Phenomenally Hardy Traits Found in Backyard Chicken Genetics

Local Heritage Breed Chickens Most Suitable for Backyards and Smallholders

Phenomenally Hardy Traits Found in Backyard Chicken Genetics

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Are you looking for a hardy, fertile, long-living, and productive flock? Local backyard chickens have long proven to remain productive and healthy for longer in outdoor conditions. They even forage for the majority of their feed. Heritage breed chickens possess unique genetic resources. These give them a survival advantage in their place of origin. These birds fare best when free ranging, whether in American backyards or rural villages in Africa. Some possess amazing abilities to resist or recover from diseases. Some can survive illnesses that seriously threaten poultry farming. Such traits have inspired a number of studies into chicken genetics to discover their secrets. Sadly, many heritage chickens are now rare breeds. Nevertheless, our future depends on us preserving such unique chicken breeds.

Chicken Genetics Studies and Worldwide Collaboration

During the last decade, scientists have got together to study locally adapted backyard chickens in Africa. As a result, they have recorded how these community chickens’ genes respond to poultry diseases. Some resist such devastating diseases as virulent Newcastle disease (vND). Others are tolerant of environmental hardships, such as high temperatures and altitudes.

Chickens living freely in an area over many generations are called ecotypes. Researchers have identified genetic differences between ecotypes relating to their varying responses to such challenges. Pinpointing these genes could help breeders develop more resilient flocks. PennState professor Vivek Kapur led an international team of scientists looking into the chicken genetics of immunity. They carried out an innovative study of the immune response of embryo cells. They identified genes that help Egyptian Fayoumi chickens resist vND. Then they compared the Fayoumi’s immune response to that of the more susceptible Leghorn chicken.

The Fayoumi chicken: genetics studies found the secret to the breed’s resilience. Photo credit: Joe Mabel/flickr CC BY-SA 2.0.

The Amazing Hardiness of African Backyard Chickens

“These local ecotypes of chickens have been running around backyards for hundreds of years, even in the face of constant exposure to Newcastle disease,” noted Kapur. “So, evolutionarily, there’s something innate that has enabled them to survive in this environment where the disease is endemic.”

Research confirms that Fayoumi chickens are less susceptible to many diseases. Examples include Salmonella, coccidiosis, Marek’s Disease, Avian Influenza, Rous sarcoma virus, and vND. They are also fertile, thrifty, heat-tolerant, and excellent at foraging and avoiding predators. In addition, they lay plentifully, and their eggs have thick protective shells. These factors make them ideal smallholder chickens in a low-input, free-range system. For this reason, they are especially valuable as African village chickens in regions that face conditions and diseases common in their homeland.

Ethiopian smallholder barnyard. Photo credit: Rod Waddington/flickr CC BY-SA 2.0.

In Africa, such abilities are of utmost importance, since smallholders are responsible for 80–90% of some countries’ production. Therefore, small farms will benefit enormously from including resilience and disease-resistance traits in their breeding plans.

The Economic Burden of Disease Outbreak and Prevention

Although vaccines and medications exist in Africa, economic and practical issues often limit smallholders’ ability to take up such options. “If you have 20 chickens in your backyard, for example, you first have to find someone who will come give your flock the vaccine and there’s a cost involved in that whole process and, on top of that, the vaccine has to be available,” clarifies Kapur. “The barriers, both real and perceptional, are therefore rather high for backyard farmers to vaccinate their chickens.”

Susan Lamont led a study of African chicken genetics at Iowa State University. “Addressing Newcastle disease through genetic resistance is of particular importance,” says she, “because most vaccines available to combat the disease require refrigeration, which often is not an option in areas of Africa with limited access to electricity.”

Family feeding native chickens in Uganda. Photo credit: James Karuga/Wikimedia Commons CC BY-SA 4.0.

Newcastle disease threatens poultry production in many African countries. “Newcastle disease is an important poultry pathogen,” said Megan Schilling, who earned her doctorate through the study at PennState. “You might not hear much about this disease in the U.S. as it is generally well-controlled, but it’s endemic in a lot of African and Asian countries. If a virulent strain is introduced into a flock, it will wipe out the flock and cause significant economic burden, particularly for smallholder farmers.”

How Susceptible Are Chickens to Disease?

Countries employing more industrialized methods have traded hardiness for productivity gains in a protective, high-input system. “… birds that are bred for high productivity, as is the case in high-income countries—they put on weight very quickly, produce a lot of eggs,” Kapur explains. “Their survival in the presence of infectious diseases was not selected for because there is usually a trade-off between increased resistance to disease and egg or meat production.” However, even such countries are not immune to outbreaks of vND. Virulent Newcastle disease struck California in 2018/2019, and resulted in losses of over 100,000 backyard birds and 1.2 million commercial chickens.

