Research Article

 

Effect of Replacement of Soybean Meal with Toasted Pigeon Pea (Cajanus cajan) Seed Meal on Growth Performance of Broiler Chickens

 

Yonatan Kassu Yesuf1*, Aklilu Getahun Adema2

1Wolaita Sodo University, Department of Animal and Range Sciences, Wolaita Sodo, Ethiopia;2Wolaita Zone Livestock and Fishery Resource, Wolaita Sodo, Ethiopia;

 

Received | January 02, 2021; Accepted | June 8, 2021; Published | July 28, 2021

*Correspondence | Yonatan Kassu Yesuf, Wolaita Sodo University, Wolaita Sodo, Ethiopia; Email: kassuyonatan@gmail.com

Citation | Yesuf YK, Adema AG (2021). Effect of replacement of soybean meal with toasted pigeon pea (Cajanus cajan) seed meal on growth performance of broiler chickens. Adv. Anim. Vet. Sci. 9(9): 1355-1361.

DOI | http://dx.doi.org/10.17582/journal.aavs/2021/9.9.1355.1361

ISSN (Online) | 2307-8316; ISSN (Print) | 2309-3331

Copyright © 2021 Adema et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

 

INTRODUCTION

 

Poultry production is one area of livestock production with a significant contribution to human food production. However, poultry producers in the tropics particularly in Ethiopia have been limited by scarcity and the high market price of conventional protein and energy concentrates. In the case of commercial poultry production feed accounts for 60-70% of the total cost of production (Thirumalaisamy et al., 2016). The large segment of the energy acquirement of poultry is obtained from cereal grains, which are cultivated mainly for human consumption in the tropics. Thus poultry production is directly competitive with human population for the available scarce energy feed resource. Moreover, there is a shortfall in the supply of soybean meal used as protein source source in the tropics, including Ethiopia. Therefore, a conventional source of raw materials, which are less exploited by man, is one of the solutions to reduce the cost of production and contribute to the increased supply of animal protein to the rich of poor people (Amin and Cheah, 2010). One of such feed sources that could be used to reduce the problem of the high cost of conventional protein sources in livestock diets with particular reference to poultry is the pigeon pea (Igene et al., 2012).

 

Pigeon pea has a good nutritional profile that could replace maize and soybean (Amaefule and Obioha, 2001). It seems to be a better and cheaper protein source for poultry feeding as compared to other legume grains. Pigeon pea (Cajanus cajan) seed contains crude protein (CP) of 22–27%, crude fiber (CF) of 7.3–10%, nitrogen-free extract (NFE) of 61.2%, ether extract (EE) of 1.7–2.1%, ash of 3.1–4.2%, and lysine of about 7.59%. It is also a good source of soluble vitamins, especially thiamin, riboflavin, niacin, and choline (Ahmed et al., 2006). However, like most legumes pigeon pea seeds also contain some anti-nutritional factors such as oligosaccharides (raffinose and verbascose), polyphenols (phenols and tannins), phytolectins, and enzyme inhibitors (Saxena et al., 2010). The effect of the antinutritional factors could be reduced through processing and supplementation with the enzyme (Akintunde et al., 2010). Heat treatment has been established as an effective method of destroying these antinutritional factors. Therefore, this study was conducted to study the feasibility of replacing soybean meal with toasted pigeon pea (Cajanus cajan) seed meal in the broiler diet.

 

MATERIALS AND METHODS

 

Preparation of pigeon pea seeds

The experiment was conducted in the Poultry Farm of Agriculture Technical Vocational Education and Training College, Wolaita Sodo. The pigeon pea (Cajanus cajan) seed was obtained from the local market. The seed was toasted on a hot plate at 100 °C for 15 min (Etuk et al., 2002). The toasted seeds were spread out in the air to cool, dehulled, ground and included in the treatment diets as shown in Table 1.

 

Ethical consideration

The experimental chicks were treated or managed according to an animal experimental protocol approved by the Ethics Commission of the Wolaita Sodo University.

 

Experimental ration and treatments

Four treatments of each of the starter and finisher broilers rations were prepared. The treatment rations were formulated to be iso-caloric and iso-nitrogenous according to the standard for commercial broiler birds recommended by Leeson and Summers (2005). The starter and finisher control treatment diet were formulated to contain about 35% and 28% soybean meal, respectively. Therefore, four broiler treatment diets containing 0, 10, 20, and 30% of Pigeon pea as a replacement of soybean meal were formulated as shown in Table 1.

