HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Summary Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Dozier, W. A. Articles by Branton, S. L. Search for Related Content PubMed Articles by Dozier, W. A., III Articles by Branton, S. L.

Dietary Apparent Metabolizable Energy and Amino Acid Density Effects on Growth and Carcass Traits of Heavy Broilers¹

W. A. Dozier, III^*,2, A. Corzo, M. T. Kidd and S. L. Branton^*

^* Poultry Research Unit, Agricultural Research Service, USDA, Mississippi State 39762; and Department of Poultry Science, Mississippi State University, Mississippi State 39762

Correspondence: ² Corresponding author: bdozier{at}msa-msstate.ars.usda.gov

	SUMMARY

TOP SUMMARY DESCRIPTION OF PROBLEM MATERIALS AND METHODS RESULTS DISCUSSION CONCLUSIONS AND APPLICATIONS REFERENCES AND NOTES

 
Two experiments (EXP) were conducted to evaluate the interactive effects of dietary AME and amino acid (AA) density (total basis) on broiler chickens from 42 to 56 d of age. In EXP 1, diets were formulated to contain low AME (3,140 kcal/kg) and moderate AME (3,240 kcal/kg) in combination with moderate AA (16.2% CP, 0.88% Lys, and 0.75% TSAA) and high AA (18.0% CP, 0.98% Lys, and 0.83% TSAA) and fed to male broilers. Dietary treatments in EXP 2 were diets formulated to contain moderate AME (3,220 kcal/kg) and high AME (3,310 kcal/kg) combined with moderate and high AA concentrations used in EXP 1 and fed to male and female broilers. In general, dietary AME and AA did not interact to influence growth and meat yield responses. Broilers provided the low AME diet in EXP 1 consumed more feed and had poorer feed conversion but had higher total breast meat yield than birds fed the moderate AME diet. In EXP 2, broilers fed the high AME diet from 42 to 56 d had increased BW gain, decreased feed consumption, and improved feed conversion. Feeding the high AA diets in both EXP decreased feed consumption, improved feed conversion, and increased total breast meat yield. Nutritionists establishing nutritional programs for heavy broilers late in development from 2.5 to 3.6 kg may need to consider increasing AA density to optimize breast meat yield. Increasing the AME content of the diet improves feed conversion but not breast meat yield.

Key Words: broiler • lysine • methionine • metabolizable energy

	DESCRIPTION OF PROBLEM

TOP SUMMARY DESCRIPTION OF PROBLEM MATERIALS AND METHODS RESULTS DISCUSSION CONCLUSIONS AND APPLICATIONS REFERENCES AND NOTES

 
In the United States, the number of broilers marketed to heavy market weights (>3.6 kg) have been increasing. Energy and amino acids (AA) contributing ingredients represent most of the diet cost for broiler chickens. Broilers marketed to 3.6 kg consume approximately 7.5 kg of feed, with about 70% of cumulative feed intake occurring from 2.0 to 3.6 kg. Therefore, providing diets formulated to contain AME and AA in excess or at suboptimum concentrations to broiler chickens may decrease profits by increased feed cost or reduced meat yield.

The deleterious effects of high environmental temperature on broiler growth have been well documented [1, 2]. In an effort to ameliorate inadequate nutrient consumption and poor growth responses associated with heat stress conditions, the interactive effects of nutrition and high ambient temperature have been reported [3, 4, 5, 6, 7, 8]. May and Lott [9] determined that the optimum environmental temperature for 3.0-kg male broilers based on growth rate and feed conversion was 12 and 16°C, respectively. If temperature is lowered too aggressively before broilers reach 3.0 kg, then feed conversion could be adversely affected. Conversely, if temperature is not reduced as broilers approach heavy BW, performance will be limited. Heavy broilers exposed to low environmental temperatures (14 to 16°C) grow faster than birds exposed to moderate or high temperatures (>21°C); therefore, increased AA and AME to accrete lean tissue may be warranted. With the advancement of environmental control for poultry housing, maintaining temperatures from 14 to 16°C for heavy broilers during fall and winter months is achievable. Research has been less extensive with broilers provided feeds differing in nutrient density subjected to low environmental temperatures [10]. Published results involving broiler chickens provided diets differing in AME and AA density exposed to low environmental temperatures approaching heavy market weights (3.6 kg) have not been reported.

