- Email: [email protected]
Digestible lysine responses of male broilers from 14 to 28 days of age subjected to different environmental conditions1
©2009 Poultry Science Association, Inc.
Digestible lysine responses of male broilers from 14 to 28 days of age subjected to different environmental conditions1 W. A. Dozier III,*2,3 A. Corzo,† M. T. Kidd,† P. B. Tillman,‡ J. L. Purswell,* and B. J. Kerr§
Primary Audience: Live Production Managers and Nutritionists SUMMARY Dietary amino acid requirements are influenced by environmental conditions. Two experiments examined growth responses of male Ross × Ross TP 16 broilers fed diets varying in digestible Lys concentrations from 14 to 28 d of age under different environmental conditions. Experiment 1 was conducted in July 2007, whereas experiment 2 was initiated during October 2007. In each experiment, dietary treatments consisted of 6 concentrations of digestible Lys and a positive control. Digestible Lys ranged from 0.90 to 1.25% in increments of 0.07% and from 0.92 to 1.32% in increments of 0.08% for experiments 1 and 2, respectively. Linear and quadratic improvements were observed for BW gain and feed conversion in experiments 1 and 2, respectively. In experiment 2, the digestible Lys requirement was estimated at 1.19% based on a quadratic broken-line model and a quadratic regression equation. Digestible Lys intakes that corresponded to the optimal digestible Lys response based on a dietary percentage were estimated at 1,280 and 1,404 mg/d for experiments 1 and 2, respectively. These results suggest that the need for dietary Lys varied considerably with broilers reared in environmental conditions simulating winter vs. summer production when expressed on a digestible Lys intake basis. Key words: amino acid, broiler, lysine 2009 J. Appl. Poult. Res. 18:690–698 doi:10.3382/japr.2009-00016
DESCRIPTION OF PROBLEM Much emphasis has been placed on formulating diets on a digestible (dig) amino acid (AA) basis [1–4]. Accurate dig AA requirements for 1
the modern broiler are needed to formulate diets on a dig AA basis for widespread implementation to occur throughout the US broiler industry. Feeding diets adequate in Lys is critical during the early stages of development to optimize sub-
Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the USDA and Mississippi State University. 2 Corresponding author: [email protected] 3 Present address: 201 Poultry Science Building, Department of Poultry Science, Auburn University, 260 Lem Morrison Drive, Auburn, AL 36849-5416.
Downloaded from http://japr.oxfordjournals.org/ at Purdue University Libraries ADMN on June 18, 2015
*USDA, Agriculture Research Service, Poultry Research Unit, PO Box 5367, Mississippi State, MS 39762-5367; †Department of Poultry Science, Mississippi State University, Mississippi State 39762; ‡Ajinomoto Heartland LLC, Chicago, IL 60631; §USDA, Agriculture Research Service, National Soil Tilth Laboratory, Ames, IA 50011
Dozier et al.: LYSINE NEEDS OF MALE BROILERS
MATERIALS AND METHODS Dietary Treatments Seven dietary treatments were fed to male broilers from 14 to 28 d of age in both experiments (Table 1). Dietary treatments consisted of 6 gradient concentrations of dig Lys and a positive control. In experiment 1, dig Lys concentrations were formulated to contain 0.90 to 1.25%, with 0.07% increments, whereas in experiment 2, dig Lys concentrations ranged from 0.92 to 1.32%, with 0.08% increments. Corn, soybean meal, peanut meal, and poultry by-product meal were the primary ingredients in the experimental diets. Peanut and poultry by-product meals were used in diet formulation so CP would not limit the growth responses to Lys. Before diet formulation, representative samples of corn, soy-
bean meal, poultry by-product meal, and peanut meal were analyzed for total AA and CP contents [23]. The dilution technique was used in diet formulations for both experiments. A summit diet was formulated to contain a high Lys concentration, with dig TSAA, Thr, Val, Ile, Trp, and Arg formulated as a ratio to dig Lys based on estimates reported previously [24]. The diet lowest in Lys was similar to the summit diet in ingredient composition, with the exception of corn and Lys·HCl, for which corn was substituted for Lys·HCl to create a low-Lys diet. The low-Lys and summit diets were supplemented with l-Thr, l-Ile, l-Val, l-Arg, and l-Trp to meet the minima of these critical AA. Bird Management Male Ross × Ross TP16 [25] chicks (experiment 1 = 675; experiment 2 = 720) were obtained from a primary breeder hatchery. Marek’s disease, Newcastle disease, and infectious bronchitis vaccinations were administered to chicks at the hatchery. Chicks were randomly distributed into floor pens (experiment 1 = 45; experiment 2 = 48) of a solid-sided facility. Each pen was equipped with used litter, a pan feeder, and a nipple water line. Ventilation consisted of a single fan producing positive pressure in the house, with still air at brooding and approximately 3.4 m3/h of airflow/bird at the end of the experiment. Heating was provided by a heat exchanger fed with hot water from a boiler system. Birds had free access to feed and water and were fed a common starter diet, which was presented in crumble form, until 14 d of age. At 14 d of age, each pen was equalized to 15 birds, and dietary treatments were fed in whole pellet form until 28 d of age. Ambient temperature set points consisted of 33°C at placement until 4 d of age, 32°C from 5 to 9 d of age, 29°C from 10 to 14 d of age, 27°C from 15 to 23 d of age, and 25°C from 24 to 28 d of age. The photoperiod was a continuous schedule, with lighting intensities of 30 lx from 0 to 7 d of age, 10 lx from 8 to 22 d of age, and 3 lx from 23 to 28 d of age. Light intensity settings were verified at the bird level (30 cm) from litter by using a photometric sensor with National Institute of Standards and Technology-traceable calibration [26] for each intensity adjustment.
Downloaded from http://japr.oxfordjournals.org/ at Purdue University Libraries ADMN on June 18, 2015
sequent growth performance and breast meat yield [5, 6]. The modern broiler consumes less feed per unit of BW gain than broilers of the previous decade [7]. Today’s high-performing broiler has a higher dietary Lys requirement from 2 to 4 wk of age [8, 9] than documented in previous research [10, 11] when subjected to thermoneutral conditions. Broilers subjected to heat stress conditions experience increased latent heat loss and decreased plasma thyroxine and triiodothyronine concentrations [12–14]. These complex metabolic reactions associated with heat stress conditions adversely affect the growth and feed intake of broilers [15–21]. Energy balance of the broiler is dependent on the relationship between latent and sensible heat loss [22]. Optimal temperature set points (25 to 28°C) for 2- to 4-wk-old broilers can typically be attained in commercial practice throughout most of the year, but pronounced differences in humidity occur during winter and summer grow-outs. Digestible AA requirements may be lower when broilers are exposed to RH simulating summer production. Studies evaluating dig AA requirements of the growing broiler reared under diverse environmental conditions are sparse. This study examined the dig Lys requirements of male broilers from 2 to 4 wk of age that were subjected to differing environmental conditions based on growth performance.
691
JAPR: Research Report
692
Table 1. Composition of diets provided during a 14- to 28-d production period (%, as-fed basis)
Item
Moderate environment (experiment 2)
Low Lys
High Lys
Control
Low Lys
High Lys
Control
66.01 8.96 15.00 5.00 0.64 1.08 0.87 0.24 0.30 0.46 0.29 0.36 0.24 0.24 0.05
65.92 8.96 15.00 5.00 0.64 1.08 0.87 0.24 0.30 0.46 0.74 0.36 0.24 0.24 0.05
61.34 27.72
65.99 22.87
—
—
—
—
—
68.33 6.17 12.50 5.46 1.50 1.08 0.87 0.14 0.40 0.91 0.29 0.48 0.33 0.28 0.08 0.40 0.22 0.08 0.15 0.05 3,141 20.5 1.03 1.32 0.94 0.90 1.03 0.22 1.39 0.88 0.44 0.22
3,141 20.7 0.81 1.08 0.71 0.83 0.91 0.18 1.16 0.88 0.44 0.22
0.08 0.15 0.05
0.08 0.15 0.05
0.08 0.15 0.05
68.95 6.17 12.50 5.46 1.50 1.08 0.87 0.14 0.40 0.54 0.29 0.48 0.33 0.28 0.08 0.40 0.22 0.08 0.15 0.05
3,125 19.8 0.93 0.90 0.88 0.88 0.98 0.21 1.31 0.88 0.44 0.22
3,125 20.2 0.93 1.25 0.88 0.88 0.98 0.21 1.31 0.88 0.44 0.22
3,130 21.0 0.84 1.11 0.78 0.78 0.87 0.20 1.19 0.88 0.44 0.22
3,137 20.0 1.03 0.84 0.94 0.90 1.03 0.22 1.39 0.88 0.44 0.22
—
…
5.00 2.60 1.04 0.83 0.35 0.22 0.27 0.16 0.20
— — —
—
5.50 2.39 0.99 0.81 0.30 0.30 0.24 0.24 0.08
— — — — —
0.08 0.15 0.05
1
Vitamin and mineral premix included, per kilogram of diet: vitamin A (vitamin A acetate), 4,960 IU; cholecalciferol, 1,653 IU; vitamin E (source unspecified), 27 IU; menadione, 0.99 mg; vitamin B12, 0.015 mg; folic acid, 0.8 mg: d-pantothenic acid, 15 mg; riboflavin, 5.4 mg; niacin, 45 mg; thiamine, 2.7 mg; d-biotin, 0.07 mg; pyridoxine, 5.3 mg; manganese, 90 mg; zinc, 83 mg; iron, 121 mg; copper, 12 mg; iodine, 0.5 mg; selenium, 0.3 mg. 2 Sacox 60 (Intervet Inc., Millsboro, DE) provided 60 g/907 kg of salinomycin.
