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Comparison of broiler performance when fed diets containing corn grain with insect-protected (corn rootworm and European corn borer) and herbicide-tolerant (glyphosate) traits, control corn, or commercial reference corn–revisited1
Comparison of Broiler Performance When Fed Diets Containing Corn Grain with Insect-Protected (Corn Rootworm and European Corn Borer) and Herbicide-Tolerant (Glyphosate) Traits, Control Corn, or Commercial Reference Corn—Revisited1 M. L. Taylor,*,2 G. Hartnell,* M. Nemeth,* K. Karunanandaa,* and B. George† *Monsanto Company, 800 N. Lindbergh Blvd., St. Louis, Missouri 63167; and †Colorado Quality Research, 400 East County Road 72, Wellington, Colorado 80549 weights, feed intake, feed conversion, and adjusted feed conversion), carcass yield (chill, fat pad, breast, thigh, wing, and drum weight), or percentage of moisture, protein, and fat in breast meat and moisture and fat in thigh meat. Thigh protein was similar (P > 0.05) in broilers fed diets containing MON 88017 × MON 810 and conventional control or all commercial reference corns; however, differences (P < 0.05) were noted for the percentage of thigh protein among broilers fed the control and 2 of the 5 reference diets, attributable to biological variability among the conventional corn hybrids. Broilers overall performed consistently and had similar carcass yield and meat composition when fed diets containing MON 88017 or MON 88017 × MON 810 as compared with those fed the conventional control and commercial diets, supporting a conclusion of nutritional equivalence.
(Key words: broiler performance, carcass yield, Cry3Bb1, Cry1Ab, CP4 EPSPS) 2005 Poultry Science 84:1893–1899
INTRODUCTION Traits such as insect protection and herbicide tolerance have been introduced into corn to provide growers with effective and environmentally sound methods to control weeds and certain insect pests. MON 88017 expresses a variant of the wild-type Cry3Bb1 protein from Bacillus thuringienisis that protects against feeding damage caused by corn rootworm larvae (CRW; Diabrotica sp.). MON 88107 also expresses a 5-enolpyruvylshikimate-3-phosphate synthase protein from Agrobacterium sp. strain CP4 (CP4 EPSPS), which confers tolerance to the Roundup family of agricultural herbicides. MON 88017 × MON 810 was developed by conventional breed-
2005 Poultry Science Association, Inc. Received for publication July 23, 2004. Accepted for publication December 16, 2004. 1 This paper was originally published in the April 2005 issue of Poultry Science 84:587–593. The paper is being republished in full due to statistical errors in the original publication. 2 To whom correspondence should be addressed: Mary.L.Taylor@ monsanto.com.
ing of MON 88017 with MON 810 that expresses the Cry1Ab protein from Bacillus thuringienisis subsp. kurstaki strain HD-1 (Sanders et al., 1998), conferring insect protection from the European corn borer (Ostrinia numbilalis) and other lepidopteran pests. The rapidly growing broiler chicken is a useful animal model to compare the wholesomeness of genetically enhanced corn with conventional corn because of its sensitivity to changes in nutrient quality and its exposure to relatively high levels of the test material (corn) in the diet. This experiment was conducted to compare the nutritional value of MON 88017 or MON 88017 × MON 810 with control and commercial corn by measuring performance, carcass yield, and meat quality parameters in broilers.
MATERIALS AND METHODS Broilers and Housing This experiment was conducted in accordance with the principles and guidelines for the care and use of
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ABSTRACT A 42-d feeding experiment with growing Ross × Ross 508 broilers showed that the nutritional value of insect-protected and herbicide-tolerant corn was comparable to that of the genetically similar control and 5 commercial reference corn hybrids. MON 88017 provides protection from feeding damage by coleopteran pest corn rootworm and is tolerant to the action of glyphosate, the active ingredient in the Roundup family of agricultural herbicides. MON 88017 × MON 810 was developed by the traditional breeding of MON 88017 with MON 810, which provides protection from the European corn borer and other lepidopteran pests. A randomized complete block design was used with 8 dietary treatments in each of 5 replicated blocks of pens. No differences among diets were observed (P > 0.05) in performance (final live
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TAYLOR ET AL. Table 1. Proximate (%) and amino acid (mg/g) composition1 of MON 88017, MON 88017 × MON 810, conventional control, and commercial corn MON 88017
MON 88017 × MON 810
Control
Asgrow RX708
Pioneer 34B23
Burrus 789
Burrus 582
Burrus 569
Crude protein Crude fat Moisture Carbohydrates Crude fiber Aspartic acid Threonine Serine Glutamic acid Proline Glycine Alanine Cystine Valine Methionine Isoleucine Leucine Tyrosine Phenylalanine Histidine Lysine2 Arginine Tryptophan
9.12 3.40 11.3 75.0 1.93 6.06 3.17 4.69 18.2 8.47 3.60 6.99 2.07 4.55 2.01 3.23 11.3 3.38 4.46 2.98 2.85 4.48 0.54
8.81 2.85 11.0 76.2 1.58 5.60 3.03 4.41 17.4 8.03 3.27 6.73 2.05 4.24 1.94 3.04 11.0 3.10 4.22 2.79 2.48 3.89 0.53
9.58 3.28 11.1 74.9 1.27 6.32 3.29 4.89 19.4 8.83 3.58 7.51 2.12 4.73 2.01 3.49 12.3 2.21 4.72 3.05 2.90 4.06 0.55
7.65 3.26 12.0 76.0 1.73 5.22 2.57 4.33 15.5 6.56 3.11 6.12 1.64 3.63 1.40 2.61 9.56 2.81 3.85 2.22 2.34 3.72 0.48
7.95 3.24 10.7 77.0 2.25 5.62 2.80 4.11 15.7 7.18 3.25 6.12 1.73 3.83 1.54 2.71 9.50 2.75 3.84 2.38 2.55 4.14 0.52
8.50 3.00 16.3 70.9 2.09 5.68 2.87 4.38 16.3 7.13 3.34 6.47 1.77 4.07 1.45 2.81 10.1 2.85 4.04 2.55 2.42 3.94 0.54
8.91 3.14 14.6 72.1 2.28 6.26 2.98 4.76 18.4 6.86 3.54 7.20 1.84 4.22 1.53 3.02 11.1 2.99 4.29 2.60 2.59 4.43 0.56
7.79 3.82 16.9 70.4 2.08 5.38 2.90 4.24 15.4 6.93 3.46 6.28 1.82 3.86 1.53 2.63 9.21 2.69 3.80 2.53 2.37 4.17 0.50
1
Analyses were conducted at Covance Laboratories, Madison, WI. Values for single analyses reported for MON 88017, MON 88017 × MON 810 and conventional control and the mean of duplicate analyses reported for the 5 commercial references. 2
agricultural animals in research (Federation of Animal Science Societies, 1999) and, as applicable, was in compliance with FDA (1979) and EPA (1983) rules. Broiler chickens of a high yielding commercial strain (Ross × Ross 508) were obtained2 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 on the first study day. The broilers were randomly assigned by gender to pens with concrete floors (1.5 × 0.9 m, providing approximately 0.09 m2 per bird) with 10 to 13 cm of clean wood shavings in a building with environmentally controlled incandescent lighting and temperature. Incandescent lighting was provided 23 to 24 h per day for approximately the first 5 d of the experiment and for 10 to 16 h for the remainder of the experiment. The target room temperature was 34°C at the start of the experiment, which was gradually decreased each day to a target room temperature of 23°C from d 30 through the remainder of the experiment. 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. Environmental conditions (floor space, temperature, lighting, bird density, and feeder and water space) were similar for all treatments.
2
Hoover’s Hatchery, Rudd, IA. Romer Laboratories, Union, MO.
3
Experimental Design A randomized complete block design was used with eight dietary treatments (MON 88017, MON 88017 × MON 810, conventional control, and five commercial diets). For each of the 8 treatment groups, there were 120 broilers placed in pens (total of 960 broilers): 5 pens of males (12 broilers/pen) and 5 pens of females (12 broilers/pen). Initially, there were an additional 2 broilers in each pen to compensate for early chick mortality during the first few days post hatch. At d 8, the group size was adjusted to 10 broilers/pen, in an effort to increase the sensitivity of the growth-based experiment. The initial criterion for removal of additional birds was slow growth, followed by random selection, which was the reason for the removal of the majority of birds.
