The effect of
DL
-methionine and betaine on growth
performance and carcass characteristics in broilers
$
E. Esteve-Garcia
a,*, Stefan Mack
baDepartment of Animal Nutrition, Institut de Recerca i Tecnologia AgroalimentaÁries (IRTA),
Centre de Mas BoveÂ. Apartat 415, 43280 Reus, Spain
bDegussa-HuÈls AG, Applied Technology Feed Additives, P.O. Box 13 45, D-63403 Hanau, Germany
Received 11 October 1999; received in revised form 16 February 2000; accepted 22 June 2000
Abstract
An experiment was conducted to determine if betaine could replace methionine in a methionine de®cient diet. In order to avoid the effects of betaine as methyl group donor or as osmoprotectant or coccidiostat enhancer, suf®cient amounts of methyl donating compounds were added and clean conditions were used to reduce the coccidiosis challenge.
A total of 576 day-old female broiler chicks were fed one of six diets in a 3 (0, 0.6, 1.2 g/kg of
DL-methionine)2(0 and 0.5 g/kg of betaine) factorial arrangement between 0 and 41 days. The basal diet contained 3.2 g/kg (0±21 days), 2.8 g/kg (21±38 days) and 2.5 g/kg (38±41 days), of methionine, respectively; 3.4 g/kg (0±21 days), 3.6 g/kg (21±38 days) and 3.5 g/kg (38±41 days) of cystine. There were eight replicates of 12 birds per treatment. Performance was determined at 21 and 41 days. At the end, carcass and breast yields were determined on nine chickens per replicate, and abdominal fat on three chickens per replicate.
There were no signi®cant interactions between betaine and DL-methionine. DL-methionine improved (P<0:001) body weight and feed to gain at 21 and 41 days whereas the effects of betaine
were relatively small and not signi®cant (P>0:10). Breast yield increased at all levels of DL
-methionine addition (P<0:001), while betaine increased carcass yield (P<0:05). These results
suggest that betaine does not replace methionine in its function as essential amino acid in protein metabolism, but may improve carcass yield.#2000 Elsevier Science B.V. All rights reserved.
Keywords:Methionine; Betaine; Broiler chickens; Performance; Carcass yield
87 (2000) 85±93
$Parts of this manuscript were presented at the 10th European Poultry Conference, Jerusalem, Israel.
*Corresponding author. Tel.:34-977-34-32-52; fax:34-977-34-40-55
E-mail address: enric.esteve@irta.es (E. Esteve-Garcia).
1. Introduction
The methionine sparing effect of betaine has been the subject of some controversy. Some experiments on maize-soyabean meal diets and several levels of coccidial challenge have shown positive responses to betaine supplementation in methionine de®cient diets (Virtanen and Rumsey, 1996). The responses obtained with betaine were comparable to those ofDL-methionine, when two parts of supplemental methionine were
replaced by one part of betaine. According to the authors, the diets contained choline levels in accordance with NRC (1994) recommendations and ionophores as coccidiostats. In contrast to these results Rostagno and Pack (1996) using a diet based on maize, sorghum and soyabean meal and supplemental choline to provide adequate supply of methyl groups found small and non-signi®cant responses to betaine supplementation, which were not comparable to those found with supplemental methionine. In another experiment, Schutte et al. (1997) fed a complex diet containing maize, wheat, tapioca, peas, feather meal, soyabean and other minor ingredients, and a maize soy diet. All diets were supplemented with choline. Again, the response to betaine in both diets was small and not signi®cant, and there was no signi®cant diet by betaine interactions. It is interesting to note that betaine signi®cantly improved oven-ready yield and breast meat yield, although the effect on breast meat yield was inferior to that obtained with methionine.
In pigs, Emmert et al. (1998) did not observe any response to betaine or choline in a methionine de®cient diet. The aim of this study was to examine the effect of supplemental levels of either DL-methionine or betaine to a methionine de®cient diet,
which was adequate in methyl donating compounds, on growth performance and carcass quality of broiler chickens.
