1Department of Poultry Science and 4Experimental Statistics Unit, Mississippi State University, Mississippi State, Mississippi 39762; 2South Central Poultry Research Laboratory, Agricultural Research Service, United States Department of Agriculture, Mississippi State, Mississippi 39762; and 3Department of Poultry Science, Clemson University, Clemson, South Carolina 340379
ABSTRACT
In two trials, the effects of F-strain Mycoplasma gallisepticum (FMG) on the contents of egg yolks from commercial Single Comb White Leghorn laying hens were investigated over a production cycle. Ten hens were assigned to each of 8 (trial 1) or 16 (trial 2) negative pressure fiberglass biological isolation units. Birds in half of the total units served as sham-inoculated controls, and those in the other half were inoculated with FMG at 12 wk of age. Eggs were collected and yolks were harvested at various times during the prepeak, peak, and postpeak periods of both trials for constituent analysis. Yolk constituents analyzed in these trials included moisture, total lipids, cholesterol, triglycerides, phospholipids, and fatty acids. In both trials, total yolk lipid at 22 wk of age was significantly decreased in birds inoculated with FMG. In trial 1, yolk cholesterol at 28 wk was significantly decreased in FMG-inoculated birds. Yolk linoleic acid in trial 1 and yolk stearic and arachidonic acids in trial 2 were significantly increased in FMG-inoculated birds compared to FMG-free birds. In trial 2, yolk myristic, palmitoleic, and oleic acid percentages were significantly decreased in FMG-inoculated birds compared to FMG-free birds. These data suggest that alterations in egg production in commercial layers in response to an FMG infection at 12 wk of age are associated with changes in yolk composition.
Key Words: egg, layer, lipid, Mycoplasma gallisepticum, yolk
Poultry Science 82:577-584, 2003
©2003 by the Poultry Science Association. All rights reserved.
1Department of Biochemistry and Molecular Biology, 3Department of Poultry Science,
4Experimental Statistics Unit, 5College of Veterinary Medicine, Mississippi State University, Mississippi State, MS 39762; 2and USDA-ARS, South Central Poultry Research Laboratory, Mississippi State, MS 39762,
SUMMARY
Mycoplasma gallisepticum (MG), a reproductive/respiratory pathogen in poultry, has been implicated in suboptimum egg production and decreased hatchability. Commercial layer hens raised in a controlled environment were inoculated with the S6 strain of MG at 20 wk of age. The S6 inoculation had no effect on bird weight, egg production, digestive tract weight and length, or histopathologic lesion scores, although significant differences were noted in the lengths and weights of various portions of the reproductive tract. This study shows that S6MG inoculation does not detrimentally affect layer hen performance when in the absence of environmental stressors customary to a caged layer facility.
Key words: Mycoplasma gallisepticum, egg production, S6
Avian Diseases 47:96-100, 2003
1Department of Biochemistry and Molecular Biology, 2Department of Poultry Science, 3Experimental Statistics Unit, 4College of Veterinary Medicine,
Mississippi State University, Mississippi State, MS 39762; and 5USDA-ARS, South Central Poultry Research Laboratory, Mississippi State, MS 39762
SUMMARY
Mycoplasma gallisrpticum (MG) is a reproductive/respiratory disease in poultry implicated in suboptimum egg production and decreased hatchability. Commercial layer hens raised in a controlled environment were inoculated with the S6 strain of MG at 10 wk of age. Egg production and selected egg and egg quality parameters were quantitated over the entire lay cycle for inoculated and control birds. The S6 inoculation had no effect on bird weight, egg production, associated egg quality parameters, or histopathologic lesion scores. This study shows that in the absence of environmental stressors a prelay S6 MG inoculation does not produce detrimental effects on layer hen performance.
Key words: Mycoplasma gallisepticum, egg production, S6, egg quality
Avian Diseases 46:593-597, 2002
Department of Poultry Science, Mississippi State University, Mississippi State, Mississippi 39762
ABSTRACT
Enterococcus faecalis when administered in a growth medium or sterile saline, will cause pulmonary hypertension syndrome (PHS) in chickens. The objective of this study was to determine if frozen and/or autoclaves cultures of E. faecalis retain ability to evoke PHS. In Trial 1, chicks were inoculated with 3.6 x 107 E. faecalis (IA) in tryptic soy broth (TSB) from either a live culture or one that had been autoclaves (120 C for 20 min). Controls received TSB. Autoclaves and live cultures produced the same degree of PHS in a majority of the birds. Trial 2 used the same protocol, except a frozen (-70 C for 60 min) culture of E. faecalis was compared with the control. The results agreed with those of Trial 1, i.e., the frozen culture also produced PHS. Trial 3 was conducted to determine if E. faecalis caused PHS by producing and releasing some unknown substance into the supernatant. Incidence of PHS was based on percentage of birds exhibiting ascites fluid at 24 hr after challenge. Controls received sterile, frozen, or autoclaved TSB. As compared with controls, those birds that received challenge with E. faecalis alone, supernatant alone, and E. faecalis plus supernatant from live cultures exhibited similar incidence of ascites, whereas birds that received E. faecalis plus supernatant and supernatant alone from cultures that had been either frozen or autoclaved exhibited elevated incidence of ascites as compared with controls. Also, with frozen and autoclaved cultures, those birds that received only pelleted E. faecalis exhibited incidence of aspires that did not differ from controls. Apparently, E. faecalis produces PHS in chicks by producing and releasing an unknown toxin.