Corn Grain The MON 88017, MON 88017 × MON 810, and the control corn grain (LH59 × LH198) were produced in Madison County, IL, during the 2002 growing season. Grain from 5 conventional commercial corn references grown in the United States during 2002 was also included in the experiment. The rationale for including grain from numerous commercial references was to demonstrate the range of broiler performance and carcass characteristics when fed grain from different commercially available corn references. The commercial references were: Asgrow RX708 and Pioneer 34B23 (grown in Stark County, IL) and Burrus 789, Burrus 569, and Burrus 582 (grown in Clinton County, IL). Mycotoxin3
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Analyzed composition (as is basis)
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PERFORMANCE OF BROILERS FED GENETICALLY MODIFIED CORN Table 2. Ingredient composition of diets: MON 88017, MON 88017 × MON 810, conventional control, and commercial corn Treatment Ingredient (%)
MON 88017 × MON 810
Control
Asgrow RX708
Pioneer 34B23
Burrus 789
Burrus 582
Burrus 569
54.71 37.70 3.90 1.80 0.90 0.37 0.23 0.15 0.10 0.10 0.00 0.05
54.77 37.75 3.85 1.80 0.90 0.29 0.24 0.15 0.10 0.10 0.01 0.05
54.75 37.65 3.90 1.80 0.90 0.37 0.23 0.15 0.10 0.10 0.00 0.05
53.40 39.10 4.00 1.80 0.75 0.29 0.27 0.15 0.10 0.10 0.00 0.05
53.70 38.85 3.95 1.80 0.75 0.29 0.26 0.15 0.10 0.10 0.00 0.05
54.75 37.70 3.85 1.80 0.90 0.34 0.27 0.15 0.10 0.10 0.00 0.05
54.77 37.65 3.85 1.80 0.90 0.37 0.26 0.15 0.10 0.10 0.00 0.05
54.36 38.25 3.85 1.85 0.75 0.29 0.25 0.15 0.10 0.10 0.00 0.05
59.41 33.50 3.80 1.70 0.70 0.31 0.23 0.10 0.10 0.10 0.00 0.05
59.44 33.50 3.80 1.70 0.65 0.31 0.24 0.10 0.10 0.10 0.02 0.05
59.41 33.50 3.80 1.70 0.70 0.31 0.23 0.10 0.10 0.10 0.00 0.05
59.20 33.65 3.85 1.70 0.65 0.31 0.28 0.10 0.10 0.10 0.02 0.05
59.35 33.50 3.80 1.70 0.70 0.31 0.28 0.10 0.10 0.10 0.01 0.05
59.42 33.50 3.80 1.65 0.70 0.32 0.27 0.10 0.10 0.10 0.01 0.05
59.43 33.50 3.80 1.65 0.70 0.32 0.26 0.10 0.10 0.10 0.00 0.05
59.33 33.50 3.85 1.75 0.65 0.31 0.26 0.10 0.10 0.10 0.01 0.05
1 Trace mineral premix (SEM Minerals, Quincy, IL) contained 0.003% Ca 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, 7.7mg; 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.
and pesticide residue4 analyses of the corn grain were conducted prior to initiation of the experiment to verify that the levels were below the limits of concern for broiler performance. Proximate and amino acid analyses3 were performed on the grain according to methods of the Association of Official Analytical Chemists (2000). Carbohydrate values were calculated by difference using the fresh weight-derived data (% carbohydrates = 100% − (% protein + % fat + % moisture + % ash).
for poultry. Broilers were fed a starter diet containing approximately 55% wt/wt corn grain from d 1 through 20. For the remainder of the experiment (d 21 to 42), broilers were fed a grower/finisher diet containing approximately 60% wt/wt corn grain (Table 2). Analyses of poultry diets6 were conducted for confirmation of formulated levels of nutrient composition. Calcium and phosphorus were analyzed using inductively coupled plasma (ICP) radial spectrometry.
Diets
Measurements
Diets were formulated based on the individual nutrient analyses (Table 1) from each test, control, and commercial corn lot. Dietary protein was provided by the corn grain supplemented with commercial dehulled soybean meal. Synthetic methionine and lysine were added to the diets as needed to conform to industry standards. A coccidiostat, salinomycin (Sacox)5, was mixed into diets at a level of 60 g/ton. Diets were formulated such that the critical amino acid levels met or exceeded National Research Council (NRC, 1994) values
Broiler flocks were examined twice daily for general health. All dead birds and those euthanized due to unhealthy condition were weighed and necropsied. The probable cause of death or reason for removal was documented. Broilers were weighed at d 0 and 42 by pen and individually at experiment termination (d 43 for males and d 44 for females). Average BW per pen and BW per bird values within each treatment group were calculated for each gender. 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 was averaged for each treatment group by gender. Adjusted feed conversion was calculated by dividing the total feed consumption per pen by the total BW of the surviving broilers and those that
4
Covance Laboratories, Madison, WI. Intervet, Inc., Millsboro, DE. 6 Covance Laboratories, Madison, WI; Dairy One Laboratories, Ithaca, NY. 5
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Starter diet formulation Corn Dehulled soybean meal Soybean oil Defluorinated phosphate Limestone Salt DL-Methionine Choline chloride-60% Trace minerals1 Vitamins2 Lysine HCl Sacox (coccidiostat) Grower/finisher diet formulation Corn Dehulled soybean meal Soybean oil Defluorinated phosphate Limestone Salt DL-Methionine Choline chloride-60% Trace minerals1 Vitamins2 Lysine HCl Sacox (coccidiostat)
MON 88017
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TAYLOR ET AL. Table 3. Nutrient composition of diets: MON 88017, MON 88017 × MON 810, conventional control, and commercial corn Analyzed composition (as is basis)
MON 88017 × MON 810
Control
Asgrow RX708
Pioneer 34B23
Burrus 789
Burrus 582
Burrus 569
3081 21.3 7.8 11.5 1.37 1.25 0.52 0.35 0.21 0.79 1.08 1.59 0.99
3080 21.2 8.1 11.4 1.50 1.28 0.56 0.36 0.22 0.84 1.07 1.60 0.99
3081 21.3 7.8 10.3 1.55 1.33 0.55 0.35 0.24 0.84 1.16 1.62 1.00
3079 21.7 8.4 11.7 1.32 1.11 0.54 0.31 0.18 0.72 0.95 1.56 0.90
3079 21.2 8.6 11.6 1.42 1.21 0.62 0.34 0.19 0.76 1.04 1.56 0.90
3080 21.3 8.3 12.5 1.59 1.33 0.56 0.35 0.23 0.85 1.15 1.69 0.92
3079 22.3 8.8 12.0 1.48 1.26 0.56 0.35 0.22 0.81 1.10 1.77 0.99
3079 19.7 8.1 13.1 1.48 1.25 0.56 0.34 0.21 0.80 1.08 1.68 1.01
3132 18.1 8.2 12.3 1.37 1.13 0.46 0.33 0.21 0.73 1.02 1.32 0.87
3134 19.6 8.4 11.6 1.32 1.24 0.51 0.34 0.22 0.73 1.07 1.25 0.84
3132 19.0 8.5 10.7 1.34 1.14 0.52 0.31 0.20 0.76 1.01 1.34 0.87
3136 19.1 8.5 11.0 1.47 1.25 0.58 0.35 0.23 0.79 1.06 1.34 0.91
3133 17.7 8.8 10.8 1.50 1.29 0.59 0.36 0.21 0.84 1.06 1.51 0.94
3134 19.4 8.6 12.8 1.42 1.27 0.58 0.34 0.17 0.76 1.10 1.41 0.90
3134 20.0 9.2 12.1 1.39 1.18 0.57 0.34 0.19 0.76 1.02 1.45 0.96
3135 18.0 8.0 13.1 1.38 1.16 0.54 0.33 0.19 0.75 1.02 1.42 0.91
1
Calculated value.
died or were removed from the pen. At the end of the experiment, carcass measurements for all broilers were taken, and fat pads were collected and weighed. The first male or female broiler processed from each pen was selected for breast and thigh tissue collection. Moisture, protein, and fat analyses were conducted on breast and thigh meat samples.7
Statistical Analysis Statistical analyses were performed on starting and final live weights, feed consumption, feed conversion, adjusted feed conversion, carcass chill weight, percentage chill weight (chill weight/live weight), breast weight, percentage breast weight (breast weight/chill weight), wing weight, percentage wing weight (wing weight/chill weight), thigh weight, percentage thigh weight (thigh weight/chill weight), drum weight, percentage drum weight (drum weight/chill weight), fat pad weight, percentage fat pad (fat pad/live weight), as well as moisture, protein, and fat values for breast and thigh meat. All percentage values were calculated by dividing the response variable by chill or live weight as appropriate. Statistical analysis (ANOVA) was carried out using a linear mixed model procedure of SAS software (SAS Institute Inc., 2000).
