The proximate composition and nutritive value of the winged bean Psophocarpus tetragonolobus (L.) DC for broilers

Animal Feed Science and Technology, 11 (1984) 231--237 Elsevier Science Publishers B.V., Amsterdam --Printed in The Netherlands

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THE PROXIMATE COMPOSITION AND NUTRITIVE VALUE OF THE WINGED BEAN PSOPHOCARPUS TETRAGONOLOBUS (L.) DC F O R BROILERS

O.B. SMITH, J.O. ILORI and P. ONESIROSAN

Department of Animal Science and Plant Science, University of Ife, Ile-Ife (Nigeria) (Accepted for publication 16 February 1984)

ABSTRACT Smith, O.B., Ilori, J.O. and Onesirosan, P., 1984. The proximate compositionand nutritive value of the winged bean Psophocarpus tetragonolobus (L.) DC for broilers. Anita. Feed Sci. Technol., 11: 231--237. The proximate analysis and the efficacy of farm processing in removing trypsin inhibitors and reducing oil content of the TPT-1 variety of winged bean were determined. The farm processed bean (WBM) was given to broilers in partial or complete replacement of either soya bean meal (SBM) or groundnut cake (GNC) in order to determine its nutritive value. The farm processing technology employed was not very effective, for although trypsin inhibitors appeared to be reduced to safe levels, oil content remained high, and mortality of broilers fed on the beans was high (14%), suggesting that the beans were not effectively detoxified. Nevertheless, the bean was well accepted by the birds, and its protein appeared to have been well utilised, with a feed:gain ratio of 3.0. This value was similar (P>0.05) to those obtained for SBM (2.8) and GNC (2.7) diets. This confirms the reported high nutritional merit of the bean, and suggests that WBM can effectively replace SBM or GNC in broiler diets. Effective farm processing methods to reduce oil content and toxic factors need to be developed.

INTRODUCTION T h e c o s t o f t r a d i t i o n a l livestock feeds in d e v e l o p i n g c o u n t r i e s has maint a i n e d a s u s t a i n e d u p w a r d t r e n d since t h e e n e r g y crisis o f t h e early 1 9 7 0 ' s . This has s t i m u l a t e d research t o d e v e l o p alternative a n d c h e a p e r sources o f n u t r i e n t s f o r livestock. Since o n e o f t h e m a j o r causes o f the increasing c o s t o f livestock feeds is t h e m a n - - a n i m a l c o m p e t i t i o n f o r energy-intensive tradit i o n a l f o o d materials, alternative o r n o n - t r a d i t i o n a l livestock feed materials m u s t b e t h o s e t h a t are n o t e a t e n o r relished b y m a n . C o m p o s i t i o n a l d a t a o f t h e w i n g e d b e a n plant, P s o p h o c a r p u s tetragonolobus, i n d i c a t e t h a t it "has e x c e p t i o n a l n u t r i t i o n a l merit. T h e c r u d e p r o t e i n c o n t e n t o f t h e v a r i o u s p a r t s o f t h e p l a n t is: b e a n s o r seeds, o v e r 30% (Bailey,

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© 1984 Elsevier Science Publishers B,V:

232 1968; Cerny et al., 1971; Garcia and Palmer, 1980); roots or tubers, a b o u t 20% (Burkill, 1966; Choo, 1975; Claydon, 1975); foliage, a b o u t 25% {Masefield, 1960, 1973). According to Claydon (1975), the winged bean is a crop grown and consumed b y man on a small scale, mainly in South East Asia and the Western Pacific. It is n o t grown nor consumed to any extent in West Africa, particularly in Nigeria. The plant therefore qualifies as an alternative feed resource for livestock in this area. The present study of the protein value of the winged bean meal for broilers is the first in a series of experiments designed to study the nutritional value of various parts of the plant as livestock feeds. MATERIALS AND METHODS Six diets containing various levels of the winged bean were given to C o b b broilers from 3 to 9 weeks of age. The six diets were formulated to be isonitrogenous and iso-caloric at 24% crude protein and 3000 kcal ME/kg diet. Yellow maize and palm oil were the main energy sources, while the main protein feeds -- winged bean meal (WBM), soya bean meal (SBM) and g r o u n d n u t cake (GNC) -- were added in various amounts, as shown in Table I. The GNC used was processed industrially, while b o t h the winged beans and s o y a beans were grown locally on the farm, harvested at full maturity and processed on the farm to remove trypsin inhibitors and reduce oil content b y the following procedures. The beans were cracked into t w o halves in a grain mill, and submerged in cold water for 18--24 h, with occasional stirring. The water was subsequently decanted, fresh water was added, and the mixture was brought to boiling point. After boiling for 30 min, the beans were sifted from the water, allowed to cool and defatted b y soaking in ethyl ether for a b o u t 18 h, with occasional stirring. At the end o f the extraction period, the beans were sifted from the solvent--oil mixture, sun-dried and ground to pass through a 1-mm sieve. SIX representative samples o f the beans were then taken, and stored at - 2 0 ° C for future analyses. The processed beans (WBM and SBM) as well as the industrially processed groundnut cake were incorporated at various levels into the six experimental diets shown in Table I, which were given for 6 weeks to 210 C o b b broilers, The broilers were initially randomly distributed into 42 cages of 5 birds each, which were in turn randomly alloted to the 6 diets, to give 7 cages or replicates per treatment. The birds received the full c o m p l e m e n t o f routine vaccinations, and were fed and watered ad libitum. They were weighed initially and every 2 weeks, at which times representative samples of the diets were taken and stored at -20°C. Weekly feed intakes and overall mortality were recorded. A t the end of the trial, the birds were weighed, and t w o from each replicate (i.e. 14 per treatment) were randomly selected, killed and dressed. Dressing consisted of evisceration, with only the kidneys and lungs left in the carcass. The shanks

