Comparison of Broiler Performance when Fed Diets Containing Roundup Ready1 (Event RT73), Nontransgenic Control, or Commercial Canola Meal

Comparison of Broiler Performance When Fed Diets Containing Roundup Ready1 (Event RT73), Nontransgenic Control, or Commercial Canola Meal M. L. Taylor,*,2 E. P. Stanisiewski,† S. G. Riordan,* M. A. Nemeth,* B. George,‡ and G. F. Hartnell* *Monsanto Company, 800 N. Lindbergh Blvd., St. Louis, Missouri 63167; †Atek Medical, 620 Watson SW, Grand Rapids, Michigan 49504; and ‡Colorado Quality Research, 400 East County Road 72, Wellington, Colorado 80549

(Key words: broiler performance, canola meal, carcass yield, 5-enolpyruvylshikimate-3-phosphate synthase, glyphosate-tolerant canola) 2004 Poultry Science 83:456–461

bactrum anthropi is a commonly occurring bacterium in the rhizosphere (Lebuhn et al., 2000) and is considered to be generally nonpathogenic. Both gene products, the CP4 EPSPS and GOX proteins, are expressed constitutively in the plant, and together they are responsible for conferring tolerance to Roundup herbicide. Broiler studies are conducted to detect potential unintended effects resulting from the transformation event or from the expression of the new trait (or traits) by examining performance characteristics during a rapid growth period. This experiment assessed the nutritional value of glyphosate-tolerant canola meal as compared with conventional canola meal by measuring growth, feed conversion, carcass yield, and the percentage of moisture, protein, and fat in breast and thigh meat of broilers during a 42-d study.

INTRODUCTION Roundup Ready canola was developed through biotechnology to be tolerant to glyphosate, the active ingredient in the Roundup family of agricultural herbicides. The Roundup tolerant (RT) event number 73, was produced by the insertion of 2 genes into the canola genome: the cp4 epsps gene, derived from the common soil bacterium Agrobacterium strain CP4, which encodes for the production of the glyphosate-tolerant CP4 EPSPS enzyme (Padgette et al., 1996), and the gox gene from Ochrobactrum anthropi strain LBAA, which encodes for the production of the glyphosate degrading enzyme, glyphosate oxidase (GOX). The GOX enzyme from Ochrobactrum anthropi strain LBAA was identified from a collection of glyphosate-degrading bacteria (Hallas et al., 1988) by screening for bacteria that showed the most rapid degradation of glyphosate. Ochro-

MATERIALS AND METHODS Birds and Housing

2004 Poultry Science Association, Inc. Received for publication June 25, 2003. Accepted for publication November 10, 2003. 1 Roundup and Roundup Ready are registered trademarks of Monsanto Technology LLC. 2 To whom correspondence should be addressed: Mary.L.Taylor@ monsanto.com.

This experiment was conducted in accordance with the principles and guidelines for the care and use of agricultural animals in research (Federation of Animal Science Societies, 1999) and, as applicable, was in compliance with the Food and Drug Administration’s “Good Laboratory 456

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lar across treatments (P > 0.05). Expressed as percentage of live weight, chill weight of the broilers fed diets containing glyphosate-tolerant canola meal was not different from those fed all other diets, but some differences were observed between the nontransgenic control and commercial diets. No major differences were observed in percentage of moisture, protein, and fat in breast or thigh meat (P > 0.05) across treatments. Comparisons of the glyphosate-tolerant canola diet to the population of all other diets (combining sexes) showed no major differences (P > 0.05) in performance, carcass yields, or moisture, protein, and fat in breast and thigh meat. Broilers fed diets containing glyphosate-tolerant canola meal had similar growth performance to birds fed nontransgenic control and commercial canola diets.

