Source: AUBURN UNIVERSITY submitted to NRP
DIETARY AMINO ACID REQUIREMENTS OF BROILERS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
0218241
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
Oct 1, 2009
Project End Date
Sep 30, 2014
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
AUBURN UNIVERSITY
108 M. WHITE SMITH HALL
AUBURN,AL 36849
Performing Department
Poultry Science
Non Technical Summary
Feed ingredient cost is a major concern for broiler companies. As a result, feed costs represent 67 to 69% of the total live production costs for broilers. For example, feed cost to produce 2.0 kg broiler is $0.71, whereas $1.39 is required to produce a 3.6 kg broiler. Feed costs are relatively higher for broilers beyond four weeks of age compared with younger broilers. Amino acids are one of the most expensive nutrients in diets for broilers. Some companies reduce amino acid density of the diet two weeks prior to marketing as an effort to reduce feed cost. This approach can lead to sub-optimum growth and meat yield because maximum growth rate of broilers occurs between four and six weeks of age. Research is needed to define dietary nutrient needs late in development when feed intake is relatively high. Formulating diets either in excess or deficient in nutrients can be very costly. Dietary amino acid requirements can be expressed using the Ideal Amino Acid Concept. Lysine is the reference amino acid as other essential amino acids are expressed as a ratio to lysine. This formulation strategy does not place a minimum on crude protein within practical limits, rather minimums for valine and isoleucine dictates crude protein content. This formulation strategy can reduce diet cost by two to four dollars a ton compared with placing a minimum on crude protein. Valine and isoleucine ratios are important to help define the threshold of reducing crude protein so that growth performance and meat yield is not limited. Information is needed on the valine and isoleucine requirement to use crystalline lysine and threonine effectively in diet formulation for broilers. Accurate data are needed for the digestible ratios for methionine and cystine, threonine, valine, and isoleucine.
Animal Health Component
(N/A)
Research Effort Categories
Basic
(N/A)
Applied
(N/A)
Developmental
(N/A)
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
30232201010100%
Knowledge Area
302 - Nutrient Utilization in Animals;

Subject Of Investigation
3220 - Meat-type chicken, live animal;

Field Of Science
1010 - Nutrition and metabolism;
Goals / Objectives
Objectives 1. Evaluate growth and meat yield of broilers fed reduced crude protein diets. 2. Delineate digestible lysine, total sulfur amino acids, threonine, valine, and isoleucine requirements of broilers. Outputs will consist of conducting and analyzing experiments, presenting data at Scientific Conferences and Workshops, providing consultations to the broiler industry, and new dietary amino acid recommendations for diet formulation will be generated.
Project Methods
Day-old broiler chicks will be obtained from a commercial hatchery and randomly distributed into floor pens (25 birds per pen) of an experimental facility. Each pen will be equipped with a pan feeder, nipple water line, and pine shavings. Prior to experimentation, protein contributing ingredients will be stored and sampled. Samples will be analyzed for amino acid and crude protein composition. Digestible amino acid values will be determined from digestible coefficients and analyzed total amino acid content of the ingredients. The resultant digestible amino acid values will be used in diet formulation. Ileal amino acid digestibility of the experimental diets may be determined using broiler chicks. Live performance variables will be evaluated during the experimental period based on dietary treatment effects. Body weight, feed intake, feed conversion, amino acid intake, and amino acid intake per unit of BW gain will be calculated. The incidence of mortality will be recorded daily. One bird per pen may be bled for the collection of blood to determine blood urea nitrogen. At the end of experimentation, a sample of birds from each pen will be process to assess meat yield differences. Weights of carcass (without abdominal fat), abdominal fat, and Pectoralis major and Pectoralis minor muscles will be determined. Quadratic equations and regression broken-line models will be used to estimate amino acid requirements. With the quadratic regression equation, the digestible amino acid requirements will be estimated at 95% of the response when a quadratic response is observed (P ≤ 0.05). Digestible amino acid requirements will be also estimated using broken line methodology when a significant (P ≤ 0.05) response is detected.

