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The Effects of Energy and Amino Acid Levels on Performance and Carcass Quality of Male and Female Broilers Grown Separately1
The Effects of Energy and Amino Acid Levels on Performance and Carcass Quality of Male and Female Broilers Grown Separately 1 P. W. WALDROUP, N. M. TIDWELL,2 and A. L. IZAT Department of Animal and Poultry Sciences, University of Arkansas, Fayetteville, Arkansas 72701 (Received for publication October 27, 1989)
1990 Poultry Science 69:1513-1521 INTRODUCTION
As chick sexing at day of hatch has become less costly through the introduction of feather sexing strains, a greater percentage of broiler chickens are being raised sex-separate. Sexseparate rearing has also been spurred by the increased demand for further processed poultry items, which calls for greater uniformity of size and a wider range of bird sizes than traditional ice-packed broilers. Increasing consumer demands for portion uniformity and further processed products, particularly those using breast meat, indicate that the trend toward more sex-separate rearing will continue to increase. The acceptance of sex-separate rearing has made more relevant a question that has long been debated: Is there justification for using different diets for each sex? It has long been recognized that male broiler chickens grow
^Published with the approval of the director, Arkansas Agricultural Experiment Station. Present address: Nicholas Turkey Breeding Farms, Sonoma, CA 95476.
faster and have better feed efficiency than do female broilers. The growth rate of females starts to plateau earlier in life than does the growth rate of males, and females begin to deposit fat at earlier ages and in higher percentages than males. This would suggest that the nutritional requirements of males might be higher than for females. However, research conducted to determine if male and female broilers have different nutritional requirements has not been conclusive. Douglas et al. (1958) and Shutze et al. (1958) suggested that males had a higher protein requirement than females. However, Douglas and Harms (1960) fed a wide range of energy and protein ratios and found no interaction between sex and dietary treatment. Combs and Nicholson (1965) tested various levels of amino acids and found no significant difference in amino acid requirements for male versus female broilers. Bornstein and Lipstein (1966) found no sex-related differences for methionine needs in broilers during the finisher period. Hunchar and Thomas (1976) found only minimal differences in tryptophan requirements; males needed an average of
1513
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ABSTRACT Studies were conducted to evaluate the response of male and female broiler chickens to diets containing different levels of energy and amino acids. Two energy series were compared: 3,080, 3,135, and 3,190 kcal of ME/kg ("low") and 3,190,3,245, and 3,300 kcal of ME/kg ("high") in pelleted starter, grower, and finisher diets. Diets provided a minimum of 85, 90, 95, 100, 105, and 110% of suggested amino acid recommendations for the broiler male except for Met and TSAA, which were kept at 105%. Modifications were made in feeding periods, recognizing the differences in rate of gain and marketing ages of the two sexes. Feeding periods were 0 to 21,21 to 42, and 42 to 56 days for males and 0 to 18,18 to 35, and 35 to 49 days for females. Four floor pen trials utilizing 9,600 male and 9,600 female broilers were conducted. Birds were processed to determine dressing percentage and abdominal fat pad weights. Energy content of the diets had no significant (P>.05) effect on body weight or feed efficiency for male or female broilers. Carcass dressing percentage of females, but not males, was significantly (P<05) increased on the high energy series. Abdominal fat pad was not influenced by energy for either sex. For both sexes, increasing dietary amino acid levels resulted in significant (PS.05) linear improvements in live weights and feed utilization and a reduction in abdominal fat pad weight. There were no treatment by sex interactions for any of the parameters, indicating that both sexes responded to changes in energy and amino acid levels in a similar manner. Therefore, the results of this study do not support feeding nutritionally different diets to male versus female broilers when feeding periods are adjusted by sex. (Key words: amino acids, energy, separate sex, nutrition, broilers)
1514
WALDROUP ET AL.
MATERIALS AND METHODS
Four trials were conducted over a year to consider any seasonal influences. The first trial was started in mid-June, the second in midSeptember, the third in mid-February, and the fourth in early May. Two energy series were compared. A low energy level diet contained 3,080, 3,135, and 3,190 kcal of ME/kg in the starter, grower, and finisher rations, respectively. A high energy diet contained 3,190, 3,245, and 3,300 kcal of ME/kg in the starter, grower, and finisher rations, respectively. A designation of low or high is relative and is used in this study only to describe the two different energy series.
Amino acid standards of Thomas et al. (1986) provide separate amino acid and protein recommendations for male and female broilers, with recommendations for females being approximately 5% lower than those for males. Using the standards for males, six amino acid levels were established at 85, 90, 95, 100,105, or 110% of the suggested standard. In order to place more emphasis upon other amino acids, which seldom are limiting in corn-soybean meal type diets, Met and Met plus Cys were maintained at 105% of the suggested requirement. Each amino acid series was formulated at the two energy levels with the amino acids maintained in ratio with the dietary energy level. DL-Methionine and L-lysine HC1 were offered to the computer at no cost to encourage the use of these two ingredients and minimize overall protein and amino acid levels. Although it is virtually impossible to formulate practical type diets with exactly minimal levels of all essential amino acids, the diets in this study were formulated to provide minimal levels of excess amounts. In most instances, the requirements for lysine, arginine, threonine, and isoleucine were at minimum levels and others were at or near the minimum in most diets. All mixed feeds were subjected to Kjeldahl analysis (Association of Official Agricultural Chemists, 1970) to verify proper mixing and were found to be in agreement with calculated values. Because of the number of test diets involved in the study, amino acid analysis was conducted only on the lowest and highest amino acid level in each series. Analysis by ion-exchange chromatography was carried out by a major producer of amino acids, and results were in agreement with calculated values. The nutrient values used for the major dietary ingredients were based on a composite of amino acid values from three major laboratories (Table 1). The composition and calculated nutrient analysis of the starter, grower, and finisher diets for Experiment 1 are given in Tables 2, 3, and 4. For the other trials, diets were reformulated based upon the actual moisture and protein content of the corn and soybean meal present in the University of Arkansas feed mill at that time; adjustments were made in the amino acid content relative to the total protein and moisture content. This resulted in only slight modifications in the overall dietary composition for ensuing trials, and the diets will not be shown in tabular form.
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.0043% more tryptophan than females. Freeman (1979) reported no difference in tryptophan requirements between sexes when expressed as a percentage of the diet. Kessler and Thomas (1976) examined arginine requirements for 4- to 7-wk-old broilers and from the count of floor feathers determined mat males had a slightly higher need for arginine than females. Minear and Marion (1981) found that male broilers had a significantly higher requirement for lysine and sulfur amino acids than did female broilers. However, when separate "male" and "female" diets were developed utilizing these findings, both the males and females required the more nutrientdense "male" diet for maximum growth. Wells (1963) reported a consistently greater growth response to dietary energy for males than females. Waldroup et al. (1976) determined that male broilers utilized energy more efficiently than females; however, the response to increasing energy was linear for both sexes. Farrell et al. (1973) reported that the ME required by each sex to reach a given live weight was quite similar. Most of the previous research on differing nutrient requirements or sex-separate feeding has been conducted with birds of both sexes being tested at the same age. In consideration of the differential growth rates and feed efficiency over time, this might help to explain the inconsistent results of the previous research. In designing the present trials to study nutrient requirement of male versus female broilers, the differing growth rate patterns and present-day marketing programs of sex-separate reared broilers were considered, and feeding periods were altered accordingly.
1515
SEPARATE SEX DIETS TABLE 1. Ingredient composition values used in formulation Yellow corn
Soybean meal
Propak2
Corn gluten meal
ME, kcal/kg Protein Calcium Total phosphorus Available phosphorus Chloride Sodium Potassium Arginine Lysine Methionine Met plus Cys Tryptophan Glycine Histidine Leucine Isoleucine Phenylalanine Phe plus Tyr Threonine Valine
3,313.00 8.20 .02 .28 .10 .04 .04 .28 .39 .25 .19 .38 .07 .33 .25 1.01 .28 .41 .65 .30 .41
2,424.00 48.0 .20 .65 .26 .05 .02 1.98 3.62 3.07 .69 1.41 .65 2.28 1.39 3.76 2.23 2.47 4.25 1.90 2.36
2,645.00 61.06 5.30 3.00 3.00 .55 .60 .52 3.90 3.78 1.81 3.01 .53 5.62 1.75 5.15 1.86 2.89 4.76 2.45 3.80
3,741.00 62.00 .02 .70 21 .05 .02 .35 2.03 .95 1.66 2.79 .35 1.64 1.33 10.24 2.81 3.77 6.71 2.05 2.87
'With the exception of metabolizable energy, all values are expressed as percentage of the ingredient BIended animal protein product (H. J. Baker and Bro., New York, NY).
