The coming decades will be characterised by a growing global population (nine billion people by 2050) with two thirds of people living in cities and increasingly adding animal products to their diets. Satisfying demand in an era of scarce resources can only be done through sustainable breeding.
By Anne-Marie Neeteson,
Santiago Avendaño and Magnus Swalander, Aviagen
Projections into 2022 indicate that changes in global meat production, trade and consumption will be dominated by upcoming economies (OECD/FAO, 2013). The developing world will contribute 80% of the global meat production, while the increase in participation in demand will be dominated by Asia (+56%) and Latin America (+18%) with only moderate increments from Africa, Europe, North America with +8% each, (OECD/FAO 2013). However, there will be fewer rural farmers to satisfy these needs while available natural resources – water, energy and land – will be increasingly scarce.
Poultry meat is expected to dominate the additional meat consumed in
2022 with a share of over 40%. In this context of increasing demand and global limiting resources, there will be unprecedented pressures on the global food production systems in the next 40 years (Foresight, 2011). Feed conversion rate (FCR), the amount of feed required per kilo of product, has a central role in modulating the Food-Feed-Fuel
competition, it affects the profitability of the poultry industry, land and energy utilisation and environmental impact. There is an important strategic position of a world leading poultry breeding company to breed broiler chickens and turkeys to satisfy a growing demand in a sustainable way.
Evolution of breeding goals and genetic selection
The selection of broilers and turkeys has historically evolved towards the use of very broad breeding goals including a very wide range of characteristics with the aim of simultaneously improving productivity, efficiency, environmental impact, animal health and welfare, food quality and safety.
Image 1 (Neeteson et al, 2013) below illustrates this transition in breeding goals from 1950 to now, with more emphasis on feed efficiency, robustness and reproduction. In the
current and future scenario of Food-Feed-Fuel competition for resources,
the emphasis on feed efficiency is only becoming larger. Genetic progress is delivered to the industry through selecting pedigree lines with high accuracy for all traits included in the breeding goal.
The expression of genetic potential in commercial birds relies on the accuracy of selection in each pedigree line. Selection accuracy results from very large amounts of data gathered throughout the life cycle of the bird. These data are combined with pedigree and genomics information across generations to predict genetic values using sophisticated analytical tools.
Managing trait antagonisms
Health, welfare and reproduction traits are often somewhat antagonistic to production and environmental output traits. If this is not accounted for in the breeding programme, health, welfare or reproduction will be negatively affected when selection pressure is applied to improve FCR or production traits.
For antagonistic traits, the breeding goal is more sustainable by including both types of traits and to select simultaneously in the desirable direction. Therefore, in the presence of an antagonistic
correlation remaining significant over time, the affected traits can show genetic improvements in the desired direction. Figure 1 shows that although correlations between body weight and a range of leg deformities are somewhat antagonistic (Kapell et al, 2012), effective simultaneous selection for broiler leg strength and growth rate (1996-2012) has been achieved. This principle can be applied across the whole breeding goal which has typically between 30 to 40 traits, all of which are under selection simultaneously. The desired balance can be maintained with large enough breeding populations, high selection intensities, proper statistical methodology and accurate data recording infrastructure.
To ensure that the birds are performing well under a wide range of production environments across the globe, Aviagen has implemented multi-environment selection as from 2000 (turkeys: 2010). The elite selection candidates are grown in an optimal environment to allow the expression of genetic potential, antibiotic-free (since 1999) and bio-secure, free from pathogens like Salmonella, Mycoplasmae, Leucosis, Newcastle Disease, Avian Influenza.
The siblings (brothers and sisters) of selection candidates are grown in a separate commercial environment to express robustness where gut, digestive and immune function are challenged along with liveability, growth and uniformity. Food conversion rate is measured in both environments allowing simultaneous genetic progress across contrasting environments. This is essential as FCR will be expressed in a very wide range of environments globally with varying
levels of feed quality, management
practices, housing and gut and disease challenges. The management of the interaction between genetic potential and the specific production environment is a key strategy to deliver a continued improvement in the utilisation of resources globally.
