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Major forthcoming changes

Dossier: Livestock

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Genetic livestock improvement

Livestock production is of major socio-economic importance in ACP countries, contributing significantly to peoples’ livelihoods while playing a key role in food security and rural development, often with a critical socio-cultural dimension.

Livestock production is of major socio-economic importance in ACP countries, contributing significantly to peoples’ livelihoods while playing a key role in food security and rural development, often with a critical socio-cultural dimension.

Global demand for animal protein will double by 2040 under the combined effect of population growth, urbanisation and changing consumption patterns, according to the FAO report The State of Food and Agriculture 2009. Within 30 years, developing countries will account for more than 50% of the growth in the demand for milk, meat and eggs. Average per capita meat consumption in China has increased by more than four-fold in 30 years, a trend that is expected to carry over to Africa, with FAO predicting a doubling of per capita meat consumption on this continent by 2050.

There is no doubt that the countries concerned will have to greatly increase their livestock production. Africa already has abundant fodder resources and a large livestock population but, apart from hides and skins, it is still a net importer of animal products. However, as noted by FAO, Africa’s per capita meat consumption remains low because it has the highest population growth rate in the world, and indigenous breeds are also not very productive, epizootic disease outbreaks are frequent, livestock feed is hard to come by and sectoral policies are weak. Moreover, these are poor countries. Significant progress has nevertheless been made in countries like Botswana, Kenya, Namibia and South Africa.

Could genetic improvement help increase livestock production in ACP countries? This concerns many livestock species, including cattle, goats, sheep, pigs, poultry and fish, reared in a broad range of different livestock production systems: extensive, intensive, pastoral, agro-pastoral and peri-urban. The genetic improvement projects under way also differ, but two major trends involving different methods emerge: conservation and genetic improvement of local breeds through selection, and altering the gene pool of animals by introducing external genes via crossbreeding or using recent advanced tools.

“There is no point in having livestock with a high genetic potential if the rearing conditions are such that this potential cannot be tapped,” says Professor Ahmadou Lamine Ndiaye, honorary director of the Interstate School of Veterinary Science and Medicine of Dakar and president of the African Academy of Sciences. For years, the focus has been on genetic improvement achieved through crossbreeding and importing and adapting highly productive breeds from temperate regions, but the results have often been mixed because the success of genetic improvement closely depends on the conditions and methods of livestock production. Introducing a productive breed is not sufficient: it is also essential to enhance the animals’ diet and veterinary and other care in order to curb epidemics, and livestock pens must be tailored to local climatic conditions.

“Local cows produce 1-3 litres/day of milk in the southern Sahel, whereas 12-15 litres/day could be expected from a local breed crossbred with an improved breed. Moreover, 20-22 litres/day could be produced by a cow bred by embryo transfer from a dairy purebred. However, such animals have different needs - they have to be overfed,” says José Baechler, president of Brune Génétique Services, France. Prior to the introduction of the Brune cattle breed, mainly through artificial insemination (AI) of local cattle breeds in Burkina Faso and Niger, livestock farmers had to be instructed on how to produce fodder and other essential products. This requires training as well as a change in lifestyle - farmers have to settle down and cease their transhumance activities. “This is a crucial and very demanding choice which farmers do not always readily understand,” says Baechler. Farmers also have to separate male and female animals in their herds to avoid the risk of mating, which would quash the genetic benefit. This requires a major change in attitude.

A new setting

There has been considerable growth in milk production due to the increase in crossbreeding. This trend now prevails in Africa, driven by enhanced feeding conditions, the market and sophisticated technology.

In Kenya, milk production doubled in 10 years (5.2 billion litres in 2012) through dairy breed improvement via AI, the creation of areas devoted to fodder crops, and structuring of the sector, especially by setting up dairy producers’ cooperatives. The country is now self-sufficient in milk and 80% is produced on small-scale livestock farms. The supply policy was also favourable for production - import duties on powdered milk were hiked up by 60% in 2005.

In Madagascar, the Armor de Fifamanor dairy farm has been disseminating the Pie Rouge Norvégienne cattle breed since 1972, first through mating stations, and then by AI performed on livestock farms in the Vakinankaratra region. Some 3,500 purebred cows and 10,000 halfbreeds were produced, which significantly boosted milk production and productivity. But this centre is still experiencing difficulties at several levels: malnourished animals, AI costs are too high for livestock farmers, some embryonic mortality or abortion-inducing diseases. In addition, milk collection and prices in Vakinankaratra are unsatisfactory for livestock farmers, which has led to a decrease in milk production in recent years as farmers are less inclined to use AI or purebred bulls. However, the genetic model is not under question, it is the deterioration of the economic situation of the country which has negatively impacted on the sector.

