Metabolizable Energy Values and Amino Acid Availability of Vetch (Vicia sativa) and Ervil (Vicia ervilia) Seeds Soaked in Water and Acetic Acid

Metabolizable Energy Values and Amino Acid Availability of Vetch (Vicia sativa) and Ervil (Vicia ervilia) Seeds Soaked in Water and Acetic Acid M. T. Farran,*,1 G. W. Barbour,† M. G. Uwayjan,* and V. M. Ashkarian* *Department of Animal Sciences, Faculty of Agricultural and Food Sciences, American University of Beirut, P.O. Box 11-0236, Riad El-Solh, Beirut 1107-2020, Lebanon; and †Lebanese Agricultural Research Institute, Tal Amara, Beka’a, Lebanon (2,663), 2,840 (3,098), 3,026 (3,154), and 2,934 (3,176) kcal/ kg DM, respectively, and were, in general, higher than those of SBM. The TMEn of V increased as a result of soaking in water or acetic acid, whereas that of E decreased in 40WE and RTAAE by 492 and 920 kcal/kg DM, respectively (P < 0.05). The apparent availability of most essential amino acids in UV and UE was lower (P < 0.05) than that of SBM. Acetic acid soaking of V, irrespective of temperature, and E at 40 C resulted in apparent AA availability similar to that of SBM except for Met. The true AA availability of V treated or not, and that of E soaked at 40 C, were similar to that of SBM. Results indicated that UV and UE are energy rich ingredients but detrimental to amino acid availability. Soaking the seeds in acetic acid at room temperature and at 40 C improved the nutritional value of V and E, respectively.

(Key words: vetch, ervil, metabolizable energy, amino acid availability) 2001 Poultry Science 80:931–936

Vetch (Vicia sativa) and ervil (Vicia ervilia) seeds have been used in animal feeds, and, when treated, as an alternative source of protein in poultry diets (Perez et al., 1993; Fernandez-Figares et al., 1995; Farran et al., 1998). The presence of some antinutritional factors in the raw seeds limits their use in poultry diets. Vetch (V) contains vicine, convicine, and β-cyanoalanine (Cheeke and Shull, 1985), whereas ervil (E) contains canavanine (Angeles Garcia and Ferrando, 1992). Several detoxification methods have been reported, including autoclaving (Harper and Arscott, 1962; Farran et al., 1995; Fernandez-Figarez et al., 1995) and soaking in water or acetic acid (Farran et al., 1998). Raw, common V at 60% in the diet caused 100% mortality in 1-wk-old broiler chicks with a survival time of 4.7

to 5.1 d and a cessation of egg production in laying hens within 14 d postfeeding. Toxicity symptoms persisted after soaking the seeds in water for 24 h at room temperature; however, when they were soaked at 1:10 (wt/vol) in water at 40 C for 72 h, with a water change every 12 h (40 WV) or in 1% acetic acid at room temperature (RTAAV), or at 40 C (40AAV) for 24 h, no toxicity symptoms were observed. Moreover, the RTAAV treatment results in laying hen performance comparable to that of the control (Farran et al., 1998). Halaby (1997) showed that a diet with 60% raw E depressed weight gain and reduced feed palatability but did not result in broiler mortality over a 3-wk feeding trial. When soaked in water at 40 C for 72 h, the 60% dietary E improved broiler performance. Raw E at 60% also resulted in cessation of egg production of laying hens within 2 wk postfeeding. When the E seeds were subjected

2001 Poultry Science Association, Inc. Received for publication October 10, 2000. Accepted for publication February 25, 2001. 1 To whom correspondence should be addressed: [email protected].

Abbreviation Key: AA = amino acid; 40AA = soaked in acetic acid at 40 C; E = ervil; RTAA = soaked in acetic acid at room temperature; SBM = soybean meal; U = untreated; V = vetch; 40W = soaked in water at 40 C.