233 'TABLE I Ingredient composition and nutrient content of diets containing winged bean meal (WBM), soya bean meal (SBM) and groundnut cake (GNC) Diets WBM

SBM

GNC

WBM/GNC WBM/SBM GNC/SBM

53.2 4.0 26.7 ---

53.2 4.5 -26.2 --

47.9 5.0 -13.5 17.5

47.9 5.0 13.5 -17.5

51.4 5.5 13.5 13.5 --

(% DM) 95.4 24.4 8.8 8.5

94.6 24.5 10.8 8.5

95.1 24.2 5.8 8.8

94.8 23.9 7.8 7.9

95.2 23.9 9.5 8.5

94.8 24.5 11.3 8.8

53.7 1.59

50.8 1.61

56.3 1.57

55.2 1.58

53.3 1.59

50.2 1.60

0.65 0.63

0.67 0.62

0.66 0.61

0.66 0.61

0.66 0.61

0.66 0.61

Ingredients 1 (% fresh weight) Yellow maize 42.0 Palm oil 3.0 Soya bean meal -G r o u n d n u t cake -Winged bean meal 38.9 Nutrient contents Dry matter Crude protein Ether extract Ash Total carbohydrates ~ Calcium2 Phosphorus (available)2 Methionine2

1All diets contained 7% fish meal, 5% wheat offals, 2% dicalcium phosphate, 1.5% oyster shell, 0,1% vitamin--trace mineral mix, 0.2% DL-methionine, 0.05% amprolium -- a coccidiostat, and 0.25% manganesed salt which contained 89% NaC1 + 11% MnSO,. The vitamin--trace mineral mix supplied per kg of diet: Vitamin A, 10 000 I.U; D3, 2000 I.U.; E, 5 I.U.; K, 2.24 mg; riboflavin, 55 mg; pantothenic acid, 10 mg; nicotinic acid, 25 mg; choline, 350 mg; folic acid, 1 mg; methionine, 450 mg; Mn, 56 mg; I, 1 mg; Fe, 20 mg; Cu, 10 mg; Zn, 50 mg; Co, 1.25 mg. 2Calculated. were r e m o v e d at the tibio-tarsal j o i n t , a n d the h e a d at the first cervical verteb r a t e j o i n t . T h e c a r c a s s w e i g h t , as w e l l as w e i g h t o f t h e p a n c r e a s , s p l e e n , liver and heart, were recorded.

Chemical analyses The samples of the experimental diets were composited, sub-sampled and t o g e t h e r w i t h t h e six s u b - s a m p l e s o f p r o c e s s e d b e a n s w e r e a n a l y s e d f o r d r y m a t t e r , c r u d e p r o t e i n , e t h e r e x t r a c t a n d ash a c c o r d i n g t o t h e A s s o c i a t i o n o f Official Analytical Chemists (1975) procedures.

Statistical analysis T h e d a t a w e r e a n a l y s e d as a c o m p l e t e l y r a n d o m i s e d d e s i g n u s i n g t h e cage

234

of 5 birds as the experimental unit. Tukey's w procedure was used to separate means differing significantly, as outlined b y Steel and Torrie (1960). RESULTS AND DISCUSSION

Table II shows that the TPT-1 variety of the winged bean had lower (P < 0 . 0 5 ) protein, ether extract and ash contents than the TGM-280-3 variety of soya bean. Most published studies have routinely reported similar values for soya beans and winged beans (Claydon, 1975; Jaffe and Korte, 1976), albeit w i t h o u t indicating the varieties of either bean. The present result therefore underlines the importance of specifying the variety or lines studied. Published data on the chemical composition of a few other varieties of the winged bean are summarised in Table III. Even when converted to the same moisture levels, the values show slight differences betweenthe varieties, although sampling and analytical methods m a y account in part for the observed differences. TABLE II Chemical composition of farm processed winged bean and soya bean meals 1 Chemical co m p o n en t (% DM)

