Suitability of a Dehydrated Poultry Mortality-Soybean Meal Product for Use in Broiler Chicken Diets

2003 Poultry Science Association, Inc.

Suitability of a Dehydrated Poultry Mortality-Soybean Meal Product for Use in Broiler Chicken Diets K. M. Downs,*,1 J. B. Hess,† J. P. Blake,† R. A. Norton,† A. Kalinowski,† A. Corzo,† C. M. Parsons‡

Primary Audience: Nutritionists, Renderers, Feed Mill Managers, Live Production Personnel, Veterinarians SUMMARY In the poultry industry, several alternative methods for disposal of dead birds have been developed. This study evaluated the efficacy of a dehydrated poultry mortality-soybean meal (DPSM) product, made from 60% on-farm whole dead birds, 40% soybean oil meal, and a preservative amendment, for inclusion in broiler diets. Composite samples of the DPSM product were obtained for nutritional and microbiological analysis. A subsequent 42-d broiler growout experiment was conducted using DPSM incrementally (0 to 100%) substituted for the protein source component (i.e., soybean oil meal) in starter and grower diets. Nutritionally, the DPSM product was similar to soybean oil meal (SBOM), with approximately 51.5% CP, 2.81% Lys, 0.72% Met, 1.85% Thr, 3.14% Arg, and 1.36% TSAA. True amino acid digestibilities of DPSM, however, were higher than soybean oil meal. Likewise, crude fat (18.03%) and ash (8.00%) concentrations of DPSM were higher than those typically observed for SBOM. Although at low levels, 13 genera of bacteria (including some pathogenic organisms) were isolated from the DPSM product. When replacing SBOM in broiler starter and grower diets, DPSM, at lower, more practical replacement rates, did not significantly influence body weight, feed consumption, or feed conversion. According to the results of this study, using DPSM in partial substitution for SBOM in broiler diets was a safe, efficient, and economically feasible alternative for dead bird disposal. Key words: broiler, dehydrated poultry meal, mortality, dead bird disposal 2003 J. Appl. Poult. Res. 12:222–228

DESCRIPTION OF PROBLEM Environmentally safe and economically effective disposal of farm mortalities remains a serious challenge for U.S. broiler production. States with large populations of broilers typi1

cally produce and must dispose of large quantities of dead birds. An average 100,000-bird broiler flock (marketed at 49 d with 0.1% per day average mortality) would produce an estimated 1 ton of dead birds [1]. Using the same figures, an average integrated broiler complex pro-

To whom correspondence should be addressed: [email protected].

Downloaded from http://japr.oxfordjournals.org/ at New York University on May 23, 2015

*School of Agribusiness & Agriscience, Middle Tennessee State University, Murfreesboro, Tennessee 37132; †Department of Poultry Science, Auburn University, Alabama 36849; and ‡Department of Animal Sciences, University of Illinois, Urbana, Illinois 61801

DOWNS ET AL.: POULTRY MORTALITY-SOYBEAN MEAL

223

TABLE 1. Selected nutrient composition of dehydrated poultry mortality-soybean meal (DPSM)A Further screened DPSMB NutrientC

As-fed basis

Dry matter basis

As-fed basis

Dry matter basis

96.45 48.40 2.00 17.64 7.72 2,820 0.76 0.91 1.42 0.18 28 64 19 542

100.00 50.19 2.07 18.29 8.00 2,930 0.79 0.94 1.47 0.19 29 66 20 562

97.61 50.27 2.02 17.60 7.81 2,860 1.13 1.07 1.38 0.18 27 63 34 711

100.00 51.50 2.07 18.03 8.00 2,930 1.16 1.10 1.41 0.18 28 65 35 728

A

Auburn University Soil Testing Laboratory, Auburn University, AL. Further screened DPSM = postcollection sample screening (#4 and #8 screens); as collected DPSM = samples analyzed as collected from finished DPSM at manufacturing facility. C DM, CP, crude fiber, crude fat, ash, Ca, P, K, Mg, Mn, Zn, Cu, and Fe were determined according to the procedures of the Association of Official Analytical Chemists [8]. D Metabolizable energy calculated using the high-fat prediction equation: MEn = 31.02 × CP + 78.87 EE (NRC, [9]). B