INTRODUCTION

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ABSTRACT In two experiments we evaluated the effect of water and acetic acid soaking on ME, apparent amino acid (AA) availability, and true AA availability of vetch (V) and ervil (E) seeds. In Experiment 1, the feedstuffs were untreated (U) V or coarsely ground V soaked in water (1:10, wt/vol) at 40 C for 72 h with a water change every 12 h (40WV), vetch soaked in 1% acetic acid for 24 h at 40 C (40AAV) or at room temperature (RTAAV), or dehulled soybean meal (SBM). In Experiment 2, E seeds were subjected to the same soaking methods, and the ingredients were UE, 40WE, 40AAE, RTAAE, and SBM. Each feedstuff was precision-fed to five individually caged mature ISA Brown roosters. A group of five roosters was used to correct for metabolic and endogenous energy and amino acid losses. The AME, AMEn, TME, and TMEn of UV and UE (in parentheses) were 2,558

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to soaking treatments similar to those of V, as described above, the 40AAE proved superior to the 40WE in terms of performance but was significantly lower than that of the control. The RTAAE, however, remained detrimental to laying hens. In the present study, we evaluated the ME and apparent and true amino acid (AA) availabilities of common V and E seeds and the changes in their nutritional values in response to water and acetic acid treatments.

MATERIALS AND METHODS Experiment 1

2

Model KT30, Falling AB, S-12611 Stockholm, Sweden. Parr Instrument Co., Moline, IL 61265. Dionex BIOLC. Model 600, Dionex Corp., Sunnyvale, CA 94086.

3 4

Experiment 2 The processing steps of E seeds were similar to those of V seeds described in Experiment 1. Other experimental conditions were also similar, except for the aqueous glucose solution concentration, which was increased to 50%. The SBM sample was replicated in Experiment 2 and used as a control treatment. Average maximum and minimum ambient temperatures during the experimental period were 14.7 and 12.8 C, respectively. Data in both experiments were analyzed using the general linear models procedure for one-way ANOVA, and means were separated by Duncan’s multiple-range test where appropriate (SAS Institute, 1992).

RESULTS Experiment 1 Chemical composition and amino acid contents of SBM, UV, 40WV, 40AAV, and RTAAV, are presented in Table 1. The CP content of UV (29.83%) slightly decreased as a result of soaking in acetic acid at 40 C. Water and acetic acid soaking, however, resulted in an increase in crude fat level and a reduction in ash content. Soaking the seeds in acetic acid at 40 C resulted in the highest increase in crude fat (54%). Moreover, the 40WV was found to have the lowest ash content, which was 64% less than that of the UV. Crude fiber increased only in 40WV and RTAAV. Minor changes in amino acid concentration of V seed were observed in response to the soaking treatments. The AME, AMEn, TME, and TMEn of all V seeds, treated or not, were higher (P < 0.05) than those of SBM (Table 2). The AME and TME of UV were not significantly improved by soaking in acetic acid at room temperature. They were, however, increased (P < 0.05) when soaked in water or acetic acid at 40 C. Nitrogen correction resulted in an overall improvement (P < 0.05) in AME and TME of all treated V as compared to UV. The AMEn and TMEn of 40WV were comparable to those of 40AAV but were significantly higher than those of RTAAV. Table 3 shows the apparent and true AA availabilities of UV, 40WV, 40AAV, RTAAV, and SBM. The apparent

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Coarsely ground V seeds were soaked in water (1:10, wt/vol) at 40 C for 72 h, with a solvent change every 12 h (40WV), or in 1% acetic acid at 40 C (40AAV) or at room temperature (RTAAV) for 24 h. The seeds were then dried at room temperature. Two other experimental feed ingredients were untreated V seed (UV) and dehulled soybean meal (SBM) as a control treatment. All test feed ingredients were finely ground in a Falling mill.2 Thirty dubbed ISA Brown roosters, aged 67 wk, were distributed among individual metabolism cages placed in a closed and ventilated room. They were fed a latecycle commercial corn-SBM layer diet (Sibbald, 1986) for an adaptation period of 1 wk during the month of December. Average maximum and minimum ambient temperatures during the experiment were 12.5 and 10.4 C, respectively. Forty-eight hours prior to precision feeding, feed was withdrawn, and each bird received 40 mL of an aqueous glucose solution (38.5%) 40 and 16 h before tube feeding (McNab and Blair, 1988). Forty grams of each experimental feed ingredient was precision-fed individually to five roosters according to the method of Sibbald (1986). The set of five roosters used to correct for endogenous energy and AA losses were tube-fed 40 g of glucose rather than given no feed. Moreover, all birds were given 40 mL water by tube 32 h after force-feeding, as recommended by McNab and Blair (1988). Total excrements were individually collected in a clean aluminum tray from all birds, 48 h postprecision feeding. The excreta were carefully cleaned of feathers, stored at −22 C, freeze-dried, and ground. Conventional methods described by the Association of Official Analytical Chemists (1990) were used to determine nitrogen, ether extract, ash, crude fiber, and moisture of feed and nitrogen and moisture of excreta samples. Total nitrogen was determined by the Kjeldahl procedure, and protein content was calculated with a 6.25 conversion factor. Crude fat was determined by the Soxhlet method by using diethyl ether, and ash content was determined gravimetrically after incineration at 600 C for 24 h. Crude fiber was determined gravimetrically after digesting the samples in 0.255 N H2SO4 and 0.313 N NaOH.

