The Importance of Genetics: Biological fitness and productivity in range-based systems comparing standard turkey varieties and industrial stocks
Several standard varieties of turkeys and a commercial strain were compared in range-based production systems, in DNA analysis, and for immune system response. Although the commercial variety reached market weight in fewer days and grew to a larger size, the standard varieties had lower mortality and better immune response. DNA micro-satellite analysis showed some standard varieties are only distantly related to the commercial strains, providing valuable genetic diversity essential for the long- term sustainability of turkeys.
At the planning meeting held in July 2001, participants agreed to the following definition for range-based turkey production: (1) birds will have daily access to outdoor range, (2) birds will have daily access to forage, shelter and roosting locations, and (3) systems will NOT be 24 hour, 7 day per week housing, the single yard model (implying no range), or field pens or “chicken tractors,” too small for normal turkey behavior such as roosting, spreading wings, and exercise.
Eight farmers from across the country participated in the project. Each brought a unique set of skills to this effort. They were:
- Pam Marshall, Amenia, NY. A small scale turkey breeder & farmer; committed steward of standard varieties, with access to the New York City market.
New England Heritage Breeds Conservancy, Richmond, MA, Heather Bean Ware, Associate Director of Agriculture Education. An educational facility dedicated to the conservation of rare breeds of livestock.
Gail & Harry Groot, Hiwassee, VA. Small scale, multi species, farmers who strongly prefer standard turkeys that are naturally mating, brood own young, with good growth potential and economic return.
Gerry Cohn, Snow Camp, NC. A small scale, multi species farmer who buys poults to raise for direct sales to consumers at Thanksgiving. He prefers standard varieties with good growth potential and economic return.
Center for Environmental Farming Systems, North Carolina State University, Goldsboro, NC, Paul Mueller, Professor, Crop Science, Sustainable Agriculture Coordinator. CEFS is research farm dedicated to sustainable agriculture, including multi-species and integrated crop & livestock systems. Scientists research and demonstrate production systems that are environmentally and economically self-sustaining.
Glenn Drowns, Calamus, IA. A committed steward of hundreds of breeds and varieties of poultry, including fifteen varieties of standard turkeys, as well as hundreds of heirloom vegetables. He is dedicated to the rescue of standard turkey genetics from the brink of extinction and their long term conservation. He is a breeder and operates a moderately sized, seasonal hatchery. He does not raise birds for the processing market.
Frank Reese, Jr., Lindsborg, KS. A committed steward of standard varieties of turkeys. He is dedicated to maintaining breed standard, carcass quality in naturally mating turkeys. A significant breeder and producer of standard turkeys for the Thanksgiving market.
Paula Johnson, Las Cruces, NM. A committed steward and breeder of standard varieties of turkeys. She dedicated to the rescue of standard turkey genetics from the brink of extinction and their long term conservation.
Bourbon Red turkey poults from Privett Hatchery and a commercial strain of medium white turkey poults from British United Turkeys of America (BUTA) were shipped to each farm on either May 15 or 29, 2002. Glenn Drowns also had a combined flock of Black Spanish and Blue Slates turkeys that were from Privett. Paula Johnson had a flock of a commercial strain of large whites turkeys from Nicholas Hatchery. Each farmer received shipments of a few more than 30 poults of each variety, the extras to allow for some loss due to shipping stress. Gerry Cohn, Paul Mueller, Pam Marshall each received 60 Bourbon Red poults. Paula Johnson received 15 of each. While each farm was different, their production systems all complied with the definition of “range-based”, as defined by this collaboration.
Each farm provided the following, using forms developed specifically for the project: a detailed description of their production systems and a general overview of their farm:
- weights taken on a random subset of 5 birds once a week through slaughter;
final live weights and dressed weights of all birds;
morbidity and mortality information, with necropsy information provided when possible;
weight of feed fed to each flock;
weather data; and
observations of behavior.
The following data was have been collected:
(1) Days to Market Weight: Commercial birds performed better, as expected, attaining marketable weight in fewer days.
(a) The commercial strain (BUTA Medium White Males) attained a marketable weight in 110 – 144 days (3.6 – 4.8 months)
(b) The Bourbon Red (Privett strain) attained a harvest weight in 162 – 190 days (5.4 – 6.3 months)
(2) Average Final Live Weight. Commercial birds grew larger, weighing one-third more both at harvest and dressed, as expected. The Bourbon Red turkeys have not been selected in recent years for meat production, including those sold through hatcheries like Privett. A few independent breeders have continued to select for meat production as well as the breed standard for both color and conformation for the variety. These strains, however, are not readily available to the public.
(a) Commercial strain – Toms: Ranged from 20 – 26.3 pounds. The median was 22.2 pounds.
(b) Bourbon Red – Toms: Ranged from 12 – 16.4 pounds. The median was 15 pounds.
(c) Bourbon Red – Hens: Ranged from 8.8 – 12 pounds. The median was 10.26 pounds
(3) Average Dressed Weight.
(a) Commercial strain – Toms: Ranged from 14.92 – 19.59 pounds dressed. The median was 17.52 pounds.
(b) Bourbon Red – Toms: Ranged from 9.17 – 11.95 pounds dressed. The median was 11.3 pounds.
(c) Bourbon Red – Hens: Ranged from 6.29 – 7.45 pounds dressed. The median was 7.38 pounds
(4) Average Percent Dress Out. Percent dress out was comparable between the commercial strain and the Bourbon Red. However, the smaller final live weight for the Bourbon Reds translated into smaller dressed turkeys, many under 10 pounds. This is problematic for the producers because of the economics (feed consumption & lower poundage for sale), and for the consumers because many have come to expect larger turkeys with more breast meat.
(a) Commercial strain: Ranged from 67% – 85% dress out. The median was 75%.
(b) Bourbon Red: Ranged from 70% – 79%. The median was 75%.
