Effects of Betaine and Choline on Response to Methionine

0 downloads 0 Views 102KB Size Report
formulated to meet nutritional levels typical of top broiler producers. ..... 1C = calculated from NRC (1994); A = analyzed by Danisco Animal Nutrition, St. Louis, MO; D = difference between analyzed value ...... REFERENCES AND NOTES. 1.
2006 Poultry Science Association, Inc.

Effects of Betaine and Choline on Response to Methionine Supplementation to Broiler Diets Formulated to Industry Standards1 P. W. Waldroup,2 M. A. Motl, F. Yan, and C. A. Fritts Department of Poultry Science, University of Arkansas, Fayetteville 72701

Primary Audience: Nutritionists, Veterinarians, Poultry Processors, Researchers SUMMARY A study was conducted to evaluate the Met-sparing effects of the methyl donors, choline (CHO) and betaine (BET). Male broilers of a commercial strain were fed corn-soybean meal-based diets formulated to meet nutritional levels typical of top broiler producers. Diets were fortified with a complete vitamin premix devoid of CHO. In test diets, Met levels were as formulated, or less 0.05, 0.10, 0.15, or 0.20% Met. Within each Met level, diets received no supplemental CHO or BET or 1,000 mg of CHO/kg, 1,000 mg of BET/kg, or a combination of 500 mg each of CHO and BET/ kg. This resulted in a 4 × 5 factorial arrangement with each of the 20 treatments fed to 4 pens of 60 birds for a 56-d feeding trial. Samples of birds were processed at 42, 49, and 56 d to determine parts yield and dressing percentage. Intestinal segments were evaluated for tensile strength at these same ages. The dietary Met level had no significant impact on BW at 14 or 56 d of age, but at 35, 42, and 49 d reduction of the Met content resulted in loss of BW. Feed conversion was not affected by the Met level at 14 d but was significantly affected by reducing the Met level at all other ages. Breast meat yield was reduced in a linear manner by reductions in Met supplementation. The CHO or BET supplementation had no apparent sparing effect on Met needs but did improve feed conversion at 35 and 42 d. There was a positive effect of CHO and BET on breast yield that was independent of Met levels; CHO was as effective as BET for this purpose. No effect of CHO or BET on intestinal strength was observed in the present study. Key words: broiler, choline, betaine, methionine, sparing effect 2006 J. Appl. Poult. Res. 15:58–71

DESCRIPTION OF PROBLEM Methionine is the first limiting amino acid in broiler diets based on soybean meal, and it functions as a key intermediate in methyl group transfer. Numerous methylation reactions involve Met, in which Met is converted to S-adenosylmethionine, the methyl group donor, and 1

then to homocysteine. The back reaction requires betaine (BET) or tetrahydrofolate as the provider of the methyl group necessary to convert homocysteine to Met [1, 2]. Both Met and homocysteine are potentially toxic to cells, and both may accumulate if methyl donors or methyl acceptors are deficient. Alternative methyl donors may alleviate the dietary needs for Met by taking

Published with the approval of the Director, Arkansas Agricultural Experiment Station, Fayetteville, AR 72701. Mention of a trade name, proprietary product, or specific equipment does not constitute a guarantee or warranty by the University of Arkansas and does not imply its approval to the exclusion of other products that may be suitable. 2 Corresponding author: [email protected]

WALDROUP ET AL.: INDUSTRY BROILER DIETS

59

Table 1. Nutrient analysis of diets from the top 5 broiler companies in an agricultural survey Nutrient ME, kcal/lb Crude protein, % Lys, % TSAA, % Trp, % Arg, % Thr, % Nonphytate P, % Calcium, % Sodium, %

Starter 0–14 d

Grower 14–35 d

Finisher 1 35–42 d

Finisher 2 42–56 d

1,362.00 20.93 1.23 0.96 0.25 1.52 0.85 0.43 0.83 0.23

1,394.00 19.16 1.09 0.85 0.22 1.31 0.76 0.37 0.85 0.20

1,416.00 17.02 0.93 0.76 0.20 1.17 0.68 0.34 0.76 0.21

1,460.00 16.08 0.88 0.76 0.18 1.08 0.64 0.33 0.76 0.20

the place of Met as a methyl donor per se or by providing the methyl group necessary for the conversion of homocysteine to Met. Choline (CHO) has long been used as a vitamin supplement for broiler diets. Numerous studies have investigated the interrelationship between CHO and Met as donors of methyl groups, with considerable variation in results [3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14]. More recently, BET has been evaluated as a methyl donor as a means of reducing the needs for Met [15, 16, 17, 18, 19, 20], also with variation in results. The present trial was conducted to examine the potential value of CHO and BET, alone or in combination, in reducing the dietary needs for Met in broiler diets.

MATERIALS AND METHODS Nutritional specifications for the top 5 companies participating in a popular agricultural survey [21] were used as the basis of formulation (Table 1). Diets were formulated using corn and soybean meal of known composition and supplemental amino acids to meet exactly the specified requirements for CP, ME, Ca, available P, Na, Lys, TSAA, Arg, and Thr with only slight excesses of Try (Table 2). Feeding intervals were 0 to 14 d for starter, 14 to 35 d for grower, 35 to 42 d for finisher 1, and 42 to 56 d for finisher 2, similar to the intervals used by the top 5 companies. The amount of added Met in the diets as formulated was 0.30% for starter, 0.24% for grower, 0.20% for finisher 1, and 0.22% for finisher 2. For test diets, Met levels were 1) as formulated, 2) less 0.05%, 3) less 0.10%, 4) less 0.15%, and 5) less 0.20%. Within each Met