Nitrogen-free extract was calculated by subtracting CP, crude fat, ash, and crude fiber from the dry matter content. Gross energy of feed ingredients and excrements was determined using a Parr adiabatic oxygen bomb calorimeter.3 The gross energy excreted was corrected to zero nitrogen balance by using a factor of 8,220 cal per gram of nitrogen (Hill and Anderson, 1958). Amino acid contents were determined at the University of Maryland, College Park, Maryland, by using a Dionex amino acid analyzer.4 Samples for all amino acids were hydrolyzed in 6 N HCl for 24 h, except for Ile and Val for 72 h (Thomas et al., 1981). The AME, AMEn, TME, and TMEn of the test feed ingredients were determined by the method of Sibbald (1986), and apparent and true AA availabilities were calculated according to Likuski and Dorrell (1978).

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METABOLIZABLE ENERGY AND AMINO ACID AVAILABILITY TABLE 1. Composition of soybean meal (SBM), untreated vetch (UV) or ervil (UE) seeds, and seeds of vetch or ervil soaked in water1 (1:10, wt/vol) at 40 C (40WV, 40WE) or in 1% acetic acid at 40 C (40AAV, 40AAE) or at room temperature (RTAAV, RTAAE) for 24 h; Experiments 1 and 2 Nutrients

SBM

Moisture %

UV

6.53

8.32

40WV

40AAV

9.49

8.38

RTAAV 9.87

UE

40WE

40AAE

RTAAE

8.39

10.06

9.47

9.27

28.52 1.05 4.06 3.96 62.41

28.90 1.18 5.21 2.30 62.41

29.60 1.23 5.36 1.86 61.95

29.99 0.99 5.03 2.83 61.18

11.89 3.56 5.00 17.41 4.31 4.15 4.47 5.04 0.90 4.67 7.35 2.19 5.00 7.35 3.06 6.68

11.67 3.41 5.30 17.78 4.24 3.73 4.27 5.34 0.83 4.83 7.76 2.45 5.46 7.20 3.28 7.28

11.64 3.48 5.27 16.79 4.38 3.88 4.63 5.60 0.81 4.90 7.61 2.42 5.20 7.40 3.67 6.81

9.79 3.21 4.59 15.09 3.78 3.48 3.89 4.22 0.72 3.58 6.80 2.22 4.66 6.61 3.34 6.25

(% DM) CP Crude fat Crude fiber Ash Nitrogen-free extract

50.14 1.50 5.47 7.86 35.03

29.83 0.74 4.78 3.18 61.47

29.42 0.95 5.86 1.14 62.63

27.94 1.14 4.61 1.76 64.55

29.39 0.99 5.54 1.56 62.52 (% CP)

12.00 4.00 5.60 18.55 4.63 4.30 4.50 4.40 1.30 4.20 7.75 3.30 5.00 6.25 2.55 7.15

12.87 3.41 4.69 18.52 4.00 4.12 4.25 5.06 0.75 4.47 7.26 2.43 4.04 6.44 2.55 8.36

11.54 3.65 4.53 17.28 4.87 4.53 4.41 5.64 0.84 5.33 8.98 2.69 4.95 6.84 3.02 9.57

12.19 3.48 5.08 18.32 4.10 4.26 4.06 4.96 0.83 4.57 8.13 1.99 4.38 6.48 2.73 8.44

11.55 3.28 4.76 17.78 3.89 4.19 4.08 5.51 0.78 4.76 7.93 1.93 4.15 6.27 2.57 8.04