Progress 10/01/09 to 09/30/14

Outputs
Target Audience: The target audience is nutrionists and live production managers of broiler integrated operations. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? I organized an annual workshop involving a research update on broiler nutrition research at Auburn University to poultry nutritionists and live production managers throughout Alabama and adjoining states. This meeting was held in Cullman, Alabamain 2010 and Gardendale, Alabama from 2010-2014.In addition, data have been presented at scientific and industry conferences within and outside the United States. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

Impacts
What was accomplished under these goals? More emphasis was placed on Objective 2 than 1 due to funding opportunities. Objective 1: We presented a paper at the 2014 European Poultry Conference on feeding reduced crude protein diets to broilers from 28 to 42 days of age.Moreover, we are in the process of submitting a paper to the 2015 Poultry Science Association meeting that evaluated the additIons of L-glycine and glutamine to reduced crude protein diets. In addition, future research will evaluate responses of the less limiting amino acids in reduced crude protein diets. Objective 2: Digestible Lys Requirement: Digestible lysine requirements from 1 to 14 days of age were determinedwith Cobb and Ross broilers. Ross x Ross 708 broilers had an estimated digestible lysine requirement of 1.27%, whereas Hubbard x Cobb 500 broilers had a requirement of 1.20%. These requirement estimates are higher than previous research published in the 1994 National Research Council "Nutrient Requirements for Poultry". These results will be helpful in updating a future National Research Council "Nutrient Requirements for Poultry". Moreover, these data provide evidence that feeding to thedigestible lysine requirement will enable optimum growth rate and feed conversion during the first two weekspost-hatching. A presentation was presented at a scientific conference and one manuscript was published during 2012. In addition to evaluating the digestible lysine requirement from 1 to 14 days of age, we conducted two studies that examined responses of Hubbard x Cobb and Ross x Ross 708 broilers fed diets varying in amino acid density. Within the starter (1 to 14 days), grower (15 to 28 days), and finisher (28 to 35 days - Cobbor 28 to 42 days - Ross)periods, five digestible lysinetreatments were fed. All diets were formulated to optimum amino acid ratios relative to lysine. Growth performance, carcass characterisitcs, and economic returns were determined. In the study that evaluated responses until 42 days of age (Ross), it was determined from the this research that $0.27/bird could be obtained from feeding the lowest lysine levels used compared with feeding to the lysine requirement. Conversely, feeding the second lowest lysine treatment would reduce revenue of a poultry company by $0.18/bird when compared with the broilers fed diets at the digestible lysine requirements. For example, for a complex processing 1 million broilers per week, these differences would translate to an increase in weekly revenues of $270,000 or $180,000. The study utilizing Cobb broilers until 35 days of age provided similar results. We have given two presentations at a scientific conference and one presentation at an industry conference. The plan is to submit a manuscript for publication in the next few months. Digestible total Sulfur Amino Acid Ratios: Total sulfur amino acids to lysine ratio was determined from 1 to 14 and 42 to 56 days of age. In addition, we had planned to evaluate total sulfur amino acid to lysine ratio from 14 to 28 and 28 to 42 days of age but were not able to conductstudies with these time intervals due to funding constraints. From 1 to 14 days of age, total sulfur amino acids to lysine ratio was determined at 0.78, which higher than estimates reported in the literature 0.74-0.75. From 42 to 56 days of age, total sulfur amino acids to lysine ratio was determined at 0.76 for breast meat weight and 0.74 for breast meat yield. No ratio wasdetermined for body weight gain or feed conversion, which infers the need for total sulfur amino acids are higher for breast meat yield than growth performance. Two presentations have been given at scientific conferences and one manuscript was published in Journal of Applied Poultry Research. In addition, another manuscript should be submitted for publication in a few months. Digestible threoniine ratios: We determined the digestible threonine to lysine ratios from 1 to 14,21 to 35, and 35 to 49 days of age. We had published the digestible threonine to lysine ratio from 14 to 28 days of age prior to this project. Previous research indicated that the optimum digestible threonine to lysine ratio may increase as the bird advances with age but strong evidence was not available to support this concept. From this research, we determined that the optimum threonine to lysine ratio ranged from 0.67-0.69 among the studies based on body weight gain,feed conversion, and meatyields,but age was not a major factor. These estimates particularly, from 1 to 14 d of age, werehigher than used by the industry 0.63-0.65. We have presentedthree data sets at scientific meetings and are in the process of submitting two manuscripts for publication. Currently, the price of L-threonine (feed-grade amino acid) has increased from $1.00/lb to $2.35/ lbduring the last12 monthsas this is due to the increaseddemand of using L-threonine in diets to acheive these higher digestible threonine to lysine ratios. However, manufacturing has been unable to meet this demand and prices have increased. In the long-term, production of L-threonineshould increase but this will require multi-million dollar investmentsfrom amino acid suppliers to build additional plants. L-threonine included in the diet at a ratio of 0.65 can save approximately $9.35 per ton compared with not using the feed-grade amino acid andit is unfeasible to formulate a diet witha ratio 0.68 without the use of L-threonine through least-cost formulation.Research has provided the benefits of the higher threonine ratios due to feed conversion, body weight gain, and meat yields. Currently, for every 0.01 increase in threonine to lysine ratio feed cost will increase about $0.45/ton to $0.50/ton so the performance benefitsshould outweigh the costs if ratios supported by this research are fed. If soybean meal prices become higher than the current prices, then L-threonine will look even more attractive to poultry companies. Digestible valine to lysine ratios: We have completed one study evaluating digestible valine to lysine ratio from 28 to 42 days of age and these results were presented at the 2013 International Poultry Scientific Forum. It was determined that the valine to lysine ratio ranged form 0.76-0.78 depending upon the response criteria used to estimate the requirement. During the last 12 months, we have conducted or in the process of conductingexperimentsevaluating digestible valine to lysine ratios from 1 to 14, 14 to 28, and 28 to 42 days of age using a novel source of L-valine. These data have not been summarized at this time. Digestible isoleucine to lysine ratios: We were unable to address this part of the objective due to time and funding constraints.

