Genetic Intensification of livestock is the increase in productivity of livestock, both terrestrial and aquatic populations, with limited increase in the amount of land devoted to livestock grazing or raising. This is necessary in the face of increased demand for livestock products despite limited potential to expand grazing areas.
Whilst it may seem like a modern technology, improving livestock breeds is not a new practice. Thousands of years ago, livestock were domesticated and selected for their adaption to specific climates. Production systems were improved during the 17th century, with the rise of professional farming and selective breeding of livestock. With the emergence of the field of genetics (the study of heredity and the variation of inherited characteristics) in the 20th century, a remarkable diversity and improvement of livestock occurred around the world. Towards the latter part of the century, the discovery of molecular genetics and genomics (a branch of molecular biology concerned with the mapping of genomes) now offers the potential to breed livestock for specific desired traits and qualities more rapidly.
An estimated 700 million rural poor people globally depend on livestock for their livelihoods. In Africa, roughly one-half of the 300 million poor people depend on livestock which can account for 45% of household income. The ‘livestock revolution’ or the rapidly increasing demand for livestock products may offer opportunities for improving their incomes and livelihoods. However, several challenges such as climate change, land degradation, water shortages and emerging diseases necessitate improvements in livestock breeding to meet global food demand.
Population growth and an increase in Gross Domestic Product (GDP) since the 1970’s caused meat consumption to triple worldwide from 1980 to 2002. This demand is now led by developing countries, where the total meat and milk consumption is expected to double between 2010 and 2050. Meeting this increased demand for meat can be achieved by increasing livestock numbers significantly—but not without enormous environmental and production impacts—or by increasing the production efficiency per animal.
Recently, increases in livestock breeding efficiency have been accomplished in developed countries through the improved use of genetics and more recently genomics such that whole genome single sequences can be identified or ‘genotyped’ using microsatellite loci. Today, processes such as genomic selection are being applied to traits such as milk production in cattle and feed efficiency in chickens, cattle and pigs and could eventually be applied for traits such as methane production in cattle. However, these processes carry high costs and expertise requirements and therefore producers and consumers in the developed world have accrued most of the benefits. There is an urgency to develop similar marker aided selection (MAS) for use in developing countries.
Livestock breeding consists of several different approaches. Cross breeding refers to the process of breeding with the intention to create offspring that share the traits of both parent lineages or to produce an animal with hybrid vigour (the improved or increased function of any biological quality in a hybrid offspring). Artificial insemination (AI) is the deliberate introduction of sperm into a female’s uterus or cervix to achieve a pregnancy. Embryo transfer is the process of assisted reproduction in which fresh or frozen embryos are placed into the uterus of a female with the intent to establish a pregnancy.