“In the suburbs of Dakar, government officials and investors create model farms with stable-kept livestock, intensive production and importation of exotic bovine semen. Pure breeding is an important investment and certain conditions have to be fulfilled, such as producing fodder and having access to a market to sell dairy products,” says Ndiaye.

Supplying financially-sound high-demand urban markets is not just for peri-urban dairies. Intensive semi-industrial poultry production systems that use improved breeds for egg and meat production are increasing in the vicinity of urban centres.

Conventional poultry farming systems prevail in rural areas, with local poultry breeds mainly being reared. But projects are under way in areas such as in the Senegal River Valley to improve the performance of these family poultry farms through the introduction of sire roosters, which are crossed with local poultry breeds. This system is combined with habitat improvement, sanitary prophylaxis and feed manufacturing using local products. Significant genetic improvement can be achieved if epizootic diseases, such as the deadly Newcastle disease in Africa, are controlled. Success also depends on an animal’s nutrition conditions and possibilities for marketing livestock products.

Preserving local genetic resources

In ACP countries, as elsewhere, livestock genetic resources are broad ranging and tailored to local conditions as they have adapted and become resistant to a number of disease and climatic constraints through mutation and natural selection.

The Regional Project on Sustainable Management of Endemic Ruminant Livestock in West Africa (PROGEBE) is one of the few major genetic improvement programmes for local livestock breeds. It aims to preserve local livestock - N’Dama cattle, Djallonké sheep and trypano-tolerant West African Dwarf goats - inhabiting subhumid and humid areas of Gambia, Guinea, Mali and Senegal, where tsetse flies (vectors of animal trypanosomosis diseases) are rampant.

“Preserving doesn’t simply mean leaving as it is. Instead, it involves enhancing the value and competitiveness of livestock while facilitating market access,” says Mamadou Diop, national coordinator of PROGEBE-Senegal. This consists of preserving the animal’s environment and improving its productivity through better access to animal health services, pasture, water and improved sires. In late 2009, in partnership with ISRA, the Senegalese agricultural research institute, and in collaboration with CRZ-K, the animal research institute at Kolda, an N’Dama cattle breeding programme was launched with livestock farmers actively participating in the breeding process. Currently 14 improved stock have been disseminated to livestock farms, and this should be increased to 20 in 2014.

The low production level is generally attributed to the poor productivity of local breeds. However, as is the case for exotic breeds or crossbreeds, the productivity of local breeds could be boosted by improving the rearing farming conditions.

A genomic revolution

“According to the 2007 FAO Livestock Report, little is known about roughly 40% of domestic livestock breeds, 30% of which are considered to be endangered. It is thus essential to effectively inventory, preserve and characterise local breeds to ensure their improvement. We now have the tools required to more thoroughly characterise these populations by examining their genomes in order to pinpoint what determines their adaptation and production traits,” says Michel Naves, animal genetics engineering specialist at the Animal Research Unit of the INRA French West Indies and Guyana Research Centre. Such genotyping initiatives are carried out to address the major challenge of breeding hardier and more productive animals. Detecting adaptation traits in local breeds is crucial in the development of production systems. This especially concerns adaptation to changing climatic conditions through, for instance, the identification of heat tolerant genes, particularly in pigs. “Local breeds, especially tropical ones, which are subjected to very substantial seasonal variations, are often able to mobilise their reserves when resources are scarce and to replenish them when fodder is more abundant, while also making use of a diverse range of food resources.

New genotyping tools and, even more importantly, high throughput sequencing will enable major genetic resource selection progress to be achieved over the next 5-10 years. “This will concern genetic characterisation of populations (mapping their genomes), screening for ‘selection signatures’ (traces left in the genome by natural selection processes), searches for genetic markers associated with biological adaptation, or production processes and genetic improvement via the breeding of more productive animals, crossing tests and inbreeding management,” confirms Naves. Developing countries do not yet have access to advanced technology, but this situation is rapidly changing. “Five to 10 years ago, it took several months to map a cow’s complete genomic sequence at a price of tens of thousands of Euros. Nowadays, the results take 15-30 days and costs €3,000,” says Naves.

With genomics progress, genetic improvement choices should not just be limited to selecting a local breed (safer but much slower) or introducing an exotic breed (faster, but more risky and fragile). Certain traits of local breeds can now be ‘borrowed’ and inserted in a more productive breed so that it will be better adapted to local constraints, otherwise traits could be sought in local breeds and subsequently exploited to boost the productivity of these animals without upsetting their adaptation features. Tapping the potential of local breeds also helps preserve genetic diversity, which is currently threatened.