Measurements The following measurements were common for both experiments. True AA digestibility of corn, soybean meal, poultry by-product meal, peanut meal, the low-Lys diet, the summit diet, and the control diet were determined using cecectomized Single Comb White Leghorn roosters at the University of Georgia [27] (Table 2). A 35-g sample of the diet or ingredient was tube-fed to 6 or 8 cecectomized roosters. Roosters were individually housed and fasted 24 h before the test
[27]. All excreta voided over the following 48-h period were collected and freeze-dried. Amino acid concentrations in the diets and excreta were determined at Ajinomoto Heartland LLC [28]. Performic acid oxidation [28] was conducted before acid hydrolysis for the determination of Met and Cys, whereas all other AA were determined after acid hydrolysis. Ambient temperature and RH were measured using 2 data loggers [29] during experimentation, and dew point was calculated from ambient temperature and RH. Birds and feed were weighed on d 14 and 28 for
Downloaded from http://japr.oxfordjournals.org/ at Purdue University Libraries ADMN on June 18, 2015
Ingredient, % Ground corn Soybean meal (48% CP) Peanut meal (41% CP) Poultry by-product meal Poultry oil Dicalcium phosphate Calcium carbonate Sodium chloride Sodium bicarbonate dl-Met l-Lys·HCl l-Thr l-Val l-Ile l-Trp l-Gly l-Arg Choline chloride Mineral and vitamin premix1 Cocciodostat2 Calculated analysis AMEn, kcal/kg CP, % Digestible TSAA, % Digestible Lys, % Digestible Thr, % Digestible Ile, % Digestible Val, % Digestible Trp, % Digestible Arg, % Calcium, % Nonphytate phosphorus, % Sodium, %
Humid environment (experiment 1)
Dozier et al.: LYSINE NEEDS OF MALE BROILERS
693
Table 2. True amino acid digestibility of experimental diets provided to cecectomized roosters1 Humid environment (experiment 1) Amino acid
Low Lys
High Lys
Control
Low Lys
High Lys
Control
1.08 0.77 0.25 0.97 1.09 0.92 1.55 0.46 1.54 0.95 1.04 1.83 3.31 0.74 0.90 0.60
1.46 0.77 0.26 1.01 1.11 0.87 1.65 0.47 1.58 0.95 1.02 1.87 3.37 0.75 0.91 0.61
1.17 0.69 0.24 0.90 0.98 0.85 1.31 0.54 1.67 1.06 1.05 2.24 3.42 0.82 0.94 0.61
0.93 0.77 0.22 0.96 1.08 0.74 1.51 0.43 1.41 0.97 1.53 1.75 2.88 1.21 0.75 0.41
1.39 0.77 0.22 1.00 1.08 0.87 1.55 0.42 1.43 0.61 0.98 1.54 2.90 1.22 0.75 0.41
1.16 0.58 0.22 0.74 0.84 0.74 1.23 0.53 1.60 0.93 1.04 1.75 3.24 1.17 0.87 0.53
1
Amino acid digestibility values were determined using the total fecal collection precision-fed cecectomized rooster assay [27].
the determination of BW, BW gain, feed intake, Lys intake, and Lys intake:BW gain. Mortality was recorded daily. In experiment 2, one bird per pen was bled for the collection of blood on d 26. Blood was centrifuged at 1,800 × g for 10 min, with plasma removed and frozen at −20°C for later analyses. Frozen plasma samples were thawed at 4°C and
blood urea nitrogen was analyzed colorimetrically [30] with a spectrophotometer [31]. Statistics Gradient treatment structure was conducted as a randomized complete block design in both experiments. The 6 dose-response diets were
Table 3. Growth performance of male broilers fed gradient levels of digestible Lys from 14 to 28 d of age and subjected to a humid environment1 (experiment 1) Item Digestible Lys, % 0.90 0.97 1.04 1.11 1.18 1.25 Control (1.11%) SEM
BW, kg
BW gain, kg
Feed intake, kg
0.827 0.902 1.008 1.090 1.225 1.281 1.339 0.016
0.499 0.571 0.682 0.763 0.894 0.956 1.004 0.016
1.020 1.098 1.185 1.278 1.395 1.433 1.419 0.019
0.001 0.91 0.009
0.001 0.89 0.005
0.001 0.72 0.05
Source of variation Linear Quadratic Control vs. 1.11%2 1
Lys intake, mg/d 656 761 880 1,013 1,176 1,280 1,126 15
Lys intake:BW gain, mg/g
FCR, kg/kg Mortality, %
18.43 18.70 18.07 18.59 18.42 18.76 16.42 0.30
2.061 1.928 1.764 1.676 1.561 1.502 1.500 0.041
0.0 1.0 1.0 1.0 1.9 2.9 0.2 1.0
0.81 0.37 0.05
0.001 0.022 0.02
0.17 0.85 0.38
P-value 0.001 0.38 0.09
Values are least squares means of 7 replicate pens with 15 broilers per pen at 14 d of age. Birds fed the control diet were represented with 3 replicate pens. 2 Orthogonal contrast.
Downloaded from http://japr.oxfordjournals.org/ at Purdue University Libraries ADMN on June 18, 2015
Lys Met Cys Thr Val Ile Arg His Leu Phe Ala Asp Glu Pro Ser Tyr
Moderate environment (experiment 2)
JAPR: Research Report
694
Table 4. Digestible Lys requirement of male broilers from 14 to 28 d of age based on regression analysis Response criterion Humid environment (experiment 1) Feed conversion, kg/kg Moderate environment (experiment 2) BW gain, kg Feed conversion, kg/kg
Equation1
R2
CV,2 %
Requirement3
5.865 − 6.086 × (Lys) + 2.073 × (Lys × Lys)
0.99
0.90
1.18
−0.930 + 3.237 × (Lys) − 1.313 × (Lys × Lys) 3.647 – 3.417 × (Lys) + 1.350 × (Lys × Lys)
0.99 0.98
0.65 0.71
1.16 1.20
1
Prediction equation based on formulated digestible Lys for the optimal response. CV = (SD ÷ mean) × 100. 3 The digestible Lys requirement estimates 95% of the asymptote. 2
RESULTS Experiment 1 Male broilers fed increasing levels of dig Lys exhibited a linear response (P ≤ 0.001) with BW gain, feed intake, Lys intake, and feed conversion, but a quadratic response (P ≤ 0.02) for feed conversion (Table 3). Control-fed broilers had superior growth performance responses compared with birds provided the dose-titration diet containing 1.11% dig Lys. The dig Lys requirement was estimated as 1.18% for feed conversion based on 95% of the regression optimal response (Table 4). Feed conversion was the only variable that produced a quadratic response at P
≤ 0.05. With the broken-line methodology, the linear broken-line analysis provided a better fit than the quadratic broken-line analysis. Therefore, the linear broken-line analysis was used to estimate dig Lys requirements. Digestible Lys requirements for BW gain, feed intake, and feed conversion were estimated as 1.23, 1.22, and 1.20%, respectively (Table 5). The average dig Lys requirement was estimated as 1.21% of the diet based on BW gain and feed conversion. However, it appeared that the dig Lys levels provided in this experiment were not high enough to estimate a requirement accurately, as evidenced by the lack of a significant quadratic broken-line model and quadratic regression equation, even though requirement estimates were predicted by the linear broken-line model. Experiment 2 Providing male broilers gradient concentrations of dig Lys resulted in quadratic responses (P ≤ 0.05) for BW gain, Lys intake, and feed conversion, and linear trends (P ≤ 0.02) for BW
Table 5. Digestible Lys requirement based on broken line model analyses Response criterion Humid environment (experiment 1)2 BW gain, kg Feed intake, kg Feed conversion, kg/kg Moderate environment (experiment 2)3 BW gain, kg Feed intake, kg Feed conversion, kg/kg 1
Estimated requirement
95% CI1
P-value
R2
1.23 ± 0.017 1.22 ± 0.020 1.20 ± 0.019
1.20–1.27 1.17–1.26 1.16–1.24
0.001 0.001 0.001
0.86 0.82 0.87
1.18 ± 0.072 1.00 ± 0.016 1.24 ± 0.040
1.03–1.32 0.96–1.03 1.16–1.32
0.001 0.022 0.001
0.61 0.12 0.82
95% confidence interval of the digestible Lys requirement. The linear broken-line model is y = (L + U) × (R − x), where L is the ordinate, R is the abscissa of the breakpoint, and the value R is zero at values of x > R. Values are reported as ±SEM. 3 The quadratic broken-line model is y = (L + U) × (R – x) × (R − x), where L is the ordinate, R is the abscissa of the breakpoint, and the value R is zero at values of x > R. Values are reported as ±SEM. 2
Downloaded from http://japr.oxfordjournals.org/ at Purdue University Libraries ADMN on June 18, 2015
represented with 7 replicate pens, whereas the control diet had 3 and 6 replicate pens in experiments 1 and 2, respectively. Seven analyses were conducted [32]. Digestible Lys requirements were estimated using the regression analysis and broken-line methodology when a significant (P ≤ 0.05) response occurred.