 

Experimental design

A total of 180-day-old unsexed broiler birds (Cobb-500) were purchased from a commercial farm. The birds with an initial mean body weight of 41.44±0.71g were randomly divided into 4 dietary treatments and the four starters treatment rations were randomly assigned to the experimental chicks in a completely randomized design with three replications. The experimental chicks were introduced to the finisher treatment ration at the end of 28 days feeding trial.

 

Management of birds

The birds were raised for 7 weeks in a deep litter housing system. The house was portioned into 12 pens and all the pens had the same space and dimension of 1.50*1.65m. Wood shavings were used as litter material at a depth of 10 cm. The birds were placed under an electric brooder heated by 200-watt bulbs with gradual height adjustment. The brooding temperature was maintained at 32°C during the first week and reduced by 2°C until it reached the room temperature of 24°C. Feeds and water were provided on ad-libitum throughout the experimental period. The chicks were vaccinated against Newcastle disease and infectious bursal disease (Gumboro).

 

Chemical analysis

The dietary feed ingredients, feed offered, and refusals were analyzed Dry matter, Ether extract (EE), Crude fiber (CF), and total ash and crude proteins were determined according to the procedure of AOAC (2005). Calcium was determined by atomic absorption spectrophotometer and phosphorus by calorimetric methods as described by AOAC (2005). All samples were analyzed in the food science and nutrition research Laboratory of Ethiopia public health institute and Chemistry laboratory of Arba Minch University. The metabolizable energy (ME) was estimated by the formula: ME (Kcal/kg DM)= 3951 + 54.4EE - 88.7CF- 40.8Ash (Wiseman, 1987).

 

Bodyweight gain and feed conversion ratio (FCR)

Birds were weighed in the group at the beginning and weekly interval until the end of the experiment. The birds were weighed early in the morning before feeding. The average final body weight was calculated as the difference between the two successive weights divide by the number of birds. Average daily gain (ADG) was calculated as the mean of final body weight change to the number of experimental days. The feed conversion ratio was calculated as the ratio of average feed intake to average BW gain.

 

Nutrients intake

The feed intakes were determined as the difference between the feed offered and refused (Tusar et al., 2015). Dry matter (DM), Crude protein, and Metabolizable energy (CP and ME) were calculated by difference from offered and refusals on a dry matter basis. The DM, CP, and ME intake were computed by multiplying the daily as well as the total feed consumption by their respective DM, CP, and ME contents.

 

Table 1: Ingredients and nutrient contents of the starter and finisher diets fed to broilers.

 

Ingredients (%)		Starter phase					Finisher phase
		T1	T2		T3	T4	T1	T2		T3	T4
Maize		43	46.7		41.7	44.7	56	56		51	49.63
Soya bean meal		35	31.5		28	24.5	28	25.2		22.4	19.6
Wheat middling		13	8		9	5	5.7	5.7		7.7	7.7
Noug cake		4.3	5.5		9.5	10.5	6.07	6.07		9.07	11.07
PSM (toasted)		-	3.5		7	10.5	-	2.8		5.6	8.4
Limestone		0.7	0.7		0.7	0.7	0.7	0.7		0.7	0.7
Salt		1	1		1	1	1	1		1	1
Vitamin premix		2	2		2	2	2	2		2	1
Methionine		0.3	0.3		0.3	0.3	0.13	0.13		0.13	0.2
Lysine		0.7	0.8		0.8	0.8	0.4	0.4		0.4	0.7
Total		100	100		100	100	100	100		100	100
Nutrient content (% DM basis)
ME (kcal/kg)	2993		2990.5	2993.6		2992.7	3160.1		3160.2	3160.5		3161
Dry matter	92.64		92.76	92.81		92.79	89.46		89.59	89.91		90.14
Crude Protein	22		21.7	21.87		21.8	19.02		18.92	18.92		18.9
Crude Fiber	5.9		6.31	6.66		6.89	6.58		6.88	6.9		7.68
Ether Exract	2.46		2.28	2.31		2.16	1.78		1.90	1.92		2.18
Calcium	0.99		1	1		1.2	0.96		0.96	0.97		0.99
Phosporous	0.79		0.71	0.74		0.68	0.51		0.51	0.51		0.48

T1 = 0% PPSM; T2 = 10 % PPSM; T3 = 20 % PPSM; T4 = 30 % PPSM; ME=Metabolizable, PSM= Pigeon Pea Seed Meal.