level, diets received 1) no supplemental CHO or BET, 2) 1,000 mg of CHO/kg, 3) 1,000 mg of BET/kg, or 4) 500 mg of CHO + 500 mg of BET/kg. The CHO was supplied as a dry 60% choline chloride product [22], whereas BET was added as a crystalline 97% product [23]. This resulted in a 4 × 5 factorial arrangement of treatments. A common basal diet was mixed within each test period, and aliquots were used to mix each of the test diets. All diets contained monensin at 90 g/ton as an anticoccidial. Each treatment was fed to 4 pens of 60 male chicks. The basal diet within each feeding period was evaluated for total amino acids, and all test diets were analyzed for supplemental MET, CHO, and BET by commercial laboratories. Day-old male chicks of a commercial strain [24] were obtained from a local hatchery where they had been vaccinated in ovo for Marek’s disease and had received vaccinations for newcastle disease and infectious bronchitis posthatch via a coarse spray. They were randomly distributed among 80 pens in a curtain-sided broiler house of commercial design. Sixty birds were placed in each pen. New softwood shavings over concrete floors served as litter. Each pen was equipped with 2 tube feeders and 1 automatic water fount. Supplemental feeders and waterers were used during the first 7 d. Fluorescent lights supplemented natural daylight to provide 23 h light daily. Automatic brooder stoves and fans controlled temperature and airflow. Care and management of the birds followed recommended guidelines [25]. Group BW by pen was obtained at 14, 35, 42, 49, and 56 d. Feed consumption was determined at each feed change interval. Birds were

JAPR: Research Report

60

Table 2. Composition (g/kg) of diets formulated to nutrient standards of top broiler companies Starter 0–14 d

Grower 14–35 d

Finisher 1 35–42 d

Finisher 2 42–56 d

Yellow corn Soybean meal (48% CP) Dicalcium phosphate Poultry oil Ground limestone Feed-grade salt BMD-501 Coban-602 Vitamin premix3 Trace mineral mix4 L-Lys HCl (98%) L-Thr L-Arg DL-Met (98%) Variable5 Total

621.21 312.75 20.39 16.67 8.70 5.24 0.50 0.75 2.00 1.00 1.88 0.90 1.93 3.08 3.00 1,000.00

655.37 276.01 17.27 23.32 10.86 4.67 0.50 0.75 2.00 1.00 1.27 0.57 1.02 2.39 3.00 1,000.00

718.36 218.11 15.27 20.69 10.16 4.76 0.50 0.75 2.00 1.00 1.30 0.65 1.39 2.06 3.00 1,000.00

722.44 198.36 14.77 36.73 10.42 4.68 0.50 0.75 2.00 1.00 1.29 0.64 1.16 2.26 3.00 1,000.00

Calculated analysis ME, kcal/lb Crude protein, % Lys, % TSAA, % Met, % Trp, % Arg, % Thr, % Nonphytate P, % Calcium, % Sodium, %

1,362.00 20.93 1.24 0.96 0.63 0.27 1.52 0.85 0.43 0.84 0.23

1,394.00 19.17 1.09 0.85 0.53 0.24 1.31 0.76 0.37 0.85 0.20

1,416.00 17.02 0.93 0.76 0.48 0.20 1.17 0.68 0.34 0.76 0.21

1,460.00 16.08 0.88 0.76 0.49 0.19 1.08 0.64 0.33 0.75 0.20

Ingredient

1

Alpharma, Inc., Fort Lee, NJ. Elanco Animal Health division of Eli Lilly and Co., Indianapolis, IN. Provided per kilogram of diet: vitamin A (from vitamin A acetate), 7,714 IU; cholecalciferol, 2,204 IU; vitamin E (from DL-α-tocopheryl acetate), 16.53 IU; vitamin B12, 0.013 mg; riboflavin, 6.6 mg; niacin, 39 mg; pantothenic acid, 10 mg; menadione (from menadione dimethyl-pyrimidinol), 1.5 mg; folic acid, 0.9 mg; thiamin (from thiamin mononitrate), 1.54 mg; pyridoxine (from pyridoxineⴢHCl), 2.76 mg; D-biotin, 0.066 mg; ethoxyquin, 125 mg; Se, 0.1 mg. 4 Provided per kilogram of diet: Mn (from MnSO4ⴢH2O), 100 mg; Zn (from ZnSO4ⴢ7H2O), 100 mg; Fe (from FeSO4ⴢ7H2O), 50 mg; Cu (from CuSO4ⴢ5H2O), 10 mg; I from Ca(IO3)2ⴢH2O), 1 mg. 4 Variable amounts of choline or betaine. 2 3

checked twice daily and weight of dead birds used to adjust feed conversion. At 42, 49, and 56 d, 5 birds per pen were randomly selected for processing from among 20 birds marked at 1 d of age by a toe slit. After a 12-h fast, the birds were placed in coops and transported approximately 1 mi to the processing plant. They were weighed and processed with automated evisceration as described by Fritts and Waldroup [26]. Due to the automatic evisceration it was not possible to determine abdominal fat content. The eviscerated carcass was weighed and placed in a chiller with air agitation for 1 h. The carcasses were removed, hung on shackles, and allowed to drain for 30 min. The carcasses were

then deboned by trained technicians to determine parts yield (breast, leg quarters, and wings). Parts yield was expressed as percentage of eviscerated chilled carcass. At 42, 49, and 56 d, intestinal segments were obtained from the slaughtered birds and intestinal breaking strength and elasticity determined as described by Huff et al. [27]. The test instrument used for determining the breaking force of the intestines was a Chatillon model DFM-10 digital break force meter [28] using a 4-in. segment of intestine with a speed set at 10 in./min. Pen means served as the experimental unit. Data were subjected ANOVA as a 4 × 5 factorial arrangement of treatments using the GLM option

WALDROUP ET AL.: INDUSTRY BROILER DIETS

61

Table 3. Total and added choline content of test diets (mg/kg) Added choline (mg/kg)

Basis1

Starter 0–14 d

Grower 14–35 d

Finisher 1 35–42 d

Finisher 2 42–56 d

C A D D

1,239 1,193 417 748

1,160 1,116 414 768

1,051 1,024 420 762

981 925 418 756

0 +500 +1,000

C = calculated from NRC (1994); A = analyzed by Danisco Animal Nutrition, St. Louis, MO; D = difference between analyzed value and amount provided by the unsupplemented diet.

1

of SAS [29]. The main effects of level of supplemental Met and the various additives or combinations served as main effects; the interaction of Met levels and the various additives was also evaluated. When statistical significance among or between treatment means was observed, data were separated using the least square means option of SAS [29]. Selected data were subjected to regression analysis using the PROCREG option of SAS. Statements of probability are based on P < 0.05 unless stated otherwise.