2
All diets contained monensin sodium3 at 90 g per ton (909 kg) as an anticoccidial in the starter and grower feed. Bacitracin methylene disalicylate4 was added to all starter, grower, and finisher diets at 50 g/ton. Roxarsone5 was added to starter and grower diets at 45 g per ton. Complete vitamin and trace mineral premixes were used to meet National Research Council (1984) recommended guidelines. All diets were pelleted using steam preconditioning.6 All trials were conducted in a commercial type, curtain-sided house, which contained 96 pens divided into four blocks of 24 pens each. Within each of the blocks, there were 12 pens of 50 male and 12 pens of 50 female chicks. Chickens of a commercial broiler strain (Cobb 500) were obtained from a local hatchery and randomly allocated to pens. The pens were 2.4 x 2.25 m and were equipped wim two tube type feeders and one bell-shaped automatic waterer. Four replicate pens of males and four
3
Coban, Blanco Products Co., Indianapolis, IN 46285. ^MD-SO, A. L. Laboratories, Inc., Fort Lee, NJ 07024. ^Roxarsone 10%, Rhone-Poulenc, Inc., Atlanta, GA 30338. California Pellet Mill Master Model, California Pellet Mill Co., Crawfordsville, IN 47933.
replicate pens of females (one replicate of each sex per block) were assigned to each dietary treatment in each of the four studies for an overall total of 16 replicate pens of each sex per dietary treatment. During the first 7 days, supplemental feeder flats, and water founts were used, hi each trial new wood shavings were used as litter over concrete floors. Feed and water were provided free choice. Mortality was recorded daily, and feed efficiency was adjusted for the weight of birds that died. Modifications were made in the feeding period for both sexes. Such modifications have long been done in the turkey industry, recognizing both the different growth rate and the different marketing age of the two sexes. In the present study, feeding periods for females were 0 to 18 days on starter, 18 to 35 days on grower, and 35 to 49 days on finisher. Feeding periods for males were 0 to 21 days on starter, 21 to 42 days on grower, and 42 to 56 days on finisher. At the end of each feeding period all birds were weighed by pen, feed consumption was determined, and feed efficiency was calculated. At the end of the finisher period (49 days for females and 56 days for males) five birds from each pen were selected for processing. Birds were randomly selected with the proviso that all birds weighed within .5 standard
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Nutrient1
654.61 243.80 50.00 19.50 9.98 7.78 5.00 4.09 1.28 .97 1.00 .50 .50 1.00
20.36 .84 .46 .33 .21 1.34 1.19 .52 .88 .24 .59 1.86 .83 .79 1.04
631.12 263.37 50.00 23.31 8.93 7.78 5.00 4.09 1.51 1.00 1.00 .50 .50 1.00
21.11 .84 .46 .33 .21 1.41 1.25 .55 .92 .25 .61 1.91 .87 .82 1.08
Yellow corn Soybean meal (48.5% CP) Propak (60% CP) 2 Blended fat Dicalcium phosphate Limestone Vitamin premix3 Salt DL-methionine (98%) Lysine HC1 (98%) Trace-mineral mix* Bacitracin MD 50 5 Roxarsone 10%6 Coban 4 5 ' Calculated nutrient content, % Protein Calcium Available phosphorus Chloride Sodium Arginine Lysine Methionine Met plus Cys Tryptophan Histidine Leucine Isoleucine Threonine Valine 19.60 .84 .46 .33 .21 1.28 1.13 .52 .88 .22 .57 1.81 .80 .76 1.00
677.27 224.32 50.00 16.00 10.13 7.79 5.00 4.08 1.46 .94 1.00 .50 .50 1.00
100
18.85 .84 .46 .33 21 1.22 1.08 .53 .88 21 .55 1.76 .76 .72 .96
699.93 204.84 50.00 12.50 10.29 7.80 5.00 4.08 1.65 .91 1.00 .50 .50 1.00
95
18.10 .84 .46 .33 .21 1.16 1.02 .54 .88 .20 .53 1.71 .72 .69 .93
722.59 185.35 50.00 9.00 10.44 7.80 5.00 4.08 1.84 .89 1.00 .50 .50 1.00
90
17.34 .84 .46 .33 .21 1.10 .96 .55 .88 .19 .50 1.66 .69 .66 .89
745.25 165.87 50.00 5.50 10.59 7.81 5.00 4.08 2.03 .86 1.00 .50 .50 1.00
85
110
21.88 .87 .48 .35 .22 1.46 1.29 .57 .96 .25 .63 1.99 .91 .84 1.11
(g/kg) 581.84 278.22 50.00 48.80 10.69 8.03 5.00 4.29 1.62 1.05 1.00 .50 .50 1.00 20.86 .87 .48 .35 .22 1.39 1.23 .54 .91 .24 .60 1.89 .86 .81 1.06
608.35 261.30 50.00 46.06 10.86 8.01 5.00 4.29 1.59 .96 1.00 .50 .50 1.00
105
20.06 .87 .48 .34 .22 1.33 1.17 .55 .91 .23 .58 1.83 .82 .77 1.02
632.03 241.45 50.00 42.55 11.02 8.01 5.00 4.29 1.72 .93 1.00 .50 .50 1.00
100
19.28 .87 .48 .34 22 1.26 1.12 .56 .91 .22 .56 1.77 .78 .74 .98
655.50 221.28 50.00 38.92 11.18 8.02 5.00 4.29 1.91 .90 1.00 .50 .50 1.00
95
Blended animal protein product (H. J. Baker & Bro., New York, NY 10017).
17.71 .87 .48 .34 .21 1.13 1.00 .58 .91 .20 .52 1.67 .71 .68 .91
702.44 180.92 50.00 31.67 11.50 8.03 5.00 4.28 2.30 .84 1.00 .50 .50 1.00
85
A. L. Laboratories, Inc., F t Lee, NJ 07024.
7
Elanco Products Co., Indianapolis, IN 46285.
^hone-Poulenc, Inc., Atlanta, GA 30338.
5
^Supplied per kilogram of diet: iron, 100 mg; manganese, 100 mg; zinc, 100 mg; copper, 10 mg; iodine, 1 mg.
Supplied per kilogram of diet: vitamin A, 6,600 IU; vitamin D3, 2,200 IU; vitamin E, 6.6 IU; menadione, 3.3 mg; riboflavin, 5.5 mg; niacin, 33 mg; pantothenic acid, 8.8 mg; choline, 495 mg; thiamine, 1.1 mg; pyridoxine, 1.1 mg; vitamin B12. -01 mg; biotin, .11 mg; folacin, .66 mg; ethoxyquin, 125 mg; selenium, .1 mg.
3
2
18.49 .87 .48 .34 .22 1.20 1.06 .57 .91 .21 .54 1.72 .74 .71 .95
678.97 201.10 50.00 35.30 11.34 8.03 5.00 4.28 2.11 .87 1.00 .50 .50 1.00
90
Diets with 3,190 kcal of ME/kg, of suggested amino acid requirement
Percentage of male requirements of Thomas et al. (1986). Methionine and Met plus Cys were maintained at least 105% of suggested requirements.
105
110
Ingredient
Diets with 3,080 kcal of ME/kg, of suggested amino acid requirement
TABLE 2. Composition and calculated nutrient content of starter diets containing 3,080 and 3,190 kcal of MEIkg and different percentages of suggested amino acid requirements (Experiment 1)
aded from http://ps.oxfordjournals.org/ at Tufts University on December 13, 2016
£
§
9
§
^
ed from http://ps.oxfordjournals.org/ at Tufts University on December 13, 2016
18.29 .86 .47 .34 .21 1.10 .95 .49 .84 .19 .52 1.88 .73 .69 .93 17.31 .86 .47 .34 .21 1.04 .90 .51 .84 .18 .50 1.77 .68 .65 .88
110
22.01 .88 .49 .35 .22 1.31 1.13 .52 .92 .23 .61 2.31 .91 .83 1.11
607.09 205.44 50.00 62.85 40.70 11.38 8.37 4.38 .62 1.17 5.00 1.00 .50 .50 1.00
I(g/kg)
20.99 .88 .49 .35 .22 1.25 1.08 .50 .88 .22 .58 2.19 .86 .79 1.06
632.03 191.23 50.00 54.14 38.65 11.55 8.35 4.38 .58 1.10 5.00 1.00 .50 .50 1.00 19.97 .88 .49 .35 .22 1.19 1.03 .49 .87 .21 .56 2.08 .81 .75 1.01
656.48 177.04 50.00 45.48 36.78 11.72 8.32 4.37 .78 1.03 5.00 1.00 .50 .50 1.00 18.95 .88 .49 .35 22 1.13 .98 .51 .87 .20 .54 1.96 .76 .71 .96
680.64 162.87 50.00 36.85 35.01 11.89 8.30 4.37 1.13 .95 5.00 1.00 .50 .50 1.00
17.10 .88 .49 .35 .22 1.01 .88 .53 .87 .17 .50 1.91 .70 .66 .90
722.39 122.45 50.00 42.58 27.30 12.17 8.33 4.37 1.38 1.03 5.00 1.00 .50 .50 1.00
85
7
Elanco Products Co., Indianapolis, IN 46285.