ABSTRACT A 42-d experiment compared the nutritional value of genetically modified glyphosate-tolerant (Roundup Ready event RT73) canola meal to that of conventional canola meal when fed to rapidly growing Ross × Ross 508 broilers using a randomized complete block design. Five pens of males and 5 pens of females were used in each of 8 canola meal treatments (glyphosatetolerant, nontransgenic control, and 6 commercial varieties). Broilers (10 birds/pen) were fed approximately 25% wt/wt canola meal during the first 20 d and 20% wt/wt canola meal thereafter. In general, performance response variables for glyphosate-tolerant canola meal were not different (P > 0.05) than those for the nontransgenic and commercial canola meals. Carcass fat pad, breast meat, thighs, legs, and wings (on a percentage basis) were simi-

PERFORMANCE OF BROILERS FED TRANSGENIC CANOLA MEAL

Experimental Design A randomized complete block design was used with 8 dietary treatments (glyphosate-tolerant, nontransgenic control, and 6 commercial reference diets). For each of the 8 treatment groups, there were 100 broilers in 10 pens (10 broilers/pen) with 5 pens of males and 5 pens of females per treatment. Initially, there were an additional 2 broilers in each pen to compensate for early chick mortality during the first few days posthatch. At d 7, the group size was adjusted to 10 broilers/pen. The primary criteria for removal were slower growing broilers, followed by random selection.

Seed and Meal Oilseed of glyphosate-tolerant (Roundup Ready event RT73) and nontransgenic control canola varieties was commercially produced and harvested in 1999 in Manitoba, Canada. All samples were delivered to the Food Protein R&D Center at Texas A&M University (College Station, TX) for processing of oilseed to defatted canola meal. In

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Hoover’s Hatchery, Rudd, IA. Unifeed, Lethbridge, Alberta, Canada. 5 Romer Laboratories, Union, MO. 6 Covance Laboratories, Madison, WI. 7 Intervet, Inc., Millsboro, DE. 8 Covance Laboratories, Madison, WI; Dairy One Laboratories, Ithaca, NY. 9 University of Missouri, Experiment Stations Chemical Laboratories, Columbia, MO. 4

addition, 6 lots of commercially4 produced defatted canola meal from a mixture of reference varieties (CM1, CM2, CM3, CM4, CM5, and CM6) were also acquired for the study. Mycotoxin5 and pesticide6 analyses were conducted on the processed meal to verify that levels were below the limits of concern for broiler performance. Proximate and amino acid analyses5 were performed according to the Association of Official Analytical Chemists (2000), and an additional Kjeldahl method (Bradstreet, 1965) was used for the crude protein analyses.

Diets Dietary protein was provided by the canola meal supplemented with commercial corn and dehulled soybean meal. Diets were formulated based on the individual nutrient analyses (Table 1) for glyphosate-tolerant, nontransgenic control, and commercial canola meal. A coccidiostat, salinomycin (Sacox)7 was mixed into test diets at 60 g/ton. All diets were formulated such that the essential amino acid levels, with only the inclusion rate of canola meal fixed, met nutritional recommendations of NRC (1994) for poultry. Synthetic methionine and lysine were added to the diets as needed. For d 1 to 20, chickens were fed a starter diet containing approximately 25% wt/wt canola meal. Analyses of poultry diets8 were conducted to confirm formulated nutrient composition. For the rest of the experiment (d 21 to 42), chickens were fed a grower/finisher diet containing approximately 20% wt/wt canola meal (Table 2).

Measurements Broiler flocks were observed twice daily for general health. All dead broilers and those killed due to their unhealthy condition were weighed and necropsied. Broilers were weighed by pen at d 1 and 42 and individually at experiment termination (d 43 for males and d 44 for females). Average values for BW per pen and BW per bird within each treatment group were calculated within sex. The average feed conversion per pen was calculated for the entire duration of the experiment by dividing the total feed consumption during the experiment by the total BW of the surviving broilers in the pen. This number was averaged for each treatment group by sex. Adjusted feed conversion was calculated by dividing the total feed consumption per pen by the total BW of surviving broilers and those that died or were removed. At the end of the experiment, carcass measurements (chill weight and breast, thigh, wing and leg weights) were taken, and fat pads were weighed. The first male and female bird processed from each pen were selected for subsequent moisture, protein, and fat analyses9 of breast and thigh tissue.