cessing one million birds per week would produce an estimated 10 tons (fresh weight) of broiler mortalities per week. Thus, innovative methods must be developed to address the necessity of disposing large quantities of dead birds. Currently, the most commonly accepted methods of dead bird disposal are incineration, composting, and rendering [2]. Each method, however, presents particular challenges, with incineration being the most costly and producing particulate and odor pollution [3]. Composting is safe but requires construction of specialized facilities (e.g., composting sheds) with extensive time and management commitments [4, 5], and rendering requires specialized storage equipment (e.g., freezer units) and close proximity to a rendering facility. The current study was undertaken to evaluate an alternative processing method for dead bird disposal, as compared to conventional rendering, utilizing a grinding and drying technique to produce a dehydrated poultry mortality-soybean meal for potential inclusion in commercial broiler diets.

MATERIALS AND METHODS Dehydrated Poultry Mortality-Soybean Meal Processing Dehydrated poultry mortality-soybean meal (DPSM) used in this study was obtained from

a local manufacturing facility. Fabrication of DPSM involved a series of steps (collection, grinding, drying, amending, and screening) to produce a marketable feed-grade product. Dead birds (primarily broilers between 1 and 56 d of age) were temporarily stored in on-farm freezer units,which were periodically emptied for product transportation in modified solid waste disposal trucks to the DPSM manufacturing facility. Frozen mortalities were initially conveyed through an icebreaker to individualize carcasses for transportation to a modified grinding system. Individual frozen whole carcasses were ground to a semifine consistency and subsequently stored (22°C) until needed. Ground mortalities were dehydrated in a large drum dryer according to a proprietary procedure. As part of the DPSM processing, the dried, ground, dead bird material was combined with soybean oil meal [SBOM; (60% whole ground carcasses to 40% SBOM)] and then a Food and Drug Administration (FDA)-approved formalin-based antimicrobial feed additive (2.7 kg/ton; Termin-8) [6]. Termin8 was added for broad-spectrum bacterial population reduction. As the final processing step at the local manufacturing facility, feathers were screened from the finished DPSM product prior to final storage (22°C).

Downloaded from http://japr.oxfordjournals.org/ at New York University on May 23, 2015

Dry matter, % Crude protein, % Crude fiber, % Crude fat, % Ash, % ME, kcal/kgD Ca, % P, % K, % Mg, % Mn, ppm Zn, ppm Cu, ppm Fe, ppm

As collected DPSMB

JAPR: Research Report

224 Nutritional Analysis

Microbiological Analysis Microbiological analysis was conducted to determine the safety of the DPSM product, not the efficacy of the antimicrobial amendment. Thus, random samples were aseptically obtained throughout the storage unit from finished DPSM only, immediately placed on ice, and transported to the Auburn University Poultry Microbiology and Parasitology Laboratory for subsequent microbiological analysis (Table 4) [13]. Broiler Performance Experiment For the 42-d experiment, 300 straight-run broiler chicks were obtained from a commercial hatchery and randomized across Petersime battery cages (10 birds per cage) housed in an environmentally controlled room. Space allotment was designed to exceed the recommended cage density of 871 cm2/bird [14]. Chicks were brooded at 32°C for the first week, with a subsequent 2°C per week temperature reduction until 24°C was reached. Light was provided continuously (24 L:0 D), and birds were fed using a two-

TABLE 2. Amino acid composition and true digestibility of dehydrated poultry mortality-soybean meal (DPSM) (%)A Further screened DPSMB