Dozier et al.: LYSINE NEEDS OF MALE BROILERS
gain and feed conversion (Table 6). Blood urea nitrogen concentration numerically decreased (P ≤ 0.089) with increasing dig Lys levels and did not produce a significant quadratic response (Figure 1), so a requirement was not estimated for blood urea nitrogen concentration. Broilers fed the control diet grew faster (P ≤ 0.05) and consumed more feed (P ≤ 0.001) and dig Lys (P ≤ 0.001) than broilers fed the dose-response diet formulated at 1.08% dig Lys. Digestible
Lys requirements were predicted as 1.16 and 1.20%, respectively, for BW gain and feed conversion based on regression analysis at 95% of the optimal response (Table 4). In contrast to experiment 1, the quadratic broken-line analysis provided a better fit to this data set than did the linear broken-line analysis. Digestible Lys requirement estimates for BW gain, feed intake, and feed conversion were 1.18, 1.00, and 1.24%, respectively, based on the quadratic broken-line analysis (Table 5). The dig Lys requirement for BW gain and feed conversion was estimated as 1.20% when averaged for both requirement methodologies.
DISCUSSION With modern housing, temperature set points can be maintained for the young broiler for most of the year. However, the combination of RH ≥50% and ambient temperature at 26 to 28°C can limit the ability of the young bird to remove metabolic energy, which translates into decreased feed intake and growth performance. In the current study, the ambient temperatures were 26.9 ± 0.6°C and 26.8 ± 0.9°C for experiments 1 and 2, respectively. The dew point temperature and RH were higher in experiment 1 (18.3 ± 3.0°C; 61.7 ± 10.0%) than in experiment 2 (14.2 ± 5.3°C; 47.6 ± 10.2%). The dig Lys need
Table 6. Growth performance of male broilers fed gradient levels of digestible Lys from 14 to 28 d of age subjected to a moderate environment1 (experiment 2) Item Digestible Lys, % 0.92 1.00 1.08 1.16 1.24 1.32 Control (1.08%) SEM
BW, kg
BW gain, kg
Feed intake, kg
1.409 1.476 1.518 1.527 1.541 1.534 1.579 0.014
0.932 0.997 1.039 1.049 1.062 1.056 1.101 0.014
1.533 1.584 1.577 1.580 1.585 1.569 1.673 0.017
0.021 0.001 0.05
0.020 0.001 0.04
0.29 0.08 0.03
Source of variation Linear Quadratic Control vs. 1.08%2
Lys intake, Lys intake:BW gain, mg/d mg/g
FCR, kg/kg
Mortality, %
1,007 1,131 1,216 1,309 1,404 1,469 1,291 13
1.646 1.589 1.517 1.507 1.492 1.487 1.519 0.009
1.0 0.0 1.0 1.0 0.0 0.0 0.0 0.7
0.009 0.017 0.77
0.39 0.64 0.36
15.14 15.89 16.38 17.47 18.50 19.48 16.40 0.10
P-value 0.001 0.045 0.03
0.001 0.068 0.75
1 Values are least squares means of 7 replicate pens with 15 broilers per pen at 14 d of age. Birds fed the control diet were represented with 6 replicate pens. 2 Orthogonal contrast.
Downloaded from http://japr.oxfordjournals.org/ at Purdue University Libraries ADMN on June 18, 2015
Figure 1. Effects of digestible (dig) Lys on blood urea nitrogen (BUN) concentration (experiment 2). Doseresponse means are represented by 7 replicates (1 bird per replicate), whereas birds fed the control diet had 6 replicates (1 bird per replicate).
695
696
expressed on an intake basis differed between experiments 1 and 2, with this response possibly occurring because of dew point temperature and RH differences between the 2 experiments. One of the limitations of this research was that the broilers fed the control diet outperformed the birds fed the dose-response diets. The control diets were formulated to contain corn, soybean meal, and poultry by-product meal. In addition, the control diets contained more soybean meal than the dose-response diets. In contrast, the dose-response diets contained 15% peanut meal. The true digestibility of the experimental diets indicated that the control diet had higher true digestibility values for His, Leu, Phe, Ala, Asp, Glu, Ser, and Tyr compared with the doseresponse diets for experiments 1 and 2. Using peanut meal and less soybean meal in the doseresponse diets may have resulted in the lower amounts of His, Leu, Phe, Ala, Asp, Glu, Ser, and Tyr. The lower amounts of these AA in the dose-response diets may have resulted in poorer performance than for the broilers fed the control diet. Studies evaluating the dietary Lys requirement of growing broilers are sparse for broilers grown under heat stress conditions. In previous research, ambient temperatures were increased beyond the upper limit of the thermoneutral zone to mimic heat stress conditions, but dew point temperature and RH were not noted [20, 21]. McNaughton et al. [21] determined a lower dietary Lys requirement of broilers from 0 to 28 d of age when grown under an ambient temperature of 29.4°C compared with birds reared at 15.6°C (0.95 vs. 1.05% total dietary Lys) [21]. In contrast, Han and Baker [20] observed similar
dig Lys requirements for male broilers from 8 to 22 d of age when subjected to 24 and 37°C. Based on these published data [20, 21] with dietary Lys during the starter and grower periods, increasing the dietary Lys content did not appear to be advantageous during summer production. However, these data were based on using broilers from 15 to 30 yr ago, and the AA needs of the modern broiler have increased compared with broilers used 2 or 3 decades ago [5]. In contrast, the present research indicated that broiler performance may be improved by feeding higher dietary Lys levels during summer production. In experiment 1, performance did not reach a curvilinear response, and this did not allow an accurate requirement to be estimated. These data imply that higher dig Lys levels expressed on a percentage basis should have been fed to reach an optimal level for BW gain and feed conversion during humid conditions. It is interesting to note that feed conversion approximated 1.50 kg/kg with a dig Lys intake of 1,280 mg/d in experiment 1 and 1,309 mg/d of dig Lys intake in experiment 2 (Figure 2). However, further improvements in feed conversion were noted because dig Lys intake increased to 1,469 mg/d in experiment 2, but 1,280 mg/d was the highest dig Lys intake in experiment 1. Formulating diets to an AA intake may be advantageous, rather than formulating them on a dietary percentage, to ensure that the dietary AA needs of the broilers are met. Maintenance, rate of growth, and feed intake are factors that influence bird requirements [8]. Rostagno [35] reported dig Lys requirement estimates for broilers based on different performance indices (below average, standard, and high performing). In addition, an equation was developed to estimate the dig Lys requirements of male broilers based on the dig Lys needs for maintenance, feed intake, and BW gain [8]. This equation accounts for differences in performance and feed intake, indicating that requirement estimates can be affected by management and environmental conditions. The dig Lys requirement on an intake basis can be affected by environmental and managerial factors, and changes in dietary percentages may be warranted. The optimal dig AA requirement on an intake basis may differ for certain times of the year based on differences in BW, growth rate, and feed intake.
Downloaded from http://japr.oxfordjournals.org/ at Purdue University Libraries ADMN on June 18, 2015
Figure 2. Effects of digestible (dig) Lys intake on feed conversion (experiments 1 and 2).