Statistical Analysis Statistical analysis was carried out using a linear mixed model procedure of SAS software (SAS Institute Inc., 2001). Combining male and female measurements, mean values

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Practice Regulations for Nonclinical Laboratory Studies” (21CFR, Part 58). Broiler chickens of a high yielding commercial strain (Ross × Ross 508) were obtained3 at 1 d of age. Broilers were vaccinated for Marek’s disease at the hatchery and for Newcastle disease and infectious bronchitis at the test site at 7 d of age. The broilers were randomly assigned by sex to pens that simulated commercial conditions. Clean pens (1.5 m × 0.9 m) with concrete floors provided approximately 0.09 m2/bird on 10 to 13 cm of clean wood shavings. Walls and ceilings were insulated. Incandescent lighting was provided 23 to 24 h per day for approximately the first 5 d of the experiment and ranged from 10 to 16 h for the remainder of the experiment. The target room temperature was 34°C at the start of the experiment and was gradually decreased daily to a target of 23°C from d 30 through the end of the study. No cooling mechanism was necessary, and heat was provided via propane forced-air heaters with control via thermostats and ventilation. Daily high and low temperatures were recorded, and target temperatures were achieved. Water and feed were available ad libitum throughout the experiment. Within each pen, water was provided via a hanging automatic bell drinker (36-cm diameter), and feed was provided via a hanging tube feeder (43 cm diameter). A chick feeder tray was also placed in each pen for the first 6 d. Floor space, temperature, lighting, bird density, and feeder and water space were similar for all treatments.

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TAYLOR ET AL. TABLE 1. Proximate (%) and amino acid (mg/g) composition1 of glyphosate-tolerant canola (RT73) meal, nontransgenic control 46A65 meal, and commercial canola meal (CM 1 to 6)

CM1

CM2

CM3

CM4

CM5

Crude protein Crude fat Moisture Crude fiber Aspartic acid Threonine Serine Glutamic acid Proline Glycine Alanine Cystine Valine Methionine Isoleucine Leucine Tyrosine Phenylalanine Histidine Lysine Arginine Tryptophan

36.2 3.38 10.3 10.7 2.68 1.50 1.52 6.57 2.39 1.88 1.65 0.81 2.00 0.74 1.49 2.60 0.91 1.44 0.93 2.22 2.17 0.39

37.3 3.38 10.8 10.8 2.73 1.53 1.56 6.60 2.34 1.89 1.66 0.82 1.99 0.79 1.50 2.63 0.98 1.48 0.96 2.09 2.20 0.40

32.8 5.01 10.7 9.62 2.39 1.34 1.39 5.75 2.14 1.69 1.49 0.72 1.78 0.69 1.32 2.33 0.86 1.32 0.83 1.80 1.89 0.33

37.9 3.62 11.2 10.1 2.78 1.57 1.61 6.86 2.45 1.95 1.70 0.84 2.03 0.69 1.53 2.71 0.99 1.51 1.00 2.14 2.31 0.41

38.5 3.54 10.9 8.91 2.90 1.64 1.75 7.10 2.53 2.00 1.76 0.93 2.00 0.78 1.49 2.80 1.01 1.55 1.01 2.21 2.27 0.40

CM6

Control 46A65

Glyphosatetolerant RT73

36.3 3.57 10.8 10.5 2.68 1.48 1.51 6.52 2.35 1.87 1.65 0.82 1.99 0.71 1.47 2.57 0.88 1.44 0.93 2.15 2.12 0.38

42.8 5.15 4.55 11.7 3.10 1.71 1.76 7.48 2.80 2.17 1.89 1.01 2.30 0.81 1.79 3.07 1.10 1.72 1.16 2.45 2.71 0.51

42.7 3.96 4.81 11.9 3.23 1.79 1.81 7.79 2.79 2.20 1.91 1.04 2.33 0.84 1.81 3.15 1.14 1.75 1.19 2.39 2.78 0.51

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Analyses conducted at Covance Laboratories, Madison, WI.