As collected DPSMB

Amino acid

Total

True digestible

True digestibility

Total

True digestible

True digestibility

Lys Met Cys Thr Arg Val Ile Leu Pro His Phe Tyr Ser Glu Asp Ala

2.60 0.59 0.62 1.67 2.70 2.16 1.93 3.22 2.30 1.12 1.91 1.22 1.86 6.60 4.22 2.13

2.40 0.55 0.52 1.58 2.55 1.94 1.77 3.00 2.17 1.02 1.89 1.06 1.67 6.12 3.74 1.91

92.2 94.0 84.4 94.7 94.5 89.7 91.7 93.3 94.2 90.7 99.2 86.5 89.9 92.8 88.7 89.8

2.81 0.72 0.64 1.85 3.14 2.45 2.13 3.54 3.01 1.20 2.10 1.30 2.10 7.34 4.68 2.57

2.55 0.70 0.48 1.73 2.90 2.14 1.91 3.24 2.76 1.08 2.03 1.10 1.78 6.76 4.11 2.31

90.9 97.1 75.6 93.3 92.5 87.5 89.8 91.5 91.8 89.7 96.9 84.8 84.9 92.1 87.9 89.7

A Amino acid analysis conducted according to the procedures of Parsons [10] and Sibbald [11]. True digestible amino acid concentration and true amino acid digestibility were determined using the precision-fed cecectomized rooster bioassay. B Further screened DPSM = postcollection sample screening (#4 and #8 screens); as collected DPSM = samples analyzed as collected from finished DPSM at manufacturing facility.

Downloaded from http://japr.oxfordjournals.org/ at New York University on May 23, 2015

Composite samples were obtained from finished, stored DPSM for subsequent nutrient analysis. Prior to analysis, half of the samples were further screened (#4 and #8 screens) to remove any additional feathers and large particulate matter (not removed during DPSM processing) and half remained unscreened (as collected from manufacturing facility). Further screened (FS) and as collected (AC) DPSM samples were submitted for proximate analysis and mineral level determination [7] (Table 1). All samples were analyzed for DM, N, CF, fat, ash, Ca, P, K, Mg, Mn, Zn, Cu, and Fe according to the procedures of the Association of Official Analytical Chemists [8]. Metabolizable energy values in Table 1 were estimated using a highfat prediction equation: MEn = 31.02 (CP) + 78.87 (EE) [9]. All samples were also subjected to amino acid concentration (total and true digestible) and true digestibility (precision-fed cecectomized rooster bioassay) determination according to the procedures of Parsons [10] and Sibbald [11] (Table 2). Nutrient analysis data were compiled into an ingredient matrix, and broiler starter and grower diets were formulated

with AC DPSM using the Agri-Data Feed Formulation Program [12] (Table 3).

DOWNS ET AL.: POULTRY MORTALITY-SOYBEAN MEAL

225

TABLE 3. Ingredient composition and calculated nutrient analysis of diets containing various levels of dehydrated poultry mortality-soybean meal (DPSM) StarterA (%) 0:100C

50:50

75:25

100:0

0:100

25:75

50:50

75:25

100:0

56.16 35.03 4.30 1.70 1.30 0.45

56.16 26.27 4.30 1.70 1.30 0.45

56.16 17.52 4.30 1.70 1.30 0.45

56.16 8.76 4.30 1.70 1.30 0.45

56.16 0.00 4.30 1.70 1.30 0.45

63.65 29.78 2.60 1.50 1.20 0.48

63.65 22.34 2.60 1.50 1.20 0.48

63.65 14.89 2.60 1.50 1.20 0.48

63.65 7.44 2.60 1.50 1.20 0.48

63.65 0.00 2.60 1.50 1.20 0.48

0.75 0.23 0.08

0.75 0.23 0.08

0.75 0.23 0.08

0.75 0.23 0.08

0.75 0.23 0.08

0.50 0.21 0.08

0.50 0.21 0.08

0.50 0.21 0.08

0.50 0.21 0.08

0.50 0.21 0.08

0.00

8.76

17.51

26.27

35.03

0.00

7.44

14.89

22.34

29.78

Calculated analysis (DM basis)F CP, % 22.8 23.0 23.1 23.3 23.4 20.9 21.1 21.2 21.3 21.4 ME, kcal/kg 3,333 3,368 3,403 3,438 3,473 3,350 3,380 3,410 3,440 3,470 Ca, % 0.99 1.06 1.14 1.21 1.28 0.89 0.95 1.02 1.08 1.14 P available, % 0.48 0.55 0.62 0.69 0.76 0.44 0.49 0.55 0.61 0.67 Arg, % 1.49 1.45 1.41 1.38 1.34 1.33 1.30 1.27 1.24 1.21 Lys, % 1.23 1.21 1.19 1.17 1.15 1.09 1.08 1.06 1.04 1.02 Met, % 0.59 0.59 0.59 0.59 0.59 0.55 0.55 0.55 0.55 0.55 Met + Cys, % 0.96 0.96 0.95 0.94 0.93 0.90 0.89 0.88 0.88 0.87 Thr, % 0.87 0.86 0.85 0.84 0.83 0.79 0.78 0.77 0.77 0.76 Na, % 0.22 0.29 0.35 0.42 0.49 0.23 0.28 0.34 0.40 0.46 A

