At present, China's bovine artificial insemination technology has become widely adopted and plays a vital role in improving the quality of cattle and dairy cows. The widespread use of improved breeds has led to increased body size in beef cattle and significantly higher milk yields in dairy cows. This advancement has contributed positively to the development of the national economy. However, despite these benefits, many inseminators still face challenges during the process, which can result in serious losses for livestock production. Common issues include unprofessional techniques that may lead to reproductive tract infections, the spread of genital diseases, lower conception rates, and even injuries to both humans and animals. Additionally, improper practices can reduce milk production and create inefficiencies in breeding programs.
The following sections will outline some common non-standard operations that occur during artificial insemination, offering insights for reference and improvement.
1. **Understanding Estrus Symptoms and Ovulation Time**
Correctly identifying estrus symptoms and ovulation time is crucial for successful fertilization. Many breeders rely on rectal palpation to determine the right time for insemination. However, a lack of proper knowledge often leads to misjudgment. For example, many assume that a cow accepting mounting is definitely in heat, but this is not always the case. A more accurate assessment should consider three key factors: external behavior, mucus characteristics, and follicle development. True estrus signs include cows showing interest in other cattle, clear mucus that forms a long string, and developing follicles on the ovaries.
1.1 **Common Myths About Estrus**
Many people mistakenly believe that if a cow allows mounting, it’s definitely in heat. However, true estrus involves more than just behavioral signs. It also includes changes in the genital tract, such as normal mucus consistency, and proper follicle growth. These three aspects—external behavior, mucus condition, and follicle development—must be considered together for an accurate diagnosis.
1.2 **Errors in Timing Ovulation**
Timing the insemination correctly is essential. Some breeders believe that insemination should occur 6 to 10 hours after the end of estrus, but the correct window is actually between 4 to 16 hours. Missing this window can greatly reduce conception rates. To ensure accuracy, a rectal examination should be performed to check follicle size. When follicles reach 1.5 to 2.0 cm in diameter, with a thin, bulging tip, it’s a sign that ovulation is imminent, and insemination at this point is highly effective.
2. **Proper Technique for Rectal Examination**
Experienced breeders know the importance of rectal exams, but many skip important steps. Some directly examine the ovaries without checking the cervix, uterus, or other structures, leading to missed diagnoses of uterine inflammation or early pregnancy. The correct procedure involves gently inserting the hand into the rectum, turning the palm upward, and systematically examining the cervix, uterus, uterine horns, fallopian tubes, and finally the ovaries. This ensures a thorough evaluation of the reproductive system and helps avoid errors.
3. **Mastering the Artificial Insemination Procedure**
A well-executed artificial insemination procedure saves time and reduces the risk of injury. Key points include opening the liquid nitrogen tank carefully to prevent contamination, keeping the semen tube sterile, and properly cleaning the vulva with a 0.1% potassium permanganate solution before insertion. The insemination gun should never be placed directly against the vulva, and the operator should stand behind the cow to avoid injury. After insemination, the gun should be slowly withdrawn, and the clitoris or back should be gently pressed to prevent semen from flowing back.
4. **Misunderstandings About Timely Insemination**
Many breeders rely solely on observing estrus behavior to decide when to inseminate. While this method has some merit, it lacks precision. A more accurate approach considers both external and internal signs. For example, during late estrus, cows may become quieter, their appetite returns, and they may show resistance to mounting. Mucus becomes cloudy or pale, and rectal exams reveal a firm, elastic cervix with thinning follicles. These combined indicators help determine the best time for insemination.
By addressing these common mistakes and improving training, breeders can enhance the success rate of artificial insemination, leading to better productivity and healthier herds.