TABLE 2. Ingredient composition of diets containing glyphosate-tolerant RT73, nontransgenic control 46A65, and commercial canola meal (CM 1 to 6) Treatment Ingredient (%) Starter diet formulation Corn Canola meal Dehulled soybean meal Soy oil Defluorinated phosphate Limestone Salt DL-Methionine Choline chloride-60% Trace minerals1 Vitamins2 Lysine Sacox (coccidiostat) Grower/finisher diet formulation Corn Canola meal Dehulled soybean meal Soy oil Defluorinated phosphate Limestone Salt DL-Methionine Choline chloride-60% Trace minerals Vitamins Lysine Sacox (coccidiostat)

CM1

CM2

CM3

CM4

CM5

CM6

Control 46A65

Glyphosate-tolerant RT73

46.17 25.00 19.45 6.20 1.60 0.60 0.29 0.17 0.23 0.10 0.10 0.05 0.05

46.85 25.00 18.85 6.10 1.60 0.60 0.29 0.14 0.23 0.10 0.10 0.09 0.05

43.54 25.00 21.60 6.65 1.60 0.60 0.30 0.17 0.22 0.10 0.10 0.08 0.05

47.70 25.00 18.20 5.95 1.60 0.60 0.29 0.18 0.23 0.10 0.10 0.00 0.05

48.66 25.00 17.30 5.80 1.60 0.60 0.29 0.15 0.24 0.10 0.10 0.11 0.05

45.96 25.00 19.60 6.25 1.60 0.60 0.30 0.17 0.23 0.10 0.10 0.06 0.05

48.68 25.00 17.30 5.80 1.60 0.60 0.29 0.15 0.24 0.10 0.10 0.09 0.05

49.46 25.00 16.65 5.65 1.60 0.60 0.29 0.14 0.24 0.10 0.10 0.13 0.05

52.96 20.00 18.30 5.70 1.55 0.50 0.30 0.19 0.19 0.10 0.10 0.06 0.05

53.30 20.00 18.00 5.65 1.55 0.50 0.30 0.17 0.19 0.10 0.10 0.10 0.05

50.98 20.00 19.95 6.00 1.55 0.50 0.30 0.20 0.18 0.10 0.10 0.10 0.05

54.21 20.00 17.25 5.50 1.55 0.55 0.30 0.20 0.19 0.10 0.10 0.00 0.05

53.81 20.00 17.55 5.55 1.55 0.55 0.30 0.17 0.19 0.10 0.10 0.09 0.05

52.76 20.00 18.50 5.70 1.55 0.50 0.30 0.19 0.18 0.10 0.10 0.07 0.05

55.71 20.00 15.95 5.20 1.55 0.55 0.30 0.18 0.20 0.10 0.10 0.12 0.05

56.14 20.00 15.55 5.15 1.55 0.55 0.30 0.17 0.20 0.10 0.10 0.14 0.05

1 Trace mineral premix (SEM Minerals, Quincy, IL) contained 0.03% calcium and provided the following in milligrams per kilogram of diet: Mn, 120; Zn, 100; Fe, 40; Cu, 10; I, 1.4; Se, 0.3; and Mg, 26. 2 Vitamin premix (Roche Vitamins, Inc., Parsippany, NJ) provided the following per kilogram of diet: vitamin A, 9,350 IU from all trans-retinyl acetate; cholecalciferol D3, 3,025 IU; vitamin E, 27.5 IU from DL-α-tocopherol; vitamin B12, 13.75 µg; riboflavin, 7.7 mg; niacin, 49.5 mg; pantothenic acid, 12.1 mg; menadione, 1.925 mg; folic acid, 0.99 mg; ethoxyquin, 77 mg; biotin, 0.088 mg; thiamine, 1.925 mg; and pyridoxine, 3.08 mg.

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Analyzed composition (as-is basis)

PERFORMANCE OF BROILERS FED TRANSGENIC CANOLA MEAL

obtained for the glyphosate-tolerant diet group were compared with those from the nontransgenic control and commercial reference diet groups at the 5% level of significance using a protected Fisher’s least significant difference test (Fisher, 1949). The statistical model (ANOVA) included effects of block, treatments, sex, and sex by treatment interactions with the experimental unit being the pen. Additional statistical analyses compared the fit of responses to the glyphosate-tolerant canola meal diet to the population of responses from the nontransgenic control and commercial canola meal diets to determine if the values of the test response variables were consistent across treatments. These analyses defined 2 categories, transgenic (glyphosate-tolerant) and nontransgenic (nontransgenic control and commercial diets).