A. L. Laboratories, Inc., Ft Lee, NJ 07024. ^one-Poulenc, Inc., Atlanta, GA 30338.
5
3 Supplied per kilogram of diet: vitamin A, 6,600 IU; vitamin D3, 2,200 IU; vitamin E, 6.6 IU; menadione, 3.3 mg; riboflavin, 5.5 mg; niacin, 33 mg; pantothenic acid, 8.8 mg; choline, 495 mg; thiamine, 1.1 mg; pyridoxine, 1.1 mg; vitamin B 1 2 , .01 mg; biotin, .11 mg; folacin, .66 mg; ethoxyquin, 125 mg; selenium, .1 mg. 4 Supplied per kilogram of diet: iron, 100 mg; manganese, 100 mg; zinc, 100 mg; copper, 10 mg; iodine, 1 mg.
2
17.93 .88 .49 .35 .22 1.07 .93 .53 .87 .19 .51 1.84 .71 .67 .91
704.80 148.70 50.00 28.21 33.23 12.06 8.27 4.37 1.48 .88 5.00 1.00 .50 .50 1.00
Diets with 3,245 kcal of ME/kg, % of suggested amino acid requirement 105 100 95 90
S
CO
3
£
p—'
CO
: DIET
'Percentage of male requirements of Thomas et al. (1986). Methionine and Met plus Cys were maintained at least 105% of suggested requirements. Blended animal protein product (H. J. Baker & Bro., New York, NY 10017).
19.28 .86 .47 .34 .21 1.15 1.00 .78 .84 .20 .54 1.99 .78 .73 .98 17.10 .86 .47 .34 .21 .98 .85 .50 .84 .17 .49 1.83 .67 .64 .87
20.26 .86 .47 .34 .21 1.21 1.05 .48 .85 .21 .57 2.11 .82 .76 1.03
749.25 138.37 50.00 20.16 8.64 11.17 8.02 4.17 1.39 .84 5.00 1.00 .50 .50 1.00
21.25 .86 .47 .34 .21 1.27 1.10 .50 .89 21 .59 2.22 .87 .80 1.07
725.91 152.06 50.00 28.51 10.35 11.00 8.04 4.17 1.05 .91 5.00 1.00 .50 .50 1.00
766.10 112.73 50.00 34.58 2.81 11.27 8.07 4.17 1.28 .98 5.00 1.00 .50 .50 1.00
702.51 165.76 50.00 36.85 12.09 10.84 8.07 4.17 .75 .98 5.00 1.00 .50 .50 1.00
678.88 179.46 50.00 45.22 13.90 10.68 8.09 4.17 55 1.05 5.00 1.00 .50 .50 1.00
654.78 193.20 50.00 53.63 15.88 10.51 8.12 4.18 .59 1.12 5.00 1.00 .50 .50 1.00
Yellow corn Soybean meal (48.5% CP) Propak (60% CP)2 Com gluten meal (60% CP) Blended fat Dicalcium phosphate Limestone Salt DL-methionine (98%) Lysine HC1 Vitamin premix Trace-mineral mix'; Bacitracin MD 50 5 Roxarsone 10%6 Coban 45 7 Calculated nutrient content, % Protein Calcium Available phosphorus Chloride Sodium Arginine Lysine Methionine Met plus Cys Tryptophan Histidine Leucine Isoleucine Threonine Valine
85
110
Ingredient
Diets with 3,135 kcal of ME/kg, % of suggested amino acid requirement 105 100 95 90
TABLE 3. Composition and calculated nutrient content of grower diets containing 3,135 and 3245 kcal of ME/kg and different percentages of suggested amino acid requirements^ (Experiment 1)
SEP.
775.06 105.95 50.00 33.16 8.40 7.86 8.47 5.00 4.27 .09 1.00 .23 .50
756.82 119.61 50.00 35.70 10.67 7.74 8.47 5.00 4.27
1.00 .21 .50
17.42 .80 .41 .33 .22 1.00 .81 .38 .72 .18 .49 1.86 .68 .65 .89
738.28 133.30 50.00 38.26 13.04 7.62 8.48 5.00 4.28 .06 1.00 .19 .50
18.09 .80 .41 .33 .22 1.05 .84 .40 .75 .18 .51 1.92 .72 .68 .92
Yellow corn Soybean meal (48.5% CP) Propak (60% CP)2 Com gluten meal (60% CP) Blended fat Dicalcium phosphate Limestone Vitamin premix3 Salt DL-methionine (98%) Trace-mineral mix4 Lysine HC1 Bacitracin MD 50 5 Calculated nutrient content, % Protein Calcium Available phosphorus Chloride Sodium Arginine Lysine Methionine Met phis Cys Tryptophan Histidine Leucine Isoleucine Threonine Valine 16.09 .80 .41 .33 .22 .91 .73 .38 .70 .16 .46 1.74 .62 .60 .82
793.27 92.29 50.00 30.62 6.15 7.99 8.46 5.00 4.27 .19 1.00 .25 .50
95
15.42 .80 .41 .33 .22 .86 .69 .39 .70 .15 .44 1.69 .59 .57 .79
811.31 78.65 50.00 28.08 3.96 8.11 8.46 5.00 4.27 .38 1.00 .27 .50
90
110
14.76 .80 .41 .33 .22 .81 .65 .40 .70 .14 .42 1.63 .55 .55 .76
715.11 132.11 50.00 38.43 35.91 8.51 8.72 5.00 4.47 .07 1.00 .17 .50
17.85 .82 .42 .34 .22 1.04 .83 .40 .73 .18 .50 1.89 .71 .67 .91
18.54 .82 .42 .34 .22 1.09 .88 .41 .76 .19 .52 1.96 .74 .70 .94
105
695.90 146.27 50.00 41.07 38.38 8.38 8.72 5.00 4.48 .15 1.00 .15 .50
Vg/Kfc un,i,
829.34 65.01 50.00 25.55 1.78 8.24 8.45 5.00 4.27 .58 1.00 .29 .50
85
17.16 .82 .42 .34 .22 .99 .80 .39 .73 .17 .49 1.83 .67 .64 .87
733.95 117.98 50.00 35.80 33.58 8.64 8.71 5.00 4.47 .17 1.00 .19 .50
100
16.47 .82 .42 .34 .22 .94 .75 .40 .72 .16 .47 1.77 .64 .61 .84
752.64 103.86 50.00 33.18 31.31 8.77 8.71 5.00 4.47 .35 1.00 .21 .50
95
Blended animal protein product (H. J. Baker & Bro., New York, NY 10017).
15.09 .82 .42 .34 .22 .84 .67 .42 .72 .14 .43 1.65 .57 .56 .77
789.94 75.64 50.00 27.93 26.78 9.08 8.70 5.00 4.47 .76 1.00 .26 .50
85
5
4
A. L. Laboratories, Inc., F t Lee, NJ 07024.
Supplied per kilogram of diet iron, 100 mg; manganese, 100 mg; zinc, 100 mg; copper, 10 mg; iodine, 1 mg.
Supplied per kilogram of diet: vitamin A, 6,600 IU; vitamin D3, 2,200 IU; vitamin E, 6.6 IU; menadione, 3.3 mg; riboflavin, 5.5 mg; niacin, 33 mg; pantothenic acid, 8.8 mg; choline, 495 mg; thiamine, 1.1 mg; pyridoxine, 1.1 mg; vitamin B12, -01 mg; biotin, .11 mg; folacin, .66 mg; ethoxyquin, 125 mg; selenium, .1 mg.
3
2
15.78 .82 .42 .34 .22 .89 .71 .41 .72 .15 .45 1.71 .61 .59 .81
771.29 89.75 50.00 30.55 29.05 8.90 8.70 5.00 4.47 .56 1.00 .24 .50
90
Diets with 3,300 kcal of ME/kg, % of suggested amino acid requirement
Percentage of male requirements of Thomas et al. (1986). Methionine and Met plus Cys were maintained at least 105% of suggested requirements.