Publications


    Progress 10/01/13 to 09/30/14

    Outputs
    Target Audience: Feed ingredient cost is a major concern for broiler companies. Feed costs are relatively higher for broilers beyond four weeks of age compared with younger broilers. Amino acids are one of the most expensive nutrients in diets for broilers. Some companies reduce amino acid density of the diet two weeks prior to marketing as an effort to reduce feed cost. This approach can lead to sub-optimum growth and meat yield because maximum growth rate of broilers occurs between four and six weeks of age. Research is needed to define dietary nutrient needs late in development when feed intake is relatively high. Formulating diets either in excess or deficient in nutrients can be very costly. Dietary amino acid requirements can be expressed using the Ideal Amino Acid Concept. Lysine is the reference amino acid as other essential amino acids are expressed as a ratio to lysine. This formulation strategy does not place a minimum on crude protein within practical limits, rather minimums for valine and isoleucine dictates crude protein content. This formulation strategy can reduce diet cost by two to four dollars a ton compared with placing a minimum on crude protein. Valine and isoleucine ratios are important to help define the threshold of reducing crude protein so that growth performance and meat yield is not limited. Information is needed on the valine and isoleucine requirement to use crystalline lysine and threonine effectively in diet formulation for broilers. Accurate data are needed for the digestible ratios for methionine and cystine, threonine, valine, and isoleucine. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? Organized an annual workshop involving an update on broiler nutrition research at Auburn University to poultry nutritionists and live production managers throughout Alabama and adjoining states. This meeting was held in Gardendale, Alabama during August 2014. What do you plan to do during the next reporting period to accomplish the goals? Nothing Reported

    Impacts
    What was accomplished under these goals? Data were presented at the International Poultry Scientific Forum that relate to Objective 2. Recommendations of the digestible threonine to lysine ratio for broilers from 21 to 35 days of age. It was determined that to maintain optimum body weight gain and feed conversion ratio that a digestible threonine to lysine ratio of 0.68 is necessary. Data were presented at the European Poultry Conference that relate to Objective 1. These results have generated additional questions on future research with non-essential or less limiting amino acids.

    Publications

    • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Jiang, Z., W. A. Dozier, and P. B. Tillman. 2014. Digestible Thr to Lys ratio of male broilers from 21 to 35 days of age. International Poultry Scientific Forum (Abst.):232.
    • Type: Conference Papers and Presentations Status: Published Year Published: 2014 Citation: Dozier, W. A., III and M. T. Kidd. 2014. Effects of amino acid supplementation with reduced crude protein diets fed to broilers from 29 to 40 days of age. European Poultry Conference, Stavanger, Norway.