7 University of Missouri, Experiment Stations Chemical Laboratories, Columbia, MO.
The statistical model included effects of treatments, gender, block, and gender-by-treatment interactions, with the experimental unit being the pen. The mean values obtained for the broilers fed MON 88017 or MON 88017 × MON 810 diets were compared (combined gender) with those fed the conventional control and commercial diets at the 5% level of significance using a protected Fisher’s least significant difference test (Fisher, 1949). When a significant diet by gender interaction was noted (P < 0.15), the mean values were also evaluated by gender at the 5% level of significance. An additional statistical analysis compared data from broilers fed the MON 88017 or MON 88017 × MON 810 diets to the population of responses from broilers fed the control and commercial corn diets to determine whether the values of the test corn were within the population of the control and reference corn.
RESULTS General Observations Mycotoxin and pesticide levels in corn grain mixed into the diets were below the limits of concern for broiler performance. Alflatoxins were not detectable, and levels of fumonisins in the grain ranged from not detectable to 10 ppm. All pesticide values were below the assay limits of detection: organophosphates, 0.050 ppm; organonitrogens, 0.500 ppm; organochlorinates, 0.200 ppm; and N-methylcarbamates, 0.100 ppm. Diets were
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Starter diets ME1 (kcal/kg) Crude protein (%) Crude fat (%) Moisture (%) Arginine (%) Lysine (%) Methionine (%) Cystine (%) Tryptophan (%) Threonine (%) Valine (%) Calcium (%) Phosphorus (%) Grower/finisher diets ME1 (kcal/kg) Crude protein (%) Crude fat (%) Moisture (%) Arginine (%) Lysine (%) Methionine (%) Cystine (%) Tryptophan (%) Threonine (%) Valine (%) Calcium (%) Phosphorus (%)
MON 88017
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PERFORMANCE OF BROILERS FED GENETICALLY MODIFIED CORN 1
Table 4. Summary of broiler mortality by gender
Mortality (%) d 0 to 7 Treatment Asgrow RX708 Pioneer 34B23 Burrus 789 Burrus 582 Burrus 569 Control MON 88017 MON 88017 × MON 810
Mortality (%) d 8 to 42
Males
Females
Males
Females
1.7 0.0 0.0 1.7 0.0 5.0 1.7 0.0
0.0 0.0 0.0 0.0 0.0 1.7 0.0 3.3
8.0 6.0 2.0 8.0 6.0 2.0 6.0 2.0
4.0 4.0 0.0 2.0 2.0 2.0 2.0 0.0
1
Based on a total of 60 males and 60 females per treatment for d 0 to 7 and a total of remaining 50 males and remaining 50 females per treatment for d 8 to 42.
to be of biological significance as pair-wise comparisons between diets (combined gender) showed no differences in the thigh weights of broilers. No differences were observed in the percentages of moisture, protein, and fat in breast meat or thigh meat across treatment diets (Table 5). Population Statistical Analysis. Comparison of the data from broilers fed MON 88017 to that of the combined population of conventional control and commercial corn showed no differences in performance, meat quality, and carcass yield parameters measured (data not shown).
MON 88017
MON 88017 × MON 810
Performance Parameters. No differences were noted for performance parameters measured in broilers fed diets containing MON 88107 compared with those fed the conventional control and commercial corn (Table 5). Mean final weights of the broilers were similar to those from previously reported studies (Taylor et al., 2003a,b), and the mean pen weights of the broilers were comparable between treatments. There were no differences between treatments for live weight at d 0, live weight at d 42, total feed intake, and feed conversion. Broiler diets containing MON 88017 had adjusted feed conversion (kg/kg) similar to that of the broilers fed the nontransgenic control and all but one of the commercial reference diets, Asgrow RX708. Carcass Measurements. No differences were noted in pair-wise comparisons for carcass yield measurements of chill weight, fat pad, breast, thigh, drum, and wing weights across treatments (Table 5). There was only one instance, thigh weight (kg), for which a (P < 0.08) diet-by-gender interaction was observed (data not shown). When individual gender comparisons were made for this parameter, no differences (P > 0.05) were observed in the females. Male broilers fed diets containing MON 88017 had thigh weights similar (P > 0.05) to those of males fed diets containing the conventional control and commercial references Asgrow RX708, Pioneer 34B23 and Burrus 789, but different (P < 0.05) thigh weights than birds fed the commercial references Burrus 569 and Burrus 582. However, this result is not likely
Performance Parameters. All performance parameters of broilers fed diets containing MON 88017 × MON 810 were similar to those fed the conventional control and commercial corn. No differences were observed in live weight at d 0, live weight at d 42, total feed intake, and feed conversion across all treatments (Table 6). Broilers fed diets containing MON 88017 × MON 810 had adjusted feed conversion (kg/kg) similar to that of broilers fed all other diets; however, differences were noted among broilers fed the control and reference diets. Carcass Measurements. Pairwise comparisons for carcass measurements of chill weight, fat pad weight, breast meat, thigh, wing, and drum weights were not different across treatments (Table 6). No significant dietby-gender interactions were noted at the 5% level of significance. No differences were observed in the percentage of moisture, protein, or fat in breast and thigh meat (Table 6). Population Statistical Analysis. Comparison of the MON 88017 × MON 810 diet to the population on the other diets showed no differences in performance parameters, carcass yields, and meat quality parameters of thigh moisture, protein, and fat and breast protein and moisture. Statistically significant differences were noted for breast fat in the population comparison (data not shown). However, no differences were observed in the pairwise comparisons between treatment diets for the breast meat measurements.
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formulated to meet or exceed NRC (1994) recommendations based on the individual nutrient analyses of the grain. The nutrient assay results are presented in Table 3. A total of 9 broilers (0.9% of total) died during the first 7 d. Mortality from d 8 to d 42 averaged 3.5% and was distributed randomly across treatments (Table 4). Mortality during the first 7 d was related to bacterial infection, dehydration, refusal of feed, or ascites, and the causes of death between d 8 and 42 were primarily attributed to sudden death and ascites, which commonly occur in broilers. Remaining broilers in all treatments were in good health.
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TAYLOR ET AL.