16.76 .80 .41 .33 .22 .96 .77 .38 .71 .16 .48 1.80 .65 .63 .85
100
105
110
Ingredient
Diets with 3,190 kcal of ME/kg, % of suggested amino acid requirement
TABLE 4. Composition and calculated nutrient content of finisher diets containing 3,190 and 3J00 kcal of MEIkg and different percentages of suggested amino acid requirements (Experiment 1)
ded from http://ps.oxfordjournals.org/ at Tufts University on December 13, 2016
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SEPARATE SEX DIETS TABLE 5. Effect of dietary energy levels on body weight, feed utilization, and processing parameters of male and female broilers (combined results of four trials) Energy series Parameter
Low1
High2
SEM
Probability
Male 56-day weight, g Female 49-day weight, g Male 0- to 56-day gainifeed, g/g Female 0- to 49-day gain:feed, g/g Male dressing percentage Female dressing percentage Male abdominal fat, % of BW Female abdominal fat, % of BW
2,527 1,814
2,542 1,821
28 19
.3668 .5419 .1452 .5132
.473 .491 64.7 62.5b 2.84 3.20
.478 .495 64.9 62.9* 2.88 3.22
.006 .009 .33 .31 .07 .08
.5397 .0410 .4270 .7435
a b
deviation of the pen mean. The birds were transported to the University of Arkansas pilot processing plant, individually weighed, stunned, killed with an electric knife, scalded in a dunking scalder at 54 C, picked in a rotary drum picker, and manually eviscerated. Carcasses were chilled in a static ice bath for 1 h. Dressing percentage was calculated as dressed carcass weight without the necks and giblets divided by live weight. Abdominal fat was that fat surrounding the gizzard extending within the ischium and surrounding the bursa of Fabricius, cloaca, and adjacent abdominal muscles. Abdominal fat pad weight was calculated as a percentage of live body weight. All data were subjected to the analysis of variance (SAS Institute, 1985). Initial statistical analyses included the final production and carcass data of both sexes to determine if significant energy x sex, amino acid X sex, or energy x amino acid x sex interactions existed. These interactions were found to be nonsignificant (P>.05), indicating that sexes responded to these factors in a similar manner. Therefore, additional analyses were carried out separately for each sex. The statistical model included trial, energy level, amino acid level, block (replicate), and all two-way and three-way interactions of the main factors. Linear and quadratic regression were performed to determine the degree of response to the dietary factors. RESULTS AND DISCUSSION
There were no trial x treatment interactions, so the results of the combined trials will be presented. There were no interactions of
dietary energy, amino acid level, or energy x amino acid interactions with sex of the broiler, indicating that the response of male and female broilers to the dietary factors was similar. In addition, there were no interactions of energy x amino acids for any of the parameters examined. Dietary energy content had no significant effects (P>.05) on body weight of males and females, feed utilization by males and females, or abdominal fat pad as a percentage of body weight of males and females (Table 5). Females fed the high energy diet series had significantly (P<05) greater dressing percentage than females fed the low energy diet series. The difference between the two energy series was 110 kcal of ME/kg- Based on previous results from the authors' laboratory (Waldroup et al, 1976) the difference in energy content of the diets was probably not sufficient to result in a statistically significant response, based on the variability present in the present study. Dietary amino acid content had a significant (P<.05) influence on virtually every parameter examined except for dressing percentage (Table 6). For the overall main effect of amino acid levels, there were significant effects on male and female body weight, male feed utilization, and male and female abdominal fat as a percentage of body weight. The main effect of amino acid levels on feed utilization by females approached statistical significance (P = .07). There were no significant effects of amino acid levels on dressing percentage of male or female broilers. The response to the amino acid levels was best fit by linear
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' Means in row with no common superscripts differ significantly (K.05). Contained 3,080, 3,135, and 3,190 kcal of ME/kg in starter, grower, and finisher diets, respectively. Contained 3,190, 3,245, and 3,300 kcal of ME/kg in starter, grower, and finisher diets, respectively.
1520
WALDROUP ET AL.
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regression estimates. Slope and intercept values for significant equations are shown in Table 6. Although it has long been suggested that male and female broilers may have differing amino acid requirements, the results of this study indicate that separate diets for male and female broilers are not justified at the present time. This is in agreement with the reports of Douglas and Harms (1960), Combs and Nicholson (1965), Bomstein and Lipstein (1966), and Freeman (1979). Even in studies where differences have been indicated in specific amino acid requirements, there were only minimal differences in actual value (Hunchar and Thomas, 1976; Kessler and Thomas, 1976). The degree of response of female broilers to increasing amino acid levels in the diet of the present study was similar to that of males as indicated by the regression equations. Males and females showed a similar lack of response to the two energy levels for the production parameters examined and to the interaction of dietary energy and amino acid levels. The present study also suggests that the amino acid standards of Thomas et al. (1986) may be low in at least one essential amino acid since improved weight gains were observed in both male and female broilers at levels above the 100% recommendations. The formulations used in the present study were designed to be at or near the minimum suggested levels for as many of the indispensable amino acids as possible and made maximum usage of supplemental amino acids. Therefore, it is likely that these diets presented a greater challenge to the bird in meeting its amino acid needs than typical least-cost formulations. Although many studies indicate that amino acid requirements of the broiler chick decline with age, little research has been done to determine the optimum time at which such changes should be made. Powell and Gehle (1974) concluded that broiler chickens could be changed from high protein starter diets to lower protein finisher diets as early as 21 days of age without adversely affecting body weight and suggested that feed utilization may actually improve by changing to the finisher diet at an earlier age. However, the difference in protein content of the two diets was rather minimal in comparison to levels normally used in commercial starter and finisher diets. Gehle et al. (1974) fed broiler chickens a diet with
SEPARATE SEX DIETS
ACKNOWLEDGMENTS
The authors express their appreciation to the Degussa Corporation, Allendale, NJ for conducting the amino acid analyses for the experimental diets. REFERENCES Association of Official Agricultural Chemists, 1970. Official Methods of Analysis. 11th ed. Assoc. Off. Agric. Chem., Washington, DC. Bornstein, S., andB. Lipstein, 1966. Methionine supplementation of practical broilerration,m . The value of added
methionine in broiler finisher rations. Br. Poult. Sci. 7: 273-284. Combs, G. F., and J. L. Nicholson, 1965. Effect of protein level and quality on performance of broiler chickens separated by sex. Feedstuff's (July 31):42. Douglas, C. R., and R. H. Harms, 1960. Effects of varying protein and energy levels of broiler diets during the finishing period. Poultry Sci. 39:1003-1008. Douglas, C. R., H. J. Hochreich, and R. H. Harms, 1958. Glycine in broiler nutrition. Poultry Sci. 37:620-624. Farrell, D. J., R. B. Cumming, and J. B. Hardaker, 1973. The effects of dietary energy concentration on growth rate and conversion of energy to weight gain in broiler chickens. Br. Poult. Sci. 14:329-340. Freeman, C. P., 1979. The tryptophan requirement of broiler chick. Br. Poult. Sci. 20:27-37. Gehle, M. H„ T. S. Powell, and L. G. Arends, 1974. Effect of different feeding regimes on performance of broiler chickens reared sexes separate or combined. Poultry Sci. 53:1543-1548. Hunchar, J. G., and O. P. Thomas, 1976. The tryptophan requirement of male and female broilers during the 4-7 week period. Poultry Sci. 55:379-383. Kessler, J. W., and O. P. Thomas, 1976. The arginine requirement of the 4-7 week old broiler. Poultry Sci. 55:2379-2382. Minear, L. R., and J. E. Marion, 1981. Nutrient requirements of male and female broilers. Zootechnia (October): 16-19. National Research Council, 1984. Nutrient requirements of poultry. 8th ed. National Academy of Sciences, Washington, DC. Powell, T. S., and M. H. Gehle, 1974. Effect of different feeding regimes on performance of color sexed broilers, sexes reared separate. Nutr. Rep. Int. 10:333-337. Proudfoot, F. G., and H. W. Hulan, 1980. Performance of chicken broilers changed from starter to finisher diets at different ages. Can. J. Anim. Sci. 60:799-801. Roush, W. B., 1982. An investigation of protein levels for broiler starter and finisher rations and thetimeof ration change by response surface methodology. Poultry Sci. 62:110-116. SAS Institute, 1985. SAS® User's Guide: Statistics. SAS Institute, Inc., Cary, NC. Shutze, J. V., P. A. Thornton, and R. E. Moreng, 1958. Protein energy relationships as affected by sex and management Poultry Sci. 37:1063-1070. Thomas, O. P., A. I. Zuckerman, M. Farran, and C. B. Tamplin, 1986. Updated amino acid requirements of broilers. Pages 79-85 in: Proc. Maryland Nutr. Conf., Baltimore, MD. Waldroup, P. W., R. J. Mitchell, J. R. Payne, and Z. B. Johnson, 1976. Characterization of the response of broiler chickens to diets varying in nutrient content Poultry Sci. 55:130-145. Wells, R. G., 1963. Relationship between dietary energy level, food consumption and growth in broiler chicks. Br. Poult. Sci. 4:161-168. Yule, W. J., 1976. Optimum change to finisher diet and most efficient marketing age of sex separated broilers. Nutr. Rep. Int 14:121-124.
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24.9% CP to either 28 or 35 days of age followed by a finisher diet with 22.8% CP to 49 or 56 days of age. Final weights were slightly lower in birds fed the starter to 35 days of age, regardless of sex of bird or final marketing age. Yule (1976) changed broiler chickens from 21% CP to 18% CP at 7-day intervals beginning at 10 to 45 days of age. Body weight and feed efficiency improved linearly with increasing age of change to the finisher diet. Proudfoot and Hulan (1980) made changes from a 24% CP starter diet to a 15.9% CP finisher diet beginning at 28 days of age and at daily intervals to 33 days of age. Neither body weights nor monetary returns were significantly affected by the time of changing to finisher diets. Roush (1982) fed a series of starter diets with 13 to 33% CP followed by a series of finisher diets with 8 to 18% CP with changes made at different ages. Optimal protein levels for body weight were 26 and 19% CP for starter and finisher diets, and 30 and 26% CP for feed utilization. Body weights were optimized when diets were changed at 27 days, and feed efficiency was optimized when diets were changed at 24 days. The optimal amino acid requirements of the modern broiler chicken when grown to satisfy present market demands needs to be determined. An increasingly greater percentage of broiler males are being grown for further processed items and are consequently being grown to heavier weights than previously seen in the poultry industry. Optimal feeding systems for growing to different weight demands for the different sexes may be required.