 

Protein and energy efficiency ratio

The Protein Efficiency Ratio (PER) was calculated as the ratio of weight gained to protein consumed and the Energy Efficiency Ratio (EER) was calculated as weight gain multiplied by hundred over the total ME intake (Kamran et al., 2008).

 

Statistical analysis

Data were subjected to ANOVA using the general linear models (GLM) procedures to determine the treatment effects on growth performance traits. SAS statistical package version 9.3 was used to analyze the data (SAS, 2010). A treatment difference between group means was evaluated by Duncan’s Multiple Range Test at a 5% level of significance.

 

RESULTS AND DISCUSSION

 

Nutrient intake of broilers

Dry matter, crude protein, and Metabolizable energy intake of broiler birds fed on different levels of toasted PSM are presented in Table 2. There were significant differences (P<0.001) among treatment groups in mean daily and total DM intake during the both the starters and finishers periods. The birds fed on T3 (the ration containing 20% of PSM as substitute of soya bean meal) had significantly (P<0.05) higher daily and total DMI followed by the groups fed on T4, T2, and T1 during the finisher phase and the entire period. The group birds placed on T2 and T3 had significantly (P<0.05) higher DMI compared to the group birds fed on T1 (control treatment).

 

There was significant difference (P<0.001) in crude protein (CP) intake among treatments during the starter phase and the entire period. At the starter phase, the groups fed on the treatments containing PSM (T3,T4 and T2) showed improvement in CP intake (P<0.05) than the group birds assigned to the control treatment (T1) birds. There was a significant difference (P<0.05) among group treatments in mean daily crude protein intake during the finishers phase. From all treatments, T3 diet group birds show high (P<0.05) CP intake than the control (T1) group and the rest of the treatment birds in starter and finisher phases. Also, it was increased by 20.76%, 16.2%, and 17.44% compared to the control group during the starter, finisher, and the entire period, respectively. However, in both phases, there were no significant differences (P>0.05) in CP intake between T4 and T2 diet group birds. Although, T4 and T2 diet group birds had significantly high CP intake in contrast to the control (T1) group (P<0.05).

 

The metabolizable energy intake was high significant (P<0.001) among the dietary treatments during the starter, finisher phases, and the overall period. However, birds fed under T3 intake significantly (P<0.05) high metabolizable energy followed by T4, T2, and control (T1) during the starter phase and the entire period. Also, it was increased by 9.2% compared to the control group during the starter, finisher, and the entire period with a similar intake pattern. Whereas, during the finisher phase, birds fed under the control group (T1) had significantly less ME intake (P<0.05) followed by T4 and T2. However, the two dietary treatments (T4 and T2) had better (P<0.05) ME intake compared to the control group birds.

 

Growth performance of broilers

The effect of PSM as a replacement at different levels on broiler growth change: Bodyweight, (BW), BW gain, ADG, and FCR are shown in Table 3. The final BW, BW gain, and ADG during the starter phase were not significantly different (P>0.05) among the dietary treatment group birds. However, during the finisher phase and the overall period, there were highly significant differences (P<0.001) among the dietary treatment group. The initial BW of birds at day-old has no significant differences (P>0.05) among the treatment groups. The birds under dietary treatment T3 have significant (P<0.05) higher Final BW, BW gain, and ADG compared to the control (T1) and the rest of the treatment birds during the finisher phase and entire period and it shows an increment of 24.58% and 20.88% in BW gain in contrast to the control group birds at finisher phase and entire period, respectively. The same is true for BW and ADG. However, birds under dietary treatment T2 group had no significant difference (P<0.05) to that of the control (T1) group birds. Although there is an improvement in BW gain, the FCR was not significantly different (P>0.05) among the treatments at starter, finisher, and entire period.