JAPR: Research Report
Dozier et al.: LYSINE NEEDS OF MALE BROILERS CONCLUSIONS AND APPLICATIONS
1. Body weight gain and feed conversion were optimized with a dig Lys intake of 1,280 mg/d for experiment 1. A dig Lys intake of 1,404 mg/d provided the best feed conversion in experiment 2. 2. Digestible Lys levels were not high enough in the humid environment to determine the requirement accurately.
1. Adedokun, S. A., C. M. Parsons, M. S. Lilburn, O. Adeola, and T. J. Applegate. 2007. Comparison of ileal endogenous amino acid flows in broiler chicks and turkey poults. Poult. Sci. 86:1682–1689. 2. Garcia, A. R., A. B. Batal, and N. M. Dale. 2007. A comparsion of methods to determine amino acid digestibility of feed ingredients for chickens. Poult. Sci. 86:94–101. 3. Huang, K. H., V. Ravindran, X. Li, and W. L. Bryden. 2005. Influence of age on the apparent ileal amino acid digestibility of feed ingredients for broiler chickens. Br. Poult. Sci. 46:236–245. 4. Ravindran, V., L. I. Hew, G. Ravindran, and W. L. Bryden. 1999. A comparison of ileal digesta and excreta analysis for the determination of amino acid digestibility in food ingredients for poultry. Br. Poult. Sci. 40:266–274. 5. Dozier, W. A. III, M. T. Kidd, and A. Corzo. 2008. Dietary amino acid responses of broiler chickens. J. Appl. Poult. Res. 17:157–167. 6. Kidd, M. T., C. D. McDaniel, S. L. Branton, E. R. Miller, B. B. Boren, and B. I. Fancher. 2004. Increasing amino acid density improves live performance and carcass yields of commercial broilers. J. Appl. Poult. Res. 13:593– 604. 7. Fancher, B. I. 2006. Feeding the modern broiler— Cost-effective amino acid levels. AviaTech. Publ. Vol. 2, No. 2. Aviagen Inc., Huntsville, AL. 8. Rostagno, H., L. Pae’z, and L. Albino. 2007. Nutrient requirements of broilers for optimum growth and lean mass. World’s Poult. Sci. Assoc. France XVI Eur. Symp. Poult. Nutr., Strasbourg, France. 9. Dozier, W. A. III, A. Corzo, M. T. Kidd, P. B. Tillman, and S. L. Branton. 2009. Digestible lysine requirements of male and female broilers from fourteen to twenty-eight days of age. Poult. Sci. 88:1676–1682. 10. Labadan, M. C., K. N. Hsu, and R. E. Austic. 2001. Lysine and arginine requirements of broiler chickens at twoto three-week intervals to eight weeks of age. Poult. Sci. 80:599–606. 11. Baker, D. H., A. B. Batal, T. M. Parr, N. R. Augspurger, and C. M. Parsons. 2002. Ideal ratio (relative to lysine) of tryptophan, threonine, isoleucine, and valine for chicks during the second and third posthatch. Poult. Sci. 81:485– 494. 12. Tao, X., Z. Y. Zhang, H. Dong, H. Zhang, and H. Xin. 2006. Responses of thyroid hormones of market-size broilers to thermoneutral constant and warm cyclic temperature. Poult. Sci. 85:1520–1528.
13. Geraert, P. A., J. C. F. Padilha, and S. Guillaumin. 1996. Metabolic and endocrine changes induced by chronic heat exposure in broiler chickens: Biological and endocrinological variables. Br. J. Nutr. 75:205–216. 14. May, J. D., J. W. Deaton, F. N. Reece, and S. L. Branton. 1986. Effects of acclimation and heat stress on thyroid hormone concentration. Poult. Sci. 65:1211–1213. 15. Dale, N. M., and H. L. Fuller. 1980. Effect of diet composition on feed intake and growth of chicks under heat stress. II. Constant vs. cycling temperatures. Poult. Sci. 59:1434–1441. 16. Kubena, L. F., J. W. Deaton, F. N. Reece, J. D. May, and T. H. Vardman. 1972. The influence of temperature and sex on the amino acid requirements of the broiler. Poult. Sci. 51:1391–1396. 17. Cheng, T. K., M. L. Hamre, and C. N. Coon. 1999. Effect of constant and cyclic environmental temperatures, dietary protein, and amino acid levels on broiler performance. J. Appl. Poult. Res. 8:426–439. 18. Temim, S., A. M. Chagneau, S. Guillaumin, J. Michel, R. Peresson, and S. Tesseraud. 2000. Does excess dietary protein improve growth performance and carcass characteristics in heat-exposed chickens? Poult. Sci. 79:312–317. 19. Mendes, A. A., S. E. Watkins, J. A. England, E. A. Saleh, A. L. Waldroup, and P. W. Waldroup. 1997. Influence of dietary lysine levels and arginine:lysine ratios on performance of broilers exposed to heat or cold stress during the period of three to six weeks of age. Poult. Sci. 76:472– 481. 20. Han, Y., and D. H. Baker. 1993. Effects of sex, heat stress, body weight, and genetic strain on the dietary lysine requirement of broiler chicks. Poult. Sci. 72:701–708. 21. McNaughton, J. L., J. D. May, F. N. Reece, and J. W. Deaton. 1978. Lysine requirement of broilers as influenced by environmental temperatures. Poult. Sci. 57:57–65. 22. Simmons, J. D., B. D. Lott, and J. D. May. 1997. Heat loss from broiler chickens subjected to various wind speeds and ambient temperatures. Appl. Eng. Agric. 13:665–669. 23. Association of Official Analytical Chemists. 2000. Official Methods of Analysis. Official Methods 7.015 and 982.30, Section E (A, B, C). 17th ed. Assoc. Off. Anal. Chem., Arlington, VA. 24. Lemme, A., V. Ravindran, and W. L. Bryden. 2004. Standardized ileal amino acid digestibility of raw materials in broilers. In Proc. Multi-State Poult. Feed. Nutr. Health Manage. Conf. and Degussa Corp’s Tech. Symp., Indianpolis, IN [CD-ROM]. 25. Aviagen North America, Huntsville, AL. 26. 403125, Extech Instruments, Waltham, MA. 27. Parsons, C. M. 1985. Influence of caecectomy on digestibility of amino acids by roosters fed distiller’s dried grains with solubles. J. Agric. Sci. (Camb.) 104:469–472. 28. Ajinomoto Heartland. 2004. True Digestibility of Essential Amino Acids for Poultry. Revision 7. Ajinomoto Heartland LLC, Chicago, IL. 29. HOBO H08-003-02, Onset Computer, Bourne, MA. 30. Kit B7551-120, Pointe Scientific Inc., Lincoln Park, MI. 31. Varian Cary 50 Spectrophotometer, Varian Analytical Instruments, Walnut Creek, CA. 32. 1) The REG procedure [33] using a linear trend to explain the potential dig Lys effects; 2) the REG procedure
Downloaded from http://japr.oxfordjournals.org/ at Purdue University Libraries ADMN on June 18, 2015
REFERENCES AND NOTES
697
698
model was conducted using the NLIN procedure [33] based on published methodology [34]. 33. SAS Institute. 2004. SAS User’s Guide. Statistics. Version 9.1 Edition. SAS Inst. Inc., Cary, NC. 34. Robbins, K. R., A. M. Sexton, and L. L. Southern. 2006. Estimation of nutrient requirements using brokenline regression analysis. J. Anim. Sci. 84(E Suppl.):E155– E165. 35. Rostagno, H. 2005. Brazilian Tables for Poultry and Swine: Composition of Feedstuffs and Nutritional Requirements. 2nd ed. Universidade Federal de Vicosa Departamento de Zootecnia Vicosa, Minas Gerais, Brazil. Downloaded from http://japr.oxfordjournals.org/ at Purdue University Libraries ADMN on June 18, 2015
[33] using quadratic trend to explain potential dig Lys effects. The multiple coefficient determination values presented are based on proportion of the treatment effect that is explained by the trend; 3) the MIXED procedure [33] using linear trend to explain potential dig Lys effects; 4) the MIXED procedure [33] using a quadratic trend to explain potential dig Lys effects; the lack of fit for this analysis is the treatment effect that is not being explained by the trend. A measure of lack of fit as a component of variance was obtained from the MIXED procedure. 5) An orthogonal contrast was conducted to compare the control diet with similar dig Lys from the dose-response diet; 6) a linear-broken line model was conducted using the NLIN procedure [33] based on published methodology [34]; 7) a quadratic-broken
JAPR: Research Report
Digestible lysine responses of male broilers from 14 to 28 days of age subjected to different environmental conditions1 W. A. Dozier III,*2,3 A. Corzo,† M. T. Kidd,† P. B. Tillman,‡ J. L. Purswell,* and B. J. Kerr§
Primary Audience: Live Production Managers and Nutritionists SUMMARY Dietary amino acid requirements are influenced by environmental conditions. Two experiments examined growth responses of male Ross × Ross TP 16 broilers fed diets varying in digestible Lys concentrations from 14 to 28 d of age under different environmental conditions. Experiment 1 was conducted in July 2007, whereas experiment 2 was initiated during October 2007. In each experiment, dietary treatments consisted of 6 concentrations of digestible Lys and a positive control. Digestible Lys ranged from 0.90 to 1.25% in increments of 0.07% and from 0.92 to 1.32% in increments of 0.08% for experiments 1 and 2, respectively. Linear and quadratic improvements were observed for BW gain and feed conversion in experiments 1 and 2, respectively. In experiment 2, the digestible Lys requirement was estimated at 1.19% based on a quadratic broken-line model and a quadratic regression equation. Digestible Lys intakes that corresponded to the optimal digestible Lys response based on a dietary percentage were estimated at 1,280 and 1,404 mg/d for experiments 1 and 2, respectively. These results suggest that the need for dietary Lys varied considerably with broilers reared in environmental conditions simulating winter vs. summer production when expressed on a digestible Lys intake basis. Key words: amino acid, broiler, lysine 2009 J. Appl. Poult. Res. 18:690–698 doi:10.3382/japr.2009-00016
DESCRIPTION OF PROBLEM Much emphasis has been placed on formulating diets on a digestible (dig) amino acid (AA) basis [1–4]. Accurate dig AA requirements for 1
the modern broiler are needed to formulate diets on a dig AA basis for widespread implementation to occur throughout the US broiler industry. Feeding diets adequate in Lys is critical during the early stages of development to optimize sub-
Mention of trade names or commercial products in this publication is solely for the purpose of providing specific information and does not imply recommendation or endorsement by the USDA and Mississippi State University. 2 Corresponding author: [email protected] 3 Present address: 201 Poultry Science Building, Department of Poultry Science, Auburn University, 260 Lem Morrison Drive, Auburn, AL 36849-5416.