Winged bean (TPT-1)

Soya bean (TGM-280-3)

SE 2

Dry matter Crude protein Ether extract:

94.5 39.1 a 14.0 a 12.1a 3.9 a

94.2 48.2 b 23.8 b 20.7 b 5.3 b

0.51 1.02 0.59 0.72 0.31

Unprocessed Processed

Ash

IDuplicate analyses of one representative sample of industrially processed groundnut cake gave the following: dry matter, 94.0; crude protein, 49.3; ether extract, 5.43; ash, 4.92. 2Standard error, n = 6 observations per mean. a'bMeans on the same row bearing different superscripts differ significantly (P < 0.05), TABLE III Chemical composition of other varieties of winged bean Chemical c o m p o n e n t (% as received)

Moisture Crude protein Ether extract Ash Total carbohydrates

Varieties 1 TPT-2

WB-19

Chimbu

NAS

10.4 35.9 15.8 4.9 33.0

11.6 33.7 15.9 4.1 34.7

8.2 37.8 17.0 3.7 33.3

6.7--24.6 29.8--37.4 15.0--20.4 3.6-- 4.0 28.0--31.6

~References: TPT-2, Ekpenyong and Borchers (1981); WB-19, Garcia and Palmer (1980); Chimbu, Garcia and Palmer (1980); NAS, National Academy o f Sciences (1975).

235 As shown in Table II, the raw, unprocessed beans c o n t a i n e d 14 and 24% ether e x t r a c t f o r winged bean and soya bean, respectively. When processed as described earlier, the oil c o n t e n t s d r o p p e d t o 12 and 21%, respectively; a r e d u c t i o n o f only 13% in bot h cases. A m o r e successful e x t r a c t i o n was achieved when processing was carried o u t on a small scale in the laboratory. Off c o n t e n t s declined f r o m 14 and 24% to 6.6 and 11%, respectively, for the winged and soya beans -- a 53% reduction. In o t h e r words, on-the,farm oil e x t r actio n using the simplified solvent e x t r a c t i o n t e c h n o l o g y descri bed is n o t satisfactory, and s m a l l scale farmers wishing t o use farm-grown winged bean as feed m a y have to give it u n e x t r a c t e d . The diets were f o r m u l a t e d to contain similar and adequate a m o u n t s o f essential nutrients. Analyses Showed t h a t this objective was achieved (Table I), e x c e p t f o r the fat c o n t e n t , which varied significantly because of the higher than e x p e c t e d fat left in the beans after processing. The p e r f o r m a n c e data of the birds are summarised in Table IV. F e e d intake, weight gains and efficiency o f feed utilization were similar (P ~ 0.05) across treatments, suggesting t h a t the winged bean meal was well accepted by the birds, and its p ro t ein was efficiently utilised. In o t h e r words, the winged bean can partially or c o m p l e t e l y replace either s oya bean or g r o u n d n u t cake, the two most c o m m o n l y used plant pr ot ei n sources in broiler diets. These results are in agreement with those of Carangal and Juliano (1980), Table V shows a s u m m a r y of the relative organ weights and m ort al i t y of the experimental birds. T he organ weights o f birds given SBM or WBM were similar (P ~ 0.05) to those of c ont r ol birds given commercially processed GNC. Organ weights, particularly o f t he pancreas and spleen, were used as an TABLE IV Performance of broilers fed on the experimental diets Diet Protein source number

Weight gain (g/day)

Feed intake (g/day)

Feed gain

Dressing percentage

1 2 3

28.6 30.8 32.1

86.2 85.1 86.5

3.01 2.76 2.69

63.1 a 63.9 a'b 66.4 a'b

31.3 28.6 31.4

86.6 87.4 87.5

2.76 3.06 2.79

66.3 a'b 65.5 a'b 68.3 b

0.11

1.2

4 5 6 SE 1

Winged bean (WB) Soya bean (SB) Groundnut cake (GNC) WB + GNC WB + SB GNC + SB

1.19

0.95

~Standard error, n = 7 observations per mean. a,bMeans in the same column bearing different superscripts differ significantly (P < 0.05).