    Progress 01/01/13 to 09/30/13

    Outputs
    Target Audience: The targeted audience is nutritonists and live production managers of commercial broiler companies. Changes/Problems: Nothing Reported What opportunities for training and professional development has the project provided? Nothing Reported How have the results been disseminated to communities of interest? Researchwas presented to industry representatives in Alabama, Georgia, and Mississippi at an outreach seminar. What do you plan to do during the next reporting period to accomplish the goals? These results from experiments conducted in 2013will be presented in Scientific Conferences in 2014.

    Impacts
    What was accomplished under these goals? Data were presented at the International Poultry Scientific formum and Poultry Science Annual Meeting that relate to Objective 2. Recommendations for digestible threonine and total sulfur amino acids were generated for the period from 1 to 14 days of age.Moreover, experiments were conducted and data have been analyzed but these data have not been presented at a professional meeting at this time.

    Publications

    • Type: Journal Articles Status: Accepted Year Published: 2013 Citation: Dozier, W. A., III and Y.Mercier. 2013. Ratio of digestible total sulfur amino acids to lysine of broiler chicks from 1 to 15 days of age. J. Appl. Poult. Res. 22:862-871.
    • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Meloche, K. J., P. Tillman, and W. Dozier, III. 2013. Growth performance of male broilers fed diets varying in digestible threonine from 1 to 14 days of age. International Poultry Scientific Forum (Abst.):198.
    • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Perryman, K., P. Tillman, and W. Dozier, III. 2013. Increased dietary amino acid density from 1 to 42 d of age optimizes profitability in Ross � Ross 708 male broilers. International Poultry Scientific Forum (Abst.):198.
    • Type: Conference Papers and Presentations Status: Accepted Year Published: 2013 Citation: Tillman, P., K. Perryman, W. Dozier, III. 2013. Increased dietary amino acid density from 1 to 35 d of age optimizes profitability in Hubbard � Cobb 500 male broilers. International Poultry Scientific Forum (Abst.):208.
    • Type: Conference Papers and Presentations Status: Published Year Published: 2013 Citation: Dozier, W. A., III and Y. Mercier. 2013. Digestible total sulfur amino acid to lysine ratio of male broilers from forty-two to fifty-days of age. Poult. Sci. 92 (E-suppl. 1):73.


    Progress 01/01/12 to 12/31/12

    Outputs
    OUTPUTS: Research results were presented at both scientific and industry meetings: XXIV World's Poultry Congress, Salvador, Brazil;Massey Technical Update Conference, Monogastric Research Center, Massey University, Palmerston North, New Zealand;Ajinomoto Animal Nutrition Seminar. San Jose, Costa Rica;U. S. Grains Council Poultry Nutrition Seminar. Bangkok, Thailand; U. S. Grains Council Poultry Nutrition Seminar. Jakarta, Indonesia; Colombian Veterinary Poultry Association Nutrition Seminar. Bogota, Colombia; Auburn University Nutrition Research Workshop, Gardendale, Alabama; Poultry Science Association Annual Meeting, Athens, Georgia. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: The target audience is poultry nutritionists and live production managers of commerical broiler operations. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

    Impacts
    We examined the dietary lysine requirement of broilers from 1 to 14 d of age based on growth responses. Two experiments were conducted from September to October in 2010 and 2011.It was determined from this research that the digestible lysine requirement from 1 to 14 d of age for Ross x Ross 708 broilers was 1.27%, whereas the digestible Lys requirement for Hubbard x Cobb 500 broilers was 1.21%. Moreover, we assessed the interaction of digestible valine to lysine ratios and isoleucine to lysine ratios ratios of diets fed to broilers from 28 to 42 days of age. It was determined from this research that isoleucine and valine to lysine ratios do not intereact to influence broiler performance. Minimum digestible isoleucine to lysine ratio of 67 to 70% is needed to optimize breast meat accretion.