2. Materials and methods
A total of 576 female broiler chickens of the Ross strain were used. The feeding program consisted of a starter diet till 21 days of age, a ®nisher diet till 38 days of age and a withdrawal diet till 41 days of age. The ®nisher and withdrawal diets were identical, except for the fact that the withdrawal diet did not contain halofuginone as coccidiostat (which was used in the starter and ®nisher diets). Each treatment diet was supplemented with 500 ppm choline (or 1 g/kg commercial choline chloride) in order to provide adequate amounts of labile methyl donor groups. The starter diet was based on wheat, barley, manioc, ®sh meal, full fat extruded soyabean, soyabean meal, and lard, plus a mineral, amino acid and vitamin premix. It was estimated to contain 13.0 MJ/kg of ME, 211 g/kg protein, 12 g/kg lysine, and 6.7 g/kg methioninecystine.
Table 1
Composition of the basal diets (g/kg)
Starter 0±21
Full fat extruded soyabeans 159.9 315.5
Soyabean meal 189.1 69.4
Fish meal, 20.0
Meat and bone meal, 500 g CP/kg 13.0
L-lysine HCl 1.3 1.5
Calcium carbonate 7.1 7.6
Dicalcium phosphate 17.1 11.1
Salt 2.8 2.7
Choline chloride, 50% 1.0 1.0
Minerals and vitaminsa 4.0 4.0
Stenorolc 0.5 0.5
Avizyme 1200d 1.0 1.0
Nutrient content (analysed except for metabolizable energy)
Starter Finisher Withdrawal
Metabolizable energy (MJ/kg) 13.0 13.8 13.8
Crude protein 211 200 200
Lysine 12.2 11.0 11.0
Methionine 3.2 3.0 2.5
Methioninecystine 6.6 6.6 5.7
Threonine 7.6 7.4 6.7
aA sample of 1 kg of feed contains: Vitamin A: 12000 UI; Vitamin D3: 5000 UI; Vitamin E: 30 mg; Vitamin
K3: 3 mg; Vitamin B1: 2.2 mg; Vitamin B2: 8 mg; Vitamin B6: 5 mg; Vitamin B12: 11mg; folic acid: 1.5 mg; biotin: 150mg; calcium pantotenate: 25 mg; nicotinic acid: 65 mg; Mn: 60 mg; Zn: 40 mg; I: 0,33 mg; Fe: 80 mg; Cu: 8 mg; Se: 0,15 mg; EtoxiquõÂn: 150 mg.
bWithdrawal diet did not contain stenorol and was offered at 38 days. cHoechst Roussel Vet GmbH, Wiesbaden, Germany.
dFinnfeeds International Ltd., Marlborough, Wiltshire, UK.
different amino acid concentrations of the ®nisher and withdrawal diets may re¯ect the composition of the different batches of ingredients used. However, it must be noted that all diets for each period were prepared with the same batch of ingredients, and all diets within a period had the same composition except for the supplemental betaine and methionine. The experimental diets were analysed for supplemental methionine (NFIA, 1991) and gross chemical composition (A.O.A.C., 1984). Betaine was analyzed by ion exchange chromatography with UV and Refractive Index detection (Johannsen, unpublished), based on the method of RajakylaÈ and Paloposki (1983). Results are shown in Table 2. Analyzed betaine exceeded the expected concentrations, and could be a re¯ection of the native content of the feed ingredients which seems to be highly variable (Kidd et al., 1997).
2.1. Experimental design
There were six experimental treatments, each consisting of eight pen replicates of 12 chickens. Table 3 further speci®es the study design.
2.2. Controls
Chicks were weighed in bulk on arrival and at 21 days. Weight of feed plus feed trough and live weight of the birds were recorded per pen. At the end of the experiment, on day 41, chickens were leg banded for identi®cation and were individually weighed, for Table 2
Analytical composition of the experimental diets
Moisture
T-4 105.2 76.3 203.9 4.1 0.6 1.140
T-5 106.4 75.8 205.5 4.1 1.1
T-6 105.5 75.0 207.1 4.4 1.2 1.140
Finisher T-1 104.0 98.1 203.6 3.8 0
T-2 100.9 99.7 201.3 4.0 0 1.210
T-3 101.4 96.8 201.3 3.9 0.6
T-4 98.9 101.4 195.0 4.1 0.6 1.250
T-5 99.1 98.6 202.9 4.2 1.2
T-6 104.0 96.9 203.1 4.0 1.2 1.320
Withdrawal T-1 103.8 98.4 201.8 3.6 0
T-2 105.5 97.9 202.9 3.7 0 1.140
T-3 100.4 94.2 203.1 3.3 0.6
T-4 103.3 98.1 203.4 3.5 0.6 1.110
T-5 104.4 98.5 201.9 3.7 1.2
carcass yield and abdominal fat, or for breast yield determinations. Nine chickens per pen were used for breast yield determination. Carcass yield included head and toes. Three other chickens per pen were used for abdominal fat determination. Trained personnel of the plant processed all chickens in a commercial abattoir. Specialised personnel of the plant processed the chickens used for breast yield in the same abattoir, and deboned breasts were obtained and weighed. Also, carcass yield was determined with the chickens processed for breast yield at the plant. Carcass yield included head and toes. The chickens used for abdominal fat were slaughtered, plucked and refrigerated in the processing plant, and were stored in a cold chamber at 48C overnight. The following day, they were eviscerated and abdominal fat was determined for each bird as a percent of live body weight. Abdominal fat included the fat that can be manually excised from the abdominal cavity, including that adhering to the gizzard, surrounding the bursa of Fabricius, the cloaca, and adjacent muscles, but not the mesenteric nor the perirenal fat.