Key words: E. faecalis; chicken; pulmonary; hypertension; supernatant.
Exp Biol Med 227:812-816, 2002
1Poultry Science Department, University of Arkansas and 2Nutri-Quest, Inc., Chesterfield, M0
Summary
A study was conducted to determine the minimum crude protein content of finisher diets based on corn and soybean meal supplemented with commercially available amino acids for male Large White turkeys. Diets were formulated to contain a minimals of 105% of NRC (1994) recommended levels of Met, Lys, TSAA, Thr and Trp for diets fed 16 to 20 wk of age; no other essential amino acids were specified. The crude protein content of the diets ranged from 75 to 100% of the recommended level of 16.5%. When diets were formulated to contain at least the minimum recommended levels of Met, TSAR, Lys, Thr, reducing the crude protein content of the diet to less than 85% resulted in a significant reduction in weight at 20 wk or body weight gain from 16 to 20 wk. Addition of Ile and Val to diets formulated to contain 80 or 85% of the recommended crude protein level had no significant effect on body weight or weight gain, indicating that a deficiency of these amino acids per se was not responsible for the reduction in performance on diets with low levels of crude protein. Feed conversion was more variable and was not significantly influenced by dietary crude protein.
Key words: turkeys, amino acids, crude protein, requirements
International Journal of Poultry Science 2:15-18, 2003.
Department of Poultry Science, Mississippi State University, Box 9665, Mississippi State, Mississippi 39762
SUMMARY
Allowing litter to build up in broiler houses is a common practice. This practice is accompanied by changes in the birds' environment, such as increases in ammonia emissions and litter pH. In order to evaluate mechanisms for control of the environment, it is important to understand the microbiological population and its relationship to these changes. This study was designed to investigate the relationship of microbiological populations to the number of flocks previously housed on the litter. Total numbers of aerobic and anaerobic bacteria, coliforms, Staphylococci, mold, and yeasts were determined. There was no correlation of flock numbers to
any of the litter microbial populations.
Key words: poultry litter, microflora, poultry, broiler
Journal of Applied Poultry Research 12:81-84, 2003
©2003 by Poultry Science Association, Inc. All rights reserved.
1Department of Poultry Science and 2Experimental Statistics Unit,
Mississippi State University, Mississippi State, Mississippi 39762; and 3South Central Poultry Research Laboratory,
Agricultural Research Service, United States Department of Agriculture, Mississippi State, Mississippi 39762
ABSTRACT
In two trials, the effects of an F-strain Mycoplasma gallisepticum (FMG) inoculation at 12 wk of age on the blood characteristics of commercial Single Combed White Leghorn laying hens were investigated throughout lay. Variables measured in both trials were whole blood hematocrit, plasma protein (PP), and serum cholesterol, triglycerides (ST), and calcium. In both trials, hematocrit at 20 wk of age was significantly increased in birds inoculated with FMG. In trial 1, ST and PP were significantly increased at 22 wk of age by FMG, while ST and PP were significantly decreased in FMG-inoculated birds at wk 54 and 52, respectively. When combined with the establishment of an FMG infection, the initial weeks of egg production become particularly stressful to the bird. Increases in these independent blood parameters between 8 and 10 wk postchallenge are suggestive of compensatory responses in these birds to an FMG challenge. Postpeak decreases in both ST (54 wk) and PP (52 wk) in FMG- infected birds may be the result of a more chronic effect of FMG on lipid and protein synthesis in the liver. These data are the first to suggest that alterations in egg production in response to FMG-infection in commercial layers, as noted in a previous report, may be associated with changes in hematocrit. However, because ST and PP were not affected by FMG in both trials, the responses of these blood parameters to FMG-infection may be inconsistent among flocks.