1521
1990 Poultry Science 69:1513-1521 INTRODUCTION
As chick sexing at day of hatch has become less costly through the introduction of feather sexing strains, a greater percentage of broiler chickens are being raised sex-separate. Sexseparate rearing has also been spurred by the increased demand for further processed poultry items, which calls for greater uniformity of size and a wider range of bird sizes than traditional ice-packed broilers. Increasing consumer demands for portion uniformity and further processed products, particularly those using breast meat, indicate that the trend toward more sex-separate rearing will continue to increase. The acceptance of sex-separate rearing has made more relevant a question that has long been debated: Is there justification for using different diets for each sex? It has long been recognized that male broiler chickens grow
^Published with the approval of the director, Arkansas Agricultural Experiment Station. Present address: Nicholas Turkey Breeding Farms, Sonoma, CA 95476.
faster and have better feed efficiency than do female broilers. The growth rate of females starts to plateau earlier in life than does the growth rate of males, and females begin to deposit fat at earlier ages and in higher percentages than males. This would suggest that the nutritional requirements of males might be higher than for females. However, research conducted to determine if male and female broilers have different nutritional requirements has not been conclusive. Douglas et al. (1958) and Shutze et al. (1958) suggested that males had a higher protein requirement than females. However, Douglas and Harms (1960) fed a wide range of energy and protein ratios and found no interaction between sex and dietary treatment. Combs and Nicholson (1965) tested various levels of amino acids and found no significant difference in amino acid requirements for male versus female broilers. Bornstein and Lipstein (1966) found no sex-related differences for methionine needs in broilers during the finisher period. Hunchar and Thomas (1976) found only minimal differences in tryptophan requirements; males needed an average of
1513
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ABSTRACT Studies were conducted to evaluate the response of male and female broiler chickens to diets containing different levels of energy and amino acids. Two energy series were compared: 3,080, 3,135, and 3,190 kcal of ME/kg ("low") and 3,190,3,245, and 3,300 kcal of ME/kg ("high") in pelleted starter, grower, and finisher diets. Diets provided a minimum of 85, 90, 95, 100, 105, and 110% of suggested amino acid recommendations for the broiler male except for Met and TSAA, which were kept at 105%. Modifications were made in feeding periods, recognizing the differences in rate of gain and marketing ages of the two sexes. Feeding periods were 0 to 21,21 to 42, and 42 to 56 days for males and 0 to 18,18 to 35, and 35 to 49 days for females. Four floor pen trials utilizing 9,600 male and 9,600 female broilers were conducted. Birds were processed to determine dressing percentage and abdominal fat pad weights. Energy content of the diets had no significant (P>.05) effect on body weight or feed efficiency for male or female broilers. Carcass dressing percentage of females, but not males, was significantly (P<05) increased on the high energy series. Abdominal fat pad was not influenced by energy for either sex. For both sexes, increasing dietary amino acid levels resulted in significant (PS.05) linear improvements in live weights and feed utilization and a reduction in abdominal fat pad weight. There were no treatment by sex interactions for any of the parameters, indicating that both sexes responded to changes in energy and amino acid levels in a similar manner. Therefore, the results of this study do not support feeding nutritionally different diets to male versus female broilers when feeding periods are adjusted by sex. (Key words: amino acids, energy, separate sex, nutrition, broilers)
1514
WALDROUP ET AL.
MATERIALS AND METHODS
Four trials were conducted over a year to consider any seasonal influences. The first trial was started in mid-June, the second in midSeptember, the third in mid-February, and the fourth in early May. Two energy series were compared. A low energy level diet contained 3,080, 3,135, and 3,190 kcal of ME/kg in the starter, grower, and finisher rations, respectively. A high energy diet contained 3,190, 3,245, and 3,300 kcal of ME/kg in the starter, grower, and finisher rations, respectively. A designation of low or high is relative and is used in this study only to describe the two different energy series.
Amino acid standards of Thomas et al. (1986) provide separate amino acid and protein recommendations for male and female broilers, with recommendations for females being approximately 5% lower than those for males. Using the standards for males, six amino acid levels were established at 85, 90, 95, 100,105, or 110% of the suggested standard. In order to place more emphasis upon other amino acids, which seldom are limiting in corn-soybean meal type diets, Met and Met plus Cys were maintained at 105% of the suggested requirement. Each amino acid series was formulated at the two energy levels with the amino acids maintained in ratio with the dietary energy level. DL-Methionine and L-lysine HC1 were offered to the computer at no cost to encourage the use of these two ingredients and minimize overall protein and amino acid levels. Although it is virtually impossible to formulate practical type diets with exactly minimal levels of all essential amino acids, the diets in this study were formulated to provide minimal levels of excess amounts. In most instances, the requirements for lysine, arginine, threonine, and isoleucine were at minimum levels and others were at or near the minimum in most diets. All mixed feeds were subjected to Kjeldahl analysis (Association of Official Agricultural Chemists, 1970) to verify proper mixing and were found to be in agreement with calculated values. Because of the number of test diets involved in the study, amino acid analysis was conducted only on the lowest and highest amino acid level in each series. Analysis by ion-exchange chromatography was carried out by a major producer of amino acids, and results were in agreement with calculated values. The nutrient values used for the major dietary ingredients were based on a composite of amino acid values from three major laboratories (Table 1). The composition and calculated nutrient analysis of the starter, grower, and finisher diets for Experiment 1 are given in Tables 2, 3, and 4. For the other trials, diets were reformulated based upon the actual moisture and protein content of the corn and soybean meal present in the University of Arkansas feed mill at that time; adjustments were made in the amino acid content relative to the total protein and moisture content. This resulted in only slight modifications in the overall dietary composition for ensuing trials, and the diets will not be shown in tabular form.
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.0043% more tryptophan than females. Freeman (1979) reported no difference in tryptophan requirements between sexes when expressed as a percentage of the diet. Kessler and Thomas (1976) examined arginine requirements for 4- to 7-wk-old broilers and from the count of floor feathers determined mat males had a slightly higher need for arginine than females. Minear and Marion (1981) found that male broilers had a significantly higher requirement for lysine and sulfur amino acids than did female broilers. However, when separate "male" and "female" diets were developed utilizing these findings, both the males and females required the more nutrientdense "male" diet for maximum growth. Wells (1963) reported a consistently greater growth response to dietary energy for males than females. Waldroup et al. (1976) determined that male broilers utilized energy more efficiently than females; however, the response to increasing energy was linear for both sexes. Farrell et al. (1973) reported that the ME required by each sex to reach a given live weight was quite similar. Most of the previous research on differing nutrient requirements or sex-separate feeding has been conducted with birds of both sexes being tested at the same age. In consideration of the differential growth rates and feed efficiency over time, this might help to explain the inconsistent results of the previous research. In designing the present trials to study nutrient requirement of male versus female broilers, the differing growth rate patterns and present-day marketing programs of sex-separate reared broilers were considered, and feeding periods were altered accordingly.
1515
SEPARATE SEX DIETS TABLE 1. Ingredient composition values used in formulation Yellow corn
Soybean meal
Propak2
Corn gluten meal
ME, kcal/kg Protein Calcium Total phosphorus Available phosphorus Chloride Sodium Potassium Arginine Lysine Methionine Met plus Cys Tryptophan Glycine Histidine Leucine Isoleucine Phenylalanine Phe plus Tyr Threonine Valine
3,313.00 8.20 .02 .28 .10 .04 .04 .28 .39 .25 .19 .38 .07 .33 .25 1.01 .28 .41 .65 .30 .41
2,424.00 48.0 .20 .65 .26 .05 .02 1.98 3.62 3.07 .69 1.41 .65 2.28 1.39 3.76 2.23 2.47 4.25 1.90 2.36
2,645.00 61.06 5.30 3.00 3.00 .55 .60 .52 3.90 3.78 1.81 3.01 .53 5.62 1.75 5.15 1.86 2.89 4.76 2.45 3.80
3,741.00 62.00 .02 .70 21 .05 .02 .35 2.03 .95 1.66 2.79 .35 1.64 1.33 10.24 2.81 3.77 6.71 2.05 2.87
'With the exception of metabolizable energy, all values are expressed as percentage of the ingredient BIended animal protein product (H. J. Baker and Bro., New York, NY).