General Observations Mycotoxin and pesticide levels in all canola meal incorporated into the diets were below the limits of detection for the individual assays. Diets were formulated based on the individual nutrient analyses of the meal. Protein content was higher in the glyphosate-tolerant and nontransgenic control canola meals than in the 6 commercial reference meals. Generally, all amino acids were numerically elevated in the test, and nontransgenic control varieties were compared with the reference varieties. Nonetheless, using the results of the canola meal analyses, diets were adjusted for protein by formulating the diets using supplemental soybean meal. Nutrient assay results for the starter and grower/finisher diets met the nutrient requirements of poultry (NRC, 1994) (Table 3). A total of 12 broilers (1.3% of total) died during the first 7 d primarily due to dehydration or refusal of feed. Mortality was distributed evenly across treatments (Table 4). Mortality during the rest of the study (d 7 to 42) was slightly higher than normal in this experiment averaging 7.8%, with the higher mortality occurring in males (Table 4). Higher mortality would be expected in males because they are heavier and grow faster than females. A possible explanation for the high mortality could be that the level of canola meal in these diets was higher than the recommended maximum inclusion level of 15% canola meal typically fed to broilers (Hickling, 2001). Combining sexes, the distribution of the broilers that died from d 7 to experiment termination ranged from 2% (for the CM2 and CM3 reference diets) to 17% (for the nontransgenic control 46A65 diet). The differences in mortality between commercial reference diets and test and nontransgenic control diets may be attributable to differences in processing at the 2 facilities. The causes of death between d 7 and 42 were primarily attributed to sudden death and ascites with no relationship to treatment. Remaining broilers in all treatments were in good health. The starting and final body weights of the chicks were normal, and the average body weight gain per bird was comparable among treatments.

Performance Response Variables In general, performance response variables were similar (P > 0.05) across groups of broilers fed diets containing glyphosate-tolerant, nontransgenic control, or commercial reference canola meal (Table 5). On a kilograms-per-pen basis, broilers fed diets containing glyphosate-tolerant canola meal had similar feed intakes and live weights on d 42 compared with those fed the nontransgenic control (46A65) and 4 reference diets. Broilers fed the other 2 reference diets consumed more feed (P < 0.01) and weighed more (P < 0.05) than broilers fed diets containing glyphosate-tolerant canola meal. In addition, the adjusted feed conversion for broilers fed diets containing glyphosatetolerant canola meal was similar to that of broilers fed the nontransgenic control and 3 of the 6 reference canola meal diets. Broilers fed the other 3 reference diets had slightly poorer adjusted feed conversions (P < 0.01) compared with all other groups.

Carcass Measurements Carcass measurements (percentage basis) of fat pad, breast meat, thighs, legs, and wings were similar across treatments (P > 0.05). Expressed as percentage of live weight, chill weight of the broilers fed diets containing glyphosate-tolerant canola meal was not different from that of broilers fed diets containing the nontransgenic control and all references meals. The differences in chill weight observed (P < 0.05) were among the nontransgenic control and reference varieties (Table 5). No major differences (P > 0.05) were observed in the percentage of moisture, protein, and fat in breast meat or thigh meat across treatment diets (Table 5).

Population Statistical Analysis Combining males and females, comparisons of the glyphosate-tolerant canola meal treatment group to the population of all other broilers (nontransgenic control and all reference varieties) showed no major differences (P > 0.05) in all performance parameters, carcass yields, and moisture, protein, and fat in breast and thigh meat (data not shown).

DISCUSSION The rapidly growing broiler is sensitive to changes in nutrient quality in diets and, therefore, is a useful model to evaluate the wholesomeness of protein and essential amino acid sources in meal diets (Chesson and Flachowsky, 2003). Any deficiencies in the major dietary nutrients would be expected to result in reduced growth and carcass yields. The results of this feeding experiment support the conclusion that there were no major differences in the response variables evaluated between broilers fed glyphosate-tolerant canola meal and meal from a genetically similar nontransgenic control variety. The rationale for including meal from numerous lots of commercial canola in this experi-

