POULTRY RESEARCH. REPORT 12. Feeding broilers different lysine to apparent metabolizable energy ratios during the 40 to 2000 gram live weight period.
AJINOMOTO ANIMAL NUTRITION
AJINOMOTO HEARTLAND, INC.
POULTRY RESEARCH REPORT 12
Feeding broilers different lysine to apparent metabolizable energy ratios during the 40 to 2000 gram live weight period Objective Determine the effects of varying the lysine to energy ratio on male broiler performance and carcass characteristics during the starter (40 to 750 g) and grower (750 to 2000 g) periods.
Experimental Procedures Animals Male broiler chickens of a commercial strain were allocated at one day of age between treatments derived from seven dietary lysine:apparent metabolizable energy ratios (LYS:AME) varying from 0.42 to 1.46 g/MJ. Each treatment was replicated three times with 12 chicks per replicate (cage). From each treatment, representative birds were killed when the 750 and 2000 g live weights were attained. Carcass composition was determined following removal of feathers. Protein and fat deposition rates were calculated for the live weight periods of 40
Diets Based on the diet dilution technique of Fisher & Morris (1970), a 31.5% protein (summit) diet was combined with a 13.6% protein (dilution) diet to provide protein levels ranging from 15.0 to 31.5%. Total dietary lysine levels ranged from 0.58 to 1.85%. The summit diet (Table 1) contained a lysine level of 1.4 times the assumed requirement (ARC, 1974), while all other amino acids were provided at 1.8 times the requirement. The essential amino acid levels in the dilution diet (Table 1) were set at 0.4 to 0.5 times the requirement. This ensured lysine would be the firstlimiting amino acid in all isocaloric diets (13.0 MJ/kg). The determined AME, protein and total lysine contents of the experimental diets are listed in Table 2.
to 750 and 750 to 2000 grams.
Table 1. Determined nutrient contents of summit and dilution diets Diet Summit Dilution Nutrient 31.50 13.6 Crude Protein (%) 12.7 14.0 Metabolizable Energy (MJ/kg) 1.86 0.47 Lysine (%) 1.46 0.33 Lysine:AME (g/MJ) 1.17 0.23 Methionine (%) 1.41 0.54 Threonine (%) 2.08 0.95 Alanine (%) 2.01 0.75 Valine (%) 1.38 0.55 Isoleucine (%) 3.10 1.35 Leucine (%) 1.85 0.73 Phenylalanine (%) 0.93 0.29 Histidine (%) 2.04 0.77 Arginine (%)
Table 2. Analyzed nutrient contents of experimental diets Diet Apparent ME (MJ/kg) Crude Protein (%) Total Lysine (%) Lysine:AME (g/MJ)
13.70 15.00 0.58 0.42
13.40 16.80 0.70 0.52
13.30 18.30 0.81 0.61
13.30 20.10 0.93 0.70
13.30 23.40 1.17 0.88
12.90 26.90 1.42 1.10
12.70 31.50 1.85 1.46
Results Table 3. Effect of lysine:AME ratio on the performance of male broiler chickens Live Weight Gain (g/d) LYS:AME (g/MJ) 0.42 0.52 0.61 0.70 0.88 1.10 1.46
40-750 g 15.7 18.8 24.8 27.1 31.6 32.5 31.8
750-2000 g 36.9 49.6 61.0 61.0 63.8 51.3 57.2
Feed Intake (g/d) 40-750 40.2 45.8 49.9 49.5 46.6 44.6 45.4
750-2000 g 128.3 148.2 145.9 136.5 127.0 115.4 118.3
Feed:Gain (g/g) 40-750 g 2.47 2.45 2.01 1.83 1.48 1.37 1.43
750-2000 g 3.85 2.98 2.39 2.25 1.99 2.26 2.10
Discussion The dietary LYS:AME ratio had marked effects on broiler performances (Table 3). During the starter period, growth rate and feed:gain values of broilers improved in a curvilinear fashion as the LYS:AME ratio increased to a level of 1.1 g LYS/MJ AME (1.42% dietary lysine). Providing a LYS:AME ratio of 1.46 during the starter period slightly depressed the broiler's growth rate and feed efficiency when compared to those fed the lower ratio levels. Feed intake of broilers during the 40-750 g period increased as the LYS:AME ratio increased from 0.42 to 0.62 g/MJ. Feed intake remained relatively constant as the dietary LYS:AME ratio increased above this level. During the grower period, broiler growth rate and feed:gain ratio (Table 3) improved as dietary LYS:AME ratio increased from 0.42 to 0.88 g LYS/MJ (1.17% dietary lysine). Further increases in the ratio to 1.10 or 1.46 reduced live performance as indicated by the lower daily weight gains and increased feed:gain ratios. Feed intake for broilers during this period increased after the first increase