 

Protein and energy efficiency ratio

The protein Efficiency Ratio (PER) and energy efficiency ratio (EER) of broiler birds fed on different levels of toasted pigeon pea seed meal are presented in Table 3. The PER and EER were significantly (P<0.05) differences among the treatments during the finisher phase and entire periods, while on the contrary there were no significant differences (P>0.05) among the treatment group birds at the starter phase. During the finisher phase and the entire period, the PER of birds fed dietary treatment (T2 and T3) were not significantly (P>0.05) affected compared to the control group (T1) birds. However, PER was significantly influenced (P<0.05) by dietary treatment (T3 and T4) compared to the control group (T1) and T2 group birds during the finisher phase. Similarly, during the entire period birds on dietary treatment T3 and T4 were significantly (P<0.05) considerable EER compared to the control (T1) and (T2) treatment group birds. All mortality recorded during the first week of the starter phase from T2, T3, and T4 were 1, 2, and 4 birds, respectively.

 

The 20% replacement of toasted PSM (T3) group birds had better daily DMI (18.25%) and total DMI (18.22%) compared to the control group during the overall period. The result obtained in the present study showed an improvement over the observation of Ani and Okeke (2003) that broiler starters fed 27% toasted PSM had lower feed intake than birds fed 5.5-21.5% toasted PSM diets. This is possibly due to finisher broiler are more adapted to

 

Table 2: Nutrient CP and Metabolizable energy intake of broiler birds fed partial substitution of roosted PSM at different levels.

 

Parameter	Phase	Dietary treatments					P-value
		T1	T2	T3	T4	SEM
DMI (g/bird/day)	Starter	38.87c	42.39b	44.29a	41.6b	0.51	0.001
	Finisher	104.93d	108.60c	125.29a	115.61b	0.65	< 0.001
	Entire period	76.6d	80.23c	90.58a	83.89b	0.48	< 0.001
DMI (g/bird)	Starter	816.3c	890.29b	930.23a	873.62b	10.85	0.001
	Finisher	2938.12d	3,041c	3,508.38a	3,237.05b	18.39	< 0.001
	Entire period	3754.41d	3931.3c	4,438.62a	4,110.67b	23.7	< 0.001
CPI (g/bird)	Starter	216.88c	246.44b	261.91a	248.20b	3.29	< 0.001
	Finisher	584.33c	653.57b	679.06a	612.21b	11.36	0.002
	Entire period	801.21d	900.01c	940.97a	860.41b	11.71	< 0.001
MEI (kcal/bird/day)	Starter	140.93d	147.11c	153.89a	151.83b	0.58	< 0.001
	Finisher	338.25d	364.4b	369.35a	353.06c	1.39	< 0.001
	Entire period	253.68d	264.30c	277.01a	273.30b	1.04	< 0.001

Mean values within the same row having different superscript letters are significantly different (P<0.05); PSM= Pigeon Pea Seed Meal; T1= 0% PSM; T2= 10 %PSM; T3= 20 % PSM; T4= 30 %PSM; DMI = Dry matter intake; CPI = crude protein intake; MEI=Metabolizable energy intake; SEM = Standard Error of the Mean.

 

Table 3: Performance of broiler chicks fed partial substitution of roosted PSM at different levels.

 

Parameter	Phase	Dietary treatments					P-value
		T1	T2	T3	T4	SEM
Initial BW(g)		42.32	40.57	41.42	41.45	0.52	0.212
Final BW(g)	Starter	617.41	672	691	677	22.31	0.17
	Finisher	1678.49c	1764.83c	2019.33a	1888b	28.0	<0.001
BWG(g)	Starter	575.09	631.97	649.66	636.42	22.57	0.17
	Finisher	1066.07c	1092.28c	1328.0a	1219.12b	33.85	0.002
	Entire Period	1636.2c	1724.26c	1977.9a	1846.56b	28.13	<0.001
ADG(g)	Starter	26.63	30.09	30.93	30.30	1.01	0.065
	Finisher	39.40c	40.46c	48.91a	44.7b	1.21	0.002
	Entire Period	33.4c	35.2c	40.4a	37.66b	0.56	<0.001
FCR	Starter	1.42	1.43	1.43	1.37	0.06	0.89
	Finisher	2.76	2.78	2.65	2.67	2.76	0.41
	Entire Period	2.29	2.28	2.24	2.22	2.29	0.58
	Starter	2.65	2.56	2.48	2.56	0.099	0.68
PER (g)	finisher	1.81b	1.67c	1.95ab	1.97a	0.045	0.005
	Entire period	2.04ab	1.91b	2.10ab	2.14a	0.045	0.002
	Starter	18.89	19.81	20.10	20.6	0.68	0.04
EER (g)	finisher	11.65bc	11.1c	13.24a	12.65ab	0.31	0.006
	Entire period	13.16b	12.87b	14.57a	14.23a	0.21	0.001
	Starter	-	1	2	4	-	-
Mortality	Finisher	-	-	-	-	-	-
	Entire period	-	1	2	4	-	-

