Technical & Learning Resources
|•||Enzyme Linked Immunosorbent Assay(ELISA)|
|•||Polymerase Chain Reaction (PCR)|
|•||DNA microsatellite analysis|
|•||Quantification of tannins in tree and shrub foliage|
|•||Estimation of microbial protein supply in ruminants|
|•||Urea Molasses Multinutrient Blocks|
|•||Artificial insemination (AI) of cattle|
Artificial insemination (AI) is the process of collecting sperm cells from a male animal and manually depositing them into
the reproductive tract of a female. One can cite a number of potential benefits from the use of artificial insemination.
1. Increased efficiency of bull usage: During natural breeding, a male will deposit much more semen than is theoretically needed to produce a pregnancy. In addition, natural breeding is physically stressful. Both of these factors limit the number of natural matings a male can make. However, collected semen can be diluted and extended to create hundreds of doses from a single ejaculate. Also, semen can be easily transported, allowing multiple females in different geographical locations to be inseminated simultaneously, and semen can be stored for long periods of time, meaning that males can produce offspring long after their natural reproductive lives end.
2. Increased potential for genetic selection: Because artificial insemination allows males to produce more offspring, fewer males are needed. Therefore, one can choose only the few best males for use as parents, increasing the selection intensity. Furthermore, because males can have more offspring, their offspring can be used in a progeny test program to more accurately evaluate the genetic value of the male. Finally, individual farmers can use artificial insemination to increase the genetic pool with which his or her animals can be mated, potentially decreasing effects of inbreeding.
3. Decreased costs: Male animals often grow to be larger than females and can consume relatively larger amounts of feed. Also, male animals are often more strong, powerful, and potentially ill-mannered and thus require special housing and handling equipment.
4. Increased safety for animals and farmers: As mentioned, male animals can become large and aggressive. These factors mean that maintaining a bull on a farm may be dangerous. Also, because of the relatively larger size of adult males than females, natural mating is more likely to result accidents and injury to either the cow or the bull than is artificial insemination.
5. Reduced disease transmission: Natural mating allows for the transfer of venereal diseases between males and females. Some pathogens can be transmitted in semen through artificial insemination, but the collection process allows for the screening of disease agents. Collected semen is also routinely checked for quality, which can help avoid problems associated with male infertility.
Artificial insemination has some potential drawbacks, however, that must be considered. First, it can be more labourious. Male animals instinctively detect the females that are in the correct status for conception. With artificial insemination the detection work falls on the responsibility of the farmer. Poor detection results in decreased rates of fertility. Also, increasing the number of offspring per male has selective advantages only if the best males can be accurately determined. Otherwise this process only decreases the genetic variability in a population. Increasing the number of offspring per male always reduces the gene pool. The benefits of more intense selection must be balanced against the negative effects of decreased variation.
- Guidelines and Recommendations for Improving Artificial Breeding of Cattle and Buffalo in Asia(2004) [pdf]
- Guidelines and Recommendations for Improving Artificial Breeding of Cattle in Africa (2003) [pdf]
|•||Selective Breeding and Gene Technologies|
|•||Nuclear Glossary [106 kb, pdf]|
|•||DNA Replication [Quicktime]|
|•||DNA Structure [Quicktime]|
|•||Polymerase Chain Reaction [Quicktime]|
|•||Reverse Transcription Polymerase Chain Reaction (RT-PCR) [Flash Movie]|
|•||Restriction Enzymes (RE) [Flash Movie]|