Leeson et al. [11] determined that providing broilers suboptimum caloric density from 35 to 49 d did not affect final BW and meat yield, because birds were able to compensate by adjusting feed intake. But, feed conversion was adversely affected. Dozier et al. [12] recently evaluated diets varying in AME content fed to Ross x Ross 308 broilers from 1.5 to 3.9 kg. Increasing AME from 3,220 to 3,310 kcal/kg decreased feed consumption and improved feed conversion by 8 points in broilers subjected to low temperatures but limited breast meat yield. Lysine intake decreased from 48.4 to 47.8 g/bird as AME increased from 3,220 to 3,310 kcal/kg during 30 to 59 d of age. In an additional experiment (EXP), these authors determined that increasing CP, Lys, and TSAA concentrations by 4% [withdrawal 1 (from 30 to 47 d) = 17.2 to 17.9% CP, 0.71 to 0.74% TSAA, and 0.89 to 0.93% Lys; withdrawal 2 (from 48 to 59 d) = 16.2 to 16.9% CP, 0.70 to 0.73% TSAA, and 0.83 to 0.86% Lys] in a diet formulated to contain 3,310 kcal/kg of AME ameliorated the negative response of breast meat yield associated with decreased AA intake of the high AME diet (3,310 kcal of AME/kg) under moderate temperatures (24°C). McNaughton and Reece [6] also demonstrated that increasing the Lys content to 1.05% (total basis) with diets formulated to 3,250 kcal of AME/kg increased BW gain when 2.0-kg broilers were exposed to a moderate temperature (26.7°C), but the response for dietary AME was decreased to 3,100 kcal of AME/kg as dietary Lys was decreased to 0.96%.

The response to AA may be influenced by the AME concentration of the diet in broilers grown to heavy weights late during development when subjected to low environmental temperature. These EXP evaluated growth and meat yield responses of Ross x Ross 708 broilers to diets formulated to contain low, moderate, or high AME concentrations in combination with moderate or high AA density.

	MATERIALS AND METHODS

TOP SUMMARY DESCRIPTION OF PROBLEM MATERIALS AND METHODS RESULTS DISCUSSION CONCLUSIONS AND APPLICATIONS REFERENCES AND NOTES

 
Bird Husbandry
Two EXP were conducted. In each EXP, 2,500 Ross x Ross 708 [13] one-day-old chicks were obtained from a commercial hatchery and reared in a common environment from 1 to 41 d of age. Chicks were vaccinated at the hatchery for Marek’s disease, Newcastle disease, and infectious bronchitis. At 12 d of age, Gumboro vaccination via water was administered. At 42 d, 60 birds (EXP 1 = 60 males; EXP 2 = 30 males and 30 females) were randomly distributed into each of 32 floor pens (0.09 m²/bird) of a solid-sided facility. Each pen was equipped with 2 hanging feeders, a nipple drinker line (15 nipples), and fresh pine shavings. Feed and water were available for ad libitum consumption. Feed was presented as whole pellets. Percentage of pellets and percentage of durability index were determined in EXP 2 [14]. Temperature was set as 21°C at the initiation of experimentation and reduced as the birds progressed in age, with a final set point of 15°C at 53 d of age. Temperature set points were selected to simulate a winter grow-out. Ventilation was provided at approximately 3.4 m³/h of airflow, and a chilled water air conditioning system was used to control temperature. Experiment 1 was conducted from September through November 2004, and EXP 2 was from February to April 2005. The lighting regimen was continuous with an intensity of 3 lx.

Dietary Treatments
In both EXP, experimental diets were fed in the form of whole pellets from 42 to 56 d of age. Diets were conditioned during pelleting at 82°C, and pellets approximated 4.76 mm. The dietary treatments for EXP 1 consisted of diets formulated to contain the following: 1) moderate AME and high AA, 2) moderate AME and moderate AA, 3) low AME and high AA, and 4) low AME and moderate total AA concentrations (Table 1). The moderate and low AME were 3,240 and 3,140 kcal/kg, respectively. Calculated ingredient values for AME used in formulation were from the NRC [15]. High and moderate total AA concentrations were 18% CP, 0.98% Lys, and 0.83% TSAA and 16.2% CP, 0.88% Lys, and 0.75% TSAA, respectively. The moderate AME concentration was chosen because it is in the acceptable range of AME used in commercial practice for broilers from 2.5 to 3.6 kg. The low AME was selected because it was 100 kcal/kg below the moderate dietary AME concentration. The moderate AA concentration is typical of industry practice for broilers from 2.5 to 3.6 kg. High dietary AA was increased 10% above CP, Lys, and TSAA concentrations of the moderate AA. The high dietary AA concentration is indicative of broiler companies using dietary AA specifications to optimize breast meat yield with heavy broilers.