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RESULTS

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TAYLOR ET AL. 1

TABLE 3. Nutrient composition of diets containing glyphosate-tolerant RT73, nontransgenic control 46A65, and commercial canola meal (CM 1 to 6) Analyzed composition (as-is basis)

CM2

CM3

CM4

CM5

CM6

Control 46A65

Glyphosate-tolerant RT73

3,079 23.1 8.3 11.4 1.45 1.27 0.61 0.42 0.21 0.87 1.15 1.21 0.252 0.84

3,080 22.8 9.3 10.9 1.02 1.09 0.51 0.42 0.18 0.76 0.99 1.24 0.240 0.92

3,080 23.1 9.6 9.4 1.29 1.19 0.57 0.46 0.20 0.92 1.09 1.27 0.240 0.88

3,079 24.8 8.9 9.0 1.25 1.08 0.54 0.46 0.20 0.77 1.05 1.15 0.232 0.89

3,081 21.9 8.4 8.9 1.23 1.19 0.46 0.43 0.18 0.80 1.07 1.17 0.259 0.86

3,080 23.5 9.0 7.9 1.31 1.22 0.49 0.45 0.21 0.84 1.10 1.28 0.255 0.86

3,081 24.8 9.1 9.3 1.38 1.28 0.55 0.48 0.21 0.85 1.12 1.13 0.225 0.88

3,080 23.9 9.4 9.2 1.38 1.24 0.51 0.52 0.23 0.83 1.10 1.22 0.244 0.93

3,136 23.5 9.1 9.0 1.20 1.08 0.51 0.39 0.18 0.74 0.97 1.12 0.221 0.83

3,137 22.8 9.1 7.6 1.19 1.12 0.48 0.40 0.18 0.74 1.01 1.03 0.220 0.82

3,135 21.9 9.5 8.5 1.22 1.12 0.55 0.41 0.17 0.78 0.95 1.19 0.246 0.81

3,135 22.0 8.8 8.5 1.13 1.00 0.51 0.40 0.19 0.71 0.97 1.11 0.218 0.83

3,135 21.5 8.5 7.1 1.25 1.14 0.50 0.42 0.18 0.76 1.03 1.02 0.208 0.77

3,134 21.9 8.7 7.1 1.11 1.04 0.52 0.43 0.18 0.72 0.96 1.16 0.217 0.82

3,134 22.3 8.8 8.6 1.19 1.11 0.53 0.43 0.17 0.73 0.99 1.05 0.227 0.83

3,135 22.3 9.0 8.6 1.21 1.15 0.51 0.42 0.19 0.79 0.97 1.07 0.204 0.86

1

Amino acid analysis conducted at Covance Laboratories, Madison, WI, and remaining analyses at Dairy One Laboratories, Ithaca, NY. Calculated value.

2

ment was to demonstrate the range of broiler performance and carcass characteristics when fed meal from different lots of commercial canola. In the few cases where differences between the nontransgenic control and reference meals were observed, the values were similar to literature values using Ross × Ross broiler strains (Esteve-Garcia and Llaurado, 1997; Kidd and Kerr, 1997; Smith et al., 1998; Farran et al., 2000). Upon comparison of individual treatment diets fed to broilers, birds had similar performance and carcass yield when fed diets containing glyphosate-tolerant, non-

transgenic control, or commercial canola meal. As a result, it was concluded that the feeding value of canola meal derived from canola containing the glyphosate-tolerant trait was nutritionally equivalent to that of meal derived from a nontransgenic control variety and other commercially available canola meal. This finding was consistent with results obtained in a previous study in which lambs were fed with glyphosate-tolerant canola (Stanford et al., 2002) and with the fact that glyphosate-tolerant canola with event RT73 is compositionally similar to nontransgenic control canola (Nickson and Hammond, 2002). These data

TABLE 4. Summary of broiler mortality by sex1 Mortality (%) d 0 to 7 Treatment2 CM1 CM2 CM3 CM4 CM5 CM6 Parental control 46A65 Glyphosate-tolerant RT73

Mortality (%), d 7 to 42

Males

Females

Males

Females

0.0 0.0 3.3 1.7 0.0 0.0 0.0 1.7

1.7 0.0 5.0 1.7 0.0 3.3 1.7 0.0

10.0 0.0 0.0 10.0 12.0 14.0 24.0 18.0

2.0 4.0 4.0 2.0 4.0 2.0 10.0 8.0

1 A total of 60 males and 60 females per treatment for d 0 to 7; a total of remaining 50 males and remaining 50 females per treatment for d 7 to 42. 2 CM1 to CM6 are commercial canola meals.