1

For 72 h with a water change every 12 h.

availability of all essential AA (except for Ile, His, and Arg) and nonessential AA (except for Asp and Ala) in UV was lower than that of SBM (P < 0.05). Compared to UV, water soaking significantly lowered the apparent His availability and did not appreciably improve the apparent availability of other AA. Acetic acid, however, irrespective of soaking temperature, increased the apparent availability of Asp, Ser, Glu, Val, Leu, Phe, and Lys, resulting in apparent AA availability profile similar to that of SBM, except for Met (P < 0.05). True AA availability of treated V or UV was found to be similar to that of SBM. Only His bioavailability of 40WV was significantly lower than that of 40AAV.

Experiment 2 The CP content of UE seeds (28.52% DM) slightly increased by soaking in acetic acid, irrespective of tempera-

ture (Table 1). Treatment by 40W or 40AA slightly increased crude fat of E seeds. In response to water and acetic acid treatments, crude fiber increased and ash content decreased. Moreover, soaking in 1% acetic acid solution at 40 C resulted in the highest increase in crude fiber (32%) and maximal decrease in ash (53%). Compared to UE, all amino acids, except Tyr and His, were found to decrease as a result of RTAA treatment. The treatment of 40W or 40AA resulted in an amino acid profile similar to that of UE. The ME and AA availability results of SBM in this trial were comparable to those obtained in Experiment 1. The AME and TME values of UE (2,663 and 3,154 kcal/kg DM, respectively) were not significantly different from those of 40WE, 40AAE, and SBM. The RTAAE, however, had the lowest (P < 0.05) AME and TME among all treatments (Table 2). The AMEn and TMEn of 40AAE were slightly lower than those of UE. The 40W treatment re-

TABLE 2. AME, AMEn, TME, and TMEn (kcal/kg DM) of soybean meal (SBM), untreated vetch (UV) or ervil (UE) seeds, and seeds of vetch or ervil soaked in water1 (1:10, wt/vol) at 40 C (40WV, 40WE) or in 1% acetic acid at 40 C (40AAV, 40AAE) or at room temperature (RTAAV, RTAAE) for 24 h; Experiments 1 and 2 Experiment 1 (Vetch)

AME AMEn TME TMEn TME difference (%)2

Experiment 2 (Ervil)

SBM

UV

40WV

40AAV

RTAAV

SEM

SBM

UE

40WE

40AAE

RTAAE

SEM

2,281c 2,547d 2,699c 2,642d −2.11

2,558b 2,840c 3,026b 2,934c −3.04

2,945a 3,265a 3,413a 3,360a −1.55

2,837a 3,114ab 3,304a 3,209ab −2.88

2,686ab 3,038b 3,154ab 3,132b −0.70

85.1 62.4 85.1 62.4

2,472a 2,598b 2,853a 2,673b −6.31

2,663a 3,098a 3,154a 3,176a +0.70

2,370a 2,606b 2,860a 2,684b −6.15

2,649a 2,907a 3,140a 2,985a −4.94

1,713b 2,178c 2,204b 2,256c +2.36

92.5 75.9 92.5 75.9

Within experiment, means in the same row with no common superscripts differ significantly (P < 0.05). For 72 h with a water change every 12 h. 2 (TMEn − TME) × 100. TME a–d 1

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Amino acids Asp Thr Ser Glu Pro Gly Ala Val Met Ile Leu Tyr Phe Lys His Arg

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TABLE 3. Apparent and true amino acid availability (%) of dehulled soybean meal (SBM), untreated vetch seeds (UV), or vetch soaked in water1 (1:10, wt/vol) at 40 C (40WV) and in 1% acetic acid for 24 h at 40 C (40AAV) or at room temperature (RTAAV); Experiment 1 Amino acids Asp Thr Ser Glu Pro Ala Val Met Ile Leu Tyr Phe Lys His Arg

Apparent amino acid availability (%) SBM

UV ab

82.88 75.73a 78.94a 85.55ab 77.08a 72.50ab 77.41a 82.77a 75.17 83.60a 76.74a 83.58a 82.77a 70.92ab 83.76