Table 5. Performance and carcass yield comparison of broilers fed MON 88017, conventional control corn, and commercial corn (mean values of combined males and females) Control
Asgrow RX708
Pioneer 34B23
Burrus 789
Burrus 582
Burrus 569
Treatment P
LSD1 5.0%
37.683 2.344 3.801 1.619 1.518bc
37.267 2.331 3.579 1.539 1.503c
37.700 2.321 3.808 1.644 1.563a
37.167 2.297 3.637 1.589 1.536abc
37.700 2.336 3.818 1.633 1.531abc
37.815 2.309 3.857 1.673 1.532abc
38.833 2.314 3.689 1.595 1.550ab
NS NS NS NS P < 0.05
0.778 0.060 0.253 0.116 0.036
1.659 71.773 0.030 1.312 0.448 26.970 0.290 17.469 0.222 13.357 0.193 11.678
1.641 71.904 0.030 1.313 0.437 26.597 0.286 17.389 0.223 13.586 0.192 11.750
1.621 71.564 0.031 1.384 0.432 26.658 0.282 17.362 0.219 13.469 0.189 11.709
1.620 72.021 0.031 1.390 0.435 26.813 0.285 17.627 0.216 13.313 0.189 11.689
1.639 71.851 0.029 1.271 0.441 26.935 0.285 17.393 0.221 13.492 0.192 11.755
1.612 71.658 0.029 1.273 0.438 27.197 0.282 17.467 0.217 13.422 0.189 11.737
1.624 71.998 0.028 1.224 0.438 26.968 0.279 17.138 0.217 13.398 0.191 11.821
NS NS NS NS NS NS NS NS NS NS NS NS
0.045 0.569 0.003 0.130 0.016 0.472 0.010 0.348 0.007 0.212 0.005 0.172
75.052 23.105 0.819
74.835 23.226 0.841
75.098 23.222 0.808
75.109 23.020 0.837
75.012 23.045 0.898
75.169 22.873 0.876
75.075 22.988 0.819
NS NS NS
0.383 0.438 0.271
76.157 20.872 2.176
76.278 21.418 2.164
76.389 20.954 2.082
76.251 20.742 2.420
76.397 20.922 2.513
76.318 20.994 2.214
76.423 20.588 2.211
NS NS NS
0.450 0.641 0.665
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 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
Table 6. Performance and carcass yield of broilers fed MON 88017 × MON 810, conventional control corn, and commercial corn (mean values of combined males and females)
Performance Live weight (g/bird), d 0 Live weight (kg/bird), d 42 Feed intake (kg/bird) Feed conversion (kg/kg) Adjusted feed conversion2 (kg/kg) Carcass yield Chill weight (kg) Chill weight (% of live weight) Fat pad weight (kg) Fat pad weight (% of live weight) Breast weight (kg) Breast weight (% of chill weight) Thigh weight (kg) Thigh weight (% of chill weight) Drum weight (kg) Drum weight (% of chill weight) Wing weight (kg) Wing weight (% of chill weight) Breast meat analysis Moisture (%) Protein (%, as-is basis) Fat (%, as-is basis) Thigh meat analysis Moisture (%) Protein (%, as-is basis) Fat (%, as-is basis)
MON 88017 × MON 810
Control
Asgrow RX708
Pioneer 34B23
Burrus 789
Burrus 582
Burrus 569
Treatment P
LSD1 5.0%
37.259 2.288 3.664 1.602 1.534ab
37.267 2.331 3.579 1.539 1.503b
37.700 2.321 3.808 1.644 1.563a
37.167 2.297 3.637 1.589 1.536ab
37.700 2.336 3.818 1.633 1.531ab
37.815 2.309 3.857 1.673 1.532ab
38.833 2.314 3.689 1.595 1.550a
NS NS NS NS P < 0.05
0.765 0.062 0.256 0.121 0.035
1.612 71.972 0.028 1.261 0.435 26.925 0.278 17.268 0.216 13.416 0.190 11.780
1.641 71.904 0.030 1.313 0.437 26.597 0.286 17.389 0.223 13.586 0.192 11.750
1.621 71.564 0.031 1.384 0.432 26.658 0.282 17.362 0.219 13.469 0.189 11.709
1.620 72.021 0.031 1.390 0.435 26.813 0.285 17.627 0.216 13.313 0.189 11.689
1.639 71.851 0.029 1.271 0.441 26.935 0.285 17.393 0.221 13.492 0.192 11.755
1.612 71.658 0.029 1.273 0.438 27.197 0.282 17.467 0.217 13.422 0.189 11.737
1.624 71.998 0.028 1.224 0.438 26.968 0.279 17.138 0.217 13.398 0.191 11.821
NS NS NS NS NS NS NS NS NS NS NS NS
0.047 0.495 0.003 0.133 0.015 0.474 0.011 0.374 0.008 0.203 0.005 0.178
75.447 22.581 1.071
74.835 23.226 0.837
75.098 23.222 0.723
75.109 23.020 0.808
75.012 23.045 0.898
75.169 22.873 0.876
75.075 22.988 0.841
NS NS NS
0.669 0.779 0.275
76.282 20.928 1.991
76.278 21.418 2.164
76.389 20.954 2.082
76.251 20.742 2.420
76.397 20.922 2.513
76.318 20.994 2.214
76.423 20.588 2.211
NS NS NS
0.483 0.658 0.618
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 adjusted by dividing the total feed consumption/pen by the total BW of the surviving broilers and those that died or were removed from the pen. a,b 1
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Performance Live weight (g/bird), d 0 Live weight (kg/bird), d 42 Feed intake (kg/bird) Feed conversion (kg/kg) Adjusted feed conversion2 (kg/kg) Carcass yield Chill weight (kg) Chill weight (% of live weight) Fat pad weight (kg) Fat pad weight (% of live weight) Breast meat weight (kg) Breast meat weight (% of chill weight) Thigh weight (kg) Thigh weight (% of chill weight) Drum weight (kg) Drum weight (% of chill weight) Wing weight (kg) Wing weight (% of chill weight) Breast meat analysis Moisture (%) Protein (%, as-is basis) Fat (%, as-is basis) Thigh meat analysis Moisture (%) Protein (%, as-is basis) Fat (%, as-is basis)
MON 88017
PERFORMANCE OF BROILERS FED GENETICALLY MODIFIED CORN
DISCUSSION
REFERENCES Association of Official Analytical Chemist. 2000. Official Methods of Analysis of AOAC International. 17th rev. ed. Methods 923.03, 925.09, 926.08, 955.04, 960.39, 979.09, and 982.30. AOAC International, Gaithersburg, MD.
Environmental Protection Agency. 1983. 40 CFR Part 160. Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). EPA, Washington, DC. 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, UK. Food and Drug Administration. 1979. Dept. of Health and Human Services. 21 CFR Part 58. Good Laboratory Practice Regulations for Nonclincal Laboratory Studies. FDA, Washington, DC. George, C., W. P. Ridley, J. C. Obert, M. A. Nemeth, M. L. Breeze, and J. D. Astwood. 2004. Corn rootworm protected corn: The composition of grain and forage from corn rootworm protected corn event MON 863 is equivalent to that of conventional corn (Zea mays L.). J. Agric. Food Chem. 52:4149–4158. National Research Council. 1994. Nutritional Requirements of Poultry. 9th rev. ed. National Academy Press, Washington, DC. Ridley, W. P., R. S. Sidhu, P. D. Pyla, M. A. Nemeth, M. L. Breeze, and J. D. Astwood. 2002. A Comparison of the Nutritional Profile of Roundup Ready威 Corn Event NK603 to that of Conventional Corn (Zea mays L.). J. Agric. Food Chem. 50:7235–7243. Sanders, P. R., T. C. Lee, M. E. Groth, J. D. Astwood, and R. L. Fuchs. 1998. Safety assessment of insect-protected corn. Pages 241–255 in Biotechnology and Safety Assessment. 2nd rev. ed. J. A. Thomas, ed. Taylor Francis, New York. SAS Institute Inc. 2000. SAS Online Doc. SAS Institute Inc., Cary, NC. Taylor, M. L., G. F. Hartnell, S. G. Riordan, M. A. Nemeth, K. Karunanandaa, B. George, and J. D. Astwood. 2003a. Comparison of broiler performance when fed diets containing grain from roundup ready (NK603), yieldgard × roundup ready (MON 810 × NK603), Non-transgenic Control, or Commercial Corn. Poult. Sci. 82:443–453. Taylor, M. L., Y. Hyun, G. F. Hartnell, S. G. Riordan, M. A. Nemeth, K. Karunanandaa, B. George, and J. D. Astwood. 2003b. Comparison of broiler performance when fed diets containing grain from yieldgard rootworm (MON 863), yieldgard plus (MON 810 × MON 863), nontransgenic control, or commercial reference corn hybrids. Poult. Sci. 82:1948–1956.