Key words: blood, hematology, layer, lipid, Mycoplasma gallisepticum
Poultry Science 82:1397-1402, 2003
1Department of Poultry Science and 4Experimental Statistics Unit, Mississippi State University, Mississippi State, Mississippi 39762; 2South Central Poultry Research Laboratory, Agricultural Research Service, United States Department of Agriculture, Mississippi State, Mississippi 39762; and 3Department of Poultry Science, Texas A&M University, College Station, Texas 77843
ABSTRACT
Experimental inoculation with the F-strain of Mycoplasma gallisepticum (FMG) at 12 wk of age has been shown to affect the performance, liver, reproductive organs, and yolk lipid characteristics of commercial layers. Therefore, this study was conducted to determine the serum lipoprotein characteristics of commercial egg-laying hens at 16 wk of age and throughout lay after inoculation with FMG at 12 wk of age. Mean diameters of very low density lipoproteins (VLDL) were determined for the 10th, 50th, and 90th percentiles of serum total VLDL of each hen. Percentages of total serum cholesterol recovered in VLDL and low and high density lipoprotein particle classes were also determined. Inoculation of birds with FMG at 12 wk did not change the physical properties or relative concentrations of their circulating lipoproteins. However, the age of the bird had significant differential effects on all the parameters examined. These data demonstrate that FMG-inoculation at 12 wk of age does not affect the lipoproteins of laying hens, but because these birds were housed in biological isolation units, these results do not preclude the possibility that these yolk precursors may be affected in FMG-infected birds that are housed in facilities in which there are increased levels of environmental stress. These data further suggest that alterations in liver, reproductive organs, and yolk lipid characteristics in response to FMG, as noted in previous reports on commercial layers, are not mediated through changes in circulating VLDL diameters.
Key words: layer, lipoprotein, liver, Mycoplasma gallisepticum, serum
Poultry Science 82:1630-1636, 2003
Department of Poultry Science, Mississippi State University, Box 9665, Mississippi State, Mississippi 39762
SUMMARY
Allowing litter to build up in broiler houses is a common practice. This practice is accompanied by changes in the birds' environment, such as increases in ammonia emissions and litter pH. In order to evaluate mechanisms for control of the environment, it is important to understand the microbiological population and its relationship to these changes. This study was designed to investigate the relationship of microbiological populations to the number of flocks previously housed on the litter. Total numbers of aerobic and anaerobic bacteria, coliforms, Staphylococci, mold, and yeasts were determined. There was no correlation of flock numbers to any of the litter microbial populations.
Key words: poultry litter, microflora, poultry, broiler
2003 Journal of Applied Poultry Research 12:81-84
1 Mississippi State University, Department of Poultry Science and 3 Mitchell
Memorial Library, PO Box 5188, Mississippi State, MS 39762 and 2 USDA-ARS,
Richard B. Russell Agricultural Research Center, PO Box 5677, Athens, GA
30613, USA
Academic poultry science in the United States had its origins in the early part of the 20 th
century. It reached its peak with 45 active departments in the 1940’s, but then started to
decline significantly in the 1960’s. Today, there are only 7 active departments. There have
been a number of published theories as to why as the industry grew the academic programs
disappeared. Declining student numbers and failure to address industry concerns are the
primary theories. This paper addresses all of the available published work together to present
the situation as it evolved and point to the potential outcome.
Keywords: poultry science; academic; departmental status
World’s Poultry Science Journal 59:303-313
Effects of an S6 Strain of Mycoplasma gallisepticum Challenge at Onset of Lay on Digestive and Reproductive Tract Characteristics in Commercial Layers
T. A. Parker,1 S. L. Branton,2 M. S. Jones,3 E. D. Peebles,3 P. D. Gerard,4 K. O. Willeford,1 G. T. Pharr,5 and W. R. Maslin5
Effects of an S6 Strain of Mycoplasma gallisepticum Challenge Before Beginning of Lay on Various Egg Characteristics in Commercial Layers
T. A. Parker,1 S. L. Branton,5 M. S. Jones,2 E. D. Peebles,2 P. D. Gerard,3 K. O. Willeford,1 M. R. Burnham,2 and W. R. Maslin4
Pulmonary Hypertension Syndrome in Young Chickens Challenged With Frozen and Autoclaves Cultures of Enterococcus faecalis
J. D. Tankson, J. P. Thaxton, and Y. Vizzier-Thaxton
Evaluation of crude protein needs for Large White male turkeys from 16 to 20 weeks of age
1P. W. Waldroup, 1C. A. Fritts, 1J. H. Kersey, 1E. A. Saleh, 2B. J. Kerr and 2 M. T. Kidd
Relationship of Broiler Flock Numbers to Litter Microflora
Y. Vizzier Thaxton, C. L. Balzli, and J. D. Tankson
Effects of F-strain Mycoplasma gallisepticum Inoculation at Twelve Weeks of Age on the Blood Characteristics of Commercial Egg Laying Hens
M. R. Burnham,1 E. D. Peebles,1 S. L. Branton,3 M. S. Jones,1 and P. D. Gerard2
©2003 by Poultry Science Association, Inc. All rights reserved.