40WV b

76.85 58.91b 65.08c 80.03c 60.75c 63.36b 62.87b 44.24b 68.40 73.35b 59.42b 71.41b 75.84c 68.57b 80.81

ab

78.93 58.57b 67.37bc 80.76bc 63.42bc 66.00ab 70.42ab 45.05b 76.27 78.73ab 64.67b 77.06ab 76.30bc 60.47c 81.12

40AAV a

84.85 69.87ab 74.17ab 87.18a 70.44ab 74.30ab 75.71a 49.30b 79.04 83.04a 70.38ab 81.36a 83.51a 77.44a 85.74

True amino acid availability (%)

RTAAV a

84.05 69.48ab 73.51ab 86.70a 69.13abc 75.60a 77.26a 53.44b 80.00 82.53a 70.21ab 79.95a 82.30ab 70.71ab 84.31

SEM

SBM

UV

40WV

40AAV

RTAAV

SEM

1.90 3.40 2.41 1.65 2.60 3.40 3.24 7.49 3.42 2.06 3.26 2.18 1.94 2.26 1.57

88.09 84.77 88.22 90.40 86.75 81.01 86.21 89.82 82.23 89.61 86.44 89.19 88.13 80.36ab 89.25

85.04 76.89 82.62 88.12 78.56 78.00 76.70 70.62 80.64 84.02 78.70 83.05 84.57 81.37ab 88.67

87.36 76.20 82.93 89.16 80.65 80.43 82.82 78.39 86.28 87.86 83.44 86.92 85.22 74.37b 88.90

91.96 85.15 88.42 93.80 86.13 87.31 87.13 78.71 88.65 91.52 88.07 90.69 91.01 87.23a 92.71

91.29 85.18 88.21 93.30 85.00 88.15 87.18 79.00 88.88 90.93 88.01 89.48 89.83 80.87ab 91.35

1.90 3.40 2.41 1.65 2.60 3.40 3.24 7.49 3.42 2.06 3.26 2.18 1.94 2.26 1.57

sulted in values that were comparable to those of SBM but significantly lower than those of UE and 40AAE. The lowest AMEn and TMEn (P < 0.05) resulted from the RTAAE treatment. The apparent availability of Thr, Ser, Pro, Met, Tyr, Lys, His, and Arg in UE seeds was lower than that of SBM (P < 0.05). Compared to UE, RTAAE decreased the apparent availability of most AA and significantly lowered that of Asp, Ser, Glu, Pro, Val, Ile, Leu, Tyr, and Phe (Table 4). The 40W treatment of E seeds increased the apparent availability of Arg only (P < 0.05). The apparent availability of all AA in 40AAE was similar to that of SBM except for Met, which was not improved by any of the soaking methods. The true AA availability in UE, except for Lys and Arg, was comparable to that of SBM (Table 4). In general, compared to UE, RTAA lowered the true availability of

all AA and significantly decreased that of Asp, Ser, Glu, Pro, Ile, Leu, Tyr, and Phe. On the other hand, 40W significantly improved the true availability of Arg but not of Lys. The Lys availability, however, was improved (P < 0.05) in 40AAE, whereas all other true AA availability values were comparable to those of SBM.

DISCUSSION The CP of UV (29.83%) and UE (28.52%) in this study were higher than those reported by Perez et al. (1993) and Fernandez-Figares et al. (1995). Castanon and Perez¨ nol (1994) reported lower Lanzac (1990) and Yalc˛in and O CP values for UV and UE, respectively. The variation between the proximate analysis results of UV and UE in this study and those reported in the literature could be attributed to the difference in the variety of seeds ana-

TABLE 4. Apparent and true amino acid availability (%) of dehulled soybean meal (SBM), untreated ervil seeds (UE), or ervil seeds soaked in water1 (1:10, wt/vol) at 40 C (40WE) and in 1% acetic acid for 24 h at 40 C (40AAE) or at room temperature (RTAAE); Experiment 2 Amino acids Asp Thr Ser Glu Pro Ala Val Met Ile Leu Tyr Phe Lys His Arg

Apparent amino acid availability (%) SBM

UE a

82.36 75.71a 78.89a 85.90a 76.09a 72.34a 72.83a 87.53a 76.75a 81.70a 78.65a 83.62a 81.23a 76.26a 84.59a