(5) Feed conversion. The Bourbon Red turkeys required 20% more feed per pound of weight gain than the commercial strain. Again, the commercial strain has been rigorously selected for feed efficiency and rapid weight gain. This may come at the expense of skeletal development, expressing itself as joint problems, especially in older breeds. The standard turkey varieties, like the Bourbon Red, develop their skeletal and internal organs prior to adding significant muscle mass.
(a) Commercial strain: Feed conversion ranged from 3.49 to 6.32 pounds of feed per pound of weight. The median was 4.99 pounds of feed per pound of weight. (Adjusted for mortality)
(b) Bourbon Red: Feed conversion ranged from 5.36 pounds of feed per pound of weight. The median was 7.06 pounds of feed per pound of weight. (Adjusted for mortality)
(6) Mortality. Mortality was higher among the commercial strain. Dr. Bill Pierson, Poultry Immunologist at Virginia Tech, had anticipated an even greater mortality. Mortalities occurred at three distinct times. Shipping stress was a significant cause of loss, especially among the commercial birds. We experienced a particularly cold spell when we were shipping birds to participants. This combined with problems resulting from a change in the US Postal Service contractor for expedited shipping contributed increased mortality. Brooder mortalities were also high. Improved management in the brooder, including preventing predation by rodents and snakes, will reduce these mortalities. Predation, especially in the final weeks of growth took a significant toll among the Bourbon Reds. Early preparation for preventing predation is necessary to curtail this expensive loss.
(a) Commercial strain: Participants lost between 4% and 98%. The median was 75%
(b) Bourbon Red: Participants lost between 3% and 55%. The median was 31%.
(7) Morbidity. All participants reported heat stress related behaviors in the commercial strain, including panting, reduced activity, standing in water, and “flushing”(watery manure as a result of increased water intake). One participant had most of his commercial strain succumb to a respiratory disease. Dr. Pierson said the lung and cardiac to body mass ratio is no longer in balance, making it very difficult for the birds to tolerate stressors. This imbalance can also result in spontaneous death. While autopsies were not performed, Dr. Pierson suspected that the mortalities in the commercial strain reported by the one participant were due to failure of the lung immune system caused by either a mycoplasma or E. coli.
(8) Economic analysis. Because of the high rate of mortality, the economic analysis favored the Bourbon Reds because of the significantly greater pounds of meat produced at season’s end. Caring for the birds to reduce brooder deaths and to prevent predation will enhance the economics of both the commercial and the standard varieties significantly.
(a) Production cost, adjusted for mortality. Production cost is calculated as cost per poult divided by the survival rate, plus cost for feed, plus the cost of processing. This sum was divided by the total average dressed weight.
(i) Commercial strain: $2.58/pound
(ii) Bourbon Red: $2.77/pound
(b) Pounds of meat produced.
(i) Commercial strain: 4.38 pounds/poult started; 234.6 pounds of meat produced from 30 started poults.
(ii) Bourbon Red: 7.80 pounds/poult started; 131.25 pounds of meat produced from 30 started poults.
Other producers, who have begun raising standard turkeys following this on-farm phase of the study, and who experienced fewer mortalities, have reported that the industrial turkey cost ~$1.00/pound to raise, and the standard varieties averaged ~ $2.00/pound in production costs.
The actual price per pound charged by participants in this study varied widely. One participant had no access to processing facilities or to markets. She gave her birds away. Others charged between $1.25 and $4.00/pound depending on their market. Recent data collected from new turkey producers show standard varieties selling for $2.50 – 4.00 per pound from the farm, and commercial strain turkeys selling for $2.00 – $2.50/pound.
Significance and Justification:
Presently, commercial or industry turkeys have been selected based on their growth rates, meat potential (i.e. broad breasts), white coloring and their ability to artificially reproduce in controlled commercial environments. The outcome of this selection is a bird with high feed efficiency and growth characteristics. However, there are costs to this type of management system. The turkey gene pool has narrowed considerably. Natural breeding can not occur in these commercial birds due to the anatomical characteristics of these genetically altered lines. Other problems encountered include; hypertension, ruptured aortas, skeletal failure of weight support and immune dysregulation. As a result, the industry has had to make significant financial investment to control disease. The long-term outcome does not appear favorable for the commercial bird. One obvious direction would be to expand the gene pool.
The standard varieties of turkey have been in existence in range-based farms for years with some lines pre-dating the commercial. Minimal research has been conducted on these lines. However, the fact that these lines have remained in existence for many of these years would seem to indicate that their immune system and production indices would warrant evaluation.
Standard varieties of turkeys possess genetic characteristics that code for optimal immune response and may potentially serve as a useful gene pool for enhancing the commercial lines.
Aim 1: To compare select production indices in standard and commercial turkey lines at various stages of growth.
Rationale: Commercial turkeys have been selectively bred for their production performance traits at the expense of the birds’ other resources. The current commercial bird’s gene pool is so narrow that there is no room to genetically manipulate this line. Aim 1 assessed, of the 5 standard varieties studied, if any of the lines were comparable to the commercial line in production indices.
Aim 2: To employ an immune testing panel of assays to evaluate immunophenotypes of the standard turkey lines to the chosen commercial line.
Rationale: Commercial turkeys have been shown to be relatively immunologic-incompetent. As a result, the industry has had to create, at great costs, clean environments in which these commercial birds can be raised.
Aim 3: To evaluate the genetic molecular markers of the 5 standard varieties to assess the potential genetic differences or similarities to the commercial lines.
Rationale: If production and immunologic parameters are different across the standard varieties with respect to the commercial lines, then it suspected that genetic differences also exist. Three molecular markers systems: Randomly Amplified Polymorphic DNA (RAPD), microsatellite and SNPs were employed.
Virginia Tech’s study primarily investigated the immune status of 5 standard turkey varieties and compared them to commercial lines in select production endpoints in a controlled laboratory setting. The standard varieties evaluated were the Blue Slate, Bourbon Red, Narragansett, Royal Palm and Black Spanish. The goal was to identify varieties of standard turkeys that were comparable to the commercial line in production performance but were stronger immunologically than the commercial lines. We were also evaluating the degree of genetic similarity among the five lines. We achieved the objectives of our work ahead of schedule. Thus, we were able to follow up this study by doing additional work by performing an in vivo challenge. We also evaluated the capacity of these standard varieties to circulate Vitamin C, a potent anti-oxidant. A summary of our findings is presented in this text.