    Publications

    • Dozier, W. A., III, P. B. Tillman, and J. Usry. 2012. Interactive effects of digestible valine and isoleucine to lysine ratios provided to male broilers from four to six weeks of age. J. Appl. Poult.Res. 21:838-848.
    • Dozier, W. A., III and R. L. Payne. 2012. Digestible Lys requirements of female broilers from 1 to 15 days of age. J. Appl. Poult. Res. 21:348-357.
    • Dozier, W. A., III, P. Tillman, and J. Usry. 2012. Effects of varying digestible Val and Ile ratios in diets fed to Ross x Ross 708 male broilers from 26 to 40 d of age. XXIV World's Poultry Congress, Salvador, Brazil.
    • Dozier, W. A., III and Y. Mercier. 2012. Digestible TSAA to Lys ratio for male broilers from 1 to 14 d of age. XXIV World's Poultry Congress, Salvador, Brazil.
    • Dozier, W. A., III. 2012. Dietary amino acid strategies to optimize broiler growth and meat yield. Massey Technical Update Conference, Monogastric Research Center, Massey University, Palmerston North, New Zealand.
    • Meloche, K. J., P. B. Tillman, R. B. Shirley, and W. A. Dozier, III. 2012. Digestible valine to lysine ratio of male broilers from twenty-six to forty-two days of age. Poult. Sci. 91 (Suppl. 1):38.


    Progress 01/01/11 to 12/31/11

    Outputs
    OUTPUTS: Listed below are four papers that were presented at either scientific or technical conferences. Dozier, W. A., III, P. Tillman, and J. Usry. 2011. Interactive effects of digestible Val and Ile ratios with Ross x Ross 708 male broilers from 26 to 41 d of age. 18th European Symposium on Poultry Nutrition. Cesme, Izmir, Turkey. 3 pp. Dozier, W. A., III and R. L. Payne. 2011. Digestible Lys requirements of female broilers from 1 to 15 days of age. Poult. Sci. 90 (E-Suppl. 1):87. Rose, L. N., R. D. Mitchell, R. L. Payne, and W. A. Dozier, III. 2011. Broiler responses to diets varying in digestible lysine, valine, and isoleucine from 21 to 35 days of age. International Poultry Scientific Forum (Abst.):7. Gehring, C. K. and W. A. Dozier, III. 2011. Poultry nutrition update. Auburn University Nutrition Research Workshop, Gardendale, Alabama, August 17. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

    Impacts
    We determined that 454 g of L-Valine could be added to the diet from 28 to 42 d of age without compromising broiler growth and meat yield. In addition, we determined that valine and isoleucine are co-limiting with broilers fed diets containing 3% poultry by-product meal. Based on these data, it is important to determine valine and isoleucine requirements for broilers. These results have been instrumental in valine being produced on a large scale. The commerical production of valine will aid in reducing diet cost as well as reducing nitrogen output by the bird.

    Publications

    • Corzo, A., W. A. Dozier, III, L. Mejia, C. D. Zumwalt, M. T. Kidd, and P. B. Tillman. 2011.Nutritional feasibility of L-valine inclusion in commercial broiler diets. J. Appl. Res. 20:284-290.
    • Dozier, W. A., III, A. Corzo, M. T. Kidd, P. B. Tillman, and S. L. Branton. 2011. Determination of the fourth and fifth limiting amino acids of broilers fed diets containing maize, soybean meal, and poultry by-product meal from 28 to 42 days of age. Br. Poult. Sci. 52:238-244.


    Progress 01/01/10 to 12/31/10

    Outputs
    OUTPUTS: Listed below are five papers that were presented at either scientific or technical conferences. Dozier, W. A., III. 2010. Early broiler responses to dietary amino acids. Multi-State Poultry Nutrition Conference. Dozier, W. A., III, A. Corzo, M. T. Kidd, and P. B. Tillman. 2010. Digestible lysine requirements of Cobb x Cobb 700 male broilers from twenty-eight to forty-two days of age. Poult. Sci. 89 (E-Suppl. 1):210. de Leon, A. C., W. B. Roush, A. Corzo, W. A. Dozier, and M. T. Kidd. 2010. Dietary lysine and energy response surface estimates for growing broilers. International Poultry Scientific Forum (Abst.):9. Kidd, M. T., W. A. Dozier, III, P. B. Tillman, R. E. Loar, and A. Corzo. 2010. Dietary addition of L-valine for commercial broilers. International Poultry Scientific Forum (Abst.):25. Dozier, W. A., III, A. Corzo, M. T. Kidd, P. B. Tillman, and S. L. Branton. 2010. Determination of the fourth and fifth limiting amino acids from 28 to 42 d of age fed diets containing poultry by-product meal. International Poultry Scientific Forum (Abst.):38. PARTICIPANTS: Dr. Alex Corzo, Mississippi State University Dr. Michael Kidd, University of Arkansas TARGET AUDIENCES: Poultry nutritionists and live production managers from broiler companies. PROJECT MODIFICATIONS: Not relevant to this project.