2
All diets contained monensin sodium3 at 90 g per ton (909 kg) as an anticoccidial in the starter and grower feed. Bacitracin methylene disalicylate4 was added to all starter, grower, and finisher diets at 50 g/ton. Roxarsone5 was added to starter and grower diets at 45 g per ton. Complete vitamin and trace mineral premixes were used to meet National Research Council (1984) recommended guidelines. All diets were pelleted using steam preconditioning.6 All trials were conducted in a commercial type, curtain-sided house, which contained 96 pens divided into four blocks of 24 pens each. Within each of the blocks, there were 12 pens of 50 male and 12 pens of 50 female chicks. Chickens of a commercial broiler strain (Cobb 500) were obtained from a local hatchery and randomly allocated to pens. The pens were 2.4 x 2.25 m and were equipped wim two tube type feeders and one bell-shaped automatic waterer. Four replicate pens of males and four
3
Coban, Blanco Products Co., Indianapolis, IN 46285. ^MD-SO, A. L. Laboratories, Inc., Fort Lee, NJ 07024. ^Roxarsone 10%, Rhone-Poulenc, Inc., Atlanta, GA 30338. California Pellet Mill Master Model, California Pellet Mill Co., Crawfordsville, IN 47933.
replicate pens of females (one replicate of each sex per block) were assigned to each dietary treatment in each of the four studies for an overall total of 16 replicate pens of each sex per dietary treatment. During the first 7 days, supplemental feeder flats, and water founts were used, hi each trial new wood shavings were used as litter over concrete floors. Feed and water were provided free choice. Mortality was recorded daily, and feed efficiency was adjusted for the weight of birds that died. Modifications were made in the feeding period for both sexes. Such modifications have long been done in the turkey industry, recognizing both the different growth rate and the different marketing age of the two sexes. In the present study, feeding periods for females were 0 to 18 days on starter, 18 to 35 days on grower, and 35 to 49 days on finisher. Feeding periods for males were 0 to 21 days on starter, 21 to 42 days on grower, and 42 to 56 days on finisher. At the end of each feeding period all birds were weighed by pen, feed consumption was determined, and feed efficiency was calculated. At the end of the finisher period (49 days for females and 56 days for males) five birds from each pen were selected for processing. Birds were randomly selected with the proviso that all birds weighed within .5 standard
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Nutrient1
654.61 243.80 50.00 19.50 9.98 7.78 5.00 4.09 1.28 .97 1.00 .50 .50 1.00
20.36 .84 .46 .33 .21 1.34 1.19 .52 .88 .24 .59 1.86 .83 .79 1.04
631.12 263.37 50.00 23.31 8.93 7.78 5.00 4.09 1.51 1.00 1.00 .50 .50 1.00
21.11 .84 .46 .33 .21 1.41 1.25 .55 .92 .25 .61 1.91 .87 .82 1.08
Yellow corn Soybean meal (48.5% CP) Propak (60% CP) 2 Blended fat Dicalcium phosphate Limestone Vitamin premix3 Salt DL-methionine (98%) Lysine HC1 (98%) Trace-mineral mix* Bacitracin MD 50 5 Roxarsone 10%6 Coban 4 5 ' Calculated nutrient content, % Protein Calcium Available phosphorus Chloride Sodium Arginine Lysine Methionine Met plus Cys Tryptophan Histidine Leucine Isoleucine Threonine Valine 19.60 .84 .46 .33 .21 1.28 1.13 .52 .88 .22 .57 1.81 .80 .76 1.00
677.27 224.32 50.00 16.00 10.13 7.79 5.00 4.08 1.46 .94 1.00 .50 .50 1.00
100
18.85 .84 .46 .33 21 1.22 1.08 .53 .88 21 .55 1.76 .76 .72 .96
699.93 204.84 50.00 12.50 10.29 7.80 5.00 4.08 1.65 .91 1.00 .50 .50 1.00
95
18.10 .84 .46 .33 .21 1.16 1.02 .54 .88 .20 .53 1.71 .72 .69 .93
722.59 185.35 50.00 9.00 10.44 7.80 5.00 4.08 1.84 .89 1.00 .50 .50 1.00
90
17.34 .84 .46 .33 .21 1.10 .96 .55 .88 .19 .50 1.66 .69 .66 .89
745.25 165.87 50.00 5.50 10.59 7.81 5.00 4.08 2.03 .86 1.00 .50 .50 1.00
85
110
21.88 .87 .48 .35 .22 1.46 1.29 .57 .96 .25 .63 1.99 .91 .84 1.11
(g/kg) 581.84 278.22 50.00 48.80 10.69 8.03 5.00 4.29 1.62 1.05 1.00 .50 .50 1.00 20.86 .87 .48 .35 .22 1.39 1.23 .54 .91 .24 .60 1.89 .86 .81 1.06
608.35 261.30 50.00 46.06 10.86 8.01 5.00 4.29 1.59 .96 1.00 .50 .50 1.00
105
20.06 .87 .48 .34 .22 1.33 1.17 .55 .91 .23 .58 1.83 .82 .77 1.02
632.03 241.45 50.00 42.55 11.02 8.01 5.00 4.29 1.72 .93 1.00 .50 .50 1.00
100
19.28 .87 .48 .34 22 1.26 1.12 .56 .91 .22 .56 1.77 .78 .74 .98
655.50 221.28 50.00 38.92 11.18 8.02 5.00 4.29 1.91 .90 1.00 .50 .50 1.00
95
Blended animal protein product (H. J. Baker & Bro., New York, NY 10017).
17.71 .87 .48 .34 .21 1.13 1.00 .58 .91 .20 .52 1.67 .71 .68 .91
702.44 180.92 50.00 31.67 11.50 8.03 5.00 4.28 2.30 .84 1.00 .50 .50 1.00
85
A. L. Laboratories, Inc., F t Lee, NJ 07024.
7
Elanco Products Co., Indianapolis, IN 46285.
^hone-Poulenc, Inc., Atlanta, GA 30338.
5
^Supplied per kilogram of diet: iron, 100 mg; manganese, 100 mg; zinc, 100 mg; copper, 10 mg; iodine, 1 mg.
Supplied per kilogram of diet: vitamin A, 6,600 IU; vitamin D3, 2,200 IU; vitamin E, 6.6 IU; menadione, 3.3 mg; riboflavin, 5.5 mg; niacin, 33 mg; pantothenic acid, 8.8 mg; choline, 495 mg; thiamine, 1.1 mg; pyridoxine, 1.1 mg; vitamin B12. -01 mg; biotin, .11 mg; folacin, .66 mg; ethoxyquin, 125 mg; selenium, .1 mg.
3
2
18.49 .87 .48 .34 .22 1.20 1.06 .57 .91 .21 .54 1.72 .74 .71 .95
678.97 201.10 50.00 35.30 11.34 8.03 5.00 4.28 2.11 .87 1.00 .50 .50 1.00
90
Diets with 3,190 kcal of ME/kg, of suggested amino acid requirement
Percentage of male requirements of Thomas et al. (1986). Methionine and Met plus Cys were maintained at least 105% of suggested requirements.
105
110
Ingredient
Diets with 3,080 kcal of ME/kg, of suggested amino acid requirement
TABLE 2. Composition and calculated nutrient content of starter diets containing 3,080 and 3,190 kcal of MEIkg and different percentages of suggested amino acid requirements (Experiment 1)
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18.29 .86 .47 .34 .21 1.10 .95 .49 .84 .19 .52 1.88 .73 .69 .93 17.31 .86 .47 .34 .21 1.04 .90 .51 .84 .18 .50 1.77 .68 .65 .88
110
22.01 .88 .49 .35 .22 1.31 1.13 .52 .92 .23 .61 2.31 .91 .83 1.11
607.09 205.44 50.00 62.85 40.70 11.38 8.37 4.38 .62 1.17 5.00 1.00 .50 .50 1.00
I(g/kg)
20.99 .88 .49 .35 .22 1.25 1.08 .50 .88 .22 .58 2.19 .86 .79 1.06
632.03 191.23 50.00 54.14 38.65 11.55 8.35 4.38 .58 1.10 5.00 1.00 .50 .50 1.00 19.97 .88 .49 .35 .22 1.19 1.03 .49 .87 .21 .56 2.08 .81 .75 1.01
656.48 177.04 50.00 45.48 36.78 11.72 8.32 4.37 .78 1.03 5.00 1.00 .50 .50 1.00 18.95 .88 .49 .35 22 1.13 .98 .51 .87 .20 .54 1.96 .76 .71 .96
680.64 162.87 50.00 36.85 35.01 11.89 8.30 4.37 1.13 .95 5.00 1.00 .50 .50 1.00
17.10 .88 .49 .35 .22 1.01 .88 .53 .87 .17 .50 1.91 .70 .66 .90
722.39 122.45 50.00 42.58 27.30 12.17 8.33 4.37 1.38 1.03 5.00 1.00 .50 .50 1.00
85
7
Elanco Products Co., Indianapolis, IN 46285.
A. L. Laboratories, Inc., Ft Lee, NJ 07024. ^one-Poulenc, Inc., Atlanta, GA 30338.
5
3 Supplied per kilogram of diet: vitamin A, 6,600 IU; vitamin D3, 2,200 IU; vitamin E, 6.6 IU; menadione, 3.3 mg; riboflavin, 5.5 mg; niacin, 33 mg; pantothenic acid, 8.8 mg; choline, 495 mg; thiamine, 1.1 mg; pyridoxine, 1.1 mg; vitamin B 1 2 , .01 mg; biotin, .11 mg; folacin, .66 mg; ethoxyquin, 125 mg; selenium, .1 mg. 4 Supplied per kilogram of diet: iron, 100 mg; manganese, 100 mg; zinc, 100 mg; copper, 10 mg; iodine, 1 mg.