Progress Summaries for the proposal plus additional studies:
Summary of Aim 1 and Aim 2: This study compared the following immunological and production characteristics of five standard varieties of turkeys (Blue Slates, Black Spanish, Royal Palms, Bourbon Reds, and Narragansetts) one commercial breed (British United Turkeys of America): lymphocyte recovery, leukocyte proliferation in response to Concanavalin A at 5 microg/ml, 50 microg/ml and phorbol 12-myristate 13-acetate (PMA) 0.02 microg/ml with ionomycin 0.40 microg/ml, T-cell subset flow cytometric analysis, packed cell volume (PCV), total protein (T.P.), hatchability, weight gain, and five point differentials. The British United Turkeys gained more than twice the weight of the standard varieties between nine and thirteen weeks of age. The British United Turkeys consistently had a lower Packed Cell Volume and total proteins values than the standard varieties at nine, eleven and thirteen weeks of age. For all three time points the heterophil/lymphocyte ratio decreased with one exception – except for an increase in the B.U.T at thirteen weeks of age. Trends in the average lymphocyte recoveries were variable within the standard and commercial varieties. During all three time points that were evaluated the B.U.T. had a much lower mitogen response supporting the conclusion that they are functionally weaker to non-specific stimulation.
The British United Turkeys of America (B.U.T.) gained more than twice the amount of weight than any of the standard varieties between nine and thirteen weeks of age (Figure 1). Based on my observations, the weight gain of the turkeys was inversely related to the amount of the “flight or fight” response, as the bird’s “flight or fight” response increased the amount of weight that they gained decreased.
Egg Hatch and Infertility Analysis
Hatchability of the standard varieties was as a whole lower than what has been reported for the commercial line. However, the British United Turkey eggs were not evaluated at the same hatchery. Within the standard varieties, the Blue Slates, Bourbon Reds, and Narragansetts had the highest hatchability. The mean number of infertile eggs was lower for Royal Palms and Naragansetts (Table 1).
Packed Cell Volume and Total Protein Analysis
When compared to the standard varieties, B.U.T. consistently had lower packed cell volumes and total proteins at nine, eleven and thirteen weeks of age (Table 2).
Five Point Leukocyte Differential Analysis
Average heterophil/lymphocyte numbers declined in all six varieties of birds during all three weeks, except for the B.U.T.which increased in week thirteen (Figure 2). Bourbon Reds, Royal Palms and Blue Slates had the lowest mean heterophil/lymphocyte ratios of the six lines.
At nine, eleven and thirteen weeks of age, the Black Spanish, Bourbon Reds and Narragansetts had a consistent statistically significant decrease in the number of basophils. Royal Palms were consistent in their basophil numbers at nine and eleven weeks of age, but had statistically significant decrease at thirteen weeks of age (Data not shown). Blue Slates and B.U.T. had a statistically significant decrease between nine and eleven weeks, then had a statistically significant increase between eleven and thirteen weeks of age.
Blue Slates had consistent monocyte numbers at nine and eleven weeks of age, but the percentage decreased at thirteen weeks of age. Black Spanish, Royal Palms, B.U.T. and Narragansetts decreased in percentage of monocytes between nine and eleven weeks of age, then decreased at thirteen weeks of age. Bourbon Reds decreased in percentage of monocytes between nine and eleven weeks, then remained constant between eleven and thirteen weeks of age.
Average lymphocyte recovery increased between nine and eleven weeks of age, then decreased between eleven and thirteen weeks of age in the Blue Slates, Black Spanish, and B.U.T. (Data not shown). Royal Palm average lymphocyte recovery decreased each for all three weeks of the experiment (Data not shown). Bourbon Reds, and Narragansetts average lymphocyte recovery increased each week for all three time points (Data not shown).
When compared to Blue Slates, Black Spanish, Royal Palms, and Bourbon Reds, the B.U.T. had a significantly lower proliferation response to Concanavalin A (Con A) at a concentration of 5 microg/ml at nine, eleven and thirteen weeks of age. When compared to Royal Palms, B.U.T. had a higher proliferation response to Con A at a concentration of 5 microg/ml at nine weeks, the same amount of response at eleven weeks and a lower response at thirteen weeks of age. All five standard varieties had a higher proliferation response to Con A at a concentration of 50 microg/ml for all three time points. B.U.T. proliferation response to phorbol 12-myristate 13-acetate 0.02 microg/ml with ionomycin (PMA/I) at 0.40 microg/ml was lower than the Blue Slates, Royal Palms, and Bourbon Reds for all three time points. Black Spanish and Narragansetts had a higher proliferation response to PMA/I at nine weeks of age, and a lower response at eleven and thirteen weeks of age, when compared to the B.U.T.
Figure 3 caption. Average Proliferation response to Concanavalin A (Con A) at a concentration of 5 microg/ml, 50 microg/ml and to phorbol 12-myristate 13-acetate 0.02 microg/ml with ionomycin (PMA/I) 0.40 microg/ml at nine weeks of age.
Figure 4 caption. Average Proliferation response to Concanavalin A (Con A) at a concentration of 5 microg/ml, 50 microg/ml and to phorbol 12-myristate 13-acetate 0.02 microg/ml with ionomycin (PMA/I) 0.40 microg/ml at eleven weeks of age.
Figure 5 caption. Average Proliferation response to Concanavalin A (Con A) at a concentration of 5 microg/ml, 50 microg/ml and to phorbol 12-myristate 13-acetate 0.02 microg/ml with ionomycin (PMA/I) 0.40 microg/ml at thirteen weeks of age.
Analysis of the lymphocyte subsets from peripheral blood did not show any significant differences in the cell marker expression across all 6 of the varieties (data not shown).
The above summaries are part of the manuscript that is currently being completed for submission to Avian Diseases mid-April 2004.