Effects of F-strain Mycoplasma gallisepticum Inoculation on Serum Very Low Density Lipoprotein Diameter and Fractionation of Cholesterol Among Lipoproteins in Commercial Egg-Laying Hens
M. R. Burnham,1 E. D. Peebles,1 S L Branton,2 R. L. Walzem,3 and P. D. Gerard4
©2003 by Poultry Science Association, Inc. All rights reserved.
Y. Vizzier Thaxton1, C. L. Balzli, and J. D. Tankson
©2003 by Poultry Science Association, Inc. All rights reserved.The decline of academic poultry science in the United States of America
Y. Vizzier Thaxton 1 *, J.A. Cason 2 , N.A. Cox 2 , S.E. Morris 3 and J.P. Thaxton 1
1Poultry Science Department, University of Arkansas, Fayetteville, Arkansas 72701; 2 Pioneer Hi-Bred International, Johnston, Iowa 50131; 3USDA-ARS, National Small Grains Research Facility, Aberdeen, Idaho 83210
ABSTRACT
A study was conducted to determine the extent fecal P levels could be reduced while maintaining performance. Various strategies were employed including the use of a high available phosphorus hybrid of corn (HAPC), supplementation with phytase enzyme, and reduced dietary P levels. The use of HAPC resulted in a 50% reduction in phytate-bound dietary P as compared with a normal yellow dent corn (YDC) diet. Dietary nonphytate P was maintained at either NRC (1994) recommendations for appropriate age periods or reduced by 0.075 or 0.15%. Portions of the diets were supplemented with 1,000 units of phytase/kg. Male chicks of a commercial strain were grown to 56 d on the test diets. Broilers fed diets with HAPC had BW, feed conversion, livability, and tibia ash that were equal to or superior to those fed diets with YDC with considerably reduced fecal P content at any dietary level of nonphytate P. Phytase supplementation enabled birds to maintain live performance at lower levels of nonphytate P, further reducing the fecal P output. One of the greatest contributions of phytase was a reduction in mortality at the lower levels of nonphytate P. Dietary P levels could be reduced by 0.075% under NRC (1994) recommendations without adversely affecting live performance; a reduction of 0.15% in conjunction with phytase supplementation maintained BW, feed conversion, and livability but reduced tibia ash. The extent to which dietary P levels can be reduced over the entire feeding program is subject to further research.
Key Words: high available phosphorus corn, phytase, phytic acid, broilers, fecal phosphorus
2000 Poultry Science 78:1282-1289
©2000 by Poultry Science Association, Inc. All rights reserved.
1Poultry Science Department, University of Arkansas, Fayetteville, Arkansas 72701; 2 Pioneer Hi-Bred International, Johnston, Iowa 50131; and
3USDA-ARS, National Small Grain Germplasm Research Facility, Aberdeen, Idaho 83210
ABSTRACT A study was conducted to evaluate the ability of the young (0 to 3 wk) broiler chicken to utilize the P provided by a high available P corn [HAPC;
0.27% total P and 0.17% nonphytate P] in comparison with yellow dent corn (YDC; 0.23% total P and 0.03% nonphytate P), and to determine the extent to which
supplementation with exogenous phytase enzyme could reduce the demands for dietary P and subsequently reduce P excretion. Diets prepared using the two types
of corn differed in the amount of phytate-bound P, with the HAPC diets containing approximately 50% less phytate-bound P. Treatment diets were prepared by
varying the amount of dicalcium phosphate, and ranged from 0.10 to 0.50% nonphytate P for YDC diets, and from 0.18 to 0.50% nonphytate P for HAPC diets.
Sublots of each diet were supplemented with 800 units/kg phytase. Each diet was fed to six pens of five male chicks of a commercial broiler strain from 1 to 21 d of
age. Regression analysis was used to estimate nonphytate P requirements for each corn type with and without phytase supplementation.
Key Words: broilers, high available phosphorus corn, phytic acid, phytase, fecal phosphorus
2000 Poultry Science 78:1451-1459
1Poultry Science Department, University of Arkansas, Fayetteville, Arkansas 72701; and 2 Heartland Lysine, Inc., Chicago, Illinois 60631
ABSTRACT A study was conducted to evaluate the relationship of dietary Lys and other essential amino acids (EAA) in diets for broilers. Diets were formulated
based upon NRC (1994) recommendations. Within each age period, diets contained NRC recommended levels of Lys with other EAA at 100, 110, 120, or 130%
of NRC. The diets were then supplemented with 0.1, 0.2, or 0.3% additional Lys, resulting in a 4 × 4 factorial arrangement with four levels of Lys (NRC, + 0.1%, +
0.2%, and + 0.3% Lys) and four levels of other EAA (100, 110, 120, and 130% of NRC). Each of the 16 treatments was fed to six replicate pens of 25 male
broilers of a commercial strain. At 56 d, five birds per pen were processed to determine dressing percentage and carcass yield.
