Scientists try their best to increase the proportion of cows giving birth to calves;
(1) The project "X/Y Sperm Separation in Dairy Cows-Sex Control" passed the expert appraisal.
[Source: Xinhuanet Inner Mongolia Channel Time: 2005- 10-2 1 Author: reporter Zhang Zhang]
On September 27th, the project "X/Y Sperm Separation in Dairy Cows-Research on Key Technologies of Sex Control Industrialization" hosted by Inner Mongolia Saikexing Biotechnology Co., Ltd. passed the expert appraisal. The sperm separation speed and bull utilization rate of this project have reached the international leading level, which is conducive to promoting the rapid scale of dairy farming in China and providing milk source for the development of dairy processing industry.
The base plays a very important role.
The Science and Technology Department of Inner Mongolia Autonomous Region hired domestic experts to conduct technical appraisal of the project in Hohhot and Linger. Experts from the appraisal committee believe that SX- Moflo, a special equipment for sperm separation, was introduced from American XY Company for the first time. Through the improvement of sperm dyeing technology, the production efficiency of the equipment was increased by more than 65,438 0.5 times, the separation speed was increased to 5,000-6,000 sperm per second, and the separation accuracy was over 95%. At the same time, it solves the problem of poor sperm separation effect (accuracy of X and Y sperm separation) caused by individual differences of breeding bulls abroad, improves the utilization rate of breeding bulls to over 90%, and expands the utilization rate of breeding bull genetic resources and the production efficiency of sex-controlled frozen semen.
This achievement not only has important academic significance, but also has broad industrial application value. In this project, after improving the formula of frozen liquid (adding sugar and enzyme bioactive substances) and freezing technology, * * * breeds cows 126 1 time, including 576 pregnant cows and 342 pregnant cows, which has achieved good results and laid a foundation for the large-scale popularization and application of semen control of dairy cows in the next step.
Established in 2003, Inner Mongolia Saikexing Biotechnology Co., Ltd. is the first biotechnology enterprise in China authorized by American XY Company to conduct research on mammalian sperm separation and apply sex control commercialization technology to dairy cows and beef cattle. The project of "X/Y Sperm Separation-Sex Control in Dairy Cows" was sponsored by Secco Star Company and completed by China Agricultural University, Inner Mongolia University, Beijing Dairy Cow Center and Inner Mongolia Livestock Improvement Workstation.
(2) Sex control of dairy cows is in the ascendant.
The income of dairy farming mainly comes from milk production income and calving income. At present, the price difference between male and female calves in the market is more than 10 times, and the majority of dairy farmers are eager to improve the conception rate of female calves. But in general, the probability of cows breeding male calves and female calves is 50/50. Therefore, countries all over the world actively study and apply methods such as sperm separation, embryo sex identification, and control of conception environment in dairy cow production, so as to artificially control the sex of dairy cow offspring, selectively produce female calves, and improve dairy cow breeding efficiency.
Sperm separation technology is based on the difference theory of X and Y sperm, such as the difference of DNA content and the different mobility of X and Y sperm. After fertilization, X sperm and eggs are fertilized to develop into female individuals, and Y sperm and eggs are fertilized to develop into male individuals, thus obtaining offspring of the expected sex. Sperm separation methods include centrifugation, sedimentation, filtration, fluorescent pigment labeling, electrophoresis, immunomagnetic method, flow cytometry and so on. This method has high accuracy, but the technology is complex, many operation links must be carried out in large laboratories, and the instruments and equipment are very expensive. It is still in the pilot stage in China, and some methods are still controversial in theory. According to reports, scientists have entered the trial production stage at the Tianfeng improved livestock breeding base in Daqing City. Xinjiang Academy of Animal Husbandry cooperated with experts from Cornell University in the United States. The first batch of 22 sex-controlled embryos produced by sperm separation technology in Hutubi Cattle Farm have given birth to 1 1 calf.
Embryo sex identification is based on embryo segmentation and embryo freezing technology, and embryo transfer is carried out after sex identification. The methods of embryo identification include cytological observation of X and Y chromosomes and immunological detection of H-g antigen on the surface of male embryo cells with specific antibodies. This method has the highest accuracy, but there are three outstanding problems in its popularization and application: First, it is difficult to support technology (such as embryo segmentation). The second is the high cost. In actual production, the yield of donor cattle is generally required to be above 8000 kg, and only 5-7 embryos are taken at a time. If embryos are picked more than 3-4 times a year, reproductive system diseases are prone to occur, and the loss of milk production is even greater. At the same time, drugs such as embryo cleaning solution and embryo culture solution are imported, which leads to high pretreatment cost of donor cattle. At present, bioengineering companies produce a calf at a cost of 4500-5000 yuan, which is equivalent to the price of a calf in the market. Third, the pregnancy rate is low, only about 50%. At present, there are few bioengineering companies that implement commercial operation in China. According to reports, experts from Beijing Amber Embryo Biotechnology Center, China Agricultural University and Canadian Pacific Genetic Center transferred embryos to 108 yellow cattle in three batches, of which 56 were pregnant, with a success rate of 52%.
