryo.

 In livestock farming for the production of milk or the expanded reproduction of the herd, there is a need for preferential production of females, for the production of meat and wool - males. The solution to this problem will improve the efficiency of livestock.

 To regulate the floor of the proposed method, 6 groups of cattle were formed, 50 pairs each (a total of 300 pairs), depending on age. The experiments used cows of black-motley breed aged 3 to 12 years old and bulls of Holstein breed of different ages.

 Example 1. The first group was formed from first-calf cows (3 years old) and bulls older than 7 years old. As a result, 36 calves (72%) and 14 heifers (28%) were obtained from calving from them. calves were born 2.6 times more than calves.

 In the 2nd group, cows older than 7 years old were inseminated with sperm of bulls of 3 years of age. Bulls prevailed in their offspring: there were more of them than heifers 3.5 times - 77 and 23%, respectively.

 In the offspring of cows older than 7 years old and bulls older than 7 years old (group 3) 32 bulls and 17 heifers were obtained - 65 and 35%, respectively (see table).

 Example 2. In the 4th group were selected cows at the age of 5 years and bulls of the same age (5 years). From them 1.9 times more heifers were obtained than calves - 34% of calves and 66% of calves (see table).

 Example 3. In the offspring of 5-year-old cows and 3-year-old bulls (group 5), the ratio of gobies and heifers was close to 1: 1–43 and 57%, respectively.

 In the 6th group, from cows older than 7 years and bulls of 5 years old, approximately the same number of bulls and heifers was born - 28 bulls and 22 heifers -56 and 44%, respectively (see table).

 The data obtained indicate the influence of physiological changes in the body of animals associated with age on the sex ratio in their offspring. It was established that both very young and old parents received more females, and in other age combinations (one of the middle-aged parents) the sex ratio is close to genetically determined.

The proposed method is quite simple to use and safe for animals. Its use allows
- get in the offspring more bulls or heifers, depending on the need;
- to exclude a specific effect on the body of animals and, therefore, the occurrence of stress and allergic reactions in them;
- exclude additional material and labor costs for the preparation and administration of the drug.

Sources of information taken into account
1. Maksimovsky L.F. The possibility of a directed effect on the formation of the sex ratio of the offspring of mammals. Agricultural Biology, 1988, 1, pp. 10-18.

 2. Parshutin G.V., Rumyantseva E.Yu. Sex regulation in chickens. Livestock, 1966, 3, pp. 79-85.

 3. Patent 2142704, cl. A 61 D 19/00 is a prototype.

Claims (1)

 The method of sex regulation in animals, for example, cattle, which consists in using physiological changes that occur in the animal organism, characterized in that physiological changes associated with age are used, and in order to obtain more bulls in the offspring, the age selection of pairs is carried out in this way so that there are first-calf cows and bulls older than 7 years old, or cows older than 7 years old and bulls 3 years old, or cows older than 7 years old and bulls older than 7 years old, and for the predominance of heifers in the offspring there are pairs of cows and bulls of five years of age.

Images