in LYS:AME from 0.42 to 0.52 g/MJ. Further increases in this dietary ratio did not have a significant effect on feed intake until a level of 1.10 g LYS/MJ AME was reached. At this level, the broiler reduced feed intake substantially. Greater protein deposition (Table 4) was evident for broilers during the starter period as the dietary LYS:AME ratio increased to a level of 1.1 g/MJ (1.42% dietary lysine). Protein deposition of broilers tended to plateau with further increase in the LYS:AME ratio. Protein deposition was linearly related to protein intake when protein intake was below requirements for optimum growth. The carcass protein content for the 750 g broiler increased as the LYS:AME ratio increased to 1.1 g/MJ. Fat deposition (Table 4) increased initially as dietary lysine increased and then gradually declined with continued increases in lysine levels. The carcass fat content of birds during this period continually declined as the dietary lysine:AME ratio increased.
Table 4. Effect of lysine:AME ratio on broiler carcass composition Protein Deposition Protein Content Fat Deposition (g/d) (%) (g/d) LYS:AME (g/MJ) 400-750 g 750-2000g 750g 2000g 40-750g 750-2000g 0.42 2.36 5.74 15.1 15.9 2.58 6.54 0.52 2.81 7.59 15.6 16.4 2.63 7.12 0.61 3.65 10.21 15.6 17.1 3.15 7.33 0.70 4.26 10.60 15.9 17.6 3.42 6.62 0.88 5.01 11.32 16.2 18.0 3.20 4.32 1.10 5.20 9.00 16.5 18.2 2.84 3.22 1.46 5.20 10.33 16.5 18.6 2.64 3.08
Protein deposition increased as the dietary LYS:AME ratio was raised to 0.88 g/MJ AME during the grower period (Table 4). Further increases in this ratio to 1.10 g/MJ caused a decline in protein deposition. Initially, the relationship of protein deposition as a function of protein intake was linear when protein intake was below requirements. Carcass protein content increased as the LYS:AME ratio was raised to 0.88 g/MJ for the 2000 g live weight broiler. Fat deposition (Table 4) declined with each successive increase in the LYS:AME ratio above 0.61 g/MJ (0.81% dietary lysine). Carcass fat content declined with each increase in the LYS:AME ratio. The results would indicate that for optimum live performance plus maximum protein deposition and reduced carcass fat content, male broilers would require 1.10 g lysine/MJ (1.42% dietary lysine) for the 40-750 g and 0.88 g lysine/MJ (1.17% dietary lysine) for the 750 to 2000 g liveweight periods. A similar dietary lysine requirement to support optimum broiler performance during the 1 to 3 week age period was reported by Gous and Morris (1985). Sinurat & Balnave (1985) indicated that by supplying 0.89 g dietary lysine/MJ of metabolizable Conclusion 1. Supplying 1.1 g LYS/MJ AME in a 12.9 MJ/kg ration (1.42% total lysine) during the starter period supported optimum growth performance and maximum protein deposition for male broilers. 2. A dietary LYS:AME ratio of 0.88 g/MJ for the grower period provided maximum weight gain and optimum feed efficiency for male boilers. This LYS:AME ratio corresponds to 1.17% dietary lysine for a diet containing 13.3 MJ of AME per kg of diet. 3. Corresponding with increased feed intake, fat deposition increased with each increase in the dietary lysine:AME ratio up to 0.7 g/MJ during