The principle of controlling the conception environment is that the sperm with Y chromosome has poor acid resistance and the sperm with X chromosome has strong acid resistance. When the pH value of thawing solution is lower than 6.8, the sperm containing X chromosome is more active than the sperm containing Y chromosome, and it is easy to combine with eggs, so dairy cows will give birth to more calves after pregnancy. There are two control methods. One is arginine method, in which arginine is diluted with normal saline, and a certain concentration of 1 ~ 2ml solution is injected into vagina 20 ~ 30min before insemination, and more females are produced at the concentration of 10%. One is the PH control method. When the pH of thawing solution is 6.4, the calving rate is the highest, reaching 765,438 0.0%. The method has the advantages of easily available raw materials, convenient operation and low cost. According to reports, Zhang Jushun of Zhongwei County Animal Husbandry Station in Ningxia, Chen Shounan of Yucheng County Animal Husbandry Bureau in Henan and Li Fanglai of Wenling have conducted many experiments, but the results are not stable. It is reported that Beijing Sanniu Xingye Science and Technology Development Co., Ltd. has successfully developed a kind of milk cow sex control capsule, and its sex control calving rate has reached more than 80%, and it has obtained the national patent certificate.
(3) The application test of "mother calf essence" to improve the performance of calves.
Nur Mohammad 1 Zhao Jiankang 2 Abu Lizi? Wu Siman 2 Ma and Muti 1 Baoshan 2
(1 ... Xinjiang Wensu County Variety Improvement Station, Xinjiang Wensu 843100; 2. College of Animal Science, Xinjiang Agricultural University, Urumqi, Xinjiang 830052)
The experiment of using "calving hormone" to improve the calving rate of Holstein cattle, Simmental cattle, hybrid cattle and local cattle showed that the average calving rate of the experimental group was 76.3%, while that of the control group was 38.4%, which was 37.9% higher than that of the control group, and the difference was extremely significant (P < 0.0 1). There was no obvious difference among breeds, and the highest calving rate of hybrid cattle was 8 1.0%, which achieved ideal results.
Keywords: calf, calf
1 preface
With the development of cattle industry, in order to improve the economic benefits of cattle industry, various localities have increased the intensity of variety improvement. However, due to the wide application of frozen semen breeding technology, the proportion of calves in dairy cows has decreased. According to statistics, the calving rate of frozen semen is 32.4% ~ 46.2%, which seriously restricts the development of cattle industry, affects the process of variety improvement in various places and affects cattle farmers.
Cows are singletons, and the growth rate of the total number of cows in natural state is less than 9%. A cow can only breed 1 baby a year, and can only provide 3-4 effective offspring (cows) in a lifetime. At present, the conventional artificial insemination breeding technology is far from meeting the needs of industrial development. The development of cattle industry in China is slow and the production level is low. The important reasons are backward breeding technology, long breeding cycle and low rate of improved varieties. Only by rapidly improving the level of improved varieties and expanding improved cattle herds can the cattle industry achieve high yield, high quality and high efficiency.
In the past 20 years, many experiments and studies on sex control have been carried out at home and abroad, such as separating X sperm and Y sperm by centrifugation, filtration and electrophoresis. And embryo sex identification technology before embryo transfer. However, due to cost and other reasons, it is not widely used in production practice, especially the research on how to solve the decline of calving rate of cold-matched dairy cows has not been reported. In order to completely change the current situation of low calving rate of dairy cows, the College of Animal Science of Xinjiang Agricultural University set up a research group on "Calving Cows" on 1996. After formula screening, reagent synthesis, toxicity experiment and preliminary application, the "female calf essence" for sex control injection of dairy cows was finally developed.
This experiment was carried out in Xinjiang Production and Construction Corps 122 Corps, Habahe County and Wensu County, and achieved good results.
2 materials and methods
2. 1 Selection and grouping of experimental cattle
There were 370 Holstein cows in Corps 122, including 60 cows in experimental group/KLOC-0 and 2 cows in control group10. 80 crossbred cows in Habahe county were all experimental groups. 640 Holstein cattle, Simmental cattle, hybrid cattle and local cattle in Wensu County were divided into experimental group and control group respectively. There are 8 groups with 80 cows in each group.
2.2 Sources of test drugs and frozen semen
"Calf essence" (pilot product) was developed and produced by College of Animal Science, Xinjiang Agricultural University. It is a liquid preparation with the dosage of 1. 1ml∕ branch (65438 0 amp) and 1.3ml∕ branch (65438 0 amp) respectively.
