1 General technical measures to increase the productivity of dairy cows 1.1 Feed nutrient malnutrition or high nutritional levels will affect the estrus, conception rate, embryo quality, reproductive system function, endocrine balance, and various complications during childbirth (difficulty, There are different degrees of influence, such as no placenta, mesolitis, and reduced pregnancy rate. Feeders should formulate diets according to different physiological characteristics and growth production stages of dairy cows according to common feed nutrient ingredients and feeding standards, and use rough and reasonable matching, and implement scientific breeding to maintain 7-8 percent of the status of dairy cows. Predatory production causes a serious negative balance during lactation. 1.2 Reducing heat-stressed dairy cows is a cold-tolerant animal with a suitable temperature of 0-21°C and an optimum temperature of 6-8°C. Summer temperatures are often as high as 30°C or even higher, and feed intake and milk production for dairy cows The performance of breeding, breeding, etc. has a serious impact, so reducing the impact of heat stress on dairy cows is an important part of the summer feeding management. 1.3 Post-natal monitoring Cow postpartum monitoring is under normal science feeding and management conditions. From the beginning of childbirth to 60 days after childbirth, genitals are applied to postpartum cows through observation, testing (testing), and laboratory tests. Comprehensive system monitoring with obstetric diseases as the main content, timely treatment and treatment of diseases or reproductive disorders of the cow's reproductive system, and early uterus purification treatment for individuals with endometritis, to promote the recovery of postpartum cow reproductive function as soon as possible. 1.4 Reducing Reproductive Obstacles of High-producing Dairy Cows Dairy cows have temporary or permanent infertility due to their reproductive barriers, mainly including chronic metritis, latent endometritis, chronic cervicitis, ovarian incompetence, persistent corpus luteum, and ovarian cysts. Delayed ovulation, reproductive immune disorders, and negative nutritional balance cause delays in reproduction of the reproductive system, and high-yielding cows are more common. There are three main factors that cause dairy cows to have reproductive obstacles: one is improper feeding and management, the other is genital organ diseases, and the third is reproductive technology mistakes. The main countermeasures are scientific and rational feeding and management, strict reproduction of technical norms, implementation of post-natal monitoring of cows, and improvement of cow infertility prevention and control. 2 Technical measures to increase milk cow detection rate and breeding rate 2.1 Estrus detection Heat detection is an important part of dairy cows' feeding and management. Observing three times a morning, evening, morning and evening oestrous observations can significantly increase the detection rate of cows' estrus. The method for improving the detection rate of cows' estrus mainly consists of artificial observation method, tail paint method (group breeding), rectal examination method, etc. It can be used in combination with multiple methods, and the detection rate is higher and more accurate. 2.2 Timely detection and treatment of non-estrus or lack of estrus. Milk cows are not estrus or estrus. Most of them are related to nutrition. The nutritional level of cows and feeding management measures should be adjusted in time. In the case of non-estrus or estrus-induced cows due to reproductive problems, based on the correct diagnosis, pregnant hormone gonadotropins (pmsg), cloprenol (1c1), and triad hormones can be used for aphrodisiac. Received good results, but different drugs, different doses and treatment methods have different effects. 3 Technical measures to improve the conception rate of dairy cows 3.1 The use of high-quality frozen semen is directly related to the conception rate of dairy cows. When introducing frozen sperm, in addition to requiring the selected bull has a high tpi performance index, it should also have good reproductive performance. It was determined that the introduced frozen sperm should be extracted from a certain percentage of frozen semen at the time to perform semen quality inspection including sperm viability, density, and acrosome integrity rate. After the introduction of frozen sperm, semen quality should be checked regularly to ensure the safety and high quality of the frozen essence used for breeding. 3.2 Insemination techniques Rectal grasping insemination is a common method for dairy cow breeding. It must strictly follow the insemination operation technical regulations, timely and accurately send a certain amount of semen into the appropriate part of the estrous cow's uterus, to avoid damage to the reproductive tract. It is the fundamental guarantee for improving the conception rate of dairy cows. 3.3 Insemination of dairy cows within 0-6h after estrus, the rate of continuation can reach the highest, and the best insemination time can also be judged by the following performances of the cows: cows' estrus begins to weaken, that is, they turn from restless to calm; the vulva swelling begins to disappear. The color of the mucous membrane changes from flushing to pink or with violet cyan; the mucous membranes are more or less thick, slightly viscous, and the mucus picked up between the thumb and forefinger can be pulled 7-8 times continuously; the follicle diameter at the rectal examination is 1.5mm. the above. 