Measurements
In each EXP, birds and feed were weighed by pen at 42 and 56 d. At 42 d, birds were placed in 8 groups (replication) and equalized to similar BW among the treatments (EXP 1 = 2,422 ± 81 g; EXP 2 = 2,430 ± 67 g). Body weight gain, feed consumption, and feed conversion were determined for the 14-d experimental period. The incidence of mortality was recorded daily. At 57 d, 12 birds per pen (EXP 1 = 12 males; EXP 2 = 6 males and 6 females) were randomly selected for processing. Feed was removed 12 h before processing. Birds selected for processing were weighed and placed in transportation coops. The 57-d BW was used to calculate carcass and breast meat yields. Birds were electrically stunned, bled, scalded, mechanically picked, and manually eviscerated. Whole carcass (without abdominal fat) and abdominal fat were weighed. Then, carcasses were split into front and back halves and placed in ice for 18 h. The front halves were deboned, and breast fillets and tenders were weighed. Whole carcass, abdominal, and total breast meat weights were expressed as a proportion of 57-d BW to calculate yield data.

Statistics
Data were statistically evaluated as a factorial arrangement (AME x AA) in a randomized complete block design [16]. Pen location was the blocking factor. With the exception of carcass yield in EXP 2, interactions were not (P 0.05) apparent for the variables tested in these studies. Therefore, data are presented as main effect means each represented by 16 replicate pens. Pen was considered the experimental unit. Statistical significance was considered at P 0.05.

	RESULTS

TOP SUMMARY DESCRIPTION OF PROBLEM MATERIALS AND METHODS RESULTS DISCUSSION CONCLUSIONS AND APPLICATIONS REFERENCES AND NOTES

 
EXP 1
Feed consumption and feed conversion increased (P 0.001) as the main effects of dietary AME and AA density were decreased, but growth rate and mortality were not affected by the dietary treatments (Table 3). Decreasing dietary AME from 3,240 to 3,140 kcal/kg increased breast fillet and total breast yield (P 0.05), but abdominal fat percentage, carcass yield, and breast tender yield were unaffected (Table 4). The 10% increase in dietary AA density reduced (P 0.01) abdominal fat weight and yield, increased breast fillet yield (P 0.02), breast tender yield (P 0.05), and total breast meat yield (P 0.01).

View larger version (23K): [in this window] [in a new window]   Figure 1. Carcass yield of male and female broilers provided diets varying in amino acid (AA) and AME density from 42 to 56 d of age (experiment 2).

	DISCUSSION

TOP SUMMARY DESCRIPTION OF PROBLEM MATERIALS AND METHODS RESULTS DISCUSSION CONCLUSIONS AND APPLICATIONS REFERENCES AND NOTES

Results are inconsistent in the literature as to whether the modern broiler chicken has the ability to adjust caloric intake when fed diets varying in energy content [11, 12, 17, 21] or to eat to a certain capacity regardless of dietary AME [18, 19, 20]. The increase in feed consumption associated with low energy diets can affect growth and meat yield with a concurrent increase of AA intake and all other needed nutrients for tissue assimilation [11]. In the current research, broilers fed low AME (3,140 kcal/kg) diets in EXP 1 had poorer feed conversion, but final BW was not influenced compared with birds fed the moderate AME diets (3,240 kcal of AME/kg). Broilers fed the low AME diet had higher breast meat yield than birds provided diets of moderate dietary AME (3,240 kcal/kg). Broilers fed the low AME diets (3,140 kcal/kg) consumed 25.3 g of Lys, whereas birds provided diets containing 3,240 kcal of AME/kg only consumed 23.9 g of Lys. Breast meat is relatively high in Lys compared with other muscles [23], and dietary Lys has been shown to increase breast meat yield [24, 25]. In addition to Lys, TSAA and Thr consumption was 21.5 and 17.9 g for broilers fed the low AME diets (3,140 kcal/kg), respectively, compared with broilers fed diets containing 3,240 kcal of AME/kg that had TSAA and Thr intakes of 20.4 and 17.0 g, respectively.