236 TABLE V Relative organ weights and mortality of broilers fed on the experimental diets Diet number

Protein source

1 2 3 4 5 6

Liver Heart % of carcass weight

Spleen ;

Mortality (%)

Winged bean (WB) 0.28 Soya bean (SB) 0.28 Groundnut cake 0.25 (GNC) WB + GNC 0.26 WB + SB 0.29 SB + GNC 0.27

3.24 2.95 3.03

0.64 0.61 0.61

0.16 0.14 0.16

14.0 -3.0

2.97 3.02 2.94

0.61 0.61 0.51

0.19 0.15 0.15

-3.0 3.0

0.02

0.16

0.04

0.03

S.E. 1

Pancreas ~

IS.E. Standard error, n = 14 observations per mean. index of the effectiveness o f the processing m e t h o d to destroy trypsin inhibitors, since evidence exists t h a t feeding with raw winged bean results in pancreatic hyperplasia and hepatic and splenic hypoplasia (Jaffe and K o r t e , 1976; E k p e n y o n g and Botchers, 1981). Our results confirm the suggestion of Cerny et al. (1971) and Castilto et al. (1980) t h a t soaking the beans in water fo r at least 10 h, followed by boiling for 30 min, com pl et el y destroys any trypsin activity present in t h e beans. U n f o r t u n a t e l y , heat-labile trypsin inhibitors are n o t the only toxic factors in t h e bean. O t her factors identified included hemagglutinating activity, cyanide p r o d u c t i o n , amylase inhibition and a urease activity (Claydon, 1975; Jaffe and Korte, 1976; E k p e n y o n g and Borchers, 1981). Perhaps some of these factors were n o t com pl et el y inactivated b y the processing m e t h o d , and were responsible for the high m ort al i t y rate observed in the birds fed on winged bean meal as the major prot ei n source. In conclusion, the winged bean, w he n properl y processed to dest roy trypsin inhibitor and ot he r toxic factors, can effectively replace g r o u n d n u t cake or soya bean meal as t he major source of plant p r o t e i n in norm al broiler diets. Th e small-scale producer---processor m ay have to give the beans witho u t fat extraction, because efficient fat e x t r a c t i o n on the farm m a y be t o o expensive. Th e value of the full-fat winged bean for broilers needs f u r t h e r investigation, as some evidence exists t hat full-fat winged beans m a y n o t be efficiently utilised by broilers (Choo, 1975). ACKNOWLEDGEMENT This study was f unde d f r o m the Western Nigerian Marketing Board's e n d o w m e n t funds.

237 REFERENCES Association of Official Analytical Chemists, 1975. Official Methods of Analysis, 12th edn., A.O.A.C., Washington, DC. Bailey, K,V., 1968. Composition of New Guinea highland foods. Trop. Geogr. Med., 20: 141--146. Burkill, I.H., 1966. A Dictionary of the Economic Products of the Malay Peninsula. Vol. 2. Ministry of Agriculture and Cooperatives, Kuala Lumpur, Malaysia. Repr. 1st edn., London, 1936, pp. 1850--1851. Carangal, A. and Juliano, P.O., 1980. Studies on the agronomy and utilization of winged bean. San Miguel F o u n d a t i o n Report, Feb. 1980, Manilla, Phillipines. Castillo, L.S., Cerpacio, A.L., Pascual, F.Sd., Mercado, C.I., Palo, L.P. and Albenir, F., 1980. Winged bean - - wonderful non-conventional feedstuff for broilers and for egg yolk pigmentation. Proc. 17th Convention Phillipine Soc. Anim. Sci., Nov. 1980, Manilla, Phillipines. Cerny, K., Kordylas, M., Pospisil, F., Svabensky, O. and Zajic, E., 1971. Nutritive value of the winged bean (Psophocarpus palustris Desv.). Br. J. Nutr., 29: 293--299. Choo, Wong Kai, 1975. The potential for four-angled bean Psophocarpus tetragonolobus (L.) DC in Malysia to increase food supply. Proc. U M A G A / F A U M Conf. Malaysian F o o d Self-sufficiency, Petaling Jaya, Malaysia. Claydon, A., 1975. A review of the nutritional value of the winged bean Psophorcarpus tetragonolobus (L.) DC with special reference to Papua New Guinea. Sci. New Guinea, 3: 103--114. Ekpenyong, T.E. and Borchers, R.L., 1981. Some toxic factors in winged bean seeds I. Antitrypsin hemaglutinating and urease activities. Nutr. Rep. Int., 23: 865--870. Garcia, V.V. and Palmer, J.N., 1980. Proximate analysis of five varieties of winged beans, Psophocarpus tetragonolobus (L.) DC. J. F o o d Technol., 15: 469--476. Jaffe, W.C. and Korte, R., 1976. Nutritional characteristics of the winged bean in rats. Nutr. Rep. Int., 14: 449--455. Masefield, G.B., 1960. Root nodulation and agricultural potential of the leguminous genus Psophocarpus. Trop. Agric. Trinidad, 38: 225--229. Masefield, G.B., 1973. Psophocarpus tetragonolobus -- a crop with a future? Field Crop Abstr., 26: 157--160. National A c a d e m y of Sciences, 1975. The winged bean: a high protein crop for the tropics. Washington, DC. Steel, R.D. and Torrie, J.H., 1960. Principles and Procedures of Statistics. McGraw-Hill, New York, p. 481.