Downloaded from http://japr.oxfordjournals.org/ at Purdue University Libraries ADMN on June 18, 2015
*USDA, Agriculture Research Service, Poultry Research Unit, PO Box 5367, Mississippi State, MS 39762-5367; †Department of Poultry Science, Mississippi State University, Mississippi State 39762; ‡Ajinomoto Heartland LLC, Chicago, IL 60631; §USDA, Agriculture Research Service, National Soil Tilth Laboratory, Ames, IA 50011
Dozier et al.: LYSINE NEEDS OF MALE BROILERS
MATERIALS AND METHODS Dietary Treatments Seven dietary treatments were fed to male broilers from 14 to 28 d of age in both experiments (Table 1). Dietary treatments consisted of 6 gradient concentrations of dig Lys and a positive control. In experiment 1, dig Lys concentrations were formulated to contain 0.90 to 1.25%, with 0.07% increments, whereas in experiment 2, dig Lys concentrations ranged from 0.92 to 1.32%, with 0.08% increments. Corn, soybean meal, peanut meal, and poultry by-product meal were the primary ingredients in the experimental diets. Peanut and poultry by-product meals were used in diet formulation so CP would not limit the growth responses to Lys. Before diet formulation, representative samples of corn, soy-
bean meal, poultry by-product meal, and peanut meal were analyzed for total AA and CP contents [23]. The dilution technique was used in diet formulations for both experiments. A summit diet was formulated to contain a high Lys concentration, with dig TSAA, Thr, Val, Ile, Trp, and Arg formulated as a ratio to dig Lys based on estimates reported previously [24]. The diet lowest in Lys was similar to the summit diet in ingredient composition, with the exception of corn and Lys·HCl, for which corn was substituted for Lys·HCl to create a low-Lys diet. The low-Lys and summit diets were supplemented with l-Thr, l-Ile, l-Val, l-Arg, and l-Trp to meet the minima of these critical AA. Bird Management Male Ross × Ross TP16 [25] chicks (experiment 1 = 675; experiment 2 = 720) were obtained from a primary breeder hatchery. Marek’s disease, Newcastle disease, and infectious bronchitis vaccinations were administered to chicks at the hatchery. Chicks were randomly distributed into floor pens (experiment 1 = 45; experiment 2 = 48) of a solid-sided facility. Each pen was equipped with used litter, a pan feeder, and a nipple water line. Ventilation consisted of a single fan producing positive pressure in the house, with still air at brooding and approximately 3.4 m3/h of airflow/bird at the end of the experiment. Heating was provided by a heat exchanger fed with hot water from a boiler system. Birds had free access to feed and water and were fed a common starter diet, which was presented in crumble form, until 14 d of age. At 14 d of age, each pen was equalized to 15 birds, and dietary treatments were fed in whole pellet form until 28 d of age. Ambient temperature set points consisted of 33°C at placement until 4 d of age, 32°C from 5 to 9 d of age, 29°C from 10 to 14 d of age, 27°C from 15 to 23 d of age, and 25°C from 24 to 28 d of age. The photoperiod was a continuous schedule, with lighting intensities of 30 lx from 0 to 7 d of age, 10 lx from 8 to 22 d of age, and 3 lx from 23 to 28 d of age. Light intensity settings were verified at the bird level (30 cm) from litter by using a photometric sensor with National Institute of Standards and Technology-traceable calibration [26] for each intensity adjustment.
Downloaded from http://japr.oxfordjournals.org/ at Purdue University Libraries ADMN on June 18, 2015
sequent growth performance and breast meat yield [5, 6]. The modern broiler consumes less feed per unit of BW gain than broilers of the previous decade [7]. Today’s high-performing broiler has a higher dietary Lys requirement from 2 to 4 wk of age [8, 9] than documented in previous research [10, 11] when subjected to thermoneutral conditions. Broilers subjected to heat stress conditions experience increased latent heat loss and decreased plasma thyroxine and triiodothyronine concentrations [12–14]. These complex metabolic reactions associated with heat stress conditions adversely affect the growth and feed intake of broilers [15–21]. Energy balance of the broiler is dependent on the relationship between latent and sensible heat loss [22]. Optimal temperature set points (25 to 28°C) for 2- to 4-wk-old broilers can typically be attained in commercial practice throughout most of the year, but pronounced differences in humidity occur during winter and summer grow-outs. Digestible AA requirements may be lower when broilers are exposed to RH simulating summer production. Studies evaluating dig AA requirements of the growing broiler reared under diverse environmental conditions are sparse. This study examined the dig Lys requirements of male broilers from 2 to 4 wk of age that were subjected to differing environmental conditions based on growth performance.
691
JAPR: Research Report
692
Table 1. Composition of diets provided during a 14- to 28-d production period (%, as-fed basis)
Item
Moderate environment (experiment 2)
Low Lys
High Lys
Control
Low Lys
High Lys
Control
66.01 8.96 15.00 5.00 0.64 1.08 0.87 0.24 0.30 0.46 0.29 0.36 0.24 0.24 0.05
65.92 8.96 15.00 5.00 0.64 1.08 0.87 0.24 0.30 0.46 0.74 0.36 0.24 0.24 0.05
61.34 27.72
65.99 22.87
—
—
—
—
—
68.33 6.17 12.50 5.46 1.50 1.08 0.87 0.14 0.40 0.91 0.29 0.48 0.33 0.28 0.08 0.40 0.22 0.08 0.15 0.05 3,141 20.5 1.03 1.32 0.94 0.90 1.03 0.22 1.39 0.88 0.44 0.22
3,141 20.7 0.81 1.08 0.71 0.83 0.91 0.18 1.16 0.88 0.44 0.22
0.08 0.15 0.05
0.08 0.15 0.05
0.08 0.15 0.05
68.95 6.17 12.50 5.46 1.50 1.08 0.87 0.14 0.40 0.54 0.29 0.48 0.33 0.28 0.08 0.40 0.22 0.08 0.15 0.05
3,125 19.8 0.93 0.90 0.88 0.88 0.98 0.21 1.31 0.88 0.44 0.22
3,125 20.2 0.93 1.25 0.88 0.88 0.98 0.21 1.31 0.88 0.44 0.22
3,130 21.0 0.84 1.11 0.78 0.78 0.87 0.20 1.19 0.88 0.44 0.22
3,137 20.0 1.03 0.84 0.94 0.90 1.03 0.22 1.39 0.88 0.44 0.22
—
…
5.00 2.60 1.04 0.83 0.35 0.22 0.27 0.16 0.20
— — —
—
5.50 2.39 0.99 0.81 0.30 0.30 0.24 0.24 0.08
— — — — —
0.08 0.15 0.05
1
Vitamin and mineral premix included, per kilogram of diet: vitamin A (vitamin A acetate), 4,960 IU; cholecalciferol, 1,653 IU; vitamin E (source unspecified), 27 IU; menadione, 0.99 mg; vitamin B12, 0.015 mg; folic acid, 0.8 mg: d-pantothenic acid, 15 mg; riboflavin, 5.4 mg; niacin, 45 mg; thiamine, 2.7 mg; d-biotin, 0.07 mg; pyridoxine, 5.3 mg; manganese, 90 mg; zinc, 83 mg; iron, 121 mg; copper, 12 mg; iodine, 0.5 mg; selenium, 0.3 mg. 2 Sacox 60 (Intervet Inc., Millsboro, DE) provided 60 g/907 kg of salinomycin.