Measuring caloric efficiency is important to determine the utilization of the caloric intake by the bird. Calorie conversion was not affected by increasing levels of poultry oil from 1 to 42 d, but caloric conversion increased from 1 to 63 d of age [20]. Saleh [19] also reported increased caloric efficiency with increased additions of poultry oil at 42, 49, 56, and 63 d of age. Conversely, the current research found no differences in caloric conversion due to dietary AME from 42 to 56 d in EXP 1, whereas EXP 2 noted improved caloric efficiency with increased dietary AME, which was probably due to increased BW gain of broilers fed high AME diets.

Feeding higher AA density diets than commercial levels throughout production improves feed conversion, reduces abdominal fat percentage, and increases breast meat yield [26, 27, 28, 29, 30, 31]. Most of the research has examined dietary AA density throughout production, and carryover effects have occurred from the starter and grower periods. Research is sparse on evaluating dietary AA density with 2.0- to 3.5-kg broilers. Dozier et al. [31] reported that providing high AA (36 to 47 d = 1.05% Lys; 48 to 59 d = 1.00% Lys) density diets from 36 to 59 d of age improved feed conversion by 3 and 7 points compared with moderate (36 to 47 d = 0.95% Lys; 48 to 59 d = 0.91% Lys) and low (36 to 47 d = 0.85% Lys; 48 to 59 d = 0.82% Lys) AA density diets, respectively, but final BW was not influenced by dietary AA density. Decreasing AA density from high to low reduced total breast meat yield by 0.7 percentage points. This is in agreement with the current research that found poorer feed conversion and reduction in total breast meat yield as dietary AA density was decreased from high to moderate during 42 to 56 d of age, whereas there was no change in final BW.

In general, dietary AA x AME interactions did not occur for variables measured in the present research, with the exception for carcass yield in EXP 2. An interaction was not significant for total breast meat, perhaps suggesting that the interaction for carcass yield may have occurred due to differences in dark meat yield. Kidd et al. [29] reported that broilers fed high AA density diets increased saddle and drumstick yields at 35 d but not at 55 d. Other research has noted differences in thigh and drumstick yields with varying dietary AA density [27].

In the current research, a significant finding was that decreasing AME from 3,240 to 3,140 kcal/kg increased total breast meat yield, but feed conversion was adversely affected. With the increased production of ethanol occurring in the United States, the cost for energy-contributing feedstuffs is likely to increase. This research indicates that decreasing AME to 3,140 kcal/kg resulted in poor feed conversion without negatively affecting BW gain or breast meat yield. Future research should determine the minimum AME concentration that can be used in formulation without adversely affecting feed conversion or cost per BW gain and breast meat due to the potential increase in cost for energy contributing ingredients. During times of low poultry oil prices, high AME concentrations can be used to improve live performance. Results from EXP 2 indicated 14- and 26-point improvements, respectively, in feed conversion and energy intake per BW gain. This has the potential to reduce live production costs for broilers grown to heavy BW during winter production. However, dietary AA may need to be increased to compensate for reduced AA intake when using diets formulated to high AME.

Another important finding observed from this research was that broilers adjusted feed intake to compensate for reduced dietary AA concentration. The change in feed intake as affected by dietary AA density was a 4% increase, which was similar to responses of decreasing AME that resulted in 5 and 3% increase in feed intake, respectively, for EXP 1 and 2. Response of altering feed intake by dietary AA with 42- to 56-d-old broilers is different compared with 1- to 35-d-old broilers [29, 30]. This finding may not be applicable during a summer growout. Even though older broilers fed moderate AA density did increase feed intake, feed conversion and breast meat yield were adversely affected.

	CONCLUSIONS AND APPLICATIONS

TOP SUMMARY DESCRIPTION OF PROBLEM MATERIALS AND METHODS RESULTS DISCUSSION CONCLUSIONS AND APPLICATIONS REFERENCES AND NOTES

 

1. In general, increasing dietary AME decreased feed consumption and improved feed conversion but did not increase breast meat yield.
   
2. Feeding broilers the diet formulated to 3,140 kcal of AME/kg increased breast meat yield compared with birds provided diets containing 3,240 kcal of AME/kg. The improved breast meat yield was probably due to increased feed intake associated with the low AME diet that translated to an additional 1.3, 1.1, and 0.9 g of Lys, TSAA, and Thr intake.
   