Key Words: broiler, lysine, amino acid, carcass yield, breast meat
2001 Poultry Science 80:1472-1479
Poultry Science Department, University of Arkansas, Fayetteville AR 72701 Phone: (501) 575-2065 FAX: (501) 575-3474 e-mail: waldroup@uark.edu
Primary Audience: Nutritionists, Broiler Production Managers, Feed Mill Managers
SUMMARY
Although several enzymes have been shown to be beneficial when added to diets based on wheat or barley, few studies have demonstrated consistent response
when corn-soybean meal-based diets are treated with enzymes. A study was conducted in which nutritionally adequate diets were fed with or without the addition of
0.1% Avizyme 1500. Avizyme contains xylanase, protease, and amylase activity and is designed to improve the nutritional value of poultry diets based on
low-viscosity grains, such as corn and sorghum, and containing significant levels of soybean meal. Each diet was fed to 48 pens of 65 male broilers. Body weights
and feed conversions were obtained at 16, 35, 42, and 49 d of age. At 35, 42, and 49 d, five birds per pen were processed to determine dressing percentage and
parts yield.
CONCLUSIONS AND APPLICATIONS
1. The results of the present study, in conjunction with those of the other cited studies, indicate that addition of 0.1% Avizyme 1500 to corn-soybean meal-based
broiler diets may result in improved growth and feed conversion.
Key words: broiler, enzyme, abdominal fat, growth performance
2002 Journal of Applied Poultry Research 11:29-33
Poultry Science Department, University of Arkansas, Fayetteville, Arkansas 72701
Primary Audience: Nutritionists, Veterinarians, Production Managers, Researchers
SUMMARY
Cholecalciferol (VIT-D3) and 25-hydroxycholecalciferol (25-OH-D3) were each used to provide 125, 250, 500, 1,000, 2,000, or 4,000 IU/kg of vitamin D
activity in a nutritionally complete corn-soybean meal diet. Each treatment was assigned to four pens of 60 male broilers (Cobb 500) grown in an open-sided house
with sidewall curtains. At 21 and 42 d, BW and feed conversion were determined. Samples of birds (8 per pen) were killed at the same ages; the right tibia was
subjected to bone ash determination, and incidence and severity of tibial dyschondroplasia (TD) were determined on the left tibia.
Key words: vitamin D, broiler, tibial dyschondroplasia, 25-hydroxycholecalciferol
2003 Journal of Applied Poultry Research 12:45-52
Poultry Science Department, University of Arkansas, Fayetteville, Arkansas 72701
ABSTRACT Two trials of similar design were conducted to determine the nonphytate phosphorus (NPP) requirements for broilers from 42 to 63 d of age in diets
with or without phytase supplementation. Male broilers of a commercial strain were grown to 42 d on nutritionally complete diets with NRC (1994) recommended
levels of Ca and NPP. At 42 d, the birds were placed on experimental diets and fed to 63 d. The experimental treatments consisted of a 2 × 6 factorial arrangement
with two levels of phytase (0 or 800 U/kg) and six levels of NPP (0.10 to 0.35% in 0.05% increments). Body weight gain, feed conversion, and mortality were
determined during the period. At 49, 56, and 63 d, excreta samples were taken, and samples of birds were killed for tibia ash determination.
Key Words: broiler, phosphorus, phytase, eutrophication, waste management
2003 Poultry Science 82:294-300
Poultry Science Department, University of Arkansas, Fayetteville, Arkansas 72701
Primary Audience: Nutritionists, Veterinarians, Production Managers, Researchers
SUMMARY
Cholecalciferol (VIT-D3) and 25-hydroxycholecalciferol (25-OH-D3) were each used to provide 125, 250, 500, 1,000, 2,000, or 4,000 IU/kg of vitamin D activity
in a nutritionally complete corn-soybean meal diet. Each treatment was assigned to four pens of 60 male broilers (Cobb 500) grown in an open-sided house with
sidewall curtains. At 21 and 42 d, BW and feed conversion were determined. Samples of birds (8 per pen) were killed at the same ages; the right tibia was subjected
to bone ash determination, and incidence and severity of tibial dyschondroplasia (TD) were determined on the left tibia.