Measurements The following measurements were common for both experiments. True AA digestibility of corn, soybean meal, poultry by-product meal, peanut meal, the low-Lys diet, the summit diet, and the control diet were determined using cecectomized Single Comb White Leghorn roosters at the University of Georgia [27] (Table 2). A 35-g sample of the diet or ingredient was tube-fed to 6 or 8 cecectomized roosters. Roosters were individually housed and fasted 24 h before the test
[27]. All excreta voided over the following 48-h period were collected and freeze-dried. Amino acid concentrations in the diets and excreta were determined at Ajinomoto Heartland LLC [28]. Performic acid oxidation [28] was conducted before acid hydrolysis for the determination of Met and Cys, whereas all other AA were determined after acid hydrolysis. Ambient temperature and RH were measured using 2 data loggers [29] during experimentation, and dew point was calculated from ambient temperature and RH. Birds and feed were weighed on d 14 and 28 for
Downloaded from http://japr.oxfordjournals.org/ at Purdue University Libraries ADMN on June 18, 2015
Ingredient, % Ground corn Soybean meal (48% CP) Peanut meal (41% CP) Poultry by-product meal Poultry oil Dicalcium phosphate Calcium carbonate Sodium chloride Sodium bicarbonate dl-Met l-Lys·HCl l-Thr l-Val l-Ile l-Trp l-Gly l-Arg Choline chloride Mineral and vitamin premix1 Cocciodostat2 Calculated analysis AMEn, kcal/kg CP, % Digestible TSAA, % Digestible Lys, % Digestible Thr, % Digestible Ile, % Digestible Val, % Digestible Trp, % Digestible Arg, % Calcium, % Nonphytate phosphorus, % Sodium, %
Humid environment (experiment 1)
Dozier et al.: LYSINE NEEDS OF MALE BROILERS
693
Table 2. True amino acid digestibility of experimental diets provided to cecectomized roosters1 Humid environment (experiment 1) Amino acid
Low Lys
High Lys
Control
Low Lys
High Lys
Control
1.08 0.77 0.25 0.97 1.09 0.92 1.55 0.46 1.54 0.95 1.04 1.83 3.31 0.74 0.90 0.60
1.46 0.77 0.26 1.01 1.11 0.87 1.65 0.47 1.58 0.95 1.02 1.87 3.37 0.75 0.91 0.61
1.17 0.69 0.24 0.90 0.98 0.85 1.31 0.54 1.67 1.06 1.05 2.24 3.42 0.82 0.94 0.61
0.93 0.77 0.22 0.96 1.08 0.74 1.51 0.43 1.41 0.97 1.53 1.75 2.88 1.21 0.75 0.41
1.39 0.77 0.22 1.00 1.08 0.87 1.55 0.42 1.43 0.61 0.98 1.54 2.90 1.22 0.75 0.41
1.16 0.58 0.22 0.74 0.84 0.74 1.23 0.53 1.60 0.93 1.04 1.75 3.24 1.17 0.87 0.53
1
Amino acid digestibility values were determined using the total fecal collection precision-fed cecectomized rooster assay [27].
the determination of BW, BW gain, feed intake, Lys intake, and Lys intake:BW gain. Mortality was recorded daily. In experiment 2, one bird per pen was bled for the collection of blood on d 26. Blood was centrifuged at 1,800 × g for 10 min, with plasma removed and frozen at −20°C for later analyses. Frozen plasma samples were thawed at 4°C and
blood urea nitrogen was analyzed colorimetrically [30] with a spectrophotometer [31]. Statistics Gradient treatment structure was conducted as a randomized complete block design in both experiments. The 6 dose-response diets were
Table 3. Growth performance of male broilers fed gradient levels of digestible Lys from 14 to 28 d of age and subjected to a humid environment1 (experiment 1) Item Digestible Lys, % 0.90 0.97 1.04 1.11 1.18 1.25 Control (1.11%) SEM
BW, kg
BW gain, kg
Feed intake, kg
0.827 0.902 1.008 1.090 1.225 1.281 1.339 0.016
0.499 0.571 0.682 0.763 0.894 0.956 1.004 0.016
1.020 1.098 1.185 1.278 1.395 1.433 1.419 0.019
0.001 0.91 0.009
0.001 0.89 0.005
0.001 0.72 0.05
Source of variation Linear Quadratic Control vs. 1.11%2 1
Lys intake, mg/d 656 761 880 1,013 1,176 1,280 1,126 15
Lys intake:BW gain, mg/g
FCR, kg/kg Mortality, %
18.43 18.70 18.07 18.59 18.42 18.76 16.42 0.30
2.061 1.928 1.764 1.676 1.561 1.502 1.500 0.041
0.0 1.0 1.0 1.0 1.9 2.9 0.2 1.0
0.81 0.37 0.05
0.001 0.022 0.02
0.17 0.85 0.38
P-value 0.001 0.38 0.09
Values are least squares means of 7 replicate pens with 15 broilers per pen at 14 d of age. Birds fed the control diet were represented with 3 replicate pens. 2 Orthogonal contrast.
Downloaded from http://japr.oxfordjournals.org/ at Purdue University Libraries ADMN on June 18, 2015
Lys Met Cys Thr Val Ile Arg His Leu Phe Ala Asp Glu Pro Ser Tyr
Moderate environment (experiment 2)
JAPR: Research Report
694
Table 4. Digestible Lys requirement of male broilers from 14 to 28 d of age based on regression analysis Response criterion Humid environment (experiment 1) Feed conversion, kg/kg Moderate environment (experiment 2) BW gain, kg Feed conversion, kg/kg
Equation1
R2
CV,2 %
Requirement3
5.865 − 6.086 × (Lys) + 2.073 × (Lys × Lys)
0.99
0.90
1.18
−0.930 + 3.237 × (Lys) − 1.313 × (Lys × Lys) 3.647 – 3.417 × (Lys) + 1.350 × (Lys × Lys)
0.99 0.98
0.65 0.71
1.16 1.20
1
Prediction equation based on formulated digestible Lys for the optimal response. CV = (SD ÷ mean) × 100. 3 The digestible Lys requirement estimates 95% of the asymptote. 2
RESULTS Experiment 1 Male broilers fed increasing levels of dig Lys exhibited a linear response (P ≤ 0.001) with BW gain, feed intake, Lys intake, and feed conversion, but a quadratic response (P ≤ 0.02) for feed conversion (Table 3). Control-fed broilers had superior growth performance responses compared with birds provided the dose-titration diet containing 1.11% dig Lys. The dig Lys requirement was estimated as 1.18% for feed conversion based on 95% of the regression optimal response (Table 4). Feed conversion was the only variable that produced a quadratic response at P
≤ 0.05. With the broken-line methodology, the linear broken-line analysis provided a better fit than the quadratic broken-line analysis. Therefore, the linear broken-line analysis was used to estimate dig Lys requirements. Digestible Lys requirements for BW gain, feed intake, and feed conversion were estimated as 1.23, 1.22, and 1.20%, respectively (Table 5). The average dig Lys requirement was estimated as 1.21% of the diet based on BW gain and feed conversion. However, it appeared that the dig Lys levels provided in this experiment were not high enough to estimate a requirement accurately, as evidenced by the lack of a significant quadratic broken-line model and quadratic regression equation, even though requirement estimates were predicted by the linear broken-line model. Experiment 2 Providing male broilers gradient concentrations of dig Lys resulted in quadratic responses (P ≤ 0.05) for BW gain, Lys intake, and feed conversion, and linear trends (P ≤ 0.02) for BW
Table 5. Digestible Lys requirement based on broken line model analyses Response criterion Humid environment (experiment 1)2 BW gain, kg Feed intake, kg Feed conversion, kg/kg Moderate environment (experiment 2)3 BW gain, kg Feed intake, kg Feed conversion, kg/kg 1
Estimated requirement
95% CI1
P-value
R2
1.23 ± 0.017 1.22 ± 0.020 1.20 ± 0.019
1.20–1.27 1.17–1.26 1.16–1.24
0.001 0.001 0.001
0.86 0.82 0.87
1.18 ± 0.072 1.00 ± 0.016 1.24 ± 0.040
1.03–1.32 0.96–1.03 1.16–1.32
0.001 0.022 0.001
0.61 0.12 0.82
95% confidence interval of the digestible Lys requirement. The linear broken-line model is y = (L + U) × (R − x), where L is the ordinate, R is the abscissa of the breakpoint, and the value R is zero at values of x > R. Values are reported as ±SEM. 3 The quadratic broken-line model is y = (L + U) × (R – x) × (R − x), where L is the ordinate, R is the abscissa of the breakpoint, and the value R is zero at values of x > R. Values are reported as ±SEM. 2
Downloaded from http://japr.oxfordjournals.org/ at Purdue University Libraries ADMN on June 18, 2015
represented with 7 replicate pens, whereas the control diet had 3 and 6 replicate pens in experiments 1 and 2, respectively. Seven analyses were conducted [32]. Digestible Lys requirements were estimated using the regression analysis and broken-line methodology when a significant (P ≤ 0.05) response occurred.