Fine tube frozen semen was provided by Xinjiang Uygur Autonomous Region Livestock and Poultry Breeding and Improvement Station, and the breeds were Holstein and Simmental respectively.
2.3 Test Time and Method
The examination time for this application is from July 2002 to June 2003 at 5438+00.
The cows in the experimental group and the control group are naturally estrus cows. In the experimental group, before estrus mating, 1 branch of "female calf hormone" was accurately input into the cervix 3㎝ (the same as the insemination site) with a particle insemination device, and then the insemination device was slowly withdrawn, and insemination was conducted every 0.5h The conventional rectal grasping uterine insemination method was adopted. The control group only received artificial insemination. Other conditions were the same as those of the control group. Make records at the beginning of the experiment, including pregnancy, calving, calf gender statistics and other records and analysis.
3 Results and analysis
3. 1 test results
The experiment on three experimental sites 1090 cows showed that the pregnancy rates of the experimental group and the control group were 77.3% and 78. 1% respectively, and there was no significant difference between them (P > 0.05). The average calving rate was 76.3% and 38.4% respectively, and the experimental group was 37.9% higher than the control group, with significant difference (P > 0.05). According to the test results, the calving rate among different breeds is between 765,438 0.9% and 865,438 0.0%, and there is no significant difference among different breeds. The highest is hybrid cattle, followed by local cattle, as shown in Table 65,438+0. This experiment has achieved good results.
Table 1 Statistical Table of "Female Calving Element" Unit: Head, %, ml
test base
In the dose test group, the rate of female calves in the control group increased (
Percentage points)
match
grow
count
suffer
embryo
Digital acceptance
embryo
Calving rate, reproductive number, pregnancy number, pregnancy rate, calf number
public
Mother, mother
calf
speed
public
Mother, mother
calf
speed
Corps 122 Holstein Cattle1.3160135 84.430105 77.8210/79 85.2/KLOC-0.
Habahe hybrid cattle1.3805872.511.4781.0
Holstein cattle in Wensu county1.1.806480.018 4671.9 806581.335 3046.225.7.
Simmental cattle1.1.806075.0164473.3 806277.5 36 26 41.931.4.
Hybrid cattle1.1.80 62 77.51.6 46 74.2 80 60 75.0 36 24 40.0 34.2
Local cattle1.1.80 54 67.51.43 79.6 80 53 66.3 30 23 43.4 36.2
The average is 560 433 77.310233176.3 530 41978.125816138.437.9.
3.2 Benefit analysis
According to the current market situation, the market price ratio of 1 female calf is 1 male calf is high 1000 ~ 2000 yuan (the market price of pure Holstein female calf is 4000-5000 yuan higher than that of male calf), and only 433 pregnant cows in the experimental group can give birth to 164 female calves. More than 76 Holstein calves were produced, which increased the direct economic income by about 300,000 yuan. At the same time, it can promote the improvement of cattle structure, increase milk production, improve the improvement effect of cattle, and play a positive role in promoting the economic development of minority areas.
4 discussion
4.65438+
4.2 There is a certain correlation between different doses and the weight of cattle. It can be seen from the table 1 that the therapeutic effect of "calf essence" in 1.3ml∕ branch is better than that in 1. 1ml∕ branch. Because Holstein cows and Simmental cows are heavier, 65438 is applicable. It is suggested that the dosage of "calf essence" should be increased to 1.7ml for cattle weighing more than 600㎏, 1.5ml for cattle weighing 500㎏ and 1.3ml for cattle weighing less than 450㎏. It is possible that.
References:
[1] Xu Linping, Han Jianlin, Cao Shizhen. Sex control of cattle [J]. China Dairy Cows, 2000, (5): 3 1-32.
[2], Kang, Bao Shan, et al. Study and application of calf essence to improve the calving effect of dairy cows [J]. Xinjiang Animal Husbandry, 2003, (2): 30-3 1.
Experiment on improving the rate of female calves by using mire
Nurmamat 1 Zhao Jiangkang 2 Abliz? Osman 2 Mahmoud 1 Baoshan 2
(1. Livestock Breeding and Improvement Station in Wensu County, Xinjiang, 843100; 2. College of Animal Science, Xinjiang Agricultural University, Urumqi, Xinjiang, 830052)
Abstract: The experiment of raising the calf rate of Holstein cattle, Simmental cattle, hybrid cattle and local cows was carried out by using mudulin. The results showed that the calving rate of the experimental group (76.3%) was 38.4% higher than that of the control group (37.9%) (P < 0.01). The rate of female calves in local breeding group was the highest (8 1.0%).
Key words: Mudusu cow calf
About the author: Nurmamati (1965-), male, from Xinjiang, undergraduate, majoring in animal husbandry, mainly engaged in animal husbandry production and management.
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