Early Signs of Pregnancy & Estrus in Cows: Visual Cues & Tips

What is Estrus (heat) in Cows?

The heat period in cows or heifers refers to the time when they are ready to conceive or become pregnant through insemination or mating with a bull. Typically, this period occurs every 18 to 24 days, with an average of 21 days for non-pregnant cows. The duration of the heat period averages around 15 hours but can range from 2 to 30 hours.

Here are some common signs of heat in cows:

1. Mucus discharge from the vulva or on the tail.
2. Swelling (inflammation) of the vulva and a change in color from pink to red.
3. Mounting other cows or allowing other cows to mount them.
4. Reduction in milk production in lactating cows.
5. Loss of appetite for some time.
6. Slight rise in body temperature.
7. Frequent urination.
8. Excitement and nervousness causing the cow to run from place to place while bellowing.
9. Standing closer to the bulls to be mounted.

Signs of Pregnancy in Cattle:

1. The cow will not go into heat 21 days after mating.
2. Enlargement or protrusion of the abdomen at five months.
3. The udder becomes filled with milk.
4. The cervix seals.
5. A veterinary officer can detect the corpus luteum in the ovary by inserting his hands into the rectum.

Artificial Insemination (A.I):

Artificial insemination is a method of breeding cows in which an inseminating syringe is inserted through the vulva and vagina to deposit semen in the lower part of the uterus, replacing natural mating with a bull.

Advantages of Artificial Insemination:

1. Control or elimination of venereal or bleeding diseases.
2. Control of inbreeding on the farm.
3. Improvement of the herd by using semen from different types of bulls.
4. Cost-effectiveness by redirecting funds from buying and maintaining bulls to purchasing more cows.
5. Economic benefits, as paying for A.I service is cheaper than keeping a bull.
6. Utilization of semen from old, lame, and deceased bulls, which is not possible in natural mating.
7. Prevention of injury in small cows and heifers by avoiding mating with larger, heavier bulls.
8. Controlled breeding through a systematic program.
9. Increased fertilization rates, as spermatozoa can be deposited strategically.
10. Availability of semen from high-quality breeds in remote areas where such breeds are not accessible.
11. Introduction of new stock into countries where purebred sires would struggle to survive.
12. Easy detection of infertility or sterility.
13. Serving multiple animals from a single ejaculate.

Disadvantages of Artificial Insemination:

1. Inability to successfully perform AI on females without obvious heat periods or those with unpredictable heat cycles.
2. Limited success if inferior sires are used, such as those with low milk, meat, wool production, or disease.
3. The requirement for experienced personnel to carry out A.I procedures.
4. Challenges associated with semen storage, which is done in specialized containers using liquid nitrogen (-193°C) or solid carbon dioxide (-79°C).
5. Absence of natural mating experiences for the animals.

Conclusion

In conclusion, understanding the heat period in cows and the signs of pregnancy is crucial for successful breeding and herd management. By recognizing the indications of heat in cows, such as mucus discharge, vulva swelling, and behavioral changes, farmers can optimize insemination and ensure timely conception.

Artificial insemination offers numerous advantages, including disease control, genetic improvement, cost-effectiveness, and increased breeding control. However, it is important to consider the limitations of A.I, such as the need for experienced personnel and proper semen storage.