Ph. D.
VP of Science & Technology
Nicholas Turkeys
Introduction
The poultry industry is widely recognized as one of the most efficient sectors in all of agriculture. Poultry production has demonstrated phenomenal improvement in both the cost and efficiency of production over the last 4 or 5 decades. These improvements have been the result of innate biological advantages, the adoption of favorable technologies, and a dynamic industry structure that is well suited to take advantage of these opportunities.
Genetic advances have played a key role in the advancement of poultry production. Genetic selection of poultry species is very efficient due to high reproductive rates and rapid turn-over of generations. The poultry primary breeding industry is unique within animal agriculture and has played a key role in the development of the poultry industry. However, two inseparable factors are often forgotten in relation to the impact of genetic improvement on industry practice and commercial performance. First, genetic change is a continuous process and, consequently, both performance and management requirements will change over time. Second, primary breeders are in the business of creating genetic potential – potential which cannot be realized without optimized management.
Product of change
In simple biological terms, improvement of turkey market weights over the last 40 years has been extraordinary (Figure 1). Commercial live weight has increased 85% for toms and almost 60% for hens between 1966 and 2004 (Ferket, 2004). This is an average increase of over 0.4 pounds (200g) per year for toms over this time period and represents the combined impact of changes in genetics, nutrition and other management factors. Havenstein and coworkers observed similar increases in body weight and significant improvements in feed conversion and carcass and breast meat yield as a direct result of genetic selection (Havenstein, et. al., 2004). Thus, on an economic basis, the combined impact and interaction of genetics, nutrition, bird health, and management systems have all contributed to the relatively low cost of turkey products in the marketplace.
Growth is a very dynamic process and involves the coordinated interactions of many physiological systems. While the industry generally quantifies growth on an absolute basis as the weight achieved at market age, growth is actually a non-linear process which is commonly described using a growth curve (Figure 2). Growth rate can be quantified incrementally as weight gain for a fixed period of time, generally in terms of gain per day or gain per week. From a physiological perspective, relative growth rate can be expressed as incremental weight gain relative to body size. These latter measures are quite revealing. Relative growth is greatest during the brooding phase when body size doubles in week two of life while maximal incremental gain is observed between 14 and 15 weeks of age. These periods represent "critical phases of development"; stressors, which interfere with growth and development process during these periods, can have long lasting, even permanent affects.
Genetics for the future
Just as the industry has evolved over the last four decades, the goals and strategies of the breeding industry have changed over time. In the 1960's, breeding goals were primarily focused on improving growth rate and, to a lesser extent, egg production. Today breeders must have strategies to improve reproduction (egg production and hatchability), other economically important traits (feed conversion and yield) and welfare or support traits (liveability, leg strength, cardiovascular health). Interestingly, breeders are currently making annual improvements in body weight, which are equal or greater than in the 1960's despite all these competing interests. This has been possible due to more efficient structuring of breeding populations, developments in selection index theory and application of new technologies.
In the future, application of technology will play an even greater role in achieving the proper balance between reproductive, economic and support traits and improving the overall pace of genetic improvement.
Technology assists genetic selection in one of two ways; by improving the accuracy and efficiency of selection or by providing a measurement which supports selection to improve "non-traditional" traits. Improving the accuracy of selection allows the breeder to either make more annual progress or to use less selection pressure to produce similar progress and divert the extra selection pressure to other traits of interest. Characteristics like cardio-vascular health, immune function and meat quality represent non-traditional traits which cannot be easily assessed through simple measurement or visual evaluation. However, medical and research technologies can provide opportunities to measure physiological and quality traits and improve bird health, welfare and economic performance.
While genetics clearly has and will continue to play an important role in ongoing improvements in commercial and economic performance in the poultry industry, the dominant role of environment cannot be underestimated. The most genetically influenced traits are only about 40% heritable which suggests that up to 60% of the variation in these traits is subject to environmental influences. Indeed, there is tremendous variation in commercial performance across the industry even with the same genetics (Figure 3) with as much as a 30% deviation between the best and the worst producing flocks. Thus, there is significant opportunity and benefit for producers that optimize management conditions.
Evolving challenge
The first step in accepting this challenge is the recognition that we are dealing with moving targets due to continuing genetic development and that the genetic potential exceeds current field performance. This suggests that there is an opportunity and a need for evolving management techniques.
While it is not possible to predict all the practical implications of this change, there are some basic principles which will help guide future management approaches:
- The modern turkey is a high performance animal and requires a high degree of management. Basic inputs (housing, management and nutrition) must always be evaluated against continuing performance improvement.
- Efficiency will continue to increase meaning that turkeys will produce more output (weight and meat yield) from a unit of input (nutrients). Consequently, proper nutrition, the combined impact of feed formulation, ingredient quality, nutrient availability, gastrointestinal health and feed intake, will have an even greater impact on commercial performance in the future.
- Stress is our adversary – While this has always been true, stress will have an even greater impact on performance in the future as it interferes with items 1 and 2.
- Change will be inevitable as the industry continues to adapt to increasingly complex economic, political and social pressures. Primary breeders will support the industry by continuing to improve economically important characteristics and providing a good balance between breeder output, commercial performance, and health and welfare traits. Consumer preferences will be very influential for the production sector; focus on convenience, health and flavour will influence the types of products the industry produces while interest in animal welfare and food safety will change the way in which we produce them.
Conclusion
The poultry industry has been subject to much change over the past four to five decades but has been successful, in part, due to its focus on innovation. Future challenges appear every bit as daunting as those of the past. In the long run it will not be possible to manage flocks "the way we have always done things"; however, producers that are willing to change and embrace innovation will be rewarded with even greater productivity.
References
Ferket, P. R., 2004. Exclusive Survey: Tom weights up seven percent. WATT Poultry USA.
Havenstein, G. B., P. R. Ferket, J. L. Grimes, M. A, Quershi, and K. E. Nestor, 2004. Changes in the performance of turkeys- 1966-2003. Pages 1-13 in Proceedings of the 27th Technical Turkeys Conference, Macclesfield, Cheshire, UK.
From Proceedings of the "Midwest Poultry Federation Convention", St. Paul, Minnesota, U.S.A.