Key words: vitamin D, broiler, tibial dyschondroplasia, 25-hydroxycholecalciferol
2003 Journal of Applied Poultry Research 12:45-52
1Poultry Science Department, University of Arkansas, Fayetteville AR 72701, USA
2Pioneer Hi-Bred International, Inc., Johnston IA 50131, USA
3USDA-ARS, National Small Grains Research Facility, Aberdeen, ID 83210, USA
Abstract:
Large White turkeys were fed diets containing either normal yellow dent corn (YDC) or a corn mutation containing low phytate phosphorus and high available phosphate corn (HAPC). Diets were considered nutritionally adequate in all respects with various degrees of reduction in available phosphorus content ( - 0.0, - 0.05, - 0.10 or - 0.15% of NRC (1994) recommendations for different feeding periods). These diets were fed with or without the addition of 1000 U/kg of phytase enzyme (Natuphos®, BASF), resulting in a total of 16 dietary treatments. Each treatment was assigned to three pens of 20 male turkeys from day-old to 20 wk of age. Body weight, feed consumption, and tibia ash were determined at 28 d intervals during the study. Male turkeys fed diets with HAPC did not differ significantly in BW or feed conversion (FC) from those fed diets with YDC, and had significantly higher tibia ash at 4, 8, and 12 wk of age. Addition of 1000 U/kg of phytase resulted in significantly higher BW at 4, 8, 12, and 16 wk of age as compared to unsupplemented controls with no significant differences in FC. The addition of phytase significantly improved tibia ash at every age. Dietary phosphorus content had no effect on BW or FC at any age. Reduction of phosphorus generally did not impair tibia ash until reduction of 0.15% below NRC (1994) recommendations. Addition of phytase aided in overcoming the reduction in phosphorus content. The combination of HAPC, addition of phytase, and reduction in dietary phosphorus content should aid in reducing phosphorus excretion without impairing performance.
Key words: Turkeys, phosphorus, high available phosphorus corn, phytase
International Journal of Poultry Science 2 (2): 83-90, 2003
2Poultry Science Department, University of Arkansas, Fayetteville, AR 72701, USA
3Ajinomoto Heartland Lysine Inc., Chicago, IL 60631, USA
Abstract:
This study was conducted to explore the extent to which CP can be reduced in corn-soybean meal broiler starter diets
by amino acid supplementation while maintaining adequate performance. Using corn and soybean meal of known
composition, diets were formulated by linear programming using a minimum of 107.5% of NRC (1994) amino acid
recommendations. No minimum CP was required; as each amino acid became limiting crystalline sources were
provided to meet the minimum specification. In sequence these were Met, Thr, Lys, Val, Ile, Arg, Phe, and Trp, resulting in eight treatments ranging from 16.61 to 22.48% CP. All diets contained 0.3% sodium bicarbonate and 0.2% aluminum hydroxide as a buffer and antacid. Three additional treatments utilized potassium sulfate to maintain a minimum dietary electrolyte balance (Na + K - Cl) of 250 meq/kg. Each treatment was fed to twelve replicate groups of six male broiler chicks from 1 to 21 d. Reducing CP below 20% while providing indispensable amino acids resulted in a
significant reduction in body weight (BW) and feed conversion ratio (FCR). Crude protein content of freeze-dried
carcasses declined and fat content increased as diet CP decreased. Feather content (actual weight or % of BW) was
not affected until the CP was reduced to less than 18%. Maintaining dietary electrolyte balance at 250 meq/kg in
reduced CP diets had no significant effect on any parameter.
Key words: Broilers, crude protein, nitrogen pollution, carcass content
International Journal of Poultry Science 3 (1): 46-50, 2004
An Evaluation of the Interaction of Lysine and Methionine in Diets for Growing Broilers
Poultry Science Department, University of Arkansas, Fayetteville, AR 72701, USA
Abstract:
Levels of lysine (Lys) and methionine (Met) in excess of NRC recommendations may result in enhanced performance,
especially in regard to breast meat yield (BMY). Some people have interpreted the "ideal Protein" concept to suggest
that amino acids such as Met should be kept in an "Ideal" ratio with Lys even though Lys may be in excess of actual
needs. The objectives of this study were twofold: 1) to evaluate the effects of levels of Lys and Met in excess of NRC recommendations in diets of male broilers grown for further processing; 2) to determine if any interaction exists
between levels of Lys and Met when minimum levels are exceeded. Three studies of identical design were conducted.
Corn, soybean meal and corn gluten meal of known composition were used to formulate basal diets for 0 to 3, 3 to 6,
and 6 to 9 wk which provided a minimum of 110% of NRC (1994) amino acid recommendations other than Lys, Met and
TSAA which were at 100% of recommended levels. From the base diets, experimental diets were derived by additions
of lysine HCl and DL methionine to provide a factorial arrangement with three levels of Lys (NRC, NRC + 0.15%, NRC +
0.3%) and four levels of Met and TSAA (NRC, NRC + 0.05%, NRC + 0.1%, NRC + 0.15%). Each of the 12 diets was fed to
two (trial 1) or four (trial 2 and 3) replicate pens of 50 male broilers (Cobb 500). Birds were weighed and feed
consumption determined at 3, 6, 7, 8, and 9 week. Samples of birds were processed at 7, 8, 9 wk for parts yield.