The arrangement of cages corresponds to a Randomized Complete Block Design, with 8 blocks and 6 experimental treatments. The arrangement of treatments corresponds to a 23 factorial with 2 levels of betaine (0 and 0.05) and 3 levels of DL-methionine (0,
0.06, and 0.12). Interactions and main effects were determined from theFvalues of the ANOVA table. For data in percentages (breast yield, carcass yield, abdominal fat) the arc sine of the square root transformation was used to stabilise the variance. Effects of methionine level in case theFvalue for methionine was signi®cant at the (P<0:05) level were separated by Ducan's multiple range test (Duncan, 1955).
3. Results
Performance is shown in Table 4. There was a marked and highly signi®cant response to methionine supplementation (P<0:001) in terms of ®nal weight and feed to gain. Body weight responded signi®cantly (P<0:05) to all levels of methionine, but differences in feed to gain were not signi®cant (P>0:05) between the medium and high level of methionine. Effect of betaine was always small and not signi®cant, although it must be noted that it was always in the direction of improving feed to gain. Mortality also tended to be higher at the high methionine level, but again the differences were not signi®cant (P>0:05).
Table 3
Experimental design
Treatment
T-1 T-2 T-3 T-4 T-5 T-6
MC content of starter/grower diet (g/kg) 6.6/5.7
DL-methionine supplementation (g/kg) 0 0 0.6 0.6 1.2 1.2
Betaine supplementation (g/kg) 0 0.5 0 0.5 0 0.5 Number of replicates per treatment 8
Number of birds per replicate 12 Total number of birds per treatment 96
At the end of the experiment, there was a marked and highly signi®cant response to methionine supplementation (P<0:001) in body weight and feed to gain. The differences between the medium and high methionine levels were not signi®cant (P>0:05) but were always in the direction of improving body weight and reducing feed to gain. The effects of betaine were small and not signi®cant (P>0:05) although they were in the direction of improving body weight and reducing feed to gain.
Results of the carcass measurements are shown in Table 5. There was a marked and signi®cant response to methionine at all levels of methionine supplementation (P<0:05) in carcass weight, breast weight and breast yield (P<0:05). There was also a signi®cant effect of betaine improving carcass yield (P<0:05) at all levels of methionine supplementation. The effect of methionine supplementation was very pronounced on abdominal fat (P<0:001) but only signi®cant (P<0:05) between the low and medium methionine levels. Abdominal fat tended to increase with methionine supplementation (and carcass weight) but as a percent of live body weight, there were no signi®cant Table 4
Body weight in grams, feed to gain ratio and liveability of chickens fed diets containing different concentrations ofDL-methionine and betainea
Dietary treatment (%) Age Liveability (%)
DL-met Betaine 21 days 41 days
BWb Fec BW FE
0 0 534 1.923 1721 2.189 97.0
0 0.05 530 1.863 1688 2.175 97.0
0.06 0 631 1.728 1910 2.083 98.0
0.06 0.05 639 1.697 1929 2.074 96.9
0.12 0 651 1.668 1957 2.059 93.9
0.12 0.05 673 1.673 2001 2.062 94.8
S.E.M. 8.3 0.0210 31.7 0.0332 2.16
Source of variation
DL-met 0.001 0.001 0.001 0.002 0.68
Betaine 0.20 0.11 0.70 0.81 0.24
DL-metbetaine 0.27 0.31 0.47 0.97 0.88
DL-metd
0 532 1.893 1704 2.182 97.0
0.06 635 1.713 1917 2.078 97.4
0.12 662 1.681 1979 2.061 94.3
0 vs. 0.06 and 0.12 0.01 0.01 0.01 0.01 0.88
0.06 vs. 0.12 0.01 0.06 0.07 0.60 0.10
Betained
0 605 1.772 1862 2.110 96.3
0.05 614 1.744 1873 2.104 96.2
aBody weight in kilograms per chicken.