AIM # 3: Genetic Analysis of the Five Standard Varieties of Turkeys
Presently, little data exists concerning the degree of genetic similarity among most of the recognized varieties of standard turkeys. To begin to address this lack of information, the five standard varieties were investigated for molecular similarities using Randomly Amplified Polymorphic DNA (RAPD), microsatellite analysis and SNPs derived from a sequence tagged site and a cloned RAPD fragment. The results from the RAPD analyses showed that there existed 14 informative DNA fragments among the five lines. The microsatellite analyses yielded two informative alleles from three primer-pairs. Nine SNPs were detected with one appearing to be strain specific. Based on these endpoint analyses, the Royal Palms appeared to be genetically more distinct than the other four strains being most closely related to the Naragansetts.
Status: A manuscript was prepared by Dr. Ed Smith and submitted to Biochemical Genetics under the title, “Molecular analysis of the relatedness of five domesticated turkey strains”. It is currently under re-review by the journal following corrections made from the original review.
I. Endogenous Production of Ascorbic Acid in Standard Turkeys:
Physiology and Applications
The antioxidant ascorbic acid has been the subject of extensive scientific investigation since its discovery by Albert Györgyi in the 1920s. Ascorbic acid (AA) has been shown to be physiologically multifunctional, enhancing function of the innate immune system, modulating gene expression, acting as a co-factor in enzymatic reactions, and protecting organisms from free radical damage during oxidative stress. The fact that avian species have retained their ability to synthesize AA has generated much interest into the possible benefits this ability affords birds. Previous studies have suggested that in times of stress (ie. disease, heat, and environmental stressors) endogenous AA may not provide adequate protection. Some studies have shown benefits in supplementation of domestic avian species with dietary AA.
The purpose of this study was to modify a reduction-based spectrophotometric method to specifically quantify AA levels in avian tissue and plasma samples. The goal was to develop an assay that was rapid, specific for AA, accurate and reproducible. A secondary aim of this study was to use this assay to determine if endogenously produced AA levels varied between varieties and between sexes of the same variety. The assay presented here is novel in that it has never been attempted in avian species and it provides a method for not only specific measurement of AA in plasma but in tissue samples as well. The experiments performed were designed to evaluate the efficacy and reliability of this assay in plasma and/or tissues of different avian species. Below are the data from a submitted manuscript that reviews the standard turkey varieties.
Assay of standard turkeys for breed and sex differences in endogenous ascorbic acid production.
Plasma ascorbic acid concentrations were analyzed in samples from each of the 96 standard turkeys in the study. Fourteen birds out of the 96 were excluded in order to age-match the study. The 14 that were excluded were older than the remaining 82. It was found that there were statistically significant differences between the breeds (Figure 1) when analyzed with ANOVA (p-value < 0.01). The Naragansett turkeys had the lowest average ascorbic acid concentration (0.54) – approximately half that of the Black Spanish turkeys, which had the highest average plasma AA concentration overall. These results show that there are breed differences in endogenous ascorbic acid production in historic turkeys as measured by plasma ascorbic acid concentration.
When gender differences were analyzed across breeds, a statistically significant difference was found between males and females (Fig 2), with a p-value of 0.011. Within breeds, only the Blue Slate and the Royal Palm turkeys showed a statistically significant gender difference in plasma AA concentrations.
First, the study of plasma levels of AA in standard turkeys showed significant breed differences in average plasma AA. The birds in this study did not receive AA supplementation, thus the plasma AA concentration was solely the result of endogenous production. Differences in endogenous AA production in breeds may point to an adaptive mechanism originally acquired to protect against environmental stresses present in certain groups during breed divergence. Future genetic studies are required to validate such a hypothesis. A definitive study would include comparison of gene expression for enzymes in the ascorbic acid synthetic pathway (i.e. L-gulono lactone oxidase) among breeds.
Figure 1 caption. Intervarietal differences in plasma AA concentrations of standard turkeys. Analysis was conducted with 82 age-matched standard turkeys across 5 different varieties. Plasma AA concentrations averaged for each variety are shown here graphically. Statistical analysis showed significant difference in plasma AA concentration between breeds (p<0.01). The Naragansett turkeys showed an average plasma [AA] approximately half that of the Black Spanish turkeys, with the other 3 breeds falling in between.
Figure 2 caption. Analysis of gender differences in plasma [AA] of standard turkeys. A statistically significant difference was found between gender across varieties while only Blue Slate and Royal Palm standard turkeys showed significant intra-varietal gender differences in plasma [AA]. That is, [AA] levels were different across genders becoming statisically significant only in the Bourbon Red, Blue Slate and Royal Palm.
Status: A manuscript was submitted to Poultry Science in the fall of 2003. It was rejected not on the merits of the work, but rather the reviewers felt that the manuscript would be more appropriate in a nutrition-oriented journal. We are in the process of reformatting the manuscript for that purpose as well as incorporating the constructive criticisms that accompanied our refusal letter. A May 1, 2004 submission is planned.
II. Comparison of Immunological Profiles between Commercial Line and Standard Varities of Turkeys Following challenge with HEV and E. coli.
The purpose of this study was to compare immunologic profiles of BUTA turkey to a number of standard varieties of turkeys. Peripheral blood was collected every two days from flocks of age-matched birds consisting of a commercial line (BUTA—BUT-8, British United Turkeys of America) and standard varieties (Royal Palm, Narragansett, Bourbon Red, Blue Slate, and Black Spanish). At six weeks of age, the turkeys were challenged with HEV (Hemorrhagic Enteritis Virus). Blood was collected on days 0, 2, 4, and 6, before they were exposed to E. coli at 108 CFU/mL on the seventh day. Immune endpoints measured included: lymphocyte recovery enumeration and sizing, lymphocytic function using in vitro mitogen proliferation assays with Alamar Blue™, and morphologic analysis from cytospins. On day 0, the BUTAs exhibited a high proliferative response to the T-cell mitogen Concavalin A (100ìg/mL) the Blue Slates and Royal Palms responded comparably. However, by day 6, post-challenge, the BUTAs exhibited the lowest proliferative response to mitogens compared to the standard varieties, Blue Slates, Royal Palms, and Black Spanish had the highest proliferative response to Con A. Additionally, the peripheral blood lymphocyte recovery increased for the standard varieties, but remained low for the BUTAs. Following exposure to E. coli on day 7 of the study, the BUTAs demonstrated a negative response to the mitogens, and all but two had died: One died by day 10, one died on day 11. In contrast, the majority of the standard turkeys survived past three days of bacterial infection surviving to the study termination. In summary, these results indicate a significant difference in immunologic response exists between the BUTA production and historic turkeys. These observations supports are theory that select lines of the standard turkey could serve as a contributing gene pool to the commercial lines, expanding its gene pool and allowing for other management options of these birds.