Fat Content (%) 750g 15.9 14.2 13.1 12.5 10.4 9.1 8.6
2000g 17.6 15.2 13.0 12.0 8.4 7.6 6.8
energy would support optimum weight gain and feed efficiency of broilers (22 to 45 days of age) when reared under a moderate temperature (cyclic) environment. These same authors found abdominal fat content of broiler carcass to decrease as the LYS:ME ratio of the diet increased. Examining dietary energy and amino acid levels for male broilers, Waldroup et al (1990) reported energy content of the diet had no effect on body weights or feed efficiency regardless of age period studies. The dietary energy difference between the high and low energy series represented 110 kcal ME/kg within each age period. Increasing the amino acid levels resulted in significant improvements for live weights and feed utilization of male broilers, plus a reduction in abdominal fat pad. Optimal weight gains, feed efficiency ratios and abdominal fat content of broilers, day 0 to 56, were attained by feeding 105 to 110% of suggested amino acid requirements (Thomas et al, 1986). These levels for dietary lysine would correspond to 0.92 to 0.97 g/MJ (starter); 0.80 to 0.83 g/MJ (grower); and 0.60 to 0.64 g LYS/MJ of ME for the finisher phase. the starter period and to 0.61 g/MJ during the grower period. In both periods, fat deposition (g/d) declined with each further increase in the lysine:AME ratio. In contrast, carcass fat content at both 750 and 2000 g declined with each increase in the dietary lysine:AME ratio. 4. The results obtained in this study clearly show the differences that can occur between various trials as exemplified by the suggested higher levels of lysine:AME of this research, compared to that of Waldroup et al (1990). This could be due to genotype and nutritional differences, thereby demonstrating the importance of biological growth models which can assist in identifying the differences.
Bibliography Agricultural Research Council, 1974. The Nutrient Requirements of Farm Livestock. No. 1, Poultry 2nd Edition, London, HMSO. *Campbell, R.G, & R.J. Johnson, 1990. Interrelationships between dietary protein and energy intake on protein deposition and performance of male broiler chickens. Proc. Arkansas Nutrition Conference. pp. 44-54. Fisher, C. & T.R. Morris, 1970. The determination of the methionine requirement of laying pullets by a diet dilution technique. Br. Poult. Sci. 11:67. Gous, R.M. & T.R. Morris, 1985. Evaluation of a diet dilution technique for measuring the response of broiler chickens to increasing concentrations of lysine. Brit. Poult. Sci. 26: 147-161. To Change: Kilograms Pounds Calorie Joule g/MJ g/Mcal
To: Pounds Kilograms Joule (J) Calorie (cal) g/Mcal g/MJ
Sinurat, A.P. & D. Balnave, 1985. Effect of dietary amino acids and metabolizable energy on the performance of broilers kept at high temperatures. Br. Poult. Sci. 26: 117-128. Thomas, O.P., A.I. Zuckerman, M. Farran & C.B. Tamplin, 1986. Updated amino acid requirements of broilers. Prod. Maryland Nutrition Conference, Baltimore, MD. pp. 79-85. Waldroup, P.W., N.M. Tidwell & A.L. Izat, 1990. The effects of energy and amino acid levels on performance and carcass quality of male and female broilers grown separately. Poultry Sci. 69: 1513-1521. Note: In order to convert metric values to U.S. standards, use the following procedure: Multiply By: 2.205 0.454 4.185 0.239 4.185 0.239
*Principal reference (Poultry Research Report #12 is an excerpt from the paper presented by Dr. Roger Campbell at the 1990 Arkansas Nutrition Conference).
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