Conservation of the genetic diversity of local chickens

A cheaper way to freeze reproductive cells could help secure food production in low- and middle-income tropical countries. An inexpensive cryopreservation method could help preserve 1,600 local chicken breeds, which are an important source of income for small farmers in these areas.

Environmentally resilient birds The

scientific breakthrough could also help preserve local poultry genes for efforts to develop climate or disease resistant birds and for food production.

A team from the Center for Tropical Livestock Genetics and Health (CTLGH) and the Roslin Institute, along with commercial partners Cobb-Europe, tested a simple method in which chicken reproductive organs were removed from embryos, sexed and frozen.

After thawing, reproductive cells were injected into sterile surrogate embryos. Male germ cells were injected into male embryos, and female cells into female embryos.

Control of reproductive genes

Studies using fluorescent proteins to label donor cells and a method of controlling the reproductive genes carried by both parents, known as surrogate breeding of female sires, have shown that the chicks are fully descended from the donor parents. Experiments have shown that freezing the entire reproductive organ is more important than freezing individual reproductive cells.

Commenting on the study, Dr. Tuanjun Hu of the Roslin Institute and CTLGH said: “This simple, low-cost, low-tech biobank will benefit poultry farmers all over the world, large or small. This will reduce the cost of breeding stock and improve chick welfare by reducing the number of birds in research facilities.”

Dr. Mike McGrew, Program Manager, added: “Although cryopreservation of adult reproductive cells is a common practice, it is problematic in poultry and in vitro alternatives are technically complex and expensive. This simple method does not require the creation of cells in vitro in the laboratory, making it easier and cheaper to keep chickens, which benefits both commercial and small farmers.”

Preservation of chicken diversity

And Prof. Appolinaire Jikeng, director of CTLGH, concluded: “Chicken is a key animal for millions of smallholder farmers in low- and middle-income countries. This simple and inexpensive method, developed as part of a CTLGH collaboration between Roslin, ILRI and Cobb-Europe, will preserve chicken diversity so that farmers can breed birds that are resilient to extreme climatic conditions and provide a reliable source of food and income for farming families.”

* The study was published in eLife and was funded by the Bill & Melinda Gates Foundation, the British Foreign and Commonwealth Office and the National Center for Animal Replacement, Refinement and Reduction in Research.