A diluent for improving the quality of yak fresh semen and frozen semen and its application.

Abstract

This invention belongs to the technical field of yak semen diluents, specifically relating to a diluent for improving the quality of fresh and frozen yak semen and its application. The diluent of this invention is a mixture of Kasu frozen semen and α-ketoglutarate, wherein the concentration of α-ketoglutarate is 200-1200 μg / mL. Research in this invention has found that the addition of α-ketoglutarate significantly improves the quality of both fresh and frozen yak semen. Specifically, sperm motility is significantly enhanced, survival rate is greatly improved, and the thawing effect after cryopreservation is more ideal. This improvement not only effectively solves the problem of poor quality of frozen yak semen but also provides a strong guarantee for improving the success rate of artificial insemination.

Description

Technical Field

[0001] This invention belongs to the field of yak semen diluent technology, specifically relating to a diluent for improving the quality of fresh and frozen yak semen and its application. Background Technology

[0002] Yaks are a special breed of cattle living on and around the Qinghai-Tibet Plateau, large livestock adapted to the high-altitude environment characterized by low oxygen, extreme cold, and strong ultraviolet radiation. The harsh plateau environment, with its long cold season and short warm season, severely limits the growth, development, and efficient reproduction of yaks. Under natural conditions, a male yak can only mate with about 20 female yaks per year, resulting in low stamina utilization. Furthermore, due to seasonal breeding limitations, female yaks typically conceive only once every two years or twice every three years, leading to low reproductive efficiency. Currently, artificial insemination technology is widely used for the rapid breeding of superior livestock. While this technology is used in yak production, its widespread application in yak breeding is still limited by issues such as the quality of frozen yak semen.

[0003] Extensive research revealed that the quality of frozen yak semen is generally low, and sperm motility significantly decreases after thawing with prolonged cryopreservation, sometimes failing to reach the 35% required for artificial insemination. The reasons for this may include: First, the quality of breeding yak semen is low; the harsh living environment, rudimentary feeding conditions, and low nutritional levels of yaks may fundamentally affect semen quality. Second, cryopreservation methods are inadequate; current cryopreservation protocols largely reference those for beef and dairy cattle semen, which may not be suitable for yak semen. Third, the semen diluent is not suitable; yak semen has unique components, necessitating the development of a specialized semen diluent protocol for its cryopreservation. Although commercially available Kasu frozen semen can improve sperm quality to some extent, its effect remains limited and has not fundamentally overcome technological bottlenecks. A new system for improving yak semen quality is urgently needed. Summary of the Invention

[0004] To address the problems existing in the prior art, this invention provides a diluent for improving the quality of fresh and frozen yak semen and its application.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a diluent for improving the quality of yak fresh semen and frozen semen, which is composed of a mixture of kasu frozen semen and α-ketoglutarate.

[0006] This invention represents a significant breakthrough in the field of yak reproductive technology. It is the first discovery that adding α-ketoglutarate as a diluent to Kasu frozen semen can significantly improve the quality of both fresh and frozen yak semen. This innovative achievement not only solves a key problem that has long hindered the development of artificial insemination technology for yaks, but also lays a solid foundation for accelerating the breeding process of superior yak breeds through artificial insemination.

[0007] For a long time, the low reproductive efficiency of yaks has been a major factor restricting their population development and the breeding of superior breeds. Under natural reproductive conditions, yaks have a long reproductive cycle, with female yaks typically giving birth once every two years or twice every three years, and the breeding capacity of male yaks is also subject to many limitations. Although artificial insemination technology has been widely used in other livestock breeds, its application in yak breeding has always been limited due to the difficulty in achieving ideal quality frozen semen from yaks. Poor frozen semen quality is mainly manifested in low sperm motility and low survival rate, which significantly reduces the success rate of artificial insemination.

[0008] The innovation of this invention lies in its in-depth study of the characteristics of yak semen and the key factors affecting sperm motility during cryopreservation. For the first time, it proposes adding α-ketoglutarate as a diluent to Kasu frozen semen. The research results show that the addition of α-ketoglutarate significantly improves the quality of both fresh and frozen yak semen. Specifically, sperm motility is significantly enhanced, survival rate is greatly improved, and the thawing effect after cryopreservation is more ideal. This improvement not only effectively solves the problem of poor quality in frozen yak semen but also provides a strong guarantee for improving the success rate of artificial insemination.

[0009] Furthermore, the concentration of α-ketoglutaric acid in the diluent is 200~1200 μg / mL.

[0010] Secondly, the present invention provides the application of the diluent in improving the quality of yak semen.

[0011] Furthermore, the semen is fresh semen or frozen semen.

[0012] Furthermore, the diluent is used to enhance yak sperm motility.

[0013] Furthermore, when the yak semen is fresh, the diluent is used to enhance sperm motility and rapid forward movement.

[0014] Furthermore, when the yak semen is frozen semen, the diluent is used to enhance the forward and rapid movement of sperm, and reduce the slow and stationary movement of sperm.

[0015] Furthermore, the yak semen and the diluent are diluted at a volume ratio of 1:4 to 6.