3. Increasing dietary AA concentrations by 10% improved feed conversion by 10 and 7 points and increased total breast meat yield by 0.5 and 0.6 percentage points, respectively, in EXP 1 and 2.
   

	FOOTNOTES

 
¹ Mention of trade names or commercial products in this publication is solely to provide specific information and does not imply recommendation or endorsement by the USDA.

	REFERENCES AND NOTES

TOP SUMMARY DESCRIPTION OF PROBLEM MATERIALS AND METHODS RESULTS DISCUSSION CONCLUSIONS AND APPLICATIONS REFERENCES AND NOTES

 

1. Charles, D. R. 1986. Temperature for broilers. World’s Poult. Sci. J. 42:249–258.[ISI]
2. Howlider, M. A., and S. P. Rose. 1987. Temperature and growth for broilers. World’s Poult. Sci. J. 43:228–237.[ISI]
3. Adams, R. L., F. N. Andrews, E. E. Gardiner, W. E. Fontaine, and C. W. Carrick. 1962. The effect of environmental temperature on the growth and nutritional requirements of the chick. Poult. Sci. 41:588–594.[ISI]
4. Dale, N. M., and H. L. Fuller. 1980. Effect of diet composition on feed intake and growth of chicks under heat stress. II. Constant vs. cycling temperature. Poult. Sci. 59:1434–1441.[ISI][Medline]
5. Reece, F. N., B. D. Lott, and J. W. Deaton. 1984. The effects of feed form, protein profile, energy level, and gender on broiler performance in warm (26.7°C) environments. Poult. Sci. 63:1906–1911.[ISI][Medline]
6. McNaughton, J. L., and F. N. Reece. 1984. Response of broiler chickens to dietary energy and lysine levels in a warm environment. Poult. Sci. 63:1170–1174.[ISI][Medline]
7. Han, Y., and D. H. Baker. 1993. Effects of sex, heat stress, body weight, and genetic strain on the dietary lysine requirement of broiler chicks. Poult. Sci. 72:701–708.[ISI][Medline]
8. Cheng, T. K., M. L. Hamre, and C. N. Coon. 1997. Effect of temperature, dietary protein, and energy levels on broiler performance. J. Appl. Poult. Res. 6:1–17.[Medline]
9. May, J. D., and B. D. Lott. 2001. Relating weight gain and feed:gain of male and female broilers to rearing temperature. Poult. Sci. 80:581–584.[Abstract/Free Full Text]
10. Reece, F. N., and J. L. McNaughton. 1982. Effects of dietary nutrient density on broiler performance at low and moderate environmental temperatures. Poult. Sci. 61:2208–2211.[ISI][Medline]
11. Leeson, S., L. Caston, and J. D. Summers. 1996. Broiler responses to dietary energy. Poult. Sci. 75:529–535.[ISI][Medline]
12. Dozier, W. A., III, C. J. Price, M. T. Kidd, A. Corzo, J. Anderson, and S. L. Branton. 2006. Growth performance, meat yield, and economic responses of broilers fed diets varying in metabolizable energy from 30 to 59 days of age. J. Appl. Poult. Res. 15:367–382.[Abstract/Free Full Text]
13. Aviagen North America, Huntsville, AL.
14. American Society of Agricultural Engineers. 1993. Cubes, pellets, and crumbles-definitions and method for determining density, durability, and moisture. Standard S269.4. American Society of Agricultural Engineers Yearbook of Standards. Am. Soc. Agric. Eng., St. Joseph, MI.
15. NRC. 1994. Nutrient Requirements of Poultry. 9th rev. ed. Natl. Acad. Press, Washington, DC.
16. SAS Institute. 2004. SAS User’s Guide: Statistics. Version 9.1 ed. SAS Inst., Inc., Cary, NC.
17. Leeson, S., L. Caston, and J. D. Summers. 1996. Broiler response to energy or energy and protein dilution in the finisher diet. Poult. Sci. 75:522–528.[ISI][Medline]
18. Hidalgo, M. A., W. A. Dozier III, A. J. Davis, and R. W. Gordon. 2004. Live performance and meat yield responses of broilers to progressive concentrations of dietary energy maintained at a constant metabolizable energy-to-crude protein ratio. J. Appl. Poult. Res. 13:319–327.[Abstract/Free Full Text]