Fed from d 0 to 21. Fed from d 22 to 42. DPSM-to-SBOM ratio. Dehydrated poultry mortality-soybean meal substituted soybean oil meal (SBOM) at an incremental 25% rate for a total of five dietary treatments; 0% substitution rate = no DPSM included (SBOM alone is the sole protein source); 100% substitution rate = DPSM is the sole protein source (no SBOM included). D Provides the following per kilogram of diet: vitamin A, 8,000 IU (retinyl palmitate); cholecalciferol, 2,000 IU; vitamin E (DL-α-tocopheryl acetate), 8 IU; menadione, 2 mg; riboflavin, 5.5 mg; pantothenic acid, 13 mg; niacin, 36 mg; choline, 5,00 mg; vitamin B12, 0.02 mg; folic acid, 0.5 mg; thiamin, 1 mg; pyridoxine, 2.2 mg; biotin, 0.05 mg; ethoxyquin, 125 mg; I, 1 mg; Cu, 6 mg; Mn, 65 mg; Co, 0.2 mg; Fe, 55 mg; Zn, 55 mg; Se, 0.3 mg. E Coban-60 (132 mg/kg). F Based on analytical values in Tables 1 and 2 and NRC [9]. B C

feed program of starter (d 0 to 21) and grower (d 22 to 42) formulated to exceed NRC requirements [9]. Ingredient composition and calculated nutrient analysis of starter and grower diets are included in Table 3. Feed and water were provided ad libitum. Dietary treatments were randomly assigned to individual cages and consisted of five incremental replacement levels of SBOM and DPSM [0, 25, 50, 75, and 100% SBOM replacement; 0% replacement level = no DPSM included (control; SBOM alone is the sole protein source), 100% replacement level = protein source is entirely DPSM (no SBOM included)]. Each of the five treatments was administered to six replicate

pens. Birds and feed were weighed at weekly intervals to determine average live BW, feed consumption (d 0 to 21, d 22 to 42, d 0 to 42), and feed conversion (d 0 to 21, d 22 to 42, d 0 to 42). For this experiment, data were analyzed as a completely randomized design with battery cage representing the experimental unit. Treatment main effects significance for BW, feed consumption, and feed conversion were determined using the general linear models procedure of the SAS statistical package [15]. When treatment main effects were significantly different (P < 0.05), linear and quadratic effects of equal incremental increases in DPSM were evaluated using

Downloaded from http://japr.oxfordjournals.org/ at New York University on May 23, 2015

Ingredient Corn Soybean oil meal Poultry fat Dicalcium phosphate Ground limestone NaCl Vitamin-trace mineral premixD DL-Methionine Monensin sodiumE Dehydrated poultry mortality-soy

25:75

GrowerB (%)

JAPR: Research Report

226 TABLE 4. Bacterial isolates recovered from dehydrated poultry mortality-soybean meal (DPSM)A,B,C Organism

A Auburn University Poultry Microbiology and Parasitology Laboratory, Auburn University, AL. B Pooled samples. C Due to low levels (<250 cfu/g), isolates were not enumerated.

orthogonal polynomials. Means were separated at an α-level of 0.05 using Tukey’s test for multiple comparisons [15].