RESULTS Total and added CHO contents of mixed feeds are listed in Table 3. Calculated values for CHO in the basal diet were based on NRC [30]. Added CHO levels were determined by subtracting total CHO content of the diets with no added CHO from that of diets with 500 or 1,000 mg of CHO/kg added. Analyzed levels for the unsupplemented basal diet were slightly less than calculated; added levels for the 500 and 1,000 mg/kg levels over all age periods averaged approximately 417 and 758 mg/kg, respectively. Analyzed BET content of the mixed feeds is shown in Table 4. Total BET levels in diets with 500 and 1,000 mg/kg added Table 4. Analyzed betaine content of test diets (mg/ kg)1 Feeding period Starter Grower Finisher 1 Finisher 2 1

Added betaine (mg/kg)

Age fed

None

500

1,000

0–14 d 14–35 d 35–42 d 42–56 d

81 80 BDL2 77

560 546 444 625

1,132 1,121 916 1,130

Analyzed by Danisco Animal Nutrition, St. Louis, MO. Below detection limits.

2

BET averaged 544 and 1,075 mg/kg, respectively. Low levels of BET were found in the basal diets; levels from 35 to 42 d were below assay detection limits, perhaps due to different sources of corn and soybean meal. Calculated and analyzed levels of supplemental Met are shown in Table 5. Analyzed levels were in close agreement with calculated levels over the entire range of test diets. Thus, the test diets were considered to contain the anticipated levels of CHO, BET, and Met. The effect of levels of CHO, BET, and Met on BW at different ages is shown in Table 6. When compared by ANOVA, the Met content of the diet had no significant effect on BW at 14 or 56 d of age. At 35 and 42 d of age, however, reduction of Met to 0.15 and 0.10%, respectively, less than that in the commercial diets significantly reduced BW compared with the control group. At 49 d, a reduction of more than 0.05% resulted in a significant reduction in BW. However, when subjected to regression analysis, a significant linear regression of BW on level of Met was observed at all ages. For each 0.01% reduction in level of Met, there were BW reductions of 0.68, 5.44, 7.08, 5.74, and 4.72 g at 14, 35, 42, 49, and 56 d of age, respectively (R2 of 0.79, 0.85, 0.86, 0.97, and 0.91, respectively). Numerical improvements in BW were frequently observed when CHO or BET was added alone or in combination; however, these did not reach a level of statistical significance (P < 0.05). There was no interaction between Met level and the addition of CHO or BET, alone or in combination. The effect of levels of CHO, BET, and Met on feed conversion at different ages is shown in Table 7. No significant effect of Met on feed conversion was observed at 14 d; however,

JAPR: Research Report

62

Table 5. Calculated and analyzed level of supplemental Met in test diets (% of diet) Reduction from standard (%) 0 −0.05 −0.10 −0.15 −0.20

Basis1

Starter 0–14 d

Grower 14–35 d

Finisher 1 35–42 d

Finisher 2 42–56 d

C A C A C A C A C A

0.310 0.304 0.259 0.267 0.209 0.215 0.158 0.152 0.108 0.111

0.241 0.228 0.191 0.170 0.140 0.139 0.089 0.079 0.039 0.037

0.208 0.192 0.158 0.145 0.107 0.098 0.056 0.051 0.008 0.013

0.228 0.218 0.178 0.182 0.127 0.123 0.077 0.065 0.026 0.025

C = calculated level; A = analyzed by Degussa Corporation, Allendale, NJ.

1

cumulative feed conversion at 35, 42, 49, and 56 d was significantly influenced by Met level of the diet. In general, a reduction of up to 0.10% below the industry average Met level could be achieved without a significant change in feed conversion. Greater reductions in Met had a detrimental effect. Regression analysis indicated a quadratic response to levels of Met, with a breakpoint at approximately 0.10% removal of Met at 35, 42, 49, and 56 d (Figure 1). The addition of 1,000 mg of CHO/kg, 1,000 mg of BET/kg, or the combination of 500 mg of each significantly improved feed conversion over the birds fed the unsupplemented diets at 35, 42, 49, and 56 d of age with little difference among these 3 treatments. At 14 d, there was a significant interaction of CHO and BET supplementation with level of Met. However, this followed no consistent pattern and was not observed at other ages, although it neared significance at 42 (P = 0.08) and 49 (P = 0.06) d of age. No significant differences among or between dietary treatments were observed for mortality (Table 8). Birds were grown on new softwood shavings and received an anticoccidial and a growth-promoting antibiotic throughout the duration of the study. Mortality was within normal limits for our facility. Dietary treatments had no significant effects on dressing percentage of birds at 42, 49, or 56 d of age (Table 9). Because fat deposits contained in the viscera were removed from the carcass by the automatic evisceration, it was not possible to determine the amount of

abdominal fat. There were no indications of interaction of Met levels and the addition of CHO or BET, alone or in combination. Significant dietary effects on breast yield at 42, 49, and 56 d of age were observed (Table 10). Reduction of Met levels below that of the top industry producers resulted in significant reduction in breast yield that followed a linear trend. Each reduction of 0.01% in Met level from that used by the top industry producers resulted in losses of 0.08, 0.12, and 0.08% of breast meat yield at 42, 49, and 56 d, respectively (R2 of 0.92, 0.92, and 0.83, respectively). Addition of 1,000 mg of CHO/kg, 1,000 mg of BET/kg, or a combination of 500 mg of each to the diets resulted in significant improvements in breast yield at 42, 49, and 56 d of age. This response was independent of level of Met in the diet, as evidenced by lack of an interaction of Met and the 2 supplements. No differences between the response to CHO or BET and the combination of the 2 was observed at 42 or 49 d; at 56 d the breast yield of birds fed BET alone was superior to that of birds fed CHO alone, with the combination of the 2 intermediate between the 2 supplements. Tensile strength of intestinal segments is shown in Table 11. There was no significant effect of levels of Met or of the addition of CHO or BET, alone or in combination. As mentioned previously an anticoccidial was fed for the duration of the study, and a growth promoting antibiotic known to be effective against clostridial infection was also included in all diets. Periodic examination of birds that died during