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Starter diets ME (kcal/kg)2 Crude protein (%) Crude fat (%) Moisture (%) Arginine (%) Lysine (%) Methionine (%) Cystine (%) Tryptophan (%) Threonine (%) Valine (%) Calcium (%) Sodium (%) Phosphorus (%) Grower finisher diets ME2 (kcal/kg) Crude protein (%) Crude fat (%) Moisture (%) Arginine (%) Lysine (%) Methionine (%) Cystine (%) Tryptophan (%) Threonine (%) Valine (%) Calcium (%) Sodium (%) Phosphorus (%)

CM1

461

PERFORMANCE OF BROILERS FED TRANSGENIC CANOLA MEAL TABLE 5. Performance and carcass yield comparison of broilers fed glyphosate-tolerant RT73, nontransgenic control 46A65, and commercial canola meal (CM 1 to 6) in diets (mean values of combined males and females) Treatment

Performance Live weight (g/pen), d 0 Live weight (kg/pen), d 42 Feed intake (kg/pen) Feed conversion (kg/kg)2 Adjusted feed conversion3 (kg/kg) Carcass yield Chill weight (kg/bird) Chill weight (% of live wt) Fat pad (% of live wt) Breast meat (% of chill wt) Thigh (% of chill wt) Leg (% of chill wt) Wing (% of chill wt)

Control 46A65

CM1

CM2

CM3

CM4

CM5

CM6

Treatment P

LSD1 5.0%

480.4 19.28bc 33.94c 1.77 1.61c

489.4 18.43c 33.54c 1.84 1.61c

483.0 20.31abc 34.91bc 1.73 1.62bc

485.6 21.69a 36.67ab 1.70 1.67a

489.6 21.89a 37.03a 1.70 1.67a

486.4 20.27abc 35.34abc 1.75 1.64ab

491.0 20.73ab 35.33abc 1.71 1.62bc

487.8 20.38ab 35.18abc 1.70 1.62bc

NS <0.05 <0.01 NS <0.01

10.14 1.96 1.94 0.10 0.03

1.60 70.1abc 1.27 24.93 16.66 14.43 12.04

1.55 69.2c 1.18 25.17 16.55 14.29 12.03

1.54 69.7abc 1.15 25.63 16.62 14.43 12.11

1.54 69.5bc 1.24 25.04 16.74 14.59 12.20

1.57 70.4ab 1.14 25.20 16.44 14.48 12.14

1.57 70.4ab 1.20 25.46 16.63 14.31 12.04

1.59 70.4ab 1.24 25.27 16.89 14.45 12.00

1.60 70.6a 1.25 25.35 16.87 14.47 12.15

NS <0.05 NS NS NS NS NS

0.06 0.95 0.16 0.64 0.34 0.24 0.20

75.25 23.74 0.82

75.10 23.71 0.86

75.26 23.65 0.82

75.13 23.76 0.82

75.12 23.91 0.76

75.22 23.67 0.81

75.37 23.69 0.92

74.96 23.97 0.87

NS NS NS

0.47 0.52 0.25

76.64 21.14 2.16

76.61 20.51 2.29

76.64 21.12 2.50

76.69 20.61 2.20

76.39 20.90 2.36

76.45 20.94 2.72

76.36 20.82 2.41

76.74 20.65 2.16

NS NS NS

0.75 1.05 0.65

Individual treatment means with the same superscript letter in the same row were not statistically different (P > 0.05). Least significant difference between 2 means (P < 0.05). 2 Feed conversion calculated by dividing the total feed consumption per pen by the total BW per pen of surviving broilers. 3 Feed conversion adjusted by dividing the total feed consumption per pen by the total BW of the surviving broilers and those that died or were removed from the pen. a–c 1

further support the conclusion that the genetically modified glyphosate-tolerant (Roundup Ready event RT73) canola is as nutritious as conventional canola.