Although significant differences in performance were noted among trials due to environmental temperature there was
no trial x treatment interaction so data were combined. There were no significant interactions between Lys and Met for any parameter when both were fed equal to or in excess of NRC recommendations. Increasing Lys above NRC
recommendations significantly improved BW and FCR at 21 d but not at later ages; BMY was improved by increasing
Lys only at 63 d. Increasing Met above NRC significantly improved FCR at 42 and 56d; there was no significant effect
of Met levels on BMY at any age. Results of this study suggest that people formulating diet on "Ideal Protein" basis
should not elevate the level of Met if lysine is in excess of its minimum needs.
Key words: Broilers, lysine, methionine, carcass yield, breast meat
International Journal of Poultry Science 3 (1): 51-60, 2004
Last modified: December 5, 2003.Nonphytate Phosphorus Requirement and Phosphorus Excretion of Broiler Chicks Fed Diets
Composed of Normal or High Available Phosphate Corn with and Without Microbial Phytase
P. W. Waldroup,1 J. H. Kersey,1 E. A. Saleh,1 C. A. Fritts,1 F. Yan,1 H. L. Stilborn, 2 R. C. Crum, Jr.,2 and V. Raboy3
The greatest need for nonphytate P was for maximum tibia ash, with requirements of 0.39, 0.29, 0.37, and 0.32% in diets with YDC, YDC plus phytase, HAPC,
and HAPC plus phytase, respectively. Addition of phytase liberated approximately 50% of the phytate-bound P from each diet. These levels were sufficient to
support body weight, feed conversion, and livability. Fecal P content of broilers fed diets with YDC at the NRC (1994) recommended level of 0.45% nonphytate P
was 1.21%, whereas at the respective requirement points indicated above, the P content was 1.09, 0.87, 0.78, and 0.64% in feces from broilers fed diets with
YDC, YDC plus phytase, HAPC, and HAPC plus phytase, respectively. Thus, fecal P output could be reduced while maintaining optimum performance by the use
of reduced dietary nonphytate P, introduction of HAPC, and phytase supplementation. One of the greatest benefits of phytase supplementation appeared to be
maintaining livability at lower dietary levels of nonphytate P.
©2000 by Poultry Science Association, Inc. All rights reserved.
Relationship of Dietary Lysine Level to the Concentration of All Essential Amino Acids in
Broiler Diets
J. Si,1 C. A. Fritts,1 D. J. Burnham,2 and P. W. Waldroup1
There were no significant interactions between level of Lys and levels of other EAA for live performance or carcass characteristics. The BW was significantly
increased at 21 and 42 d by addition of + 0.1% Lys above NRC but not at 56 d. There was no significant effect of other EAA on BW at any age. The effects of
Lys on feed conversion were varied. At 21 and 42 d, addition of 0.1% Lys to diets containing the NRC Lys level significantly improved feed conversion; response
to 0.2 or 0.3% Lys were varied. No significant effects of Lys on feed conversion were observed at 56 d. Increasing the level of EAA resulted in significant
improvements in feed conversion at 21, 42, and 56 d, generally following a linear trend.
Dietary Lys levels had no significant effects on dressing percentage, breast meat yield, or abdominal fat content. The level of other EAA significantly influenced
dressed yield but had no significant influence on carcass yield. These results indicate that NRC (1994) levels of Lys and other EAA are adequate for optimum
performance of male broilers processed at 56 d but may be less than adequate at younger ages.
©2001 by Poultry Science Association, Inc. All rights reserved.
AVIZYME IMPROVES PERFORMANCE OF BROILERS FED CORN-SOYBEAN MEAL-BASED DIETS
M. B. CAFÉ, C. A. BORGES, C. A. FRITTS, and P. W. WALDROUP
Birds fed the diets supplemented with Avizyme had significantly higher body weights at 16, 35, and 49 d as compared to birds fed the unsupplemented diets.
Response in feed conversion was inconsistent. Mortality at 16, 35, and 42 d was significantly less among birds fed the diets supplemented with Avizyme. Addition of
Avizyme had no consistent effect on dressing percentage or yield of breast, thigh, or wing components. Abdominal fat, expressed as percentage of the carcass, was
consistently increased by Avizyme supplementation, the differences being statistically significant at 42 and 49 d. This result suggests that birds fed the diets containing
Avizyme obtained a greater amount of net energy from their diets.
2. This response is probably due to the improvement in the overall digestibility of crude protein, starch, and fat in the diets.
3. This response may be mediated to some extent by the quality of the soybean meal used in the diets.
©2002 by Poultry Science Association, Inc. All rights reserved.