Continuous investments and a long-term view in research and development are critical to develop novel ways to accurately improve the ability to transform feed into quality meat while at the same time strengthening the skeletal and metabolic support system of the birds. The following are three highlights
representing significant milestones in Aviagen’s investment on R&D for improving FCR.
Lifetime FCR and water intake
Individual FCR recordings using transponder technology to measure growth efficiency and feeding behaviour in a competitive pen environment started in chickens in 2004 and in turkeys in 2006. Each visit to the feeder (time, consumption and length) is recorded allowing extensive feeding behaviour studies. In 2012 Aviagen Turkeys expanded this technology further with ‘water stations’ - the system is now being implemented in broilers. It records not only feed but also drinking behaviour of the individual birds. This strategy enables selecting individual birds with the highest genetic potential for feed and water efficiency, while identifying birds with a genetic sensitivity to develop compromised
gut health, generating wet litter and dermatitis, excluding them from breeding populations in the future.
Understanding gut health
Gut health has a major impact on the bird’s ability to digest and transform feed in an efficient way into animal protein. Detailed research has been undertaken into the factors compromising gut health, from the pathogens living in the gut, the bacterial communities residing in the gut and the interaction with the bird’s genes. Identifying key bacteria that either compromise or improve gut health will help selecting for stronger gut health and to develop strategies to combine management tools for optimal gut health and functioning. A good functioning gut which will ultimately improve bird robustness and FCR.
Use of genomics information
Since June 2012, Aviagen includes genomics information in the routine selection of its elite lines. Genomics information can be used to improve all traits in the breeding programme, including live performance, critically feed conversion rate, health, disease resistance and welfare. In addition to the observed and measured performance of birds in a range of environments, it is now possible to see the unique qualities of each bird at the genetic sequence level. Genomics information is particularly important for selecting traits that are expressed in one sex (e.g. reproductive traits) but can be used as additional information to increase selection accuracy in any trait in the breeding goal.
The global impact of feed conversion rate (FCR) in the food-feed-fuel
The food-feed-fuel competition makes arable land an increasingly scarce resource. Improvement of livestock feed efficiency alleviates this. The 2010 global chicken meat consumption was 86.5 million tonnes (~123.6 million tonnes body weight). Our conservative estimate of the global commercial field improvement in FCR is -0.015 kg/kg each year, equivalent to cumulative annual savings of 0.015 x 123.6 = 1.85 million tonnes of feed. The main chicken producing
countries realised a 2010 harvest yield of 466 tonnes of wheat per km2, so the above FCR improvement frees up 1.85 million/466 = about 4 000 km2 of arable land, an area the size of 1.5 times Luxembourg or 3.3 times New York City (Neeteson et al, 2013). The FCR improvements are cumulative and
realised every year. With the realised cumulative FCR improvements over the last 30 years we now need around 120,000 km2 less land for these 86.5 MT of poultry meat, that is two thirds of the agricultural area of India.
Environmental impact of genetic improvement
Aviagen is actively participating in research focused on assessing the effect of genetic changes on the environmental impact in broiler and turkey production systems. Results from a Life Cycle Analysis (LCA) in chickens showed that genetic improvement in FCR has the greatest potential to reduce the environmental impact of broilers when compared to body weight, liveability, and carcass yield. A cumulative genetic improvement of -0.45 kg feed per kg of product over 15 years (-0.03 kg/kg per year) could reduce global warming potential of meat poultry production by 19%, and eutrophication and acidification potential by over 30%.
The Aviagen investments have resulted in continuously improved FCRs, while reducing the environmental impact and improving the health and support
systems of broilers and turkeys. In a future scenario of increasing demand and limited resources, Aviagen breeding goals are defined to deliver genetic potential to optimise resource utilisation while minimising the environmental impact.
References available upon request