[0016] The present invention has the following beneficial effects: This invention has broad application prospects. By improving the quality of frozen yak semen, the mating ability of male yaks can be effectively enhanced, and the reproductive cycle of female yaks can be shortened, thereby significantly improving the reproductive efficiency of yaks. This will help accelerate the breeding of superior yak breeds and promote the large-scale and modern development of yak farming. Furthermore, this invention provides valuable lessons and references for improving the reproductive techniques of other plateau livestock, possessing significant scientific value and practical significance.

[0017] In summary, this invention is a milestone in the field of yak breeding technology. It not only provides a completely new approach and method for solving the problem of low yak reproductive efficiency, but also opens up new avenues for promoting the sustainable development of yak farming and the breeding of superior breeds. Detailed Implementation

[0018] The present invention will be described in detail below with reference to specific embodiments, but should not be construed as limiting the present invention. Unless otherwise specified, the technical means used in the following embodiments are conventional means well known to those skilled in the art, and the materials, reagents, etc. used in the following embodiments can be obtained commercially unless otherwise specified.

[0019] Example 1: Preparation of a diluent for improving the quality of yak semen and frozen semen 1) Kasu frozen semen The product, named Optidyl™ diluent, consists of ultrapure water, egg yolk, glycerol, carbohydrates, mineral salts, buffers, and antibiotics (with penicillin, streptomycin, lincomycin, and zearalenone added according to EU standards 2003 / 43 / CE and CEE88 / 407). It was manufactured and developed by IMV Casu in France and complies with ISO9001:2000 production standards. It was purchased from Shanghai Casu Biotechnology Co., Ltd., product number 020996.

[0020] 0) Preparation of diluent α-Ketoglutarate was added to Kasu frozen semen in a gradient and mixed thoroughly. The concentrations added were 200 μg / mL, 600 μg / mL and 1200 μg / mL, respectively.

[0021] Example 2: Detection of the effect of diluent on the quality of yak fresh semen and frozen semen The yak semen was diluted with the diluent prepared in Example 1 at a volume ratio of 1:5, that is, 1 part semen was added to 5 parts diluent.

[0022] Sperm quality was assessed using a computer-assisted sperm analysis (CASA) system before cryopreservation (18 hours) and after thawing (15 days). Cryopreservation was performed in liquid nitrogen, following the temperature drop profile described below:

[0023] 4℃ to -10℃, 2.5 minutes; -10℃ to -100℃, 2.5 minutes; -100℃ to -140℃, 2.0 minutes; maintain at -140℃. Recovery is a 37℃ water bath for 30 seconds.

[0024] Analysis of fresh semen stored at low temperature (4℃) showed that the addition of 1200 μg / mL α-ketoglutarate significantly improved sperm motility, including forward motility and rapid motility (Table 1). This indicates that α-ketoglutarate has the ability to improve sperm quality before cryopreservation.

[0025] Table 1. Effects of gradient addition of α-ketoglutarate on the quality of fresh yak semen stored at low temperatures. After 15 days of cryopreservation, the quality of the thawed sperm was tested. It was found that α-ketoglutarate at concentrations of 200 μg / mL, 600 μg / mL, and 1200 μg / mL significantly improved sperm motility, with both forward motility and slow-moving motility significantly higher than the control group. Simultaneously, the above concentrations of α-ketoglutarate significantly reduced slow-moving and stationary motility (Table 2), indicating that the addition of α-ketoglutarate can significantly improve the quality of yak frozen semen.

[0026] Table 2. Effects of gradient addition of α-ketoglutarate on the quality of yak frozen semen Based on the above results, the addition of α-ketoglutarate can improve the quality of yak semen and frozen semen.

[0027] It should be noted that when numerical ranges are mentioned in the claims of this invention, it should be understood that the two endpoints of each numerical range and any value between the two endpoints can be selected. To avoid redundancy, the present invention describes preferred embodiments.

[0028] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

Claims

1. A diluent for improving the quality of yak semen and frozen semen, characterized in that, It is made from a mixture of frozen semen and α-ketoglutarate.

2. The diluent for improving the quality of yak semen and frozen semen according to claim 1, characterized in that, The concentration of α-ketoglutarate in the diluent is 200~1200 μg / mL.

3. The use of the diluent according to any one of claims 1 to 2 in improving the quality of yak semen.

4. The application of the diluent according to claim 3 in improving the quality of yak semen, characterized in that, The semen is either fresh semen or frozen semen.

5. The application of the diluent according to claim 4 in improving the quality of yak semen, characterized in that, The diluted solution is used to improve yak sperm motility.

6. The application of the diluent according to claim 5 in improving the quality of yak semen, characterized in that, When the yak semen is fresh, the diluent is used to enhance sperm motility and rapid forward movement.

7. The application of the diluent according to claim 6 in improving the quality of yak semen, characterized in that, When yak semen is frozen semen, the diluent is used to improve sperm motility and rapid forward movement, and to reduce sperm motility and stationary movement.

8. The application of the diluent according to claim 4 in improving the quality of yak semen, characterized in that, The yak semen and diluent were diluted at a volume ratio of 1:4 to 6.

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