WALDROUP ET AL.: INDUSTRY BROILER DIETS

63

Table 6. Effects of levels of methionine, choline, and betaine on body weight of male broilers at different ages (means of 4 pens of 60 birds/treatment)

Reduction in Met (%) 14 d BW (g) 0.00 0.05 0.10 0.15 0.20 Average 35 d BW (g) 0.00 0.05 0.10 0.15 0.20 Average 42 d BW (g) 0.00 0.05 0.10 0.15 0.20 Average 49 d BW (g) 0.00 0.05 0.10 0.15 0.20 Average 56 d BW (g) 0.00 0.05 0.10 0.15 0.20 Average

No choline or betaine

1,000 mg of choline/kg

1,000 mg of betaine/kg

500 mg of choline/kg 500 mg of betaine/kg

346 334 338 316 332 333

336 334 307 322 329 325

340 344 342 320 330 335

323 329 320 333 312 323

1,882 1,846 1,847 1,748 1,731 1,811

1,859 1,891 1,790 1,785 1,757 1,816

1,887 1,935 1,819 1,824 1,802 1,854

1,799 1,841 1,839 1,851 1,747 1,815

1,857ab 1,878a 1,824ab 1,802bc 1,759c

2,474 2,480 2,395 2,337 2,246 2,386

2,493 2,496 2,413 2,385 2,345 2,426

2,460 2,497 2,401 2,407 2,376 2,428

2,413 2,438 2,421 2,448 2,333 2,411

2,460ab 2,478a 2,407bc 2,394c 2,325d

2,981 2,906 2,892 2,816 2,805 2,880

2,992 2,956 2,875 2,889 2,892 2,921

2,955 3,003 2,931 2,894 2,886 2,934

2,964 2,930 2,906 2,943 2,863 2,921

2,973a 2,949ab 2,901bc 2,886bc 2,861c

3,380 3,308 3,337 3,296 3,239 3,312

3,389 3,381 3,299 3,328 3,345 3,348

3,381 3,434 3,358 3,240 3,390 3,361

3,427 3,353 3,309 3,364 3,252 3,341

3,394 3,369 3,326 3,307 3,307

0–14 d

Source of variance Met level Supplements Met × supplements CV

0–35 d

0–42 d

P diff

SEM

P diff

SEM

0.45 0.34 0.81

6 6 13

0.001 0.37 0.62

20 19 40

7.94

4.83

P diff

SEM

0.0001 20 0.37 18 0.52 40 3.50

0–49 d

Average 336 335 326 323 325

0–56 d

P diff

SEM

P diff

SEM

0.01 0.40 0.94

24 23 50

0.24 0.72 0.82

33 30 65

3.63

4.13

Means within an age with common superscripts do not differ significantly (P < 0.05).

a–d

the study by a qualified poultry veterinarian revealed no indication of coccidiosis.

DISCUSSION Results of the present study indicate that reduction in Met and TSAA levels from those

currently used by the top broiler producers may result in loss of live performance and in breast meat yield. Reduction of more than 0.10% from current values could be tolerated without adverse effects on BW gain or feed conversion; however, breast meat yield was negatively af-

JAPR: Research Report

64

Table 7. Effects of levels of Met, choline, and betaine on feed conversion by male broilers at different ages (means of 4 pens of 60 birds/treatment)

Reduction in Met (%) 0–14 d feed:gain 0.00 0.05 0.10 0.15 0.20 Average 0–35 d feed:gain 0.00 0.05 0.10 0.15 0.20 Average 0–42 d feed:gain 0.00 0.05 0.10 0.15 0.20 Average 0–49 d feed:gain 0.00 0.05 0.10 0.15 0.20 Average 0–56 d feed:gain 0.00 0.05 0.10 0.15 0.20 Average

No choline or betaine

1,000 mg of choline/kg

1,000 mg of betaine/kg

500 mg of choline/kg 500 mg of betaine/kg

1.133bcd 1.186a 1.132bcd 1.166abc 1.141bc 1.151

1.154abc 1.138bc 1.136bcd 1.148abc 1.167abc 1.149

1.173ab 1.142abc 1.149abc 1.136bcd 1.148abc 1.150

1.163abc 1.131cd 1.139bc 1.099d 1.127cd 1.132

1.156 1.149 1.139 1.137 1.146

1.523 1.532 1.539 1.581 1.627 1.561x

1.520 1.496 1.508 1.528 1.599 1.530y

1.562 1.515 1.527 1.523 1.564 1.538y

1.513 1.500 1.499 1.531 1.570 1.523y

1.530bc 1.511c 1.518d 1.541b 1.590a

1.666 1.673 1.700 1.716 1.793 1.710x

1.649 1.648 1.646 1.672 1.747 1.673yz

1.720 1.664 1.667 1.677 1.724 1.690y

1.654 1.648 1.651 1.682 1.720 1.671z

1.672bc 1.658c 1.666c 1.687b 1.746a

1.767 1.781 1.799 1.831 1.869 1.809x

1.754 1.770 1.764 1.779 1.838 1.781yz

1.805 1.779 1.764 1.786 1.828 1.792y

1.753 1.756 1.767 1.791 1.826 1.779z

1.770c 1.772c 1.773c 1.797b 1.840a

1.904 1.904 1.916 1.945 1.994 1.933x

1.874 1.890 1.892 1.898 1.959 1.903y

1.938 1.891 1.882 1.919 1.928 1.911y

1.849 1.881 1.898 1.912 1.956 1.899y

1.891c 1.891c 1.897c 1.919b 1.959a

Average

ratio

ratio

ratio

ratio

ratio

Source of variance Met level Supplements Met × supplements CV

0–14 d

0–35 d

P diff

SEM

P diff

0.41 0.08 0.049

0.008 0.007 0.016

0.0001 0.007 0.0002 0.006 0.16 0.014 1.90

2.79

SEM

0–42 d P diff

SEM

0.0001 0.007 0.0001 0.006 0.08 0.015 1.78

0–49 d P diff

SEM

0.0001 0.005 0.0001 0.005 0.06 0.012 1.24

0–56 d P diff

SEM

0.0001 0.008 0.004 0.007 0.15 0.016 1.72

Means within an age with common superscripts do not differ significantly (P < 0.05). Means within a row with common superscripts do not differ significantly (P < 0.05).