Status: This paper is in draft form and is currently undergoing revisions. Based on the final revision, it is scheduled to be submitted as a companion paper to the immunophenotype and production indices paper for Avian Diseases.
Summary of results for Objectives 3 & 4
The concluding remarks based on the results all the studies support that select lines of standard turkeys possess genetic traits that code for enhanced immunity and thus, allow them to perform better under social and pathogenic challenge compared to the commercial lines. However, the BUT commercial line outperformed all the standard varieties in terms of weight gain only. In this production index, none of the standard lines came even close in weight gain although Blue Slates, Black Spanish and Bourbon Reds had the highest mean weights of the standard varieties. Egg Hatch and Infertility analysis obtained from the Avian Medicine Veterinary Research Center’s Hatchery showed that the Royal Palms and Naragansetts had the lowest mean number of infertile eggs. However, Royal Palms had the lowest percentage hatchability. The BUT eggs were not evaluated.
The results of the genetic analysis, performed by Dr. Ed Smith, provided some interesting supportive data. The Naragansett and Royal Palms appeared to be the most genetically similar . This proved to be an equally similar conclusion drawn from the results of the immune, Vitamin C and challenge studies.
The immunologic data generated in the first year of the study clearly identified differences among the lines during their growth time-points. The blood smear cytology showed comparable leukocyte numbers during the 9 and 11-week period. However, by thirteen weeks the BUT birds had a much higher heterophil/lymphocyte (H/L) ratio than the standard lines. The H/L ratio is an indication of a stress response. The higher the ratio the greater the stress response, which is a negative factor in bird health. Lymphocyte proliferation assays were performed to assess the functional response of the birds lymphocytes to non-specific stimulants. At all time periods analyzed, the standard lines out performed the commercial line. Of the standard lines, the Bourbon Red, Royal Palm and Blue Slates had the stronger response to the stimulants. Packed red blood cell and total proteins analyses were higher in all of the standard lines compared to the commercial line which are all favorable endpoints. In summary, results from the immunophenotyping of the standard lines suggested that the Bourbon Red, Royal Palm and Blue Slates were stronger from an immunologic assessment. We decided to conduct a challenge study to test our hypothesis that the high immune responders would have a better outcome when challenged.
A viral-bacterial challenge experiment was included in the second year of the study.
Examining all the data collected in the HEV/ E.coli challenge study, it is clear that the production BUT-8 line of turkey was the least immuno-competent breed studied. It adapted least to bacterial or viral infection. Conversely, as projected, the Blue Slates, Black Spanish and Bourbon Red breeds possessed the most competent immune systems, as they both had the highest survival rates when infected with E. coli, and had the highest lymphocyte responses of all the breeds during the HEV and E. coli phases of the experiment.
Analysis of Ascorbic Acid (Vitamin C) levels in the standard and commercial lines was a fortuitous study. Ascorbic acid (AA) has been shown to be physiologically multifunctional, enhancing function of the innate immune system, modulating gene expression, acting as a co-factor in enzymatic reactions, and protecting organisms from free radical damage during oxidative stress. Animals having high levels of ascorbic acid would be at an increased benefit. A unique feature with birds is that they synthesize their own ascorbic acid. Although this was not part of the original proposal, we decided to include the turkeys from this study in our ascorbic acid study. An exciting finding was that the same lines that had the more robust immune responses also had the higher mean ascorbic acid levels.
To conclude, the cumulative results of the studies would suggest that there were significance differences in the standard turkey lines when compared to the commercial line in bird immunity. Further, some of these lines had stronger immune responses than others. Analysis of the ascorbic acid (Vitamin C) blood levels paralleled the line with the stronger immune response. Thus, if the industry wished to increase or expand the gene pool of the commercial/production turkey, serious consideration is warranted to the Blue Slates, Black Spanish and Bourbon Red based on their strong immunological performance. Evaluating other historic lines of birds may locate other potential donors to the gene pool. An additional path of study would be to perform F1 crosses with the top three historic lines and evaluate their performance.
Now that data & conclusions from both the on-farm research and from Virginia Tech are available, the writing of a summary report correlating this information may now proceed.
- 2001 Slow Food USA recognizes four varieties of standard turkeys by including them on their national “Ark of Taste”
2002 Slow Food USA initiates a national promotion of standard turkeys for the holiday table. Relies on ALBC’s contacts and information to establish this program.
Summer/Fall 2002 Four producers held field days. (1) Harry & Gail Groot held a farm field day for friends and potential customers. They presented the purpose of the research and their experience. They held a taste testing. While the results showed no clear preference for the standard or the commercial variety, their customers showed their preference for the standard turkeys with their purchases. (2) Gerry Cohn held a farm open house for customers, sharing the purpose of the research and his experience. (3) New England Heritage Breeds Conservancy is open to the public. Their flocks were easily viewed by the public. A taste testing did not reveal significant difference. (4) NCSU’s Center for Environmental Farming Systems hosted the SARE National Conference in Oct 2003. Attendees visited the flocks and learned about the research objectives.