Dozier et al.: LYSINE NEEDS OF MALE BROILERS
gain and feed conversion (Table 6). Blood urea nitrogen concentration numerically decreased (P ≤ 0.089) with increasing dig Lys levels and did not produce a significant quadratic response (Figure 1), so a requirement was not estimated for blood urea nitrogen concentration. Broilers fed the control diet grew faster (P ≤ 0.05) and consumed more feed (P ≤ 0.001) and dig Lys (P ≤ 0.001) than broilers fed the dose-response diet formulated at 1.08% dig Lys. Digestible
Lys requirements were predicted as 1.16 and 1.20%, respectively, for BW gain and feed conversion based on regression analysis at 95% of the optimal response (Table 4). In contrast to experiment 1, the quadratic broken-line analysis provided a better fit to this data set than did the linear broken-line analysis. Digestible Lys requirement estimates for BW gain, feed intake, and feed conversion were 1.18, 1.00, and 1.24%, respectively, based on the quadratic broken-line analysis (Table 5). The dig Lys requirement for BW gain and feed conversion was estimated as 1.20% when averaged for both requirement methodologies.
DISCUSSION With modern housing, temperature set points can be maintained for the young broiler for most of the year. However, the combination of RH ≥50% and ambient temperature at 26 to 28°C can limit the ability of the young bird to remove metabolic energy, which translates into decreased feed intake and growth performance. In the current study, the ambient temperatures were 26.9 ± 0.6°C and 26.8 ± 0.9°C for experiments 1 and 2, respectively. The dew point temperature and RH were higher in experiment 1 (18.3 ± 3.0°C; 61.7 ± 10.0%) than in experiment 2 (14.2 ± 5.3°C; 47.6 ± 10.2%). The dig Lys need
Table 6. Growth performance of male broilers fed gradient levels of digestible Lys from 14 to 28 d of age subjected to a moderate environment1 (experiment 2) Item Digestible Lys, % 0.92 1.00 1.08 1.16 1.24 1.32 Control (1.08%) SEM
BW, kg
BW gain, kg
Feed intake, kg
1.409 1.476 1.518 1.527 1.541 1.534 1.579 0.014
0.932 0.997 1.039 1.049 1.062 1.056 1.101 0.014
1.533 1.584 1.577 1.580 1.585 1.569 1.673 0.017
0.021 0.001 0.05
0.020 0.001 0.04
0.29 0.08 0.03
Source of variation Linear Quadratic Control vs. 1.08%2
Lys intake, Lys intake:BW gain, mg/d mg/g
FCR, kg/kg
Mortality, %
1,007 1,131 1,216 1,309 1,404 1,469 1,291 13
1.646 1.589 1.517 1.507 1.492 1.487 1.519 0.009
1.0 0.0 1.0 1.0 0.0 0.0 0.0 0.7
0.009 0.017 0.77
0.39 0.64 0.36
15.14 15.89 16.38 17.47 18.50 19.48 16.40 0.10
P-value 0.001 0.045 0.03
0.001 0.068 0.75
1 Values are least squares means of 7 replicate pens with 15 broilers per pen at 14 d of age. Birds fed the control diet were represented with 6 replicate pens. 2 Orthogonal contrast.
Downloaded from http://japr.oxfordjournals.org/ at Purdue University Libraries ADMN on June 18, 2015
Figure 1. Effects of digestible (dig) Lys on blood urea nitrogen (BUN) concentration (experiment 2). Doseresponse means are represented by 7 replicates (1 bird per replicate), whereas birds fed the control diet had 6 replicates (1 bird per replicate).
695
696
expressed on an intake basis differed between experiments 1 and 2, with this response possibly occurring because of dew point temperature and RH differences between the 2 experiments. One of the limitations of this research was that the broilers fed the control diet outperformed the birds fed the dose-response diets. The control diets were formulated to contain corn, soybean meal, and poultry by-product meal. In addition, the control diets contained more soybean meal than the dose-response diets. In contrast, the dose-response diets contained 15% peanut meal. The true digestibility of the experimental diets indicated that the control diet had higher true digestibility values for His, Leu, Phe, Ala, Asp, Glu, Ser, and Tyr compared with the doseresponse diets for experiments 1 and 2. Using peanut meal and less soybean meal in the doseresponse diets may have resulted in the lower amounts of His, Leu, Phe, Ala, Asp, Glu, Ser, and Tyr. The lower amounts of these AA in the dose-response diets may have resulted in poorer performance than for the broilers fed the control diet. Studies evaluating the dietary Lys requirement of growing broilers are sparse for broilers grown under heat stress conditions. In previous research, ambient temperatures were increased beyond the upper limit of the thermoneutral zone to mimic heat stress conditions, but dew point temperature and RH were not noted [20, 21]. McNaughton et al. [21] determined a lower dietary Lys requirement of broilers from 0 to 28 d of age when grown under an ambient temperature of 29.4°C compared with birds reared at 15.6°C (0.95 vs. 1.05% total dietary Lys) [21]. In contrast, Han and Baker [20] observed similar
dig Lys requirements for male broilers from 8 to 22 d of age when subjected to 24 and 37°C. Based on these published data [20, 21] with dietary Lys during the starter and grower periods, increasing the dietary Lys content did not appear to be advantageous during summer production. However, these data were based on using broilers from 15 to 30 yr ago, and the AA needs of the modern broiler have increased compared with broilers used 2 or 3 decades ago [5]. In contrast, the present research indicated that broiler performance may be improved by feeding higher dietary Lys levels during summer production. In experiment 1, performance did not reach a curvilinear response, and this did not allow an accurate requirement to be estimated. These data imply that higher dig Lys levels expressed on a percentage basis should have been fed to reach an optimal level for BW gain and feed conversion during humid conditions. It is interesting to note that feed conversion approximated 1.50 kg/kg with a dig Lys intake of 1,280 mg/d in experiment 1 and 1,309 mg/d of dig Lys intake in experiment 2 (Figure 2). However, further improvements in feed conversion were noted because dig Lys intake increased to 1,469 mg/d in experiment 2, but 1,280 mg/d was the highest dig Lys intake in experiment 1. Formulating diets to an AA intake may be advantageous, rather than formulating them on a dietary percentage, to ensure that the dietary AA needs of the broilers are met. Maintenance, rate of growth, and feed intake are factors that influence bird requirements [8]. Rostagno [35] reported dig Lys requirement estimates for broilers based on different performance indices (below average, standard, and high performing). In addition, an equation was developed to estimate the dig Lys requirements of male broilers based on the dig Lys needs for maintenance, feed intake, and BW gain [8]. This equation accounts for differences in performance and feed intake, indicating that requirement estimates can be affected by management and environmental conditions. The dig Lys requirement on an intake basis can be affected by environmental and managerial factors, and changes in dietary percentages may be warranted. The optimal dig AA requirement on an intake basis may differ for certain times of the year based on differences in BW, growth rate, and feed intake.
Downloaded from http://japr.oxfordjournals.org/ at Purdue University Libraries ADMN on June 18, 2015
Figure 2. Effects of digestible (dig) Lys intake on feed conversion (experiments 1 and 2).