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The rapidly growing broiler is sensitive to changes in the nutrient quality of diets they consume. Any deficiencies in the major dietary nutrients would be expected to result in reduced growth, feed conversion, and carcass yields. The results of this broiler feeding experiment support the conclusion that there are no practical differences in the parameters evaluated between broilers fed MON 88017 or MON 88017 × MON 810 and the genetically similar control corn. Pair-wise comparisons indicated that broilers generally performed equivalently and had similar carcass yield and meat composition when fed diets containing MON 88017, MON 88017 × MON 810, conventional control, or commercial reference corn. In the few cases in which differences were observed, the values were similar to values reported in the literature (Taylor et al., 2003a,b). It was concluded that grain from the genetically enhanced corn products evaluated in this study is nutritionally equivalent in broiler diets to grain from the control and commercially available corn references. This conclusion is consistent with the compositional evaluation of genetically enhanced corn expressing the Cry1Ab, CP4 EPSPS, or Cry3Bb1 proteins, which showed that there were no relevant differences in nutritional and compositional properties relative to control and commercial corn (Sanders et al., 1998, Ridley, et al., 2002, and George, et al., 2004). These data confirm and support the conclusion that the grain from MON 88017 alone or in combination with MON 810 corn is as nutritious as traditional corn.
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(Key words: broiler performance, carcass yield, Cry3Bb1, Cry1Ab, CP4 EPSPS) 2005 Poultry Science 84:1893–1899
INTRODUCTION Traits such as insect protection and herbicide tolerance have been introduced into corn to provide growers with effective and environmentally sound methods to control weeds and certain insect pests. MON 88017 expresses a variant of the wild-type Cry3Bb1 protein from Bacillus thuringienisis that protects against feeding damage caused by corn rootworm larvae (CRW; Diabrotica sp.). MON 88107 also expresses a 5-enolpyruvylshikimate-3-phosphate synthase protein from Agrobacterium sp. strain CP4 (CP4 EPSPS), which confers tolerance to the Roundup family of agricultural herbicides. MON 88017 × MON 810 was developed by conventional breed-
2005 Poultry Science Association, Inc. Received for publication July 23, 2004. Accepted for publication December 16, 2004. 1 This paper was originally published in the April 2005 issue of Poultry Science 84:587–593. The paper is being republished in full due to statistical errors in the original publication. 2 To whom correspondence should be addressed: Mary.L.Taylor@ monsanto.com.
ing of MON 88017 with MON 810 that expresses the Cry1Ab protein from Bacillus thuringienisis subsp. kurstaki strain HD-1 (Sanders et al., 1998), conferring insect protection from the European corn borer (Ostrinia numbilalis) and other lepidopteran pests. The rapidly growing broiler chicken is a useful animal model to compare the wholesomeness of genetically enhanced corn with conventional corn because of its sensitivity to changes in nutrient quality and its exposure to relatively high levels of the test material (corn) in the diet. This experiment was conducted to compare the nutritional value of MON 88017 or MON 88017 × MON 810 with control and commercial corn by measuring performance, carcass yield, and meat quality parameters in broilers.
MATERIALS AND METHODS Broilers and Housing This experiment was conducted in accordance with the principles and guidelines for the care and use of
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ABSTRACT A 42-d feeding experiment with growing Ross × Ross 508 broilers showed that the nutritional value of insect-protected and herbicide-tolerant corn was comparable to that of the genetically similar control and 5 commercial reference corn hybrids. MON 88017 provides protection from feeding damage by coleopteran pest corn rootworm and is tolerant to the action of glyphosate, the active ingredient in the Roundup family of agricultural herbicides. MON 88017 × MON 810 was developed by the traditional breeding of MON 88017 with MON 810, which provides protection from the European corn borer and other lepidopteran pests. A randomized complete block design was used with 8 dietary treatments in each of 5 replicated blocks of pens. No differences among diets were observed (P > 0.05) in performance (final live
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TAYLOR ET AL. Table 1. Proximate (%) and amino acid (mg/g) composition1 of MON 88017, MON 88017 × MON 810, conventional control, and commercial corn MON 88017
MON 88017 × MON 810
Control
Asgrow RX708
Pioneer 34B23
Burrus 789
Burrus 582
Burrus 569
Crude protein Crude fat Moisture Carbohydrates Crude fiber Aspartic acid Threonine Serine Glutamic acid Proline Glycine Alanine Cystine Valine Methionine Isoleucine Leucine Tyrosine Phenylalanine Histidine Lysine2 Arginine Tryptophan
9.12 3.40 11.3 75.0 1.93 6.06 3.17 4.69 18.2 8.47 3.60 6.99 2.07 4.55 2.01 3.23 11.3 3.38 4.46 2.98 2.85 4.48 0.54
8.81 2.85 11.0 76.2 1.58 5.60 3.03 4.41 17.4 8.03 3.27 6.73 2.05 4.24 1.94 3.04 11.0 3.10 4.22 2.79 2.48 3.89 0.53
9.58 3.28 11.1 74.9 1.27 6.32 3.29 4.89 19.4 8.83 3.58 7.51 2.12 4.73 2.01 3.49 12.3 2.21 4.72 3.05 2.90 4.06 0.55
7.65 3.26 12.0 76.0 1.73 5.22 2.57 4.33 15.5 6.56 3.11 6.12 1.64 3.63 1.40 2.61 9.56 2.81 3.85 2.22 2.34 3.72 0.48
7.95 3.24 10.7 77.0 2.25 5.62 2.80 4.11 15.7 7.18 3.25 6.12 1.73 3.83 1.54 2.71 9.50 2.75 3.84 2.38 2.55 4.14 0.52
8.50 3.00 16.3 70.9 2.09 5.68 2.87 4.38 16.3 7.13 3.34 6.47 1.77 4.07 1.45 2.81 10.1 2.85 4.04 2.55 2.42 3.94 0.54
8.91 3.14 14.6 72.1 2.28 6.26 2.98 4.76 18.4 6.86 3.54 7.20 1.84 4.22 1.53 3.02 11.1 2.99 4.29 2.60 2.59 4.43 0.56
7.79 3.82 16.9 70.4 2.08 5.38 2.90 4.24 15.4 6.93 3.46 6.28 1.82 3.86 1.53 2.63 9.21 2.69 3.80 2.53 2.37 4.17 0.50
1
Analyses were conducted at Covance Laboratories, Madison, WI. Values for single analyses reported for MON 88017, MON 88017 × MON 810 and conventional control and the mean of duplicate analyses reported for the 5 commercial references. 2
agricultural animals in research (Federation of Animal Science Societies, 1999) and, as applicable, was in compliance with FDA (1979) and EPA (1983) rules. Broiler chickens of a high yielding commercial strain (Ross × Ross 508) were obtained2 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 on the first study day. The broilers were randomly assigned by gender to pens with concrete floors (1.5 × 0.9 m, providing approximately 0.09 m2 per bird) with 10 to 13 cm of clean wood shavings in a building with environmentally controlled incandescent lighting and temperature. Incandescent lighting was provided 23 to 24 h per day for approximately the first 5 d of the experiment and for 10 to 16 h for the remainder of the experiment. The target room temperature was 34°C at the start of the experiment, which was gradually decreased each day to a target room temperature of 23°C from d 30 through the remainder of the experiment. 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. Environmental conditions (floor space, temperature, lighting, bird density, and feeder and water space) were similar for all treatments.
2
Hoover’s Hatchery, Rudd, IA. Romer Laboratories, Union, MO.
3
Experimental Design A randomized complete block design was used with eight dietary treatments (MON 88017, MON 88017 × MON 810, conventional control, and five commercial diets). For each of the 8 treatment groups, there were 120 broilers placed in pens (total of 960 broilers): 5 pens of males (12 broilers/pen) and 5 pens of females (12 broilers/pen). Initially, there were an additional 2 broilers in each pen to compensate for early chick mortality during the first few days post hatch. At d 8, the group size was adjusted to 10 broilers/pen, in an effort to increase the sensitivity of the growth-based experiment. The initial criterion for removal of additional birds was slow growth, followed by random selection, which was the reason for the removal of the majority of birds.