March, 2003 NCSU posts an excellent documentation of their research results, including coop design. Go to http://www.cefs.ncsu.edu/frsu.htm. Click on “CEFS 2002 Pastured Poultry Project” or go direct to http://www.cefs.ncsu.edu/Turkey%202002%20Web%20Report.doc
June 23-24, 2003 American Association of Animal Science, Phoenix, AZ. Presentation to National Animal Germplasm Program about the issues of turkey genetic conservation.
September 7-8, 2003 Seeds and Breeds Summit in Washington, DC. Support for public funding of breeding programs for crops & livestock, including naturally-mating turkeys.
Oct 1 – 2, 2003 Turkey Breeder Clinic, Hutchison, KS. Brought together twenty breeders of standard turkeys from across the US and Canada attended a two day clinic on how to select birds for the breeding flock. Clinician: Frank Reese, Good Shepherd Turkey Ranch. Moderated by Marjorie Bender
Oct 3, 2003 ALBC Conference, Wichita, KS. “Recovery of the Heritage Turkey: Rediscovering Their Place in the Market.” Presented research data, future directions, market opportunities to a national audience. Marjorie Bender & Frank Reese. This was followed by a break-out discussion group for more in-depth discussion of standard turkey conservation and production.
Sept – Nov 2003 Marjorie Bender and Don Bixby fielded calls from journalists and reporters from across the country about standard turkeys. ALBC’s press file sports 38 articles we were able to collect. Such high profile publications as the USA Today, Chicago Tribune, LA Times, and Mother Earth News featured standard turkeys. ALBC’s publications – ALBC News and the Snood News – have included multiple articles on this research.
October 18, 2003 Don Bixby spoke at the Bioneers Conference in San Francisco. More than 500 farmers and supporters attended a presentation on the necessity of genetic conservation. ALBC’s turkey research was highlighted.
October 20, 2003. Don Bixby visited Slow Foods USA representatives in California, including their president. Discussion included ALBC’s turkey research & SF’s market promotion.
November 12, 2003 Slow Food USA’s NC Triangle convivium sponsored a promotional dinner at Panzanella featuring Matzah Rising Farm’s turkeys.
December, 2003 Developed “Heritage Turkey Information Packet.” Outlines the basic questions potential producers need to address to be successful. Includes a resource list and hatchery list. Distributed on request at no charge. To date ALBC has distributed over 300 packets.
January 25, 2004 Southern Sustainable Ag Working Group Conference, Gainesville, FL. “The Recovery of Heritage Turkeys” by Marjorie Bender and range production by Mike Walters, Walters Hatchery, Stilwell, OK. Approximately 40 farmers attended. Animated discussion of the emerging market for range-reared, standard turkeys was raised in other sessions. This is a hot topic!
February 8-9, 2004 Don Bixby attended the National Turkey Federation Annual Conference in Savannah, GA to better understand promotion, marketing, husbandry, and genetic issues in the turkey industry.
March 13, 2004 Organic Growers School, Flat Rock, NC, “The Recovery of Heritage Turkeys” by Marjorie Bender and range production by Alex Hitt, Peregrine Farm, Graham, NC. Approximately 40 farmers attended. Again, other poultry presentations discussed turkeys with great interest.
April 5, 2004 Central Carolina Community College Sustainalbe Agriculture Program, Pittsboro, NC. “The Recovery of Heritage Turkeys” by Marjorie Bender and range production by Alex Hitt, Peregrine Farm, Graham, NC. 12 students are enrolled in the class. Cooperative Extension Agents and reporters invited.
- Range production has not been widely practiced for several decades. As a result standard varieties of turkeys – the original production birds – have essentially disappeared from commercial production. A set of beliefs and attitudes has developed with the change in production systems and preferred genomes. We surveyed attitudes of all of the farmer-collaborators about their opinions prior to the project and at the completion of the on-farm component. The performance expected of the Bourbon Red and the industrial strain did not change over time. However, the comments revealed that the more active Bourbon Reds presented unexpected management challenges for some. For others, they were either surprised that the industrial strain performed as well – or as poorly – as they did on their site. Production costs were of concern because of the smaller finished weight of the Bourbon Reds.
Farmers, researchers, and the project coordinator were in regular contact with each other throughout the 2002 production season. Phone and email conversations provided feedback about how the project was unfolding at each location, enabling us to address data collection issues, health issues. Data were submitted to ALBC monthly, allowing project staff to monitor progress and identify areas of concern. This process worked very well. Most farmer-participants were visited during the course of the year. These visits afforded project staff an opportunity to see the farms first hand. Since the communication worked so well, farm visits became less crucial.
An evaluation of the economics of range-based turkey production was accomplished by analyzing the profit/loss of the farmers who will be marketing the finished product at harvest. Please see economic analysis in Objective 3.
One measure of the project is the degree to which the project timeline and budget mirror reality. Some of the writing and outreach components of the project have lagged behind its projected timeline due to other demands on staff time. However, the project has produced more than promised in the original proposal. With remaining funds, collaborators will complete the remaining objectives. In addition, additional varieties and strains will be immunogically evaluated, and genetically analyzed.
Interest in this work can be measured by our ability to place articles in both scientific and popular venues, to obtain speaking engagements, and audience response. The overwhelmingly positive response by journalists, consumers and producers demonstrates clear success on multiple fronts. This is currently a “hot-topic”. Speaking engagements have been limited by available resources. Audience response has been even than expected. The development of a concise “How-to” manual for range-rearing standard turkeys and strategic outreach and promotion, small scale standard turkey production has the potential to be a valuable enterprise for diversified farmers and could simultaneously conserve invaluable and irreplaceable genetics.
ALBC conducted a census of turkeys in the winter of 2002-2003 to measure the effect we were having on standard turkey populations. The results of the census shows a 3-fold increase in the breeding populations of standard varieties. In 1997, 1335 breeder birds were reported. In 2003, 4227 breeder birds were reported. Individual varieties increased from 82% – 875%. The bad news is that 8 varieties remain in ALBC’s Critically endangered category. Royal Palm is Rare. Bourbon Red is Watch. Only 16 hatcheries and breeders maintain breeding flocks. Since the 1997 census of turkey, several hatcheries have discontinued breeding turkeys, others have gone out of business. The complete results are described in described in detail in “Heritage Turkeys in North America: The ALBC 2003 Heritage Turkey Census” by Marjorie E. F. Bender, available from ALBC.