40WE a

81.22 59.40bc 68.96b 81.32a 65.54b 62.09ab 68.85a 48.88b 76.61a 77.90a 65.04b 80.12a 68.25bc 59.27bc 70.93b

a

78.34 61.84bc 73.37ab 81.41a 62.74b 67.33ab 68.83a 42.40b 74.21a 77.67a 64.50b 80.40a 76.39ab 57.50c 80.58a

40AAE a

83.18 70.27ab 76.56ab 85.72a 71.01ab 73.21a 75.79a 40.81b 79.58a 81.07a 70.44ab 83.41a 80.70a 74.78ab 82.56a

True amino acid availability (%)

RTAAE b

69.74 50.61c 59.08c 73.35b 52.49c 56.38b 53.81b 32.62b 57.44b 66.96b 49.30c 69.70b 67.57c 56.68c 71.42b

SEM 2.09 3.75 2.81 1.95 3.35 4.12 3.90 7.16 2.83 2.43 3.91 2.21 2.85 5.35 2.60

SBM

UE a

89.34 87.19a 90.10a 92.43a 89.17ab 83.76ab 86.36ab 96.69 87.11a 90.15a 92.33ab 91.13a 88.82a 86.97 91.39ab

40WE a

92.68 81.38ab 88.76a 92.36a 89.69a 80.98ab 89.31ab 97.34 92.29a 92.98a 98.27a 93.60a 79.57b 77.48 83.11c

a

90.04 84.92ab 92.07a 92.27a 87.53ab 87.07ab 88.31ab 92.63 89.64a 92.01a 94.96a 92.83a 88.03ab 74.69 91.77ab

40AAE a

94.59 92.10a 94.87a 96.41a 94.38a 90.91a 93.79a 91.20 94.31a 95.23a 99.94a 96.02a 91.65a 89.73 94.16a

RTAAE b

83.09 73.94b 79.67b 85.60b 78.99b 77.10b 77.29b 90.64 77.18b 82.55b 80.98b 83.53b 79.68b 72.81 83.85bc

SEM 2.09 3.75 2.81 1.95 3.35 4.12 3.90 7.16 2.83 2.43 3.91 2.21 2.85 5.35 2.60

a–c Means in the same row under either apparent amino acid availability and true amino acid availability with no common superscripts differ significantly (P < 0.05). 1 For 72 h with a water change every 12 h.

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a–c Means in the same row under either apparent amino acid availability and true amino acid availability with no common superscripts differ significantly (P < 0.05). 1 For 72 h with a water change every 12 h.

METABOLIZABLE ENERGY AND AMINO ACID AVAILABILITY

Parsons (1991) concluded that both types of birds are equally sensitive in detecting differences in nutritional qualities. Although conventional birds were used in the present study, the current apparent AA availability results except for Met and Val are in agreement with those of Perez et al. (1993), who reported a lower ileal digestibility of all essential AA in UV as compared to SBM. The same authors also reported a lower digestibility of most essential AA in UE including Met, Lys, and Arg. Unlike V, RTAAE was detrimental not only to its ME values but also to its apparent and true AA availabilities. Treatment by 40W or 40AA, however, was found to improve the apparent AA availability (except Met) and true AA availability of V and E seeds and resulted in values comparable to those of SBM. Similarly, autoclaving was found to improve the apparent and true ileal amino acid digestibility of V and E seeds (Fernandez-Figares et al., 1995), as well as the protein and total AA digestibility of fababeans (Brufau et al., 1998). The interaction between Arg and Lys is well documented (D’Mello and Lewis, 1970; Nesheim, 1974). Moreover, the structural similarity between canavanine and Arg (D’Mello, 1991) may explain the lower true availability of Arg and Lys in UE and RTAAE seeds. The current results (Table 4) suggested that acetic acid at 40 C might have partially or totally eliminated canavanine, which was not determined in this study. It can be concluded that soaking in water or in acetic acid improved TMEn of V but not that of E seeds. The RTAA treatment improved the apparent AA availability of V but drastically lowered apparent and true AA availabilities and energy values of E seeds. Soaking in acetic acid at temperatures ≥40 C may prove beneficial in improving the nutritional value of E.