3.4 The insemination sites of milk steak eggs are mainly unilateral, unilateral ovulation in more than 90%, of which the right ovulation is significantly higher than the left, the right ovulation accounted for 54%, about 37% of the left ovulation, both sides simultaneously ovulation About 10%. To this end insemination should be rectal examination of ovulation sites, and then pass the microscopic examination of semen to the cervix deep 5-8cm ovulation side. Two inseminations were performed, and the second time was 8-12h apart. 3.5 Treatment of Infertility with Repeated Infertility There are many ways to treat infertility. The effect depends on the correct diagnosis of infertility. 4 Technical measures to increase the calving rate of calves and the survival rate of yak 4.1 Strengthen the fetus protection, so that the fertilized eggs or embryos will be free in the uterus for a long time after maturation of the full-produced dairy cows, usually only about 2 months after conception. Gradually completing the implantation process, and in the first 18d of pregnancy is the peak of embryonic death, so early embryo pregnancy susceptible to receptors inside and outside the environment, resulting in embryonic death or miscarriage, so strengthen the fetal protection, so that the entire production becomes an increase in production The main measure of the rate. First of all, we should pay attention to feeding and management, implement scientific feeding, ensure maternal and fetal nutrient needs, avoid malnutrition or hyperthermia, and heat stress and other environmental factors cause maternal endocrine disorders and changes in the body's physiological environment; do not feed rot Deterioration, irritation, frost and other feedstuffs and cold water; prevent pregnant cows from being frightened, whipped, slipping, crowded and over-exercise, to cattle with abortion history must strengthen protection measures, if necessary, can take antibiotic pills Or injection of progesterone to protect the fetus. 4.2 Strengthen the cultivation, so that the entire livelihood to strengthen the feeding and management of pregnant cows, especially in the late pregnancy, can help to increase the birth weight of calves. Newborn calves eat colostrum within 2 hours postpartum to increase calf resistance to disease. Early feeding was conducted 7 days after birth to promote cow stomach development as soon as possible. Develop a reasonable yak breeding program to ensure good growth and development of yaks. Avoid yak lying on the cold and wet ground, eating unclean food to prevent diarrhea and other diseases. 4.3 Shortening the interval between calving and shortening calving intervals can not only increase the reproductive rate but also increase milk production. After the cows have undergone delivery, drug treatment to promote uterine recovery and ovarian reproductive function recovery, early pregnancy diagnosis after mating, and timely induction of empty estrus cow breeding, is an important measure to shorten the calving interval and increase calving rate. 5 The application of modern reproductive technology Modern reproductive technology mainly includes cyclic estrus, superovulation, embryo transfer, embryo segmentation, in vitro fertilization, gender control, nuclear transplantation and other techniques. Here is a brief introduction to embryo transfer, gender control, and early pregnancy diagnosis techniques. Described. 5.1 Embryo Transfer Technology Embryo transfer is a relatively mature technology. Appropriate application in dairy cow production can not only increase milk production, but also speed up the breeding process, improve herd genetic performance, and increase the breeding speed of high-yielding dairy cows. 3- 6 times. Embryo transfer frozen embryo and fresh embryo transplantation two ways, frozen embryo transfer is the introduction of the purchase of frozen embryos, with the aid of embryo transfer equipment, in the estrus on the 7th by transrectal insemination method thawed embryos transplanted into the recipient cow uterus; Embryo transplantation is through the same period of estrus, supernumerary ovulation, identification of embryos collected, the available embryos were transplanted to the estrus treatment of the recipient cows. The effect of embryo transfer depends on the quality of donors, embryos and recipients. Currently, the pregnancy rate of frozen embryo transfer is 50%, and the pregnancy rate of fresh embryo transfer is 60%. 5.2 Gender control The natural reproduction rate of dairy cows is generally 48%. The adoption of sex control to make dairy cows with multiple raw cows plays an important role in improving the reproductive rate and economic efficiency of cows. At present, the sex control of cattle includes the two methods of embryo sex identification and sperm typing. The only feasible method for sex identification of embryos is to perform a histological examination of the embryos. The DNA of the samples is analyzed by molecular biology techniques (primarily pcr technique) and the y chromosome or PCR amplification products are used for the determination. Sperm division is currently used in electrophoresis, precipitation, centrifugation, immunoassay, flow cytometry and other physical methods to separate x and y sperm, to produce frozen sperm or direct mating, and to use chemical drugs to treat the reproductive tract. Change the acidity and alkalinity of the environment to make it more viable for acid (x sperm) or alkaline (y sperm) sperm to achieve gender control. At present, the success rate of gender control is generally 60%-70%. 5.3 Diagnosis of Early Pregnancy in Dairy Cows for Early Pregnancy Diagnosis is an urgent problem to be solved in cattle production. The diagnosis of early pregnancy includes manual observation, rectal examination, ultrasonic instrumentation, determination of progesterone in blood or breast milk, or detection using a kit. The accuracy of different methods is different, but most methods are 85%- More than 90.
Feed Additives ,Choline Chloride,Corn Products Co., Ltd. , http://www.sdbiotechnology.com