a–d x–z

fected in a linear manner. One of the first reports suggesting that amino acid levels in excess of NRC recommendations improved breast meat yield was that of Hickling et al. [31], who fed broilers a combination of 2 Met levels (100 or 116% of 1984 NRC) with 4 levels of Lys

(100, 106, 112, or 118 of 1984 NRC). The study by Hickling et al. [31] indicated that Lys above NRC levels did not improve breast meat yield unless Met was also greater than suggested by NRC. However, only 2 Met levels were compared (NRC, and 116%). Moran [32]

WALDROUP ET AL.: INDUSTRY BROILER DIETS

65

Figure 1. Feed conversion at different ages as influence by removal of various reductions in level of Met in the diet.

fed 2 strains of broilers (Ross × Ross; Steggles × Arbor Acres) diets either deficient or adequate in Met from 0 to 8 wk with processing at both 6 and 8 wk. The low Met diets reduced BW and breast yield and increased abdominal fat at 6 wk but not at 8 wk of age. The deficient diets fed from 6 to 8 wk were very near to the NRC [30] requirement. Wallis [33] demonstrated a response in breast meat yield to Met supplementation of a deficient diet but did not make any estimates about requirements for maximum yield. One of the few reports that attempt to titrate a Met requirement to optimize breast yield was that of Schutte and Pack [34]. Feeding a range of Met or TSAA levels from 14 to 38 d, they estimated a TSAA requirement of 0.84% for BW gain, 0.88% for FCR, and 0.89% for breast yield. It is difficult to compare the recommen-

dations of Schutte and Pack [34] to NRC [30] as different time periods are involved. In a recent study from our laboratory using NRC [30] feeding intervals, Si et al. [35] noted that increasing Met above NRC recommendations improved FCR at 42 and 56 d but had no effect on breast meat yield. The ability of BET to spare some of the Met needs in broiler diets is subject to considerable controversy. Virtanen and Rosi [36] conducted studies in which the basal diet was formulated to provide 75% of the NRC [30] recommendation for Met. This diet was then fortified with Met at 0.05, 0.10, or 0.15% or with BET at the same levels. There was a significant response in BW to additions of Met and BET; the authors concluded that the response to BET was greater than that obtained from Met. Virtanen and Rumsey [18] summarized a number of unpub-

JAPR: Research Report

66

Table 8. Effects of levels of methionine, choline, and betaine on mortality of male broilers (means of 4 pens of 60 males/treatment)

Reduction in Met (%) 0–14 d mortality 0.00 0.05 0.10 0.15 0.20 Average 0–35 d mortality 0.00 0.05 0.10 0.15 0.20 Average 0–42 d mortality 0.00 0.05 0.10 0.15 0.20 Average 0–49 d mortality 0.00 0.05 0.10 0.15 0.20 Average 0–56 d mortality 0.00 0.05 0.10 0.15 0.20 Average

No choline or betaine

1,000 mg of choline/kg

1,000 mg of betaine/kg

500 mg of choline/kg 500 mg of betaine/kg

4.16 2.08 2.08 4.58 3.33 3.25

2.91 5.00 5.55 6.25 2.91 4.52

2.91 3.33 2.91 3.33 2.50 3.00

2.70 4.37 3.33 3.75 2.91 3.41

3.17 3.69 3.47 4.47 2.91

5.83 2.50 3.75 6.25 5.00 4.66

3.33 6.25 6.66 8.33 3.75 5.66

3.33 3.75 6.25 4.16 2.50 4.00

4.79 5.20 4.79 5.20 4.58 4.91

4.32 4.42 5.36 5.98 3.95

5.83 5.41 4.16 8.33 6.25 6.00

4.58 7.50 8.33 9.16 4.58 6.83

4.58 3.75 7.08 5.41 2.91 4.75

5.20 5.83 5.83 6.25 7.08 6.04

5.05 5.62 6.35 7.29 5.20

6.66 6.25 5.00 8.75 9.58 7.25

6.66 8.75 10.00 9.58 4.58 7.91

5.00 4.16 9.58 6.66 3.75 5.83

6.87 6.66 6.66 8.12 10.83 7.83

6.30 6.45 7.81 8.28 7.18

9.58 7.91 9.16 10.83 12.50 10.00

8.33 11.66 12.77 13.75 7.50 10.80

5.83 5.41 10.41 8.75 4.58 7.00

8.33 7.29 9.16 9.79 12.91 9.50

8.02 8.07 10.38 10.78 9.37

Average

(%)

(%)

(%)

(%)

(%)

Source of variance Met level Supplements Met × supplements CV

0–14 d

0–35 d

0–42 d

0–49 d

0–56 d

P diff

SEM

P diff

SEM

P diff

SEM

P diff

SEM

P diff

SEM

0.54 0.35 0.91

0.66 0.63 1.41

0.37 0.49 0.70

0.79 0.75 1.69

0.31 0.34 0.74

0.83 0.79 1.78

0.56 0.34 0.34

0.98 0.93 2.09

0.33 0.10 0.64

1.17 1.12 2.51

80.33

70.09

lished research trials conducted at private research institutions using corn-soybean diets with various levels of coccidiosis challenge. They concluded that under practical field conditions with chicks maintained on built-up litter that BET was more effective in promoting growth and feed efficiency than Met. However,

60.90

58.64

54.87

Rostagno and Pack [15], using corn-sorghumsoybean meal diets supplemented with CHO to provide methyl groups, found small and nonsignificant responses to BET supplementation that were not comparable to those provided by supplemental Met. Schutte et al. [16] fed a complex diet (corn, wheat, tapioca, peas,

WALDROUP ET AL.: INDUSTRY BROILER DIETS

67

Table 9. Effects of levels of methionine, choline, and betaine on dressing percentage of male broilers at different ages (means of 4 groups of 5 birds/treatment)

Reduction in Met (%)