RESULTS AND DISCUSSION Nutritional Analysis Within the framework of nutritional composition, the DPSM samples obtained for this study were similar to SBOM (48%). Tables 1 and 2 summarize the proximate, mineral, and amino acid analyses of the DPSM product samples. A variety of compositional differences were apparent between the FS and AC samples. Mineral concentrations (i.e., Ca, P, Cu, and Fe) were appreciably higher in the AC DPSM product with 47, 17, 75, and 30% greater Ca, P, Cu, and Fe concentrations, respectively. Obviously, this compositional difference was due to the screening losses in the FS samples, but particularly influenced by loss (screening out) of large particulate matter with higher mineral composition

Downloaded from http://japr.oxfordjournals.org/ at New York University on May 23, 2015

Acinetobacter baumannii Alacaligenes faecalis Bacillus cereus Bacillus coagulans Bacillus licheniformis Bacillus megaterium Bacillus mycoides Brevundimonas diminuta Chryseobacterium gleum Enterobacter cloacae Flavimonas orzyihabitans Klebsiella pneumoniae Micrococcus luteus Micrococcus lylae Pseudomonas fluorescens Pseudomonas putida Rhodococcus rhodochrous Sphingobacterium multivorum Sphingobacterium thalpophilum Staphylococcus arlettae Staphylococcus aureus Staphylococcus chromogenes Staphylococcus sciuri Staphylococcus simulans

(e.g., bone fragments) in addition to screened feathers. Crude protein concentration of the DPSM product was 2.6% higher in the AC samples and attributed to the higher feather content of the AC product. Likewise, total and true digestible amino acid composition of the AC DPSM was 10.1 and 10.9% higher (total and true digestible amino acid basis), respectively, for the 16 amino acids evaluated. Cystine true digestible amino acid content and digestibility, however, were 0.04 and 8.8% lower, respectively, in the AC DPSM (0.52 vs. 0.48%; 84.4% vs. 75.6%) as compared to the FS DPSM product. Substitution value for typical proteinaceous feedstuffs used in broiler diets is of particular value when characterizing DPSM. Using NRC [9] nutrient compositions for SBOM (IFN #504-604), the AC DPSM product used in this study compared (as % of SBOM) to SBOM as follows: 107% (CP), 121% (ash), 26% (CF), 2,006% (fat), 117% (ME), 356% (Ca), 151% (P), 63% (K), 59% (Mg), 86% (Mn), 145% (Zn), 142% (Cu), 540% (Fe), 92% (Lys), 102% (Met), 86% (Cys), 95% (Thr), 88% (Arg), and 94% (TSAA). Based on these results, AC DPSM is similar in nutrient composition to SBOM. Notably, and expected based on the nature of the DPSM product (with bird adipose tissue), fat content of AC DPSM is much higher than that observed for SBOM. Elevated ash levels, indicated by elevated Ca, P, Mn, Zn, Cu, and Fe levels, is expected due to whole-bird inclusion (including bones and feathers with particularly high Fe and Zn levels) in the DPSM product. Although crude fiber content of SBOM is 74% higher than AC DPSM, the assayed crude fiber components are not necessarily the same between SBOM and AC DPSM (fiber fraction of plant materials vs. insoluble nitrogen of animal products). Amino acid profiles of DPSM and SBOM are reasonably similar with only lysine levels at more than a 10% differential between the two. Bone and feather content of DPSM contributed significantly to nutritional differences between it and SBOM. True amino acid digestibilities of FS and AC DPSM were higher than those of SBOM. As analyzed, average true amino acid digestibility for FS DPSM was 91.6%, 2.9% higher than published true amino acid digestibility for soy-

DOWNS ET AL.: POULTRY MORTALITY-SOYBEAN MEAL

227

TABLE 5. Influence of varying levels of dehydrated poultry mortality-soybean oil meal (DPSM) in substitution of soybean oil meal (SBOM) on broiler live performance (least squares means)A Substitution rateB DPSM (%) 0 25 50 75 100 SEM

SBOM (%) 100 75 50 25 0

Feed consumption (g)

Feed conversion (g:g)