Effect of Source and Level of Vitamin D on Live Performance and Bone Development in Growing Broilers
C. A. Fritts and P. W. Waldroup
At 21 and 42 d, the BW of birds fed the 25-OH-D3 were significantly greater than those of birds fed the VIT-D3. At 21 d, vitamin D in excess of 500 IU/kg
appeared necessary to maximize BW regardless of source. At 42 d, approximately 1,000 IU/kg was needed to maximize BW of birds fed VIT-D3, whereas no
significant difference in BW was noted among birds fed the various levels of 25-OH-D3. Bone ash at 21 and 42 d was significantly greater for birds fed the
25-OH-D3 as compared to those fed the VIT-D3. Approximately 2,000 IU/kg of VIT-D3 was needed for maximum bone ash, whereas there were no significant
differences in bone ash content of birds fed from 250 to 4,000 IU/kg from 25-OH-D3. The incidence and severity of TD was significantly lower for birds fed
25-OH-D3 and was reduced by increasing levels of vitamin D regardless of source. Results of the study show that 25-OH-D3 is more metabolically potent on a per
unit basis than VIT-D3 for support of BW, tibia ash, and reduction in incidence and severity of TD. The differences were observed primarily at lower levels of
vitamin D; at typical industry levels, few differences were observed between the two sources. Use of the 25-OH-D3 may allow for supplementation with lower
levels or may provide a greater margin of safety.
©2003 by Poultry Science Association, Inc. All rights reserved.
Phosphorus Requirements of Broiler Chicks Six to Nine Weeks of Age as Influenced by Phytase
Supplementation
F. Yan, J. H. Kersey, C. A. Fritts, and P. W. Waldroup
The lowest level of NPP, with or without phytase supplementation, was sufficient for maximum BW gain, feed conversion, and livability. Using nonlinear regression,
levels of NPP needed to optimize tibia ash in the absence of phytase were 0.31 ± 0.004%, 0.23 ± 0.02%, and 0.22 ± 0.029% at 49, 56, and 63 d, respectively.
When diets were supplemented with 800 U/kg of phytase, the NPP requirement for optimum tibia ash was 0.15 ± 0.049% at 49 d. At 56 and 63 d, no more than
0.10% NPP (lowest level tested) was sufficient to maximize tibia ash. Compared to current NRC (1994) recommendations, the application of these reduced dietary
phosphorus levels could markedly reduce excreta excretion of phosphorus by broilers.
©2003 by Poultry Science Association, Inc. All rights reserved.
Effect of Source and Level of Vitamin D on Live Performance and Bone Development in Growing Broilers
C. A. Fritts and P. W. Waldroup
At 21 and 42 d, the BW of birds fed the 25-OH-D3 were significantly greater than those of birds fed the VIT-D3. At 21 d, vitamin D in excess of 500 IU/kg
appeared necessary to maximize BW regardless of source. At 42 d, approximately 1,000 IU/kg was needed to maximize BW of birds fed VIT-D3, whereas no
significant difference in BW was noted among birds fed the various levels of 25-OH-D3. Bone ash at 21 and 42 d was significantly greater for birds fed the
25-OH-D3 as compared to those fed the VIT-D3. Approximately 2,000 IU/kg of VIT-D3 was needed for maximum bone ash, whereas there were no significant
differences in bone ash content of birds fed from 250 to 4,000 IU/kg from 25-OH-D3. The incidence and severity of TD was significantly lower for birds fed
25-OH-D3 and was reduced by increasing levels of vitamin D regardless of source. Results of the study show that 25-OH-D3 is more metabolically potent on a per
unit basis than VIT-D3 for support of BW, tibia ash, and reduction in incidence and severity of TD. The differences were observed primarily at lower levels of vitamin
D; at typical industry levels, few differences were observed between the two sources. Use of the 25-OH-D3 may allow for supplementation with lower levels or may
provide a greater margin of safety.
©2003 by Poultry Science Association, Inc. All rights reserved.
Comparison of Normal and High Available Phosphorus Corn With and Without Phytase Supplementation in Diets for Male Large White Turkeys Grown to Market Weights
F. Yan1, C. A. Fritts1, P. W. Waldroup1, H. L. Stilborn2, D. Rice2, R. C. Crum, Jr.2 and V. Raboy3
E-mail: Waldroup@uark.edu
© Asian Network for Scientific Information 2003
Extent to Which Crude Protein May Be Reduced in Corn-soybean Meal Broiler Diets Through Amino Acid Supplementation
Jianlin Si2, C.A. Fritts2, D.J. Burnham3 and P.W. Waldroup2
E-mail: Waldroup@uark.edu
© Asian Network for Scientific Information 2004 Jianlin Si, J.H. Kersey, C.A. Fritts and P.W. Waldroup
E-mail: Waldroup@uark.edu
© Asian Network for Scientific Information 2004
Return to:
College of Agriculture & Life Sciences
Mississippi State UniversityFor information about this page, contact Sharon Whitmarsh.
For information about Mississippi State University, contact msuinfo@ur.msstate.edu.
Mississippi State University
is an equal opportunity institution.