Not all farmers can afford the costs of a high-yield industrial system. Such installations require investment. Moreover, they are dependent on a supply of feed and energy. In the future, even developed countries may struggle to maintain such systems due to resource shortages and climate change. Commercial birds are bred for high output over a short period. As a result, they do not tend to live long. Accordingly, they are less suitable for small-farm and backyard production, where longevity and self-sufficiency are prized.

Why Heritage Breed Chickens Are Vital to Sustainable Farming

Resilience and adaptability traits are vital to us all, in whatever country or society we live. Landraces, heritage breeds, and local strains are essential for poultry to survive and adapt to changing conditions. Commercial breeds are tailored for high-yield production in a sheltered environment. Consequently, they possess limited genetic variation. If we depend on commercial breeds, we will lose the genetic resources required to adapt to new situations. Those changes may come from the climate, from the spread or evolution of disease, or from changes in market demand. In addition, consumers are becoming more conscious of the need for better animal welfare. Accordingly, consumer preference is shifting towards more natural and free-range systems.

Why Heritage Breeds are the Hardiest

When chickens live naturally and need to look after themselves, they require intact natural instincts. Hardy chickens have inherited survival skills from their wild ancestors. These include predator awareness, ability to forage, agility, alertness, and good brooding and mothering skills. They also need resistance to disease, resilience, tolerance of parasites and weather conditions, and the ability to adapt. Chickens that have lived free range in an area for many generations, and survived, possess such adaptations. The longer they have managed their own survival in a particular region, the healthier and more productive they will be overall. This is why landrace animals, the native breeds, are the best survivors and have the longest productive lives. They do not initially yield as much as their purpose-bred cousins, but are dual-purpose and produce for longer.

Hardy Dominique hens are a precious source of locally-adapted American chicken genetics. Photo credit: USDA Forest Service.

Local heritage breed chickens have long been resident, and are well adapted to local conditions. Dominique and Java chickens are great examples in the U.S. They have been selected for good production while free-ranging in the backyard or barnyard. A flock raised for many generations locally will be better acclimatized to the area. So, it is better to buy from this local flock than from a climatically-different area or a recent import.

Risks to Our Productive Future

So why do heritage breeds become endangered? When farmers invest in intensive systems, the immediate return from commercial strains impresses them. So, they stop breeding local breeds. Consequently, native populations diminish and become rare. With a smaller gene pool, their productivity drops, they lose popularity and fall into obscurity. Soon they become unknown to new farmers and backyard keepers who find it easier to acquire commercial hybrids.

U.S. heritage breed: Java rooster. Photo credit: Sam Brutcher/flickr CC BY 2.0.

Even traditional breeds can lose the richness of their gene pool and the ability to adapt. This can occur through, firstly, a small breeding population and, secondly, strict standardization of traits. Researchers in Germany focused on compiling a database of breed diversity. They found that there is still considerable genetic diversity in African, South American, and some Asian and European breeds. However, they noted, “… fancy breeds, as well as the highly selected commercial layer lines, have reduced genetic diversity within the population.” In conclusion, they wrote, “It is important that such highly diverse breeds are maintained for the sustainability and flexibility of future chicken breeding.”

Better Breeding for Healthier Chickens

How can we help poultry adapt to future challenges? Firstly, we can keep heritage breeds and locally-adapted strains. Secondly, we can take care to choose birds that have a long history in the area. In addition, we can check that they are free-ranging and largely self-sufficient. Finally, we can avoid inbreeding and encourage hardy types. However, it pays not to breed too strictly to standards of color and looks. That is because this practice restricts genetic variation in other useful traits. Rather, we can embrace the beauty of natural variety!

Pennsylvania State University. 2019. Researchers find genes that could help create more resilient chickens.
Schilling, M. A., Memari, S., Cavanaugh, M., Katani, R., Deist, M. S., Radzio-Basu, J., Lamont, S. J., Buza, J. J., and Kapur, V. 2019. Conserved, breed-dependent, and subline-dependent innate immune responses of Fayoumi and Leghorn chicken embryos to Newcastle disease virus infection. Scientific Reports, 9(1), 7209.

Iowa State University. 2014. Researchers look to chicken genetics to fight hunger and poverty in Africa.
Elbetagy, A. R., Bertolini, F., Fleming, D. S., Van Goor, A., Schmidt, C., Lamont, S. J., and Rothschild, M. F. 2017. Evidence of natural selection footprints among some African chicken breeds and village ecotypes. Animal Industry Report: AS 663(1) 40, ASL R3167.

University of Göttingen. 2019. Global data resource shows genetic diversity of chickens.
Malomane, D.K., Simianer, H., Weigend, A., Reimer, C., Schmitt, A.O., Weigend, S. 2019. The SYNBREED chicken diversity panel: a global resource to assess chicken diversity at high genomic resolution. BMC Genomics, 20, 345.

Originally published in the April/May 2020 issue of Backyard Poultry and regularly vetted for accuracy.

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