Day 21

Day 42

Day 0–21

Day 22–42

Day 0–42

731 738 711 676 680 22.7

2,208 2,209 2,174 2,140 2,114 56.5

989 1,007 972 932 920 23.1

2,839 2,756 2,849 2,750 2,727 58.9

3,828 3,763 3,821 3,682 3,646 74.8

0.218

0.696

0.057C

0.459

0.315

Day 0–21

Day 22–42

Day 0–42

1.35 1.37 1.37 1.38 1.36 0.02

1.93 1.88 1.95 1.88 1.91 0.04

1.74 1.71 1.75 1.72 1.73 0.03

0.894

0.649

0.823

A

Starter fed from d 0 to 21; grower fed from d 22 to 42. DPSM substituted for SBOM at an incremental 25% rate for a total of five dietary treatments; 0% substitution rate = no DPSM included (SBOM alone is the sole protein source); 100% substitution rate = DPSM is the sole protein source (no SBOM included). C Statistically significant linear function (P = 0.006) for feed consumption between d 0 and 21. B

bean oil meal (88.7% using the cecectomized rooster bioassay) [16]. Typically, protein sources of animal origin have more favorable amino acid profiles than plant sources for use in animal feeds. Compared with SBOM, AC DPSM, however, was more variable in true amino acid digestibility. Although average true amino acid digestibility of AC DPSM was higher than soybean oil meal (90.0% vs. 88.7%), Lys, Cys, Arg, Tyr, and Ser true digestibilities of AC DPSM were 2.8% lower than SBOM (88.5% vs. 85.7%). The reduced individual true amino acid digestibility of the AC DPSM observed for some amino acids likely resulted from the higher feather content (in the AC DPSM) with a concomitant lower true amino acid availability; however, average true amino acid digestibility (overall) of AC DPSM was 1.3% higher than SBOM. When used as a total or partial SBOM replacement, formulation parameters of DPSM should be considered. However, under current pricing conditions, DPSM priced equal to SBOM and was worth approximately 99% of SBOM in broiler diet formulation. Microbiological Analysis A wide array of bacteria (aerobes and anaerobes) were isolated from collected DPSM samples (Table 4). Among these isolates were pathogenic species, including S. aureus, S. sciuri, K.

pneumoniae, and B. cereus. Likewise, the predominant spore-forming organisms were members of the Bacillus genus. However, bacterial levels (pathogenic and nonpathogenic) in finished DPSM were low and below the threshold for statistically significant enumeration (<250 cfu/g). In general, the DPSM product was determined to be relatively bacteria free. Many of the bacteria recovered could be classified as environmental contaminants, indicating postprocessing treatment contamination. Because no attempt was made to identify bacterial origin, the possibility of environmental (e.g., dust, soil, insects, etc.) and equipment contamination, as a result of poor processing facility biosecurity, cannot be eliminated. Broiler Performance Experiment In general, dietary treatment did not appreciably influence BW, feed consumption, or feed conversion throughout the DPSM feeding experiment. Live performance results are summarized in Table 5. Feed consumption between d 0 and 21 exhibited a linear (P < 0.05) reduction as DPSM levels in the starter diet increased. However, subsequent feed consumption measures (d 22 to 42 and d 0 to 42) showed no influence from DPSM level (P > 0.05). These results suggest total substitution of SBOM (or other protein sources) with DPSM (or other animal proteins) may depress early feed consumption. Although

Downloaded from http://japr.oxfordjournals.org/ at New York University on May 23, 2015

P>F Treatment main effects

BW (g)

JAPR: Research Report

228

diets at 75 and 100% substitution rates apparently compensated for early reductions in feed consumption due to high DPSM levels. Period and cumulative FCR’s were uninfluenced by dietary treatment (P > 0.05) with only a four-point spread between the highest (1.75; 50% substitution treatment) and lowest (1.71; 25% substitution treatment) cumulative (d 0 to 42) feed conversion (Table 5). Likewise, no significant linear or quadratic effects were noted (P > 0.05). Although affecting early feed consumption, DPSM (at all levels of substitution) did not alter efficiency of feed utilization.

CONCLUSIONS AND APPLICATIONS 1. As evaluated nutritionally and microbiologically in this study, DPSM is an acceptable, safe, and economic alternative to traditional protein sources and a practical method of dead bird disposal. 2. Although DPSM, as evidenced by the current study, is nutritionally comparable to SBOM, mineral and fat concentration variation must be considered in formulation procedures. 3. According to the results of this study, the maximum practical substitution rate of SBOM with DPSM in broiler starter and grower diets is between 25 and 50%. Substitution beyond 50% may result in reductions in feed consumption as was evidenced by reductions in feed consumption from 0 to 21 d in the current study.

