Beef cattle breeding and artificial insemination
Using AI within a beef cattle herd can be profitable for the farmer provided that the AI programme is managed well, with considerable attention to detail at all stages of the process. Particular attention should be paid to designing a sound animal health and nutrition programme for the herd. Training is of paramount importance in success too, since a poor technique in semen placement, semen handling and reproduction management may lead to reduced AI success rates in your beef cattle.
In using AI for beef cattle breeding, the most important aspect is detecting when a female is in estrus or ‘heat’. This occurs every 18-24 days in a sexually mature female who is not already pregnant. The cow is receptive to receiving the bull and when using a sire, he is able to detect when a cow is in estrus. However, with AI it is down to the skill of the herdsman to detect when the cow is displaying heat signals, and to time the AI procedure accordingly to ensure the best possible success rates.
The cow is only fertile once an egg has been released from her ovary (ovulation) and this occurs between 10 and 14 hours after ‘standing heat’ comes to an end. Sperm needs some time in a cow’s reproductive tract before it is capable of fertilising an egg. Therefore, Artificial insemination should take place in the last two-thirds of heat or a few hours after heat has finished, representing a window of just 12-18 hours from when an animal first comes on heat.
Semen handling in beef cattle breeding
Before the semen arrives on site, its quality and handling are the responsibility of the AI company. However, once it arrives on-farm it must be handled correctly to ensure that it remains viable. Semen taken from a bull can be stored indefinitely if stored at a critical temperature of -112 degrees Fahrenheit in a semen storage tank. If it rises above this level, even for a short period it may be damaged. Liquid nitrogen tanks are available for installation on site and some companies also offer semen storage facilities.
The insemination process
Access to the female genital tract will be via the cow’s rectum and so it is important that the person undertaking the insemination process is familiar with this before starting the procedure. Once the semen straw is thawed and the semen ready for insertion, the time that elapses from start to finish becomes critical to ensure that the semen remains viable. If more than one animal is to be inseminated, it is recommended that no more semen is thawed than can safely be placed within a 15 minute period.
Relatively few semen cells will be placed in the receiving animal and so their accurate placement is important. To achieve high insemination rates, the semen needs to be placed at the front of the cervix. Detection of the correct site can be made by understanding the change in tissue consistency, from relatively hard in the cervix to spongy in the uterus. Once the correct site has been located an AI gun or Cassou pipette is used to deposit the semen.
After poor detection of the estrus cycle, the incorrect placement of semen is the next most common reason for AI failure. Studies which have used dye deposition followed by slaughter and examination of the cow have shown that about 70 percent of those monitored animals have been inseminated incorrectly.
A cow’s uterine environment is delicate and susceptible to the introduction of infection. It provides an ideal place for bacteria to grow rapidly and so any introduction of bacteria at the beef cattle breeding AI stage can result in infection and potentially infertility in the animal. It is therefore important that the AI equipment and environment is kept sterile and clean to counter any such issues.
Using an AI Technician
If you have a number of animals requiring AI, it is worth considering employing an AI technician to conduct the AI procedure for you. These technicians are trained in the latest AI techniques and are, therefore, able to make accurate and successful placement of the semen. Whilst the cost of hiring a technician may be significant, the cost of reduced conception rates can also be expensive and impact the planned beef cattle breeding programme in place for the beef herd in question.