No choline or betaine

1,000 mg of choline/kg

1,000 mg of betaine/kg

500 mg of choline/kg 500 mg of betaine/kg

70.17 69.81 70.49 70.93 70.37 70.35

70.26 71.27 72.48 70.74 71.09 71.17

69.70 71.19 71.47 71.39 71.32 71.01

70.65 70.14 72.54 70.82 71.50 71.13

70.20 70.60 71.75 70.97 71.07

70.68 71.62 72.26 73.03 71.94 71.91

72.75 71.41 72.85 73.25 72.12 72.48

72.44 73.11 72.51 72.84 73.35 72.85

72.11 72.94 72.20 72.61 72.67 72.51

72.00 72.27 72.46 72.93 72.52

71.65 71.82 72.99 73.84 73.47 72.45

72.75 73.27 72.58 73.47 73.16 73.04

73.16 73.56 73.50 73.73 74.11 73.61

73.02 73.51 73.59 73.01 72.03 73.03

72.64 73.04 73.17 73.51 73.19

42 d dressing percentage (%) 0.00 0.05 0.10 0.15 0.20 Average 49 d dressing percentage (%) 0.00 0.05 0.10 0.15 0.20 Average 56 d dressing percentage (%) 0.00 0.05 0.10 0.15 0.20 Average Source of variance Met level Supplements Met × supplements CV

42 d

49 d

Average

56 d

P diff

SEM

P diff

SEM

P diff

SEM

0.08 0.31 0.89

0.38 0.34 0.77

0.34 0.15 0.59

0.32 0.28 0.64

0.33 0.13 0.30

0.28 0.25 0.57

2.18

feather meal, and soybean meal) and a simple corn-soybean meal diet, both supplemented with CHO and considered to be Met deficient, and evaluated the effects of supplemental BET. The response of chicks to BET was small and nonsignificant, although BET significantly improved oven-ready yield and breast meat yield. However, the effect on breast yield was inferior to that obtained by Met supplementation. Esteve-Garcia and Mack [19] evaluated the potential replacement value of Met by BET in a Met-deficient diet. Choline was added at 500 mg/kg as a methyl donor, and clean conditions were used to reduce coccidiosis challenge. There were no significant interactions between BET and Met; Met supplementation significantly improved BW and feed to gain at 21 and 41 d and significantly increased breast yield at 41 d. Addition of BET significantly improved carcass

1.76

1.58

yield (dressing percentage) with no significant change in other carcass parameters such as breast yield or abdominal fat. Esteve-Garcia and Mack [19] concluded that BET does not replace Met in its function as an essential amino acid in protein metabolism but may improve carcass yield. McDevitt et al. [20] also noted that addition of BET to diets containing added Met further improved the relative breast muscle yield. They concluded that BET could not substitute for Met in diets marginally deficient in TSAA but that BET may improve carcass composition, especially breast meat yield. Remus [37] noted that breast meat yield of tom turkeys was significantly improved by BET supplementation. The results of the present study indicate that addition of either CHO or BET at 1,000 mg/kg to a nutritionally adequate corn-soybean meal diet had little or no sparing effect on Met. Addi-

JAPR: Research Report

68

Table 10. Effects of levels of Met, choline, and betaine on breast yield at different ages (means of 4 groups of 5 birds/treatment)

Reduction in Met (%)

No choline or betaine

1,000 mg of choline/kg

1,000 mg of betaine/kg

500 mg of choline/kg 500 mg of betaine/kg

24.76 24.27 23.69 22.42 21.83 23.39y

24.48 25.19 24.73 24.15 23.46 24.40x

25.20 24.54 24.29 24.76 23.59 24.48x

24.62 24.83 24.31 24.18 23.60 24.31x

24.76a 24.71a 24.25ab 23.88b 23.12c

25.11 24.33 24.37 23.45 21.54 23.76y

26.55 25.29 24.97 25.13 23.30 25.05x

25.34 25.97 23.94 24.91 23.66 24.76x

25.94 25.70 25.78 24.12 23.56 25.02x

25.73a 25.32ab 24.76bc 24.40c 23.01d

25.55 25.23 24.01 24.49 22.60 24.38z

24.86 25.29 25.07 25.07 24.61 24.98y

26.20 25.86 25.55 25.42 24.76 25.56x

26.15 25.34 26.13 25.27 23.69 25.32xy

25.69a 25.43ab 25.19ab 25.06b 23.92c

Average

1

42 d breast yield (%) 0.00 0.05 0.10 0.15 0.20 Average 49 d breast yield (%) 0.00 0.05 0.10 .15 0.20 Average 56 d breast yield (%) 0.00 0.05 0.10 0.15 0.20 Average Source of variance Met level Supplements Met × supplements CV

42 d

49 d

56 d

P diff

SEM

P diff

SEM

P diff

SEM

0.0005 0.01 0.70

0.27 0.25 0.55

0.0001 0.0001 0.08

0.22 0.19 0.43

0.0001 0.0005 0.16

0.22 0.19 0.43

4.62

3.52

3.50

Means within an age with common superscripts do not differ significantly (P < 0.05). Means within a row with common superscripts do not differ significantly (P < 0.05). 1 Skinless, boneless breast meat (pectoralis major + pectoralis minor) as a percentage of carcass weight. a–d x–z

tion of CHO or BET to the diets did improve feed conversion at 35 or 42 d but not at other ages evaluated. One of the most significant responses observed during the present study was the positive influence of CHO or BET supplementation on breast meat yield. In agreement with that of many previous reports, addition of 1,000 mg of BET/kg resulted in increased breast yield that was independent of the Met content of the diet. However, similar improvements were noted with the addition of 1,000 mg of CHO/kg or a combination of BET and CHO, each at 500 mg/kg. Due in large measure to its osmoregulatory functions [17, 38, 39], BET appears to be of benefit in chicks infected with coccidiosis [39, 40, 41, 42, 43, 44]. Chicks in the present study

received an anticoccidial in the diet and were grown on new litter with no apparent problems with coccidial infection. Intestinal strength of chicks in the present study was not influenced by supplementation of the diet with BET or CHO. The Arg levels in this study exceeded those suggested by NRC [30] but were similar to levels used in the commercial broiler industry [21]. Keshavarz and Fuller [45, 46] demonstrated that high levels of Arg in a corn-soybean meal diet suppressed performance when Met levels were low and suggested that the adverse effect of excess Arg is due to the increased demand for methyl groups for the formation of creatine, which in turn leads to a deficiency of Met. This research was confirmed by the findings of Cham-