    Impacts
    We determined that the digestible lysine requirement from 28 to 42 days of age with broiler chickens was 1.00% of the diet. This information is useful to the poultry industry so that diets do not contain lysine in excess or at sub-marginal levels both situations can be very costly. Isoleucine and valine were shown to be co-limiting as the fourth limiting amino acid for broiler chickens from 28 to 42 d of age with corn-soybean meal based-diets containing meat and bone meal. This could result in isoleucine and valine needed to be produced commercially on a large scale as it could potentially lower both diet cost and nitrogen excretion. Supplemental valine was shown that it could be added to broiler diets without adversely affecting performance. This could lead to the commercial adoption of L-valine to be included in broiler diets. In the future, L-valine supplementation may lead to decrease cost as well as reducing nitrogen excretion.

    Publications

    • Dozier, W. A., III, A. Corzo, M. T. Kidd, P. B. Tillman, and S. L. Branton. 2010. Digestible lysine requirements of male broilers from 28 to 42 days of age. Poult. Sci. 89:2173-2183.
    • Corzo, A., W. A. Dozier, III, R. E. Loar, M. T. Kidd, and P. B. Tillman. 2010. Dietary limitation of isoleucine and valine in diets based of maize, soybean meal, and meat-and-bone meal for broiler chickens. Br. Poult. Sci. 51:558-563.
    • Berres, J., S. L. Vieira, W. A. Dozier, III, M. E. M. Cortes, R. de Barros, E. T. Nogueira, and M. Kutschenko. 2010. Broiler responses to reduced protein diets supplemented with valine, isoleucine, glycine, and glutamic acid. J. Appl. Poult. Res. 19:68-79.


    Progress 01/01/09 to 12/31/09

    Outputs
    OUTPUTS: We examined the effects of reducing valine and isoleucine ratios (reduced crude protein) of diets on growth and meat yield responses of broilers. Two experiments were conducted. The resulting data have been statistically analyzed and new applied knowledge was generated. In one experiment, we learned that crude protein content in broiler diets can be reduced by from 18.0 to 17.25% from 28 to 42 days of age without adversely feed conversion. In the other experiment, supplemental L-valine can be added to diets with a 0.50 kg inclusion rate without negatively growth rate or breast meat yield. In addition, we assessed the interaction of digestible lysine concentrations and valine and isoleucine ratios of diets fed to broilers from 21 to 35 and 36 to 49 days of age. Data have been statistically evaluated. Moreover,the digestible lysine requirement of 28 to 42 day old male broilers was determined in a subsequent study. Data have been statistically evaluated and digestible lysine requirements were shown to vary from 0.965 to 1.030% for BW gain, feed conversion, carcass weight, total breast meat weight, and total breast meat yield. No events or services have conducted with the forementioned experiments. PARTICIPANTS: Nothing significant to report during this reporting period. TARGET AUDIENCES: Nothing significant to report during this reporting period. PROJECT MODIFICATIONS: Nothing significant to report during this reporting period.

    Impacts
    Approximately 8 billion broilers are produced in the United States annually. A 1-point difference in feed conversion has an economic impact of about $6,000 per week for a broiler complex processing 1 million birds per week. In this project, increasing dietary valine and isoleucine ratios to lysine had a 4-point improvement in feed conversion of broilers from 21 to 35 and 35 to 49 days of age. It was also shown in another experiment that a reduction in dietary crude protein of 0.75 percentage- points can be fed to broilers from 28 to 42 days of age without adversely broiler performance. The reduction in crude protein content with the use of supplemental amino acids can translate to a decrease in diet cost by $2 to $5 per ton of feed without compromising broiler growth. Results from this research have the potential of improving feeding programs for broilers resulting in significant economic savings to the United States broiler industry.

    Publications

    • No publications reported this period