Corn Grain The MON 88017, MON 88017 × MON 810, and the control corn grain (LH59 × LH198) were produced in Madison County, IL, during the 2002 growing season. Grain from 5 conventional commercial corn references grown in the United States during 2002 was also included in the experiment. The rationale for including grain from numerous commercial references was to demonstrate the range of broiler performance and carcass characteristics when fed grain from different commercially available corn references. The commercial references were: Asgrow RX708 and Pioneer 34B23 (grown in Stark County, IL) and Burrus 789, Burrus 569, and Burrus 582 (grown in Clinton County, IL). Mycotoxin3
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Analyzed composition (as is basis)
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PERFORMANCE OF BROILERS FED GENETICALLY MODIFIED CORN Table 2. Ingredient composition of diets: MON 88017, MON 88017 × MON 810, conventional control, and commercial corn Treatment Ingredient (%)
MON 88017 × MON 810
Control
Asgrow RX708
Pioneer 34B23
Burrus 789
Burrus 582
Burrus 569
54.71 37.70 3.90 1.80 0.90 0.37 0.23 0.15 0.10 0.10 0.00 0.05
54.77 37.75 3.85 1.80 0.90 0.29 0.24 0.15 0.10 0.10 0.01 0.05
54.75 37.65 3.90 1.80 0.90 0.37 0.23 0.15 0.10 0.10 0.00 0.05
53.40 39.10 4.00 1.80 0.75 0.29 0.27 0.15 0.10 0.10 0.00 0.05
53.70 38.85 3.95 1.80 0.75 0.29 0.26 0.15 0.10 0.10 0.00 0.05
54.75 37.70 3.85 1.80 0.90 0.34 0.27 0.15 0.10 0.10 0.00 0.05
54.77 37.65 3.85 1.80 0.90 0.37 0.26 0.15 0.10 0.10 0.00 0.05
54.36 38.25 3.85 1.85 0.75 0.29 0.25 0.15 0.10 0.10 0.00 0.05
59.41 33.50 3.80 1.70 0.70 0.31 0.23 0.10 0.10 0.10 0.00 0.05
59.44 33.50 3.80 1.70 0.65 0.31 0.24 0.10 0.10 0.10 0.02 0.05
59.41 33.50 3.80 1.70 0.70 0.31 0.23 0.10 0.10 0.10 0.00 0.05
59.20 33.65 3.85 1.70 0.65 0.31 0.28 0.10 0.10 0.10 0.02 0.05
59.35 33.50 3.80 1.70 0.70 0.31 0.28 0.10 0.10 0.10 0.01 0.05
59.42 33.50 3.80 1.65 0.70 0.32 0.27 0.10 0.10 0.10 0.01 0.05
59.43 33.50 3.80 1.65 0.70 0.32 0.26 0.10 0.10 0.10 0.00 0.05
59.33 33.50 3.85 1.75 0.65 0.31 0.26 0.10 0.10 0.10 0.01 0.05
1 Trace mineral premix (SEM Minerals, Quincy, IL) contained 0.003% Ca 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, 7.7mg; 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.
and pesticide residue4 analyses of the corn grain were conducted prior to initiation of the experiment to verify that the levels were below the limits of concern for broiler performance. Proximate and amino acid analyses3 were performed on the grain according to methods of the Association of Official Analytical Chemists (2000). Carbohydrate values were calculated by difference using the fresh weight-derived data (% carbohydrates = 100% − (% protein + % fat + % moisture + % ash).
for poultry. Broilers were fed a starter diet containing approximately 55% wt/wt corn grain from d 1 through 20. For the remainder of the experiment (d 21 to 42), broilers were fed a grower/finisher diet containing approximately 60% wt/wt corn grain (Table 2). Analyses of poultry diets6 were conducted for confirmation of formulated levels of nutrient composition. Calcium and phosphorus were analyzed using inductively coupled plasma (ICP) radial spectrometry.
Diets
Measurements
Diets were formulated based on the individual nutrient analyses (Table 1) from each test, control, and commercial corn lot. Dietary protein was provided by the corn grain supplemented with commercial dehulled soybean meal. Synthetic methionine and lysine were added to the diets as needed to conform to industry standards. A coccidiostat, salinomycin (Sacox)5, was mixed into diets at a level of 60 g/ton. Diets were formulated such that the critical amino acid levels met or exceeded National Research Council (NRC, 1994) values
Broiler flocks were examined twice daily for general health. All dead birds and those euthanized due to unhealthy condition were weighed and necropsied. The probable cause of death or reason for removal was documented. Broilers were weighed at d 0 and 42 by pen and individually at experiment termination (d 43 for males and d 44 for females). Average BW per pen and BW per bird values within each treatment group were calculated for each gender. 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 was averaged for each treatment group by gender. Adjusted feed conversion was calculated by dividing the total feed consumption per pen by the total BW of the surviving broilers and those that
4
Covance Laboratories, Madison, WI. Intervet, Inc., Millsboro, DE. 6 Covance Laboratories, Madison, WI; Dairy One Laboratories, Ithaca, NY. 5
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Starter diet formulation Corn Dehulled soybean meal Soybean oil Defluorinated phosphate Limestone Salt DL-Methionine Choline chloride-60% Trace minerals1 Vitamins2 Lysine HCl Sacox (coccidiostat) Grower/finisher diet formulation Corn Dehulled soybean meal Soybean oil Defluorinated phosphate Limestone Salt DL-Methionine Choline chloride-60% Trace minerals1 Vitamins2 Lysine HCl Sacox (coccidiostat)
MON 88017
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TAYLOR ET AL. Table 3. Nutrient composition of diets: MON 88017, MON 88017 × MON 810, conventional control, and commercial corn Analyzed composition (as is basis)
MON 88017 × MON 810
Control
Asgrow RX708
Pioneer 34B23
Burrus 789
Burrus 582
Burrus 569
3081 21.3 7.8 11.5 1.37 1.25 0.52 0.35 0.21 0.79 1.08 1.59 0.99
3080 21.2 8.1 11.4 1.50 1.28 0.56 0.36 0.22 0.84 1.07 1.60 0.99
3081 21.3 7.8 10.3 1.55 1.33 0.55 0.35 0.24 0.84 1.16 1.62 1.00
3079 21.7 8.4 11.7 1.32 1.11 0.54 0.31 0.18 0.72 0.95 1.56 0.90
3079 21.2 8.6 11.6 1.42 1.21 0.62 0.34 0.19 0.76 1.04 1.56 0.90
3080 21.3 8.3 12.5 1.59 1.33 0.56 0.35 0.23 0.85 1.15 1.69 0.92
3079 22.3 8.8 12.0 1.48 1.26 0.56 0.35 0.22 0.81 1.10 1.77 0.99
3079 19.7 8.1 13.1 1.48 1.25 0.56 0.34 0.21 0.80 1.08 1.68 1.01
3132 18.1 8.2 12.3 1.37 1.13 0.46 0.33 0.21 0.73 1.02 1.32 0.87
3134 19.6 8.4 11.6 1.32 1.24 0.51 0.34 0.22 0.73 1.07 1.25 0.84
3132 19.0 8.5 10.7 1.34 1.14 0.52 0.31 0.20 0.76 1.01 1.34 0.87
3136 19.1 8.5 11.0 1.47 1.25 0.58 0.35 0.23 0.79 1.06 1.34 0.91
3133 17.7 8.8 10.8 1.50 1.29 0.59 0.36 0.21 0.84 1.06 1.51 0.94
3134 19.4 8.6 12.8 1.42 1.27 0.58 0.34 0.17 0.76 1.10 1.41 0.90
3134 20.0 9.2 12.1 1.39 1.18 0.57 0.34 0.19 0.76 1.02 1.45 0.96
3135 18.0 8.0 13.1 1.38 1.16 0.54 0.33 0.19 0.75 1.02 1.42 0.91
1
Calculated value.
died or were removed from the pen. At the end of the experiment, carcass measurements for all broilers were taken, and fat pads were collected and weighed. The first male or female broiler processed from each pen was selected for breast and thigh tissue collection. Moisture, protein, and fat analyses were conducted on breast and thigh meat samples.7
Statistical Analysis Statistical analyses were performed on starting and final live weights, feed consumption, feed conversion, adjusted feed conversion, carcass chill weight, percentage chill weight (chill weight/live weight), breast weight, percentage breast weight (breast weight/chill weight), wing weight, percentage wing weight (wing weight/chill weight), thigh weight, percentage thigh weight (thigh weight/chill weight), drum weight, percentage drum weight (drum weight/chill weight), fat pad weight, percentage fat pad (fat pad/live weight), as well as moisture, protein, and fat values for breast and thigh meat. All percentage values were calculated by dividing the response variable by chill or live weight as appropriate. Statistical analysis (ANOVA) was carried out using a linear mixed model procedure of SAS software (SAS Institute Inc., 2000).