JAPR: Research Report
Dozier et al.: LYSINE NEEDS OF MALE BROILERS CONCLUSIONS AND APPLICATIONS
1. Body weight gain and feed conversion were optimized with a dig Lys intake of 1,280 mg/d for experiment 1. A dig Lys intake of 1,404 mg/d provided the best feed conversion in experiment 2. 2. Digestible Lys levels were not high enough in the humid environment to determine the requirement accurately.
1. Adedokun, S. A., C. M. Parsons, M. S. Lilburn, O. Adeola, and T. J. Applegate. 2007. Comparison of ileal endogenous amino acid flows in broiler chicks and turkey poults. Poult. Sci. 86:1682–1689. 2. Garcia, A. R., A. B. Batal, and N. M. Dale. 2007. A comparsion of methods to determine amino acid digestibility of feed ingredients for chickens. Poult. Sci. 86:94–101. 3. Huang, K. H., V. Ravindran, X. Li, and W. L. Bryden. 2005. Influence of age on the apparent ileal amino acid digestibility of feed ingredients for broiler chickens. Br. Poult. Sci. 46:236–245. 4. Ravindran, V., L. I. Hew, G. Ravindran, and W. L. Bryden. 1999. A comparison of ileal digesta and excreta analysis for the determination of amino acid digestibility in food ingredients for poultry. Br. Poult. Sci. 40:266–274. 5. Dozier, W. A. III, M. T. Kidd, and A. Corzo. 2008. Dietary amino acid responses of broiler chickens. J. Appl. Poult. Res. 17:157–167. 6. Kidd, M. T., C. D. McDaniel, S. L. Branton, E. R. Miller, B. B. Boren, and B. I. Fancher. 2004. Increasing amino acid density improves live performance and carcass yields of commercial broilers. J. Appl. Poult. Res. 13:593– 604. 7. Fancher, B. I. 2006. Feeding the modern broiler— Cost-effective amino acid levels. AviaTech. Publ. Vol. 2, No. 2. Aviagen Inc., Huntsville, AL. 8. Rostagno, H., L. Pae’z, and L. Albino. 2007. Nutrient requirements of broilers for optimum growth and lean mass. World’s Poult. Sci. Assoc. France XVI Eur. Symp. Poult. Nutr., Strasbourg, France. 9. Dozier, W. A. III, A. Corzo, M. T. Kidd, P. B. Tillman, and S. L. Branton. 2009. Digestible lysine requirements of male and female broilers from fourteen to twenty-eight days of age. Poult. Sci. 88:1676–1682. 10. Labadan, M. C., K. N. Hsu, and R. E. Austic. 2001. Lysine and arginine requirements of broiler chickens at twoto three-week intervals to eight weeks of age. Poult. Sci. 80:599–606. 11. Baker, D. H., A. B. Batal, T. M. Parr, N. R. Augspurger, and C. M. Parsons. 2002. Ideal ratio (relative to lysine) of tryptophan, threonine, isoleucine, and valine for chicks during the second and third posthatch. Poult. Sci. 81:485– 494. 12. Tao, X., Z. Y. Zhang, H. Dong, H. Zhang, and H. Xin. 2006. Responses of thyroid hormones of market-size broilers to thermoneutral constant and warm cyclic temperature. Poult. Sci. 85:1520–1528.
13. Geraert, P. A., J. C. F. Padilha, and S. Guillaumin. 1996. Metabolic and endocrine changes induced by chronic heat exposure in broiler chickens: Biological and endocrinological variables. Br. J. Nutr. 75:205–216. 14. May, J. D., J. W. Deaton, F. N. Reece, and S. L. Branton. 1986. Effects of acclimation and heat stress on thyroid hormone concentration. Poult. Sci. 65:1211–1213. 15. Dale, N. M., and H. L. Fuller. 1980. Effect of diet composition on feed intake and growth of chicks under heat stress. II. Constant vs. cycling temperatures. Poult. Sci. 59:1434–1441. 16. Kubena, L. F., J. W. Deaton, F. N. Reece, J. D. May, and T. H. Vardman. 1972. The influence of temperature and sex on the amino acid requirements of the broiler. Poult. Sci. 51:1391–1396. 17. Cheng, T. K., M. L. Hamre, and C. N. Coon. 1999. Effect of constant and cyclic environmental temperatures, dietary protein, and amino acid levels on broiler performance. J. Appl. Poult. Res. 8:426–439. 18. Temim, S., A. M. Chagneau, S. Guillaumin, J. Michel, R. Peresson, and S. Tesseraud. 2000. Does excess dietary protein improve growth performance and carcass characteristics in heat-exposed chickens? Poult. Sci. 79:312–317. 19. Mendes, A. A., S. E. Watkins, J. A. England, E. A. Saleh, A. L. Waldroup, and P. W. Waldroup. 1997. Influence of dietary lysine levels and arginine:lysine ratios on performance of broilers exposed to heat or cold stress during the period of three to six weeks of age. Poult. Sci. 76:472– 481. 20. Han, Y., and D. H. Baker. 1993. Effects of sex, heat stress, body weight, and genetic strain on the dietary lysine requirement of broiler chicks. Poult. Sci. 72:701–708. 21. McNaughton, J. L., J. D. May, F. N. Reece, and J. W. Deaton. 1978. Lysine requirement of broilers as influenced by environmental temperatures. Poult. Sci. 57:57–65. 22. Simmons, J. D., B. D. Lott, and J. D. May. 1997. Heat loss from broiler chickens subjected to various wind speeds and ambient temperatures. Appl. Eng. Agric. 13:665–669. 23. Association of Official Analytical Chemists. 2000. Official Methods of Analysis. Official Methods 7.015 and 982.30, Section E (A, B, C). 17th ed. Assoc. Off. Anal. Chem., Arlington, VA. 24. Lemme, A., V. Ravindran, and W. L. Bryden. 2004. Standardized ileal amino acid digestibility of raw materials in broilers. In Proc. Multi-State Poult. Feed. Nutr. Health Manage. Conf. and Degussa Corp’s Tech. Symp., Indianpolis, IN [CD-ROM]. 25. Aviagen North America, Huntsville, AL. 26. 403125, Extech Instruments, Waltham, MA. 27. Parsons, C. M. 1985. Influence of caecectomy on digestibility of amino acids by roosters fed distiller’s dried grains with solubles. J. Agric. Sci. (Camb.) 104:469–472. 28. Ajinomoto Heartland. 2004. True Digestibility of Essential Amino Acids for Poultry. Revision 7. Ajinomoto Heartland LLC, Chicago, IL. 29. HOBO H08-003-02, Onset Computer, Bourne, MA. 30. Kit B7551-120, Pointe Scientific Inc., Lincoln Park, MI. 31. Varian Cary 50 Spectrophotometer, Varian Analytical Instruments, Walnut Creek, CA. 32. 1) The REG procedure [33] using a linear trend to explain the potential dig Lys effects; 2) the REG procedure
Downloaded from http://japr.oxfordjournals.org/ at Purdue University Libraries ADMN on June 18, 2015
REFERENCES AND NOTES
697
698
model was conducted using the NLIN procedure [33] based on published methodology [34]. 33. SAS Institute. 2004. SAS User’s Guide. Statistics. Version 9.1 Edition. SAS Inst. Inc., Cary, NC. 34. Robbins, K. R., A. M. Sexton, and L. L. Southern. 2006. Estimation of nutrient requirements using brokenline regression analysis. J. Anim. Sci. 84(E Suppl.):E155– E165. 35. Rostagno, H. 2005. Brazilian Tables for Poultry and Swine: Composition of Feedstuffs and Nutritional Requirements. 2nd ed. Universidade Federal de Vicosa Departamento de Zootecnia Vicosa, Minas Gerais, Brazil. Downloaded from http://japr.oxfordjournals.org/ at Purdue University Libraries ADMN on June 18, 2015
[33] using quadratic trend to explain potential dig Lys effects. The multiple coefficient determination values presented are based on proportion of the treatment effect that is explained by the trend; 3) the MIXED procedure [33] using linear trend to explain potential dig Lys effects; 4) the MIXED procedure [33] using a quadratic trend to explain potential dig Lys effects; the lack of fit for this analysis is the treatment effect that is not being explained by the trend. A measure of lack of fit as a component of variance was obtained from the MIXED procedure. 5) An orthogonal contrast was conducted to compare the control diet with similar dig Lys from the dose-response diet; 6) a linear-broken line model was conducted using the NLIN procedure [33] based on published methodology [34]; 7) a quadratic-broken
JAPR: Research Report