2
17.93 .88 .49 .35 .22 1.07 .93 .53 .87 .19 .51 1.84 .71 .67 .91
704.80 148.70 50.00 28.21 33.23 12.06 8.27 4.37 1.48 .88 5.00 1.00 .50 .50 1.00
Diets with 3,245 kcal of ME/kg, % of suggested amino acid requirement 105 100 95 90
S
CO
3
£
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: DIET
'Percentage of male requirements of Thomas et al. (1986). Methionine and Met plus Cys were maintained at least 105% of suggested requirements. Blended animal protein product (H. J. Baker & Bro., New York, NY 10017).
19.28 .86 .47 .34 .21 1.15 1.00 .78 .84 .20 .54 1.99 .78 .73 .98 17.10 .86 .47 .34 .21 .98 .85 .50 .84 .17 .49 1.83 .67 .64 .87
20.26 .86 .47 .34 .21 1.21 1.05 .48 .85 .21 .57 2.11 .82 .76 1.03
749.25 138.37 50.00 20.16 8.64 11.17 8.02 4.17 1.39 .84 5.00 1.00 .50 .50 1.00
21.25 .86 .47 .34 .21 1.27 1.10 .50 .89 21 .59 2.22 .87 .80 1.07
725.91 152.06 50.00 28.51 10.35 11.00 8.04 4.17 1.05 .91 5.00 1.00 .50 .50 1.00
766.10 112.73 50.00 34.58 2.81 11.27 8.07 4.17 1.28 .98 5.00 1.00 .50 .50 1.00
702.51 165.76 50.00 36.85 12.09 10.84 8.07 4.17 .75 .98 5.00 1.00 .50 .50 1.00
678.88 179.46 50.00 45.22 13.90 10.68 8.09 4.17 55 1.05 5.00 1.00 .50 .50 1.00
654.78 193.20 50.00 53.63 15.88 10.51 8.12 4.18 .59 1.12 5.00 1.00 .50 .50 1.00
Yellow corn Soybean meal (48.5% CP) Propak (60% CP)2 Com gluten meal (60% CP) Blended fat Dicalcium phosphate Limestone Salt DL-methionine (98%) Lysine HC1 Vitamin premix Trace-mineral mix'; Bacitracin MD 50 5 Roxarsone 10%6 Coban 45 7 Calculated nutrient content, % Protein Calcium Available phosphorus Chloride Sodium Arginine Lysine Methionine Met plus Cys Tryptophan Histidine Leucine Isoleucine Threonine Valine
85
110
Ingredient
Diets with 3,135 kcal of ME/kg, % of suggested amino acid requirement 105 100 95 90
TABLE 3. Composition and calculated nutrient content of grower diets containing 3,135 and 3245 kcal of ME/kg and different percentages of suggested amino acid requirements^ (Experiment 1)
SEP.
775.06 105.95 50.00 33.16 8.40 7.86 8.47 5.00 4.27 .09 1.00 .23 .50
756.82 119.61 50.00 35.70 10.67 7.74 8.47 5.00 4.27
1.00 .21 .50
17.42 .80 .41 .33 .22 1.00 .81 .38 .72 .18 .49 1.86 .68 .65 .89
738.28 133.30 50.00 38.26 13.04 7.62 8.48 5.00 4.28 .06 1.00 .19 .50
18.09 .80 .41 .33 .22 1.05 .84 .40 .75 .18 .51 1.92 .72 .68 .92
Yellow corn Soybean meal (48.5% CP) Propak (60% CP)2 Com gluten meal (60% CP) Blended fat Dicalcium phosphate Limestone Vitamin premix3 Salt DL-methionine (98%) Trace-mineral mix4 Lysine HC1 Bacitracin MD 50 5 Calculated nutrient content, % Protein Calcium Available phosphorus Chloride Sodium Arginine Lysine Methionine Met phis Cys Tryptophan Histidine Leucine Isoleucine Threonine Valine 16.09 .80 .41 .33 .22 .91 .73 .38 .70 .16 .46 1.74 .62 .60 .82
793.27 92.29 50.00 30.62 6.15 7.99 8.46 5.00 4.27 .19 1.00 .25 .50
95
15.42 .80 .41 .33 .22 .86 .69 .39 .70 .15 .44 1.69 .59 .57 .79
811.31 78.65 50.00 28.08 3.96 8.11 8.46 5.00 4.27 .38 1.00 .27 .50
90
110
14.76 .80 .41 .33 .22 .81 .65 .40 .70 .14 .42 1.63 .55 .55 .76
715.11 132.11 50.00 38.43 35.91 8.51 8.72 5.00 4.47 .07 1.00 .17 .50
17.85 .82 .42 .34 .22 1.04 .83 .40 .73 .18 .50 1.89 .71 .67 .91
18.54 .82 .42 .34 .22 1.09 .88 .41 .76 .19 .52 1.96 .74 .70 .94
105
695.90 146.27 50.00 41.07 38.38 8.38 8.72 5.00 4.48 .15 1.00 .15 .50
Vg/Kfc un,i,
829.34 65.01 50.00 25.55 1.78 8.24 8.45 5.00 4.27 .58 1.00 .29 .50
85
17.16 .82 .42 .34 .22 .99 .80 .39 .73 .17 .49 1.83 .67 .64 .87
733.95 117.98 50.00 35.80 33.58 8.64 8.71 5.00 4.47 .17 1.00 .19 .50
100
16.47 .82 .42 .34 .22 .94 .75 .40 .72 .16 .47 1.77 .64 .61 .84
752.64 103.86 50.00 33.18 31.31 8.77 8.71 5.00 4.47 .35 1.00 .21 .50
95
Blended animal protein product (H. J. Baker & Bro., New York, NY 10017).
15.09 .82 .42 .34 .22 .84 .67 .42 .72 .14 .43 1.65 .57 .56 .77
789.94 75.64 50.00 27.93 26.78 9.08 8.70 5.00 4.47 .76 1.00 .26 .50
85
5
4
A. L. Laboratories, Inc., F t Lee, NJ 07024.
Supplied per kilogram of diet iron, 100 mg; manganese, 100 mg; zinc, 100 mg; copper, 10 mg; iodine, 1 mg.
Supplied per kilogram of diet: vitamin A, 6,600 IU; vitamin D3, 2,200 IU; vitamin E, 6.6 IU; menadione, 3.3 mg; riboflavin, 5.5 mg; niacin, 33 mg; pantothenic acid, 8.8 mg; choline, 495 mg; thiamine, 1.1 mg; pyridoxine, 1.1 mg; vitamin B12, -01 mg; biotin, .11 mg; folacin, .66 mg; ethoxyquin, 125 mg; selenium, .1 mg.
3
2
15.78 .82 .42 .34 .22 .89 .71 .41 .72 .15 .45 1.71 .61 .59 .81
771.29 89.75 50.00 30.55 29.05 8.90 8.70 5.00 4.47 .56 1.00 .24 .50
90
Diets with 3,300 kcal of ME/kg, % of suggested amino acid requirement
Percentage of male requirements of Thomas et al. (1986). Methionine and Met plus Cys were maintained at least 105% of suggested requirements.