7 University of Missouri, Experiment Stations Chemical Laboratories, Columbia, MO.
The statistical model included effects of treatments, gender, block, and gender-by-treatment interactions, with the experimental unit being the pen. The mean values obtained for the broilers fed MON 88017 or MON 88017 × MON 810 diets were compared (combined gender) with those fed the conventional control and commercial diets at the 5% level of significance using a protected Fisher’s least significant difference test (Fisher, 1949). When a significant diet by gender interaction was noted (P < 0.15), the mean values were also evaluated by gender at the 5% level of significance. An additional statistical analysis compared data from broilers fed the MON 88017 or MON 88017 × MON 810 diets to the population of responses from broilers fed the control and commercial corn diets to determine whether the values of the test corn were within the population of the control and reference corn.
RESULTS General Observations Mycotoxin and pesticide levels in corn grain mixed into the diets were below the limits of concern for broiler performance. Alflatoxins were not detectable, and levels of fumonisins in the grain ranged from not detectable to 10 ppm. All pesticide values were below the assay limits of detection: organophosphates, 0.050 ppm; organonitrogens, 0.500 ppm; organochlorinates, 0.200 ppm; and N-methylcarbamates, 0.100 ppm. Diets were
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Starter diets ME1 (kcal/kg) Crude protein (%) Crude fat (%) Moisture (%) Arginine (%) Lysine (%) Methionine (%) Cystine (%) Tryptophan (%) Threonine (%) Valine (%) Calcium (%) Phosphorus (%) Grower/finisher diets ME1 (kcal/kg) Crude protein (%) Crude fat (%) Moisture (%) Arginine (%) Lysine (%) Methionine (%) Cystine (%) Tryptophan (%) Threonine (%) Valine (%) Calcium (%) Phosphorus (%)
MON 88017
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PERFORMANCE OF BROILERS FED GENETICALLY MODIFIED CORN 1
Table 4. Summary of broiler mortality by gender
Mortality (%) d 0 to 7 Treatment Asgrow RX708 Pioneer 34B23 Burrus 789 Burrus 582 Burrus 569 Control MON 88017 MON 88017 × MON 810
Mortality (%) d 8 to 42
Males
Females
Males
Females
1.7 0.0 0.0 1.7 0.0 5.0 1.7 0.0
0.0 0.0 0.0 0.0 0.0 1.7 0.0 3.3
8.0 6.0 2.0 8.0 6.0 2.0 6.0 2.0
4.0 4.0 0.0 2.0 2.0 2.0 2.0 0.0
1
Based on a total of 60 males and 60 females per treatment for d 0 to 7 and a total of remaining 50 males and remaining 50 females per treatment for d 8 to 42.
to be of biological significance as pair-wise comparisons between diets (combined gender) showed no differences in the thigh weights of broilers. No differences were observed in the percentages of moisture, protein, and fat in breast meat or thigh meat across treatment diets (Table 5). Population Statistical Analysis. Comparison of the data from broilers fed MON 88017 to that of the combined population of conventional control and commercial corn showed no differences in performance, meat quality, and carcass yield parameters measured (data not shown).
MON 88017
MON 88017 × MON 810
Performance Parameters. No differences were noted for performance parameters measured in broilers fed diets containing MON 88107 compared with those fed the conventional control and commercial corn (Table 5). Mean final weights of the broilers were similar to those from previously reported studies (Taylor et al., 2003a,b), and the mean pen weights of the broilers were comparable between treatments. There were no differences between treatments for live weight at d 0, live weight at d 42, total feed intake, and feed conversion. Broiler diets containing MON 88017 had adjusted feed conversion (kg/kg) similar to that of the broilers fed the nontransgenic control and all but one of the commercial reference diets, Asgrow RX708. Carcass Measurements. No differences were noted in pair-wise comparisons for carcass yield measurements of chill weight, fat pad, breast, thigh, drum, and wing weights across treatments (Table 5). There was only one instance, thigh weight (kg), for which a (P < 0.08) diet-by-gender interaction was observed (data not shown). When individual gender comparisons were made for this parameter, no differences (P > 0.05) were observed in the females. Male broilers fed diets containing MON 88017 had thigh weights similar (P > 0.05) to those of males fed diets containing the conventional control and commercial references Asgrow RX708, Pioneer 34B23 and Burrus 789, but different (P < 0.05) thigh weights than birds fed the commercial references Burrus 569 and Burrus 582. However, this result is not likely
Performance Parameters. All performance parameters of broilers fed diets containing MON 88017 × MON 810 were similar to those fed the conventional control and commercial corn. No differences were observed in live weight at d 0, live weight at d 42, total feed intake, and feed conversion across all treatments (Table 6). Broilers fed diets containing MON 88017 × MON 810 had adjusted feed conversion (kg/kg) similar to that of broilers fed all other diets; however, differences were noted among broilers fed the control and reference diets. Carcass Measurements. Pairwise comparisons for carcass measurements of chill weight, fat pad weight, breast meat, thigh, wing, and drum weights were not different across treatments (Table 6). No significant dietby-gender interactions were noted at the 5% level of significance. No differences were observed in the percentage of moisture, protein, or fat in breast and thigh meat (Table 6). Population Statistical Analysis. Comparison of the MON 88017 × MON 810 diet to the population on the other diets showed no differences in performance parameters, carcass yields, and meat quality parameters of thigh moisture, protein, and fat and breast protein and moisture. Statistically significant differences were noted for breast fat in the population comparison (data not shown). However, no differences were observed in the pairwise comparisons between treatment diets for the breast meat measurements.
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formulated to meet or exceed NRC (1994) recommendations based on the individual nutrient analyses of the grain. The nutrient assay results are presented in Table 3. A total of 9 broilers (0.9% of total) died during the first 7 d. Mortality from d 8 to d 42 averaged 3.5% and was distributed randomly across treatments (Table 4). Mortality during the first 7 d was related to bacterial infection, dehydration, refusal of feed, or ascites, and the causes of death between d 8 and 42 were primarily attributed to sudden death and ascites, which commonly occur in broilers. Remaining broilers in all treatments were in good health.
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TAYLOR ET AL.