REFERENCES Association of Official Analytical Chemists. 2000. Official Methods of Analysis. 17th ed. AOAC, Gaithersburg, MD. Bradstreet, R. B. 1965. The Kjeldahl Method for Organic Nitrogen, Academic, New York. Chesson, A., and G. Flachowsky. 2003. Transgenic plants in poultry nutrition. World’s Poult. Sci. J. 59:201–207. Esteve-Garcia, E., and L. Llaurado. 1997. Performance, breast meat yield, and abdominal fat deposition of male broiler chickens fed diets supplemented with DL-methionine or DL-methionine hydroxy analogue free acid. Br. Poult. Sci. 38:397–404. Farran, M. T., R. F. Khalil, M. G. Uwayjan, and V. M. Ashkarian. 2000. Performance and carcass quality of commercial broiler strains. J. Appl. Poult. Res. 9:252–257. Federation of Animal Science Societies. 1999. Guidelines for the Care and Use of Agricultural Animals in Research and Teaching, 1st rev. FASS, Savoy, IL. Fisher, R. A. 1949. The Design of Experiments. Oliver Boyd, Edinburgh. Food and Drug Administration. Department of Health and Human Services. 21 CFR Part 58. Good Laboratory Practice Regulations for Nonclinical Laboratory Studies. FDA, Washington, DC. Code Fed. Regul. Title 21, Vol. 1. Hallas, L. E., E. M. Hahn, and C. Korndorfer. 1988. Characterization of microbial traits associated with glyphosate biodegradation in industrial activated sludge. J. Ind. Microbiol. 3:377–385.

Hickling, D. 2001. Pages 16–21 in Canola Meal Feed Industry Guide. 3rd ed. Canadian International Grains Institute, Winnipeg, Manitoba, Canada. Kidd, M. T., and B. J. Kerr. 1997. Threonine responses in commercial broilers at 30 to 42 days. J. Appl. Poult. Res. 6:362–367. Lebuhn M., W. Achouak, M. Schloter, O. Berge, H. Meier, M. Barakat, A. Hartmann, and T. Heulin. 2000. Taxonomic characterization of Ochrobactrum sp. isolates from soil samples and wheat roots, and description of Ochrobactrum tritici sp. nov. and Ochrobactrum grignonense sp. nov. Int. J. Syst. Evol. Microbiol. 50:2207–2223. National Research Council. 1994. Nutritional Requirements of Poultry. 9th ed. National Academy of Sciences, Washington, DC. Nickson, T. E., and B. G. Hammond. 2002. Case study: canola tolerant to Roundup威 herbicide—An assessment of its substantial equivalence compared to non-modified canola. Pages 138– 163 in Genetically Modified Crops: Assessing Safety. K. Atherton, ed. Taylor and Francis, London. Padgette, S. R., D. B. Re, G. F. Barry, D. A. Eichholtz, X. Delannay, R. L. Fuchs, G. M. Kishore, and R. T. Fraley. 1996. New weed control opportunities: Development of soybeans with a Roundup Ready威 gene. Pages 53–84 in Herbicide-Resistant Crops. S. O. Duke, ed. Agricultural, Economic, Regulatory and Technical Aspects. CRC Lewis Publishers, Boca Raton, FL. SAS Institute Inc. 2001. Release 8, 1999–2001. SAS Institute Inc., Cary, NC. Smith, E. R., G. M. Pesti, R. I. Bakalli, G. O. Ware, and J. F. M. Menten. 1998. Further experiments on the influence of genotype and dietary protein on the performance of broilers. Poult. Sci. 77:1678–1687. Stanford, K., T. A. McAllister, J. Aalhus, M. Dugan, and R. Sharma. 2002. Effects of feeding glyphosate-tolerant canola meal on lamb growth, meat quality, and apparent feed digestability. J. Anim. Sci. 80(Suppl. 1):71.

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Breat meat analysis Moisture (%) Protein (%, as-is basis) Fat (%, as-is basis) Thigh meat analysis Moisture (%) Protein (%, as-is basis) Fat (%, as-is basis)

Glyphosate tolerant RT73