treatment effects (P>0:05). These results were also analyzed using ®nal live body weight as a covariable (not shown). The effect of the covariable was highly signi®cant for carcass yield and abdominal fat (P<0:001) but not (P>0:05) for abdominal fat as a percent of body weight. Differences in abdominal fat due to treatments disappeared when the covariable was introduced in the model, indicating that they were only due to body weight. Carcass yield showed signi®cant effects due to methionine (signi®cant at P<0:05 between low and medium levels) and to betaine (P0:055).
4. Discussion
The results of performance in the present experiment suggest that betaine cannot replace methionine in a methionine de®cient diet. This is in agreement with reports from Rostagno and Pack (1996) and Schutte et al. (1997) in the sense that the responses to betaine are small and not signi®cant, and not comparable to those obtained with methionine. The reason for the discrepancy between these results and those reported by Virtanen and Rumsey (1996) is not clear since some of the studies reported by the latter Table 5
Carcass yield, breast yield and abdominal fat of chickens fed diets containing different concentrations of
DL-methionine and betaine
0 0.05 1365 81.3 198.5 11.7 38.0 2.26
0.06 0 1553 80.9 255.9 13.3 47.3 2.49
0.06 0.05 1564 81.6 257.3 13.4 47.8 2.43
0.12 0 1619 81.1 272.4 13.6 52.0 2.71
0.12 0.05 1643 81.3 278.4 13.8 54.9 2.67
S.E.M. 19.55 0.26 4.68 0.16 3.65 0.16
P>F
DL-met 0.001 0.17 0.001 0.001 0.0067 0.14
Betaine 0.76 0.0165 0.72 0.45 0.63 0.36
DL-metbetaine 0.53 0.38 0.64 0.99 0.30 0.76
DL-met
0 1376 80.8 200.4 11.7 42.4 2.38
0.06 1560 81.2 256.9 13.3 47.4 2.46
0.12 1630 81.2 275.1 13.7 51.6 2.69
0 vs. 0.06 and 0.12 0.01 0.06 0.01 0.01 0.01 0.14
0.06 vs. 0.12 0.01 0.92 0.01 0.03 0.10 0.14
Betaine
0 1519 80.8b 243.2 12.9 47.1 2.52
0.05 1527 81.4a 245.5 13.0 46.7 2.44
aValues are means of eight replicates of 12 chickens.
bValues are means of eight replicates of nine chickens per treatment. cValues are means of eight replicates of three chickens per treatment.
investigators were done in the presence of coccidial challenge, which reportedly enhances the response to betaine (Matthews et al., 1995). Zimmerman et al. (1996) did not ®nd any bene®t of betaine supplementation in the event of a coccidial challenge. It is possible that the osmoprotective effect of betaine directly in the gut cells could help reduce the damage caused by coccidia, and the better integrity of the gut lining could lead to more ef®cient nutrient utilisation and improved performance.
A positive interaction between betaine and ionophores could occur due to the impairment of choline conversion to betaine (Tyler, 1977). However, Waldenstedt et al. (1999) found some bene®cial effect of betaine on weight gain in the occurrence of a coccidial challenge, but the effect was independent of that of narasin. In the current experiment and that of Schutte et al. (1997) no ionophoric coccidiostats were used; halofuginone was employed in the former and nicarbazin during the ®rst 21 days in the latter. It is possible that the differences between all these experiments are due to the presence of ionophores in the diet, which could impair the conversion of choline to betaine. Furthermore, in the present experiment and those of Rostagno and Pack (1996) and Schutte et al. (1997) choline supplementation was rather liberal, in order to ensure that choline was not limiting in the diet. In the experiments reported by Virtanen and Rumsey (1996) the total level of choline and the amount of supplemental choline are not stated, only that the diets satis®ed NRC (1994) requirements. It is possible that if the conversion of choline to betaine was impaired by the presence of ionophores, chickens would respond to betaine in methionine de®cient diets, and in these conditions betaine could replace part of the methionine of the diet.
