eBusiness Weekly
Martin Kadzere
Zimbabwe is next month expected to launch the artificial insemination programme as it looks to grow the national cattle herd and revive the lucrative beef industry, Minister of Higher and Tertiary Education Professor Amon Murirwa said.
The artificial insemination practice involves the collection of sperm cells from a bull and manually deposit them into the reproductive tract of a cow. The AI came following the realisation that the country had a shortage of bulls, at a time it is working on restocking following a sharp decline of the national herd since 2000.
Zimbabwe has an estimated national herd of five million, of which 45 percent are males.
“As the ministry, we have managed to build the national capability to implement artificial insemination and it is the Ministry of Agriculture, which will then have to decide on the areas where it will distribute the bull semen,” Murwira told Business Weekly.
The ministry has been working with Chinhoyi University of Technology (Animal Science Department) on the project, expected to boost the country’s restocking programme.
“We are now moving to a situation where education is playing its role as an economic enabler. We do not want education of caps and gowns but for goods and services,” he said. He added Zimbabwe had capability to produce 4 000 semen straws per hour.
Potential benefits from the use of artificial insemination
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.
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 programme 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.
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.
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 in accidents and injury to either the cow or the bull than is artificial insemination.
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.
However, artificial insemination has some potential drawbacks, however, that must be considered
First, it can be more laborious. 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.