In March 2003, the collaborators met to share their experiences and what they had learned with each other, comment on the procedures, and recommend changes for future iterations. The discussion revealed that some conclusions may not be made due to research design, but the design was sufficient to clearly indicate trends and similarities.
The collaborators also discussed and debated the larger issues relating to turkey conservation and the different networks of turkey breeders and producers that play a role in the turkey industry. The discussion resulted in a preliminary list of “next steps”. Additionally, the discussion produced a more sophisticated understanding of the segmentation of the industry and each segment’s unique needs and potential contributions to genetic conservation in turkeys. In itself, this was a significant breakthrough that provides ALBC with some key understanding needed to develop successful conservation strategy.
The segments identified are: (1)Industrial turkey production which is well organized, using a narrowly selected and exquisitely productive bird. Artificial insemination and other significant supports are necessary for production of these birds. (2) Standard turkey production employing varieties recognized by the American Poultry Association. Subset of this group include (a)Standard Turkey production and show strains characterized by birds selected for a moderate broad breasted phenotype, but retaining the ability to mate naturally Occasional outcrosses are used, although this varies from strain to strain;(b) Standard Turkey Poult Producers exemplified by hatcheries that sell poults to the public. These hatcheries have multiplier flocks that do not undergo the extreme selection of the production and show strains; (c) End-producers of standard turkeys who buy poults and grow them out. These farmers do not retain breeding stock, and are dependent on others for poult production; and (d) Farmyard-based standard turkeys that are owned and raised by small-scale producers. For effective conservation to occur strategies need to be developed that address the challenges, needs, and objectives of each segment. More information on this will be forth-coming as the year progresses.
- July 2001. Range-based turkey production systems defined by collaborators.
Feb – April 2002. Log book which defines and organizes the data to be collected was developed and distributed to participants.
Jan 2002 Arrangements made with Privett Hatchery to supply Bourbon Red turkeys, and with British United Turkeys of America (BUTA) turkeys to supply a commecial strain.
May – June, 2002. Poults ordered in early May. Shipped on May 15 and June 1, 2002, as requested by farmers.
Nov 2002. Developed survey to census breeding stock of standard varieties of turkey and to monitor poult sales. Assembled contact list.
Jan – March 2002. A pre-study survey was not developed or conducted because we ran out of time. Attitude change was assessed through a post-study survey.
May – December 2002. Farmers collected data on the turkeys from date of placement through harvest. Data was recorded in the log books and sent to ALBC on a monthly basis.
March – November 2002. Each farmer documented their production system, changes that occurred as the season progressed. Each farmer described their farming operation in detail to provide a context for the turkey evaluation. This documentation was submitted to ALBC.
May – November 2002. Drs. Bob Gogal & Bill Pierson of Viriginia Tech conducted immunologic tests of five varieties of standard turkeys and an industrial strain. This was the second of three years of testing. Dr. Ed Smith of Virginia Tech conducted molecular analysis, using DNA, of five standard turkey varieties. Additional work is clearly needed in this area.
December 2002- March 2003. Conducted census of breeding stock of standard turkey varieties and survey of poult sales. Those surveyed were unable or unwilling to share poult sales. The census of breeding stock showed that populations are continuing to climb, as a result of ALBC’s previous work.
Mid-summer – fall 2002. Sunrise Valley Farm held a field day. CEFS/NCSU and Matzah Rising Farms were hosts for the SARE national conference. All three presented the objectives of the project to visitors. The other farms were closed to protect them from increasing disease threats.
September – November 2002. Site visits were made to NEHBC (9/02), Paula’s Produce (9/02), Seldom Seen Farm (7/02), Good Shepherd Ranch (3/03), Sunrise Valley Farm (10/02), and CEFS/NCSU (10/02), and Matzah Rising Farm (9/02). Sand Hill Preservation Center provided excellent commentary and photos of the project.
January 2003. Conducted post-study survey to measure the farmers’ change in attitude about the standard and commercial turkeys on range.
January – December 2003. Data analysis complete. Conclusions drawn based on both quantitative and qualitative data.
March 2003. Conducted a post-project roundtable. Participants shared their experiences with one another and reported their results; researchers reported their results; project protocol was evaluated and modifications suggested; and next steps discussed.
Spring – Fall 2003. Immune trials continued. Direct disease challenge conducted.
Fall 2003 – Spring 2004. Presented results at three major agricultural events. Information was included in other presentations at many more agricultural and consumer events.
Summer 2003 – present. Wrote articles, provided interviews. Coverage was broad and often front page and feature length. Producers from across the country were featured.
November 2003. Submitted full proposal to SSARE PDP, entitled “Sustainable Production Systems for Range-Reared Standard Heritage Turkeys.” Funding declined
- Vitamin C study, by Dr. Robert Gogal, Virginia Tech. Submitted to scientific journal for consideration.
Immunologic Evaluation, by Dr. Robert Gogal, Virginia Tech. Being written.
Disease Challenge study, by Dr. Robert Gogal, Virginia Tech. Being written.
Genetic Analysis, by Dr. Ed Smith, Virginia Tech. Submitted to scientific journal for consideration.
Summary article drawing together the results of the on-farm research & the laboratory work by Marjorie Bender, ALBC. Being written
- Immunogical evaluation of additional varieties and strains not included in the recent research.
Genetic Analysis of additional varieties and strains not included in the recent research.
- October 1 – 2, 2004 A two-day on-farm clinic covering breeder selection, ALBC turkey research and production practices is scheduled. Sponsored by the Pennsylvania Association for Sustainable Agriculture (PASA).
Promote results through ALBC, ATTRA and other information channels.
Next steps with further funding:
- Continued promotion of standard turkeys to potential breeders and the discriminating consumer
Conduct another follow-up survey after distributing research results
Explore the certification of standard variety turkey flock to verify products
Repeat census of turkeys to continue to monitor population growth.