16.76 .80 .41 .33 .22 .96 .77 .38 .71 .16 .48 1.80 .65 .63 .85
100
105
110
Ingredient
Diets with 3,190 kcal of ME/kg, % of suggested amino acid requirement
TABLE 4. Composition and calculated nutrient content of finisher diets containing 3,190 and 3J00 kcal of MEIkg and different percentages of suggested amino acid requirements (Experiment 1)
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SEPARATE SEX DIETS TABLE 5. Effect of dietary energy levels on body weight, feed utilization, and processing parameters of male and female broilers (combined results of four trials) Energy series Parameter
Low1
High2
SEM
Probability
Male 56-day weight, g Female 49-day weight, g Male 0- to 56-day gainifeed, g/g Female 0- to 49-day gain:feed, g/g Male dressing percentage Female dressing percentage Male abdominal fat, % of BW Female abdominal fat, % of BW
2,527 1,814
2,542 1,821
28 19
.3668 .5419 .1452 .5132
.473 .491 64.7 62.5b 2.84 3.20
.478 .495 64.9 62.9* 2.88 3.22
.006 .009 .33 .31 .07 .08
.5397 .0410 .4270 .7435
a b
deviation of the pen mean. The birds were transported to the University of Arkansas pilot processing plant, individually weighed, stunned, killed with an electric knife, scalded in a dunking scalder at 54 C, picked in a rotary drum picker, and manually eviscerated. Carcasses were chilled in a static ice bath for 1 h. Dressing percentage was calculated as dressed carcass weight without the necks and giblets divided by live weight. Abdominal fat was that fat surrounding the gizzard extending within the ischium and surrounding the bursa of Fabricius, cloaca, and adjacent abdominal muscles. Abdominal fat pad weight was calculated as a percentage of live body weight. All data were subjected to the analysis of variance (SAS Institute, 1985). Initial statistical analyses included the final production and carcass data of both sexes to determine if significant energy x sex, amino acid X sex, or energy x amino acid x sex interactions existed. These interactions were found to be nonsignificant (P>.05), indicating that sexes responded to these factors in a similar manner. Therefore, additional analyses were carried out separately for each sex. The statistical model included trial, energy level, amino acid level, block (replicate), and all two-way and three-way interactions of the main factors. Linear and quadratic regression were performed to determine the degree of response to the dietary factors. RESULTS AND DISCUSSION
There were no trial x treatment interactions, so the results of the combined trials will be presented. There were no interactions of
dietary energy, amino acid level, or energy x amino acid interactions with sex of the broiler, indicating that the response of male and female broilers to the dietary factors was similar. In addition, there were no interactions of energy x amino acids for any of the parameters examined. Dietary energy content had no significant effects (P>.05) on body weight of males and females, feed utilization by males and females, or abdominal fat pad as a percentage of body weight of males and females (Table 5). Females fed the high energy diet series had significantly (P<05) greater dressing percentage than females fed the low energy diet series. The difference between the two energy series was 110 kcal of ME/kg- Based on previous results from the authors' laboratory (Waldroup et al, 1976) the difference in energy content of the diets was probably not sufficient to result in a statistically significant response, based on the variability present in the present study. Dietary amino acid content had a significant (P<.05) influence on virtually every parameter examined except for dressing percentage (Table 6). For the overall main effect of amino acid levels, there were significant effects on male and female body weight, male feed utilization, and male and female abdominal fat as a percentage of body weight. The main effect of amino acid levels on feed utilization by females approached statistical significance (P = .07). There were no significant effects of amino acid levels on dressing percentage of male or female broilers. The response to the amino acid levels was best fit by linear
Downloaded from http://ps.oxfordjournals.org/ at Tufts University on December 13, 2016
' Means in row with no common superscripts differ significantly (K.05). Contained 3,080, 3,135, and 3,190 kcal of ME/kg in starter, grower, and finisher diets, respectively. Contained 3,190, 3,245, and 3,300 kcal of ME/kg in starter, grower, and finisher diets, respectively.
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regression estimates. Slope and intercept values for significant equations are shown in Table 6. Although it has long been suggested that male and female broilers may have differing amino acid requirements, the results of this study indicate that separate diets for male and female broilers are not justified at the present time. This is in agreement with the reports of Douglas and Harms (1960), Combs and Nicholson (1965), Bomstein and Lipstein (1966), and Freeman (1979). Even in studies where differences have been indicated in specific amino acid requirements, there were only minimal differences in actual value (Hunchar and Thomas, 1976; Kessler and Thomas, 1976). The degree of response of female broilers to increasing amino acid levels in the diet of the present study was similar to that of males as indicated by the regression equations. Males and females showed a similar lack of response to the two energy levels for the production parameters examined and to the interaction of dietary energy and amino acid levels. The present study also suggests that the amino acid standards of Thomas et al. (1986) may be low in at least one essential amino acid since improved weight gains were observed in both male and female broilers at levels above the 100% recommendations. The formulations used in the present study were designed to be at or near the minimum suggested levels for as many of the indispensable amino acids as possible and made maximum usage of supplemental amino acids. Therefore, it is likely that these diets presented a greater challenge to the bird in meeting its amino acid needs than typical least-cost formulations. Although many studies indicate that amino acid requirements of the broiler chick decline with age, little research has been done to determine the optimum time at which such changes should be made. Powell and Gehle (1974) concluded that broiler chickens could be changed from high protein starter diets to lower protein finisher diets as early as 21 days of age without adversely affecting body weight and suggested that feed utilization may actually improve by changing to the finisher diet at an earlier age. However, the difference in protein content of the two diets was rather minimal in comparison to levels normally used in commercial starter and finisher diets. Gehle et al. (1974) fed broiler chickens a diet with
SEPARATE SEX DIETS
ACKNOWLEDGMENTS
The authors express their appreciation to the Degussa Corporation, Allendale, NJ for conducting the amino acid analyses for the experimental diets. REFERENCES Association of Official Agricultural Chemists, 1970. Official Methods of Analysis. 11th ed. Assoc. Off. Agric. Chem., Washington, DC. Bornstein, S., andB. Lipstein, 1966. Methionine supplementation of practical broilerration,m . The value of added
methionine in broiler finisher rations. Br. Poult. Sci. 7: 273-284. Combs, G. F., and J. L. Nicholson, 1965. Effect of protein level and quality on performance of broiler chickens separated by sex. Feedstuff's (July 31):42. Douglas, C. R., and R. H. Harms, 1960. Effects of varying protein and energy levels of broiler diets during the finishing period. Poultry Sci. 39:1003-1008. Douglas, C. R., H. J. Hochreich, and R. H. Harms, 1958. Glycine in broiler nutrition. Poultry Sci. 37:620-624. Farrell, D. J., R. B. Cumming, and J. B. Hardaker, 1973. The effects of dietary energy concentration on growth rate and conversion of energy to weight gain in broiler chickens. Br. Poult. Sci. 14:329-340. Freeman, C. P., 1979. The tryptophan requirement of broiler chick. Br. Poult. Sci. 20:27-37. Gehle, M. H„ T. S. Powell, and L. G. Arends, 1974. Effect of different feeding regimes on performance of broiler chickens reared sexes separate or combined. Poultry Sci. 53:1543-1548. Hunchar, J. G., and O. P. Thomas, 1976. The tryptophan requirement of male and female broilers during the 4-7 week period. Poultry Sci. 55:379-383. Kessler, J. W., and O. P. Thomas, 1976. The arginine requirement of the 4-7 week old broiler. Poultry Sci. 55:2379-2382. Minear, L. R., and J. E. Marion, 1981. Nutrient requirements of male and female broilers. Zootechnia (October): 16-19. National Research Council, 1984. Nutrient requirements of poultry. 8th ed. National Academy of Sciences, Washington, DC. Powell, T. S., and M. H. Gehle, 1974. Effect of different feeding regimes on performance of color sexed broilers, sexes reared separate. Nutr. Rep. Int. 10:333-337. Proudfoot, F. G., and H. W. Hulan, 1980. Performance of chicken broilers changed from starter to finisher diets at different ages. Can. J. Anim. Sci. 60:799-801. Roush, W. B., 1982. An investigation of protein levels for broiler starter and finisher rations and thetimeof ration change by response surface methodology. Poultry Sci. 62:110-116. SAS Institute, 1985. SAS® User's Guide: Statistics. SAS Institute, Inc., Cary, NC. Shutze, J. V., P. A. Thornton, and R. E. Moreng, 1958. Protein energy relationships as affected by sex and management Poultry Sci. 37:1063-1070. Thomas, O. P., A. I. Zuckerman, M. Farran, and C. B. Tamplin, 1986. Updated amino acid requirements of broilers. Pages 79-85 in: Proc. Maryland Nutr. Conf., Baltimore, MD. Waldroup, P. W., R. J. Mitchell, J. R. Payne, and Z. B. Johnson, 1976. Characterization of the response of broiler chickens to diets varying in nutrient content Poultry Sci. 55:130-145. Wells, R. G., 1963. Relationship between dietary energy level, food consumption and growth in broiler chicks. Br. Poult. Sci. 4:161-168. Yule, W. J., 1976. Optimum change to finisher diet and most efficient marketing age of sex separated broilers. Nutr. Rep. Int 14:121-124.
Downloaded from http://ps.oxfordjournals.org/ at Tufts University on December 13, 2016
24.9% CP to either 28 or 35 days of age followed by a finisher diet with 22.8% CP to 49 or 56 days of age. Final weights were slightly lower in birds fed the starter to 35 days of age, regardless of sex of bird or final marketing age. Yule (1976) changed broiler chickens from 21% CP to 18% CP at 7-day intervals beginning at 10 to 45 days of age. Body weight and feed efficiency improved linearly with increasing age of change to the finisher diet. Proudfoot and Hulan (1980) made changes from a 24% CP starter diet to a 15.9% CP finisher diet beginning at 28 days of age and at daily intervals to 33 days of age. Neither body weights nor monetary returns were significantly affected by the time of changing to finisher diets. Roush (1982) fed a series of starter diets with 13 to 33% CP followed by a series of finisher diets with 8 to 18% CP with changes made at different ages. Optimal protein levels for body weight were 26 and 19% CP for starter and finisher diets, and 30 and 26% CP for feed utilization. Body weights were optimized when diets were changed at 27 days, and feed efficiency was optimized when diets were changed at 24 days. The optimal amino acid requirements of the modern broiler chicken when grown to satisfy present market demands needs to be determined. An increasingly greater percentage of broiler males are being grown for further processed items and are consequently being grown to heavier weights than previously seen in the poultry industry. Optimal feeding systems for growing to different weight demands for the different sexes may be required.
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