The same arguments could apply for the reported responses to betaine supplementation in breast meat yield (Virtanen and Rosi, 1995) which were less pronounced in the experiments of Rostagno and Pack (1996), those of Schutte et al. (1997) and in the current experiment. On the other hand, it is interesting to note a consistent effect of betaine in improving carcass yield in all experiments. In the present experiment, carcass yield was determined in the processing plant with mechanical evisceration, which only removes intestines and part of the abdominal fat. These results would suggest that the effect of betaine could be caused by a reduction in the weight of intestines, but in view of the osmotic effects of betaine, it could be also due to increased water retention. Recently, McDevitt et al. (1999) found a signi®cant reduction in relative visceral mass by betaine and DL-methionine, which suggests that the effect of betaine observed in the current
experiment can be due to a reduction of the relative weight of the intestines. It is interesting to note that in the current experiment DL-methionine also increased carcass
yield, although the effect was not signi®cant at the P<0:05 level. The results of McDevitt et al. (1999) suggest that this effect of DL-methionine on promoting carcass
yield could be real.
5. Conclusion
signi®cant extend, in terms of performance and breast yield. However, betaine signi®cantly improved carcass yield.
Acknowledgements
The technical assistance of Mr. Lluis Llaurado is greatly appreciated.
References
Association of Analytical Of®cial Chemists, 1984. Of®cial Methods of Analysis, 14th Edition. A.O.A.C. Washington, DC.
Duncan, D.B., 1955. Multiple range and multipleFtests. Biometrics 11, 1±42.
Emmert, J.L., Webel, D.M., Biehl, R.R., Grif®ths, M.A., Garrow, L.S., Garrow, T.S., Baker, D.H., 1998. Hepatic and renal betaine-homocysteine methyltransferase activity in pigs as affected by dietary intakes of sulfur amino acids, choline, and betaine. J. Anim. Sci. 76, 606±610.
Kidd, M.T., Ferket, P.R., Garlich, J.D., 1997. Nutritional and osmoregulatory functions of betaine. World's Poult. Sci. J.53, 126±139.
Llames, C.R., Fontaine, J., 1994. Determination of amino acids in foods: collaborative study. J. A.O.A.C. 77, 1362±1402.
McDevitt, R.M., Mack, S., Wallis, I.R., 1999. The effect ofDL-methionine and betaine supplementation on growth performance and carcasss composition in male broilers. In: Proceedings of the 11th Australian Poultry Science Symposium, Sidney, pp. 73±76.
Matthews, J.O., Ward, T.L., Southern, L.L., 1995. Interactive effects of betaine (Beta®n-BCR) and Monensin in Eimeria acervulina-infected chicks, Poult. Sci. 74, 179 (Abstr.).
NRC, 1994. Nutrient Requirements of Poultry, 9th Edition. National Academy of Sciences, Washington, DC. NFIA, 1991. Laboratory Methods Compendium, Vol. 3. Amino Acids, Special Purpose, Miscellaneous Products,
Method: Supplemented Amino Acids (methionine and lysine) National Food Ingredients Association, West Des Moines, Iowa, pp. 71±72.
RajakylaÈ, E., Paloposki, M., 1983. Determination of sugars (and betaine) in molasses by high performance liquid chromatography. J. Chromatogr. 282, 595±602.
Rostagno, H.S., Pack, M., 1996. Can betaine replace supplementalDL-methionine in broiler diets? J. Appl. Poult.
Res. 5, 150±154.
Schutte, J.B., de Jong, J., Smink, W., Pack, M., 1997. Replacement value forDL-methionine in male broiler
chicks. Poult. Sci. 76, 321±325.
Tyler, D.D., 1977. Transport and oxidation of choline by liver mitochondria. Biochem. J. 166, 571±581. Virtanen, E.I., Rosi, L., 1995. Effects of betaine on methionine requirement of broilers under various
environmental conditions. In: Proceedings of the 8th Australian Poultry Science Symposium, Adelaide, pp. 88±92.
Virtanen, E., Rumsey, G., 1996. Betaine supplementation can optimize use of methionine, choline in diets. Feedstuffs 68 (42), 12±13.
Waldenstedt, L., Elwinger, K., Thebo, P., Uggla, A., 1999. Effect of betaine supplement on broiler performance during an experimental coccidial infection. Poult. Sci. 78, 182±189.
Zimmerman, N.G., Twining, P., Hater-Dennis, J., 1996. Betaine as a methionine substitute and coccidial deterrent in broilers. Poult. Sci. 75, 154.