WALDROUP ET AL.: INDUSTRY BROILER DIETS

69

Table 11. Effects of levels of methionine, choline, and betaine on tensile strength of intestine of male broilers (means of 4 groups of 5 birds/treatment)

Reduction in Met (%) 42 d peak load (kg) 0.00 0.05 0.10 0.15 0.20 Average 49 d peak load (kg) 0.00 0.05 0.10 0.15 0.20 Average 56 d peak load (kg) 0.00 0.05 0.10 0.15 0.20 Average Source of variance Met level Supplements Met × supplements CV

No choline or betaine

1,000 mg of choline/kg

1,000 mg of betaine/kg

500 mg of choline/kg 500 mg of betaine/kg

0.412 0.424 0.508 0.413 0.408 0.433

0.403 0.530 0.461 0.387 0.432 0.442

0.443 0.361 0.505 0.473 0.418 0.440

0.454 0.466 0.404 0.395 0.436 0.431

0.428 0.445 0.469 0.417 0.423

0.558 0.654 0.543 0.510 0.567 0.566

0.760 0.594 0.498 0.523 0.530 0.581

0.492 0.528 0.620 0.543 0.547 0.546

0.549 0.553 0.578 0.492 0.529 0.540

0.590 0.582 0.560 0.517 0.543

0.542 0.490 0.589 0.475 0.535 0.526

0.457 0.538 0.498 0.529 0.557 0.516

0.552 0.600 0.543 0.521 0.530 0.549

0.600 0.531 0.552 0.588 0.513 0.557

0.538 0.540 0.545 0.528 0.534

42 d

49 d

Average

56 d

P diff

SEM

P diff

SEM

P diff

SEM

0.49 0.97 0.34

0.023 0.020 0.046

0.41 0.65 0.26

0.029 0.027 0.061

0.99 0.52 0.73

0.025 0.024 0.050

21.29

ruspollert et al. [47, 48]. Arg levels used in the present study were not as high as those shown in the cited studies, and if there had been an

22.03

18.77

increased demand for methyl groups a greater response to BET or CHO should have been observed.

CONCLUSIONS AND APPLICATIONS 1. Dietary Met levels typical of top industry producers could be reduced by approximately 0.10% without adversely affecting BW gain or feed conversion. 2. Reductions in Met levels below those used by top industry producers had a significant negative effect on breast yield. 3. Addition of CHO or BET at 1,000 mg/kg or a combination of 500 mg/kg of both appeared to have no sparing effect on Met needs. 4. Addition of CHO or BET at 1,000 mg/kg or a combination of 500 mg/kg of both significantly improved feed conversion and breast meat yield of broilers independent of dietary Met levels. 5. No influence of CHO or BET supplementation was observed on intestinal strength of broilers in the present study in which coccidiosis was not an apparent problem.

JAPR: Research Report

70

REFERENCES AND NOTES 22. Chinook Group Ltd., Sombra, Ontario, Canada.

1. Finkelstein, J. D., and J. J. Martin. 1984. Methionine metabolism in mammals. Distribution of homocysteine between competing pathways. J. Biol. Chem. 259:9508–9513. 2. Emmert, J. L., T. A. Garrow, and D. H. Baker. 1996. Hepatic betaine-homocysteine methyltranferase activity in the chicken is influenced by dietary intake of sulfur amino acids, choline, and betaine. J. Nutr. 126:2050–2058. 3. Marvel, J. A., C. W. Carrick, R. E. Roberts, and S. M. Hauge. 1944. The supplementary value of choline and methionine in a corn and soybean oil meal chick ration. Poult. Sci. 23:294–297. 4. Clandinin, D. R., W. W. Cravens, J. G. Halpin, and E. B. Hart. 1946. Supplementary value of methionine, cystine, and choline in a practical soybean oil meal starter ration. Poult. Sci. 25:509–516. 5. Gerry, R. W., C. W. Carrick, and S. M. Hauge. 1948. Methionine and choline in a simplified chick ration. Poult. Sci. 27:161–168. 6. Sunde, M. L., P. E. Waibel, W. W. Cravens, and C. A. Elvehem. 1951. A relationship between antibiotics, vitamin B12, and choline and methionine in chick growth. Poult. Sci. 30:668–671. 7. West, J. W., C. W. Carrick, S. M. Hauge, and E. T. Mertz. 1951. The relationship of choline and cystine to the methionine requirement of young chickens. Poult. Sci. 30:880–885. 8. Featherston, W. R., and E. L. Stephenson. 1960. Dietary interrelationships between methionine, glycine, choline, protein level, and energy content of the chick diet. Poult. Sci. 39:1023–1029. 9. Quillen, E. C., G. F. Combs, R. D. Creek, and G. L. Romoser. 1961. Effect of choline on the methionine requirements of chickens. Poult. Sci. 40:639–645. 10. Pesti, G. M., A. E. Harper, and M. L. Sunde. 1980. Cholinemethionine nutrition of starting broiler chicks. Three models for estimating the choline requirement with economic considerations. Poult. Sci. 59:1073–1081. 11. Baker, D. H., K. M. Halpin, G. L. Czarnecki, and C. M. Parsons. 1983. The choline-methionine interrelationship for growth of the chick. Poult. Sci. 62:133–137. 12. Miles, R. D., N. Ruiz, and R. H. Harms. 1983. The interrelationship between methionine, choline, and sulfate in broiler diets. Poult. Sci. 62:495–498. 13. Tillman, P. B., and G. M. Pesti. 1986. The response of male broiler chicks to a corn-soy diet supplemented with L-methionine, L-cysine, choline, sulfate, and vitamin B12. Poult. Sci. 65:1741–1748. 14. Garcia-Neto, M., G. M. Pesti, and R. I. Bakalli. 2000. Influence of dietary protein level on the broiler chicken’s response to methionine and betaine supplements. Poult. Sci. 79:1478–1484. 15. Rostagno, H. S., and M. Pack. 1996. Can betaine replace supplemental DL-methionine in broiler diets? J. Appl. Poult. Res. 5:150–154. 16. Schutte, J. B., J. de Jong, W. Smink, and M. Pack. 1997. Replacement value of betaine for DL-methionine in male broiler chicks. Poult. Sci. 76:321–325. 17. Kidd, M. T., P. R. Ferket, and J. D. Garlich. 1997. Nutritional and osmoregulatory functions of betaine. World’s Poult. Sci. J. 53:126–139. 18. Virtanen, E., and G. Rumsey. 1996. Betaine supplementation can optimize use of methionine, choline in diets. Feedstuffs 68(42):12–13. 19. Esteve-Garcia, E., and S. Mack. 2000. The effect of DLmethionine and betaine on growth performance and carcass characteristics of broilers. Anim. Feed Sci. Technol. 87:85–93. 20. McDevitt, R. M., S. Mack, and I. R. Wallis. 2000. Can betaine partially replace or enhance the effect of methionine by improving broiler growth and carcase characteristics. Br. Poult. Sci. 41:473–480. 21. Agri-Stats, Fort Wayne IN.