REFERENCES Angeles Garcia, M., and I. Ferrando, 1992. Colorimetric estimation of canavanine in Vicia ervilia alone or mixed with other legumes. Nutr. Abstr. Rev. (Series B) 62(1):12. (Abstr.). Association of Official Analytical Chemists, 1990. Official Methods of Analysis. 15th ed. K. Herlich, ed. Association of Official Analytical Chemist, Arlington, VA. Brufau, J., D. Boros, and R. R. Marquardt, 1998. Influence of growing season, tannin content and autoclave treatment on the nutritive value of near-isogenic lines of faba beans (Vicia faba L.) when fed to leghorn chicks. Br. Poult. Sci. 39:97–105. Castanon, J.I.R., and J. Perez-Lanzac, 1990. Substitution of fixed amounts of soybean meal for field beans (Vicia faba), sweet lupins (Lipinus albus), cull peas (Pisum sativum) and vetches (Vicia sativa) in diets for high performance laying hens. Br. Poult. Sci. 31:173–180. Castanon, J.I.R., and R. R. Marquardt, 1991. Some factors affecting true metabolizable energy of fababeans (Vicia faba L.). Poultry Sci. 70:568–572. Cheeke, P. R., and L. R. Shull, 1985. Natural toxicants in feeds and poisonous plants. AVI Publishing Company, Inc., Westport, CT. D’Mello, J.P.F., 1991. Toxic amino acids. Pages 21–48 in: Toxic Substances in Crop Plants. J.P.F. D’Mello, C. M. Duffus, and J. H. Duffus, ed. The Royal Society Of Chemistry, Science Park, Cambridge, UK. D’Mello, J.P.F., and D. Lewis, 1970. Amino acid interaction in chick nutrition. Br. Poult. Sci. 11:367–385.

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lyzed. The current results showed that E, like V, is deficient in Met and rich in Lys. In general, the AA profiles of UV and UE (Table 1) are in agreement with those reported by Perez et al. (1993) and Fernandez-Figares et al. (1995). Literature on values for AME, TME, and TMEn of V was not available. The AMEn of UV in this study (2,840 kcal/kg DM) was comparable to the MEn of V (2,880 kcal/kg DM) estimated by Castanon and Perez-Lanzac (1990). On the other hand, AME, AMEn, TME, and TMEn values of UE (Table 2) were lower than those reported ¨ nol (1994). The current findings revealed by Yalc˛in and O that UE is, in general, richer in energy than UV, and both have TMEn values higher than that of SBM (Table 2), untreated fababeans (Castanon and Marquardt, 1991), and untreated peas (Igbasan and Guenter, 1996). The increase in the energy value of V in response to soaking could not be explained only by the slight increase in their respective nitrogen-free extract contents (Table 1). It could also have been due to the partial or total elimination of antinutritional factor(s), as a result of soaking the V seeds in water or acetic acid, and the consequent improvement in broiler and laying hen performance (Farran et al., 2001). Contrary to V, soaking E in water or acetic acid at 40 C did not improve its energy content. Moreover, RTAAE had ME values far lower than those of UE (Table 2). It can be speculated that the antinutritional factor(s) present in UE seeds were exacerbated by acetic acid at room temperature, thus drastically decreasing not only the ME but also the availability of AA. The low performance of laying hens fed diets containing 60% RTAAE in comparison with those on 40WE and 40AAE are in support of this hypothesis (Halaby, 1997). Moreover, work conducted by the same author showed that 60% dietary 40WE significantly improved performance of broilers as compared to 60% UE at 4 wk of age. Because nitrogen retention was negative, the AMEn values of all feedstuffs in both experiments were higher than their corresponding AME values. Nitrogen correction resulted in a reduction between 0.70 and 6.31% in the TME values of all ingredients tested in both experiments, except for those of UE and RTAAE, for which their TME increased by 0.70 and 2.36%, respectively (Table 2). The increase in TMEn was due to the fact that the nitrogen balance in RTAAE- and UE-fed birds was even more negative than the endogenous loss and their excreted energy was low. The increase in TME of UE as a result of nitrogen correction is in agreement with the findings ¨ nol (1994), who concluded that UE is an of Yalc˛in and O energy-rich ingredient but could be highly detrimental to the metabolism of nitrogen. Conventional birds have been used in amino acid digestibility assays (Likuski and Dorrell, 1978; Sibbald, 1979, 1986) without considering hindgut microbial effect on AA metabolism (Parsons, 1986). Amino acid digestibility values of meat meal (Parsons, 1986) and feather meal (Han and Parsons, 1991) obtained from intact birds were higher than those derived from cecectomized ones, but the values were highly correlated. Therefore, Han and