19. Saleh, E. A., S. E. Watkins, A. L. Waldroup, and P. W. Waldroup. 2004. Effects of dietary nutrient density on performance and carcass quality of male broilers grown for further processing. Int. J. Poult. Sci. 3:1–10.
20. Saleh, E. A., S. E. Watkins, A. L. Waldroup, and P. W. Waldroup. 2004. Consideration for dietary nutrient density and energy feeding programs for growing large male broiler chickens for further processing. Int. J. Poult. Sci. 3:11–16.
21. Griffiths, L., S. Lesson, and J. D. Summers. 1977. Influence of energy system and level of various fat sources on performance and carcass composition of broilers. Poult. Sci. 56:1018–1026.[ISI]
22. Bartov, I., S. Bornstein, and B. Lipstein. 1974. Effect of calorie to CP ratio on the degree of fatness in broilers fed on practical diets. Br. Poult. Sci. 15:107–117.[ISI]
23. Tesseraud, S., N. Maaa, R. Peresson, and A. M. Chagneau. 1996. Relative responses of protein turnover in three different skeletal muscles to dietary Lys deficiency in chicks. Br. Poult. Sci. 37:641–650.[ISI][Medline]
24. Acar, N., E. T. Moran Jr., and S. F. Bilgili. 1991. Live performance and carcass yield of male broilers from two commercial strain crosses receiving rations containing lysine below and above the established requirement between six and eight weeks of age. Poult. Sci. 70:2315–2321.[ISI]
25. Bilgili, S. F., E. T. Moran Jr., and N. Acar. 1992. Strain-cross response of heavy male broilers to dietary lysine in the finisher feed: Live performance and further processing yields. Poult. Sci. 71:850–858.[ISI][Medline]
26. Dozier, W. A., III, and E. T. Moran Jr. 2001. Response of early- and late-developing broilers to nutritionally adequate and restrictive feeding regimens during the summer. J. Appl. Poult. Res. 10:992–998.
27. Kidd, M. T., C. D. McDaniel, S. L. Branton, E. R. Miller, B. B. Boren, and B. I. Fancher. 2004. Increasing amino acid density improves live performance and carcass yields of commercial broilers. J. Appl. Poult. Res. 13:593–604.[Abstract/Free Full Text]
28. Corzo, A., M. T. Kidd, D. J. Burnham, E. R. Miller, S. L. Branton, and R. Gonzalez-Esquerra. 2005. Dietary amino acid density effects on growth and carcass of broilers differing in strain cross and sex. J. Appl. Poult. Res. 14:1–9.[Abstract/Free Full Text]
29. Kidd, M. T., A. Corzo, D. Hoehler, E. R. Miller, and W. A. Dozier III. 2005. Broiler responsiveness (Ross x 708) to diets varying in amino acid density. Poult. Sci. 84:1389–1396.[Abstract/Free Full Text]
30. Dozier, W. A., III, R. W. Gordon, J. Anderson, M. T. Kidd, A. Corzo, and S. L. Branton. 2006. Growth, meat yield, and economic responses of broilers provided three- and four-phase schedules formulated to moderate and high nutrient density during a fifty-six day production period. J. Appl. Poult. Res. 15:312–325.[Abstract/Free Full Text]
31. Dozier, W. A., III, M. T. Kidd, A. Corzo, J. Anderson, and S. L. Branton. 2006. Growth performance, meat yield, and economic responses of broilers provided diets varying in amino acid density from 36 to 59 days of age. J. Appl. Poult. Res. 15:383–393.[Abstract/Free Full Text]

This article has been cited by other articles:

				H. P. Fan, M. Xie, W. W. Wang, S. S. Hou, and W. Huang Effects of Dietary Energy on Growth Performance and Carcass Quality of White Growing Pekin Ducks from Two to Six Weeks of Age Poult. Sci., June 1, 2008; 87(6): 1162 - 1164. [Abstract] [Full Text] [PDF]

				W. A. Dozier III, M. T. Kidd, and A. Corzo Dietary Amino Acid Responses of Broiler Chickens J. Appl. Poult. Res., January 1, 2008; 17(1): 157 - 167. [Abstract] [Full Text] [PDF]

This Article Summary Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in ISI Web of Science Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Dozier, W. A. Articles by Branton, S. L. Search for Related Content PubMed Articles by Dozier, W. A., III Articles by Branton, S. L.