Table 5. Performance and carcass yield comparison of broilers fed MON 88017, conventional control corn, and commercial corn (mean values of combined males and females) Control
Asgrow RX708
Pioneer 34B23
Burrus 789
Burrus 582
Burrus 569
Treatment P
LSD1 5.0%
37.683 2.344 3.801 1.619 1.518bc
37.267 2.331 3.579 1.539 1.503c
37.700 2.321 3.808 1.644 1.563a
37.167 2.297 3.637 1.589 1.536abc
37.700 2.336 3.818 1.633 1.531abc
37.815 2.309 3.857 1.673 1.532abc
38.833 2.314 3.689 1.595 1.550ab
NS NS NS NS P < 0.05
0.778 0.060 0.253 0.116 0.036
1.659 71.773 0.030 1.312 0.448 26.970 0.290 17.469 0.222 13.357 0.193 11.678
1.641 71.904 0.030 1.313 0.437 26.597 0.286 17.389 0.223 13.586 0.192 11.750
1.621 71.564 0.031 1.384 0.432 26.658 0.282 17.362 0.219 13.469 0.189 11.709
1.620 72.021 0.031 1.390 0.435 26.813 0.285 17.627 0.216 13.313 0.189 11.689
1.639 71.851 0.029 1.271 0.441 26.935 0.285 17.393 0.221 13.492 0.192 11.755
1.612 71.658 0.029 1.273 0.438 27.197 0.282 17.467 0.217 13.422 0.189 11.737
1.624 71.998 0.028 1.224 0.438 26.968 0.279 17.138 0.217 13.398 0.191 11.821
NS NS NS NS NS NS NS NS NS NS NS NS
0.045 0.569 0.003 0.130 0.016 0.472 0.010 0.348 0.007 0.212 0.005 0.172
75.052 23.105 0.819
74.835 23.226 0.841
75.098 23.222 0.808
75.109 23.020 0.837
75.012 23.045 0.898
75.169 22.873 0.876
75.075 22.988 0.819
NS NS NS
0.383 0.438 0.271
76.157 20.872 2.176
76.278 21.418 2.164
76.389 20.954 2.082
76.251 20.742 2.420
76.397 20.922 2.513
76.318 20.994 2.214
76.423 20.588 2.211
NS NS NS
0.450 0.641 0.665
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 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
Table 6. Performance and carcass yield of broilers fed MON 88017 × MON 810, conventional control corn, and commercial corn (mean values of combined males and females)
Performance Live weight (g/bird), d 0 Live weight (kg/bird), d 42 Feed intake (kg/bird) Feed conversion (kg/kg) Adjusted feed conversion2 (kg/kg) Carcass yield Chill weight (kg) Chill weight (% of live weight) Fat pad weight (kg) Fat pad weight (% of live weight) Breast weight (kg) Breast weight (% of chill weight) Thigh weight (kg) Thigh weight (% of chill weight) Drum weight (kg) Drum weight (% of chill weight) Wing weight (kg) Wing weight (% of chill weight) Breast meat analysis Moisture (%) Protein (%, as-is basis) Fat (%, as-is basis) Thigh meat analysis Moisture (%) Protein (%, as-is basis) Fat (%, as-is basis)
MON 88017 × MON 810
Control
Asgrow RX708
Pioneer 34B23
Burrus 789
Burrus 582
Burrus 569
Treatment P
LSD1 5.0%
37.259 2.288 3.664 1.602 1.534ab
37.267 2.331 3.579 1.539 1.503b
37.700 2.321 3.808 1.644 1.563a
37.167 2.297 3.637 1.589 1.536ab
37.700 2.336 3.818 1.633 1.531ab
37.815 2.309 3.857 1.673 1.532ab
38.833 2.314 3.689 1.595 1.550a
NS NS NS NS P < 0.05
0.765 0.062 0.256 0.121 0.035
1.612 71.972 0.028 1.261 0.435 26.925 0.278 17.268 0.216 13.416 0.190 11.780
1.641 71.904 0.030 1.313 0.437 26.597 0.286 17.389 0.223 13.586 0.192 11.750
1.621 71.564 0.031 1.384 0.432 26.658 0.282 17.362 0.219 13.469 0.189 11.709
1.620 72.021 0.031 1.390 0.435 26.813 0.285 17.627 0.216 13.313 0.189 11.689
1.639 71.851 0.029 1.271 0.441 26.935 0.285 17.393 0.221 13.492 0.192 11.755
1.612 71.658 0.029 1.273 0.438 27.197 0.282 17.467 0.217 13.422 0.189 11.737
1.624 71.998 0.028 1.224 0.438 26.968 0.279 17.138 0.217 13.398 0.191 11.821
NS NS NS NS NS NS NS NS NS NS NS NS
0.047 0.495 0.003 0.133 0.015 0.474 0.011 0.374 0.008 0.203 0.005 0.178
75.447 22.581 1.071
74.835 23.226 0.837
75.098 23.222 0.723
75.109 23.020 0.808
75.012 23.045 0.898
75.169 22.873 0.876
75.075 22.988 0.841
NS NS NS
0.669 0.779 0.275
76.282 20.928 1.991
76.278 21.418 2.164
76.389 20.954 2.082
76.251 20.742 2.420
76.397 20.922 2.513
76.318 20.994 2.214
76.423 20.588 2.211
NS NS NS
0.483 0.658 0.618
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 adjusted by dividing the total feed consumption/pen by the total BW of the surviving broilers and those that died or were removed from the pen. a,b 1
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Performance Live weight (g/bird), d 0 Live weight (kg/bird), d 42 Feed intake (kg/bird) Feed conversion (kg/kg) Adjusted feed conversion2 (kg/kg) Carcass yield Chill weight (kg) Chill weight (% of live weight) Fat pad weight (kg) Fat pad weight (% of live weight) Breast meat weight (kg) Breast meat weight (% of chill weight) Thigh weight (kg) Thigh weight (% of chill weight) Drum weight (kg) Drum weight (% of chill weight) Wing weight (kg) Wing weight (% of chill weight) Breast meat analysis Moisture (%) Protein (%, as-is basis) Fat (%, as-is basis) Thigh meat analysis Moisture (%) Protein (%, as-is basis) Fat (%, as-is basis)
MON 88017
PERFORMANCE OF BROILERS FED GENETICALLY MODIFIED CORN
DISCUSSION
REFERENCES Association of Official Analytical Chemist. 2000. Official Methods of Analysis of AOAC International. 17th rev. ed. Methods 923.03, 925.09, 926.08, 955.04, 960.39, 979.09, and 982.30. AOAC International, Gaithersburg, MD.
Environmental Protection Agency. 1983. 40 CFR Part 160. Federal Insecticide, Fungicide and Rodenticide Act (FIFRA). EPA, Washington, DC. 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, UK. Food and Drug Administration. 1979. Dept. of Health and Human Services. 21 CFR Part 58. Good Laboratory Practice Regulations for Nonclincal Laboratory Studies. FDA, Washington, DC. George, C., W. P. Ridley, J. C. Obert, M. A. Nemeth, M. L. Breeze, and J. D. Astwood. 2004. Corn rootworm protected corn: The composition of grain and forage from corn rootworm protected corn event MON 863 is equivalent to that of conventional corn (Zea mays L.). J. Agric. Food Chem. 52:4149–4158. National Research Council. 1994. Nutritional Requirements of Poultry. 9th rev. ed. National Academy Press, Washington, DC. Ridley, W. P., R. S. Sidhu, P. D. Pyla, M. A. Nemeth, M. L. Breeze, and J. D. Astwood. 2002. A Comparison of the Nutritional Profile of Roundup Ready威 Corn Event NK603 to that of Conventional Corn (Zea mays L.). J. Agric. Food Chem. 50:7235–7243. Sanders, P. R., T. C. Lee, M. E. Groth, J. D. Astwood, and R. L. Fuchs. 1998. Safety assessment of insect-protected corn. Pages 241–255 in Biotechnology and Safety Assessment. 2nd rev. ed. J. A. Thomas, ed. Taylor Francis, New York. SAS Institute Inc. 2000. SAS Online Doc. SAS Institute Inc., Cary, NC. Taylor, M. L., G. F. Hartnell, S. G. Riordan, M. A. Nemeth, K. Karunanandaa, B. George, and J. D. Astwood. 2003a. Comparison of broiler performance when fed diets containing grain from roundup ready (NK603), yieldgard × roundup ready (MON 810 × NK603), Non-transgenic Control, or Commercial Corn. Poult. Sci. 82:443–453. Taylor, M. L., Y. Hyun, G. F. Hartnell, S. G. Riordan, M. A. Nemeth, K. Karunanandaa, B. George, and J. D. Astwood. 2003b. Comparison of broiler performance when fed diets containing grain from yieldgard rootworm (MON 863), yieldgard plus (MON 810 × MON 863), nontransgenic control, or commercial reference corn hybrids. Poult. Sci. 82:1948–1956.
Downloaded from http://ps.oxfordjournals.org/ at University of Michigan on June 15, 2015
The rapidly growing broiler is sensitive to changes in the nutrient quality of diets they consume. Any deficiencies in the major dietary nutrients would be expected to result in reduced growth, feed conversion, and carcass yields. The results of this broiler feeding experiment support the conclusion that there are no practical differences in the parameters evaluated between broilers fed MON 88017 or MON 88017 × MON 810 and the genetically similar control corn. Pair-wise comparisons indicated that broilers generally performed equivalently and had similar carcass yield and meat composition when fed diets containing MON 88017, MON 88017 × MON 810, conventional control, or commercial reference corn. In the few cases in which differences were observed, the values were similar to values reported in the literature (Taylor et al., 2003a,b). It was concluded that grain from the genetically enhanced corn products evaluated in this study is nutritionally equivalent in broiler diets to grain from the control and commercially available corn references. This conclusion is consistent with the compositional evaluation of genetically enhanced corn expressing the Cry1Ab, CP4 EPSPS, or Cry3Bb1 proteins, which showed that there were no relevant differences in nutritional and compositional properties relative to control and commercial corn (Sanders et al., 1998, Ridley, et al., 2002, and George, et al., 2004). These data confirm and support the conclusion that the grain from MON 88017 alone or in combination with MON 810 corn is as nutritious as traditional corn.
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