REFERENCES AND NOTES 1. Edwards, D. R., and T. C. Daniels. 1992. Environmental impacts of on-farm poultry waste disposal—a review. Bioresource Technol. 41:9–33. 2. Blake, J. P., and J. O. Donald. 1992. Alternatives for the disposal of poultry carcasses. Poult. Sci. 71:1130–1135. 3. Donald, J. O., and J. P. Blake. 1995. Installation and use of incinerators. Alabama Coop. Ext. Serv. Circular ANR-981. Alabama Coop. Ext. Service, Auburn Univ., AL. 4. Murphy, S. W., and T. S. Handwerker. 1988. Preliminary investigations of composting as a method of dead bird disposal. Pages 65–72 in Proc. Natl. Poult. Waste Manage. Symp. USDA and Ohio State Univ., Columbus, OH. 5. Payne, V. P., and J. O. Donald. 1989. Dead bird disposal. Alabama Feather Facts 10(3):1–5. 6. Termin-8, Anitox, Inc., Nacogdoches, TX. 7. Auburn University Soil Testing Laboratory. 8. Association of Official Analytical Chemists. 2002. Official Methods of Analysis. 17th ed. Association of Official Analytical Chemists, Washington, DC.

11. Sibbald, I. R. 1986. The TME system of feed evaluation: Methodology, feed composition data and bibliography. Tech. Bull. 1986-4E. Agriculture Canada, Ottawa, ON, Canada. 12. Agri-Data Systems, Inc., Annapolis, MD. 13. Microbiological analysis of DPSM samples. Samples were serially diluted (0.5% peptone), and 0.1 mL of each diluted sample was placed on the following media: bismuth sulfite agar (Difco Laboratories, Detroit, MI), EMB agar (Difco), Hektoen enteric agar (Difco), MacConkey agar (Difco), Clostridium perfringens agar (OPSP), Bacillus cereus selective agar (Oxoid Unipath, Columbia, MD), and TCBS agar (Difco). Total aerobic and anaerobic bacterial counts were obtained using blood agar (Remel, Lenexa, KS) and Reduced blood agar (Remel), respectively. Postinoculation media were incubated (37°C, 24 h) for subsequent quantification. Representative colonies were isolated and identified using one or more of the following tests: RapID ANA (Innovative Diagnostic Systems, Inc., Norcross, GA) for anaerobes, RapID ONE (Innovative Diagnostic Systems, Inc.) for gram-negative rod fermenters, RapID NF Plus (Innovative Diagnostic Systems, Inc.) for gram-negative nonfermenters, or MIDI System (MIDI, Inc., Newark, DE) for non-Enerobacteriaceae isolates. 14. Federation of Animal Science Societies. 1999. Guide for the Care and Use of Agricultural Animals in Agricultural Research and Teaching. FASS, Savoy, IL.

9. National Research Council. 1994. Nutrient Requirements of Poultry. 9th rev. ed. Natl. Acad. Sci., Washington, DC.

15. SAS Institute. 1996. SAS User’s Guide: Statistics. Version 7.0 SAS Institute, Cary, NC.

10. Parsons, C. M. 1986. Determination of digestible and available amino acids in meat meal using conventional and cecectomized cockerels or chick growth assays. Br. J. Nutr. 56:227–240.

16. Parsons, C. M., K. Hashimoto, K. J. Wedekind, Y. Han, and D. H. Baker. 1992. Effect of overprocessing on availability of amino acids and energy in soybean oil meal. Poult. Sci. 71:133–140.

Downloaded from http://japr.oxfordjournals.org/ at New York University on May 23, 2015

protein concentrations across treatments were similar for the respective feeding program (starter vs. grower), increased DPSM levels were antagonistic to feed consumption between d 0 and 21. Body weights evaluated on d 21 and 42 were not significantly influenced by DPSM substitution (P > 0.05). Numerically, d 42 body weights of birds consuming the 100% DPSM treatment were 4.3% less than those of control birds. This reduction, although not statistically significant, would prove economically substantial in the commercial broiler sector. As evidenced by these results, birds in this experiment consuming