23. Betafin, Danisco Animal Nutrition, St. Louis, MO. 24. Cobb 500, Cobb-Vantress Inc., Siloam Springs, AR. 25. FASS. 1999. Guide for the Care and Use of Agricultural Animals in Agricultural Research and Teaching. 1st rev. ed. Fed. Anim. Sci. Soc., Savoy, IL. 26. Fritts, C. A., and P. W. Waldroup. 2006. Modified phosphorus program for broilers based on commercial feeding intervals to sustain live performance and reduce total and water-soluble phosphorus in litter. J. Appl. Poult. Res. 15:(in press). 27. Huff, W. E., J. M. Balog, G. R. Bayyari, and N. C. Rath. 1994. The effect of Mycocurb, propionic acid, and calcium propionate on the intestinal strength of broiler chickens. Poult. Sci. 73:1352–1356. 28. Ametek Test and Calibration Instruments Division, Largo, FL. 29. SAS Institute. 1991. SAS User’s Guide: Statistics. Version 6.03 ed. SAS Institute Inc., Cary, NC. 30. National Research Council. 1994. Nutrient Requirements of Poultry. 9th rev. ed. Natl. Acad. Press, Washington, DC. 31. Hickling, D., W. Guenter, and M. Jackson. 1990. The effect of dietary lysine and methionine on broiler chicken performance and breast meat yield. Can. J. Anim. Sci. 70:673–676. 32. Moran, E. T., Jr. 1994. Response of broiler strains differing in body fat to inadequate methionine: Live performance and processing yields. Poult. Sci. 73:1116–1126. 33. Wallis, I. R. 1999. Dietary supplements of methionine increase breast meat yield and decrease abdominal fat in growing broiler chickens. Aust. J. Exp. Agric. 39:131–141. 34. Schutte, J. B., and M. Pack. 1995. Sulfur amino acid requirements of broiler chicks from fourteen to thirty-eight days of age. 1. Performance and carcass yield. Poult. Sci. 74:480–487. 35. Si, J., J. H. Kersey, C. A. Fritts, and P. W. Waldroup. 2004. An evaluation of the interaction of lysine and methionine in diets for growing broilers. Int. J. Poult. Sci. 3:51–60. 36. Virtanen, E., and L. Rosi. 1995. Effects of betaine on methionine requirement of broilers under various environmental conditions. Pages 88–92 in Proc. Austr. Poult. Sci. Symp. Univ. Sydney, Sydney, NSW, Australia. 37. Remus, J. 2001. Betaine for increased breast meat yield. Int. Poult. Prod. 9:22–23. 38. Kettunen, H., S. Peuranen, and K. Tiihonen. 2001. Betaine aids in the osmoregulation of duodenal epithelium of broiler chicks, and affects the movement of water across the small intestinal epithelium in vitro. Comp. Biochem. Physiol. 129A:595–603. 39. Matthews, J. O., T. L. Ward, and L. L. Southern. 1997. Interactive effects of betaine and monensin in uninfected and Eimeria acervulina-infected chicks. Poult. Sci. 76:1014–1019. 40. Augustine, P. C., J. L. McNaughton, E. Virtanen, and L. Rosi. 1997. Effect of betaine on the growth performance of chicks inoculated with mixed cultures of avian Eimeria species and on invasion and development of Eimeria tenella and Eimeria acervulina in vitro and in vivo. Poult. Sci. 76:802–809. 41. Allen, P. C., H. D. Danforth, and P. C. Augustine. 1998. Dietary modulation of avian coccidiosis. Int. J. Parasitol. 28:1131– 1140. 42. Augustine, P. C., and H. D. Danforth. 1999. Influence of betaine and salinomycin on intestinal absorption of Met and glucose and on the ultrastructure of intestinal cells and parasite development stages in chicks infected with Eimeria acervulina. Avian Dis. 43:89–97. 43. Matthews, J. O., and L. L. Southern. 2000. The effect of dietary betaine in Eimeria acervulina-infected chicks. Poult. Sci. 79:60–65.

WALDROUP ET AL.: INDUSTRY BROILER DIETS 44. Waldenstedt, L., K. Elwinger, P. Thebo, and A. Uggla. 1999. Effect of betaine supplement on broiler performance during an experimental coccidial infection. Poult. Sci. 78:182–189. 45. Keshavarz, K., and H. L. Fuller. 1971. Relationship of arginine and methionine in the nutrition of the chicks and the significance of creatine biosynthesis in their interaction. J. Nutr. 101:217–222. 46. Keshavarz, K., and H. L. Fuller. 1971. Relationship of arginine and methionine to creatine formation in chick. J. Nutr. 101:855–862. 47. Chamruspollert, M., G. M. Pesti, and R. I. Bakalli. 2002. Dietary interrelationships among arginine, methionine, and lysine in young broiler chicks. Br. J. Nutr. 88:655–660.

71

48. Chamruspollert, M., G. M. Pesti, and R. I. Bakalli. 2004. Chick responses to dietary arginine and methionine levels at different environmental temperatures. Br. Poult. Sci. 45:93–100.

Acknowledgments The authors express their appreciation to Bill Huff and Susan Watkins for their contributions as reviewers. Thanks are given to Degussa Corporation for amino acid analysis of the diets and to Danisco Animal Nutrition for contributing the betaine and for choline and betaine analysis of the diets.