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FARRAN ET AL. Likuski, H.J.A., and H. G. Dorrell, 1978. A bioassay for rapid determinations of amino acid availability values. Poultry Sci. 57:1658–1660. McNab, J. M., and J. C. Blair, 1988. Modified assay for true and apparent metabolizable energy based on tube feeding. Br. Poult. Sci. 29:697–707. Nesheim, M. C., 1974. Some aspects of amino acid interrelationships in growing chickens. Pages 34–40 in: Proceedings of the Maryland Nutrition Conference for Feed Manufacturers. University of Maryland, College Park, MD. Parsons, C. M., 1986. Determination of digestibility and available amino acids in meat meal using conventional and caecectomized cockerels or chick growth assays. Br. J. Nutr. 56:227–240. Perez, L., I. Fernandez-Figares, R. Nieto, J. F. Aguilera, and C. Prieto, 1993. Amino acid ileal digestibility of some grain legume seeds in growing chickens. Anim. Prod. 56:261–267. SAS Institute, 1992. SAS威 User’s Guide: Statistics. Version 5 Edition. SAS Institute Inc., Cary, NC. Sibbald, I. R., 1979. A bioassay for available amino acid and true metabolizable energy in feeding stuffs. Poultry Sci. 58:668–673. Sibbald, I. R., 1986. The TME system of feed evaluation: methodology, feed composition data and bibliography. Technical Bulletin 1986-4E. Animal Research Center, Ottawa, Ontario, Canada. Thomas, O. P., E. H. Bossard, C. B. Tamplin, and P. Laurans, 1981. Maryland practical broiler nutrition studies. Pages 50– 53 in: Proceedings of the Maryland Nutrition Conference for Feed Manufacturers. University of Maryland, College Park, MD. ¨ nol, 1994. True metabolizable energy Yalc˛in, S., and A. G. O values of some feedingstuffs. Br. Poult. Sci. 35:119–122.

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Farran, M. T., P. B. Dakessian, A. H. Darwish, M. G. Uwayjan, H. K. Dbouk, F. T. Sleiman, and V. M. Ashkarian, 2001. Performance of broilers and production and egg quality parameters of laying hens fed 60% raw or treated common vetch (Vicia sativa) seeds. Poultry Sci. 80:203–208. Farran, M. T., P. B. Dakessian, M. G. Uwayjan, F. T. Sleiman, and V. M. Ashkarian, 1998. Performance of broilers and layers fed high levels of treated vetch (Vicia sativa) seeds. Poultry Sci. 77(Suppl. 1):48. (Abstr.). Farran, M. T., M. G. Uwayjan, A.M.A. Miski, F. T. Sleiman, F. A. Adada, V. M. Ashkarian, and O. P. Thomas, 1995. Effect of feeding raw and treated common vetch seed (Vicia sativa) on the performance and egg quality parameters of laying hens. Poultry Sci. 74:1630–1635. Fernandez-Figares, I., L. Perez, R. Nieto, J. F. Aguilera, and C. Prieto, 1995. The effect of heat treatment on ileal amino acid digestibility of growing broilers given vetch and bitter vetch meals. Anim. Sci. 60:493–497. Halaby, W. S., 1997. Effect of feeding different levels of treated ervil seeds on the performance of broilers and layers. M.S. thesis, American University of Beirut, Beirut, Lebanon. Han, Y., and C. M. Parsons, 1991. Protein and amino acid quality of feather meals. Poultry Sci. 70:812–822. Harper, J. A., and G. H. Arscott, 1962. Toxicity of common and hairy vetch seed for poults and chicks. Poultry Sci. 41:1968–1974. Hill, F. W., and D. L. Anderson, 1958. Comparison of metabolizable energy and productive energy determinations with growing chicks. J. Nutr. 64:587–603. Igbasan, F. A., and W. Guenter, 1996. The enhancement of the nutritive value of peas for broiler chickens: An evaluation of micronization and dehulling processes. Poultry Sci. 75:1243–1252.