Develop a “How-To” manual and educational program on range-rearing standard turkeys for the holiday market. Resubmit a PDP proposal to SSARE.
Perform F1 crosses with the top three standard lines and an industrial strain and evaluate their production and immunologic performance. This might lead to the development of genetic strains with competitive production attributes that are suitable for range-rearing.
Impacts and Contributions/Outcomes
- providing producers with information about the superior health and survivability of standard turkeys in range based systems. Dr. Gogal’s research conducted immunologic tests of five varieties of standard turkeys and an industrial strain. In this third of three years of evaluation, the cumulative results of the studies strongly suggest that there are significance differences in the standard turkey lines when compared to the commercial line in bird immunity. Further, some of these lines had stronger immune responses than others. Commercial production traits are indeed negatively correlated with immunocompetence, e.g. disease resistance.
providing producers with superior price per pound for range-reared standard turkeys when sold direct to the consumer.
providing producers with sources of turkey poults. A census of turkeys conducted in the winter of 2002-2003 provided updated information on sources of standard turkeys
providing producers with information on feed conversion and management. Accurate information help producers develop realistic expectations, and enabling them to make personally and regionally appropriate decisions about starting a standard turkey enterprise.
providing a network of experienced producers with whom to consult. The participants in this project all commented on how much they learned from their participation. These producers are a valuable resource for other producers who are interested in range-rearing turkeys. Additionally, the round table meetings held as part of the planning grant and again in March 2003, connected the participants with one another, and engaged them in the big picture questions of effective genetic conservation and the varied production systems and goals of producers. These conversations and opinions informed the “next steps.”
- introducing consumers to the wonderful world of standard turkeys! This includes telling the story of standard turkeys’ cultural value in the Americas, and specifically in the United States, and their culinary value. Describing their superior health attributes which enable them to thrive outdoors develops a basis for promoting the need for their conservation.
providing consumers with information about standard turkeys, the need for their conservation, the role standard turkey varieties can play in sustainable production systems and in creating a healthier and humanely raised food product for themselves and their families.
providing consumers with direct access to producers who raise standard varieties of turkeys. In 2002, Slow Food USA collaborated with ALBC to provide consumers with range reared, standard turkeys for Thanksgiving dinners on tables across the US. Over 3000 birds were sold and distributed this way. In 2003 over 5000 were distributed through Slow Food. Many more were sold directly to the consumer by independent producers. This marketing project enhanced public awareness of standard turkeys and the need for their conservation. It also substantially increased demand for standard turkeys at all levels, including breeders and poult production; turkeys that were raised humanely on range, hatcheries who supplied turkey poults to producers, producers raising turkeys for this specialty market, and consumers who were able to enjoy the fruits of these efforts.
- increasing demand for standard turkeys. In a census of turkeys conducted from December 2002 to April 2003, the breeding populations of standard varieties of turkeys are shown to be increasing. Since 1997 the Bourbon Red turkey breeding population has increased to 1498, an increase of 98%. The Black Spanish has increased from 62 to 391, an increase of 530%. Others are showing similar gains. Standard varieties of turkeys will survive only if there is a demand for them and access to the marketplace.
documenting the standard turkeys’ genetic value to the turkey industry and the public. The industry is struggling with a narrowing genetic base as selection continues to be limited to production attributes (efficient feed conversion, rapid weight gain) to the exclusion of disease resistance, and biological fitness. The correlation of DNA analysis, Vitamin C study, immunologic evaluation and direct disease challenges demonstrating that some standard varieties (Bourbon Red, Blue Slate, and Black Spanish) have superior immune systems. The results of this study further emphasize the importance of conserving standard varieties of turkeys, as they can provide valuable resources for a changing agriculture and a threatened industry.
- increasing demand for their product, namely turkey poults, thereby enabling hatcheries to maintain larger breeding populations of standard turkeys, enhancing business, and their potential for survival in this very difficult time.
Without a doubt, this study showed that standard varieties of turkeys perform better than industrial strains in range-based systems.
During the last 12 months of funding, we will conduct DNA and immunologic evaluations of several more identified varieties and strains. Results will be summarized and published.
Thank you, SSARE, for your support. This important work would not have been possible without you!
Paula’s Produce & Farm
2442 Mayfield Lane
Las Cruces, NM 88005-5108
Office Phone: 5055263105
Virginia Polytechnic Institute & State University
Comparative Genomics Lab
Department of Animal & Poultry Sciences
Blacksburg, VA 24601
Office Phone: 5402316797
Professor, Crop Science
North Carolina State University
PO Box 7620
Raleigh, NC 27695-7620
Office Phone: 9195155825
Associate Director of Agriculture & Education
New England Heritage Breeds Conservancy
PO Box 20
Richmond, MA 01254
Office Phone: 4134438356
Sunrise Valley Farm
4615 Mountain Pride Rd.
Hiwassee, VA 24347
Office Phone: 5406393077
Good Shepherd Ranch
730 Smoky Valley Rd
Lindsborg, KS 67456-9553
Office Phone: 7852273972
Seldom Seen Farm
PO Box 351
Amenia, NY 12501-0351
Office Phone: 8453737207
Associate Professor, Large Animal Clinical Science
Virginia Polytechnic Institute & State University
Blacksburg, VA 24601-0442
Office Phone: 5402317179
Veterinary Geneticist & Pathologist
Virginia Polytechnic & State University
Blacksburg, VA 24061-0442
Office Phone: 5402314805
Research Assistant Professor of Immuno-toxicology
Virginia Polytechnic Institute & State University
Blacksburg, VA 24061-0422
Office Phone: 5402315733
Associate Professor of Avian Medicine
Virginia Polytechnic Institute & State University
Blacksburg, VA 24061-0442
Office Phone: 5402314529
Matzah Rising Farm
1105 W. Greensboro-Chapel Hill Rd
Snow Camp, NC 27349-9599
Office Phone: 3363768765