Mean values within the same row having different superscript letters are significantly different (P<0.05); PSM= Pigeon Pea Seed Meal; T1= 0% PSM; T2= 10 %PSM; T3= 20 % PSM; T4= 30 %PSM; BWG=Bodyweight gain; ADG =Average daily weight gain; FCR= Feed conversion ratio.

 

the high intake of pigeon pea seed meal than starter broiler. The increased DM intake by birds on toasted PSM diets also suggests that roasting for 30 min was able to eliminate the anti-nutritional factors in pigeon pea. Reduction in antinutritional factors when they subjected Sorrel seed to toasting. Reduction in the contents of the anti-nutritional factors suggests the ability of toasting as an effective method of detoxification Pigeon seed, therefore this might lead to an increase on feed intake. The current study finding in agreement with that of Etuk et al. (2002), who reported that there was better daily total feed intake of broiler birds fed with 20% of soaked processed PSM during starter and finisher phases.

 

The CP intake of the groups fed on T3 (20% PSM) was increased by 20.76%, 16.2%, and 17.44% compared to the control group during the starter, finisher, and the entire period, respectively. This result agreed with Igene et al. (2016) who reported that there where better daily CP intake of chicken fed with 20% of boiled PSM during the starter and finisher phases. The metabolizable energy intake of birds assigned to T3 was increased by 9.2% compared to the control group at the starter, finisher, and entire periods. However, contrary to the current finding, Tusar et al. (2015) and Ahmed et al. (2006), and Babiker et al. (2006) reported that there was no change in ME intake between the control and treatment group birds when broiler birds fed with soaked PSM at the levels of 0, 0.5, 1, 1.5%. The discrepancy with the current finding might be due to the difference in the processing method and replacement level alteration.

 

The birds under dietary treatment T3 have significant higher Final BW, BW gain, and ADG compared to the control (T1) and the rest of the treatment birds during the finisher phase and entire period and it shows an increment of 24.58% and 20.88% in BW gain and ADG in contrast to the control group birds, respectively. This result contradicts that of Etuk et al. (2002) which indicted that there was a significant depression in weight gain among birds fed diets containing 20-50% cooked pigeon pea seed meal. The result obtained in this study seems to suggest that broiler finishers can be fed diets substituting soybean by toasted PSM up to 20% without any BW deterioration. The improvement in BW gain and ADG in the current study is due to an increase in DM, CP, and ME intake which consequently leads to an increase in BW gain. Also, the effect of mixed protein sources or using more than one protein source could improve the performance of broiler across the treatment (Alhafiz et al., 2013). These coincide with Amaefule and Obioha (2005) who concluded that the replacement of 10% toasted PSM in broiler diets supported bird growth and development at finisher and overall experimental period. In other trials, Tusar et al. (2015) reported that BW gain increased with the inclusion of 10% and 15% pigeon pea, compared to the control and 5% treatment groups. Similarly, Babiker et al. (2006) reported that the more replacement of PSM greater than 10% improve BW gain and ADG of broiler was that of 7.5% and 5% dietary treatments at the finisher phase. In contrast to the current study, Abdelati et al. (2009) reported that the inclusion of 10% soaked pigeon pea seed, decorticated with an added enzyme and decorticated toasted had no effects on feed intake and BW weight gain. However, in this study, the FCR was not affected by the treatments. The findings of this study disagree with that of Etuk et al. (2002) who reported that there was a change in FCR of broiler starter and finisher chicken fed 20% of graded levels of PSM. Similarly, Alhafiz et al. (2013) reported that the birds fed with Pigeon pea recorded high FCR value. The difference in FCR might be due to the difference in the processing methods which lead to the destruction of lysine and methionine in the roasting process. Also, Wallis and Balnave (1984), stated that lysine, glutamic acid, aspartic acid, threonine most liable to be damaged by heat.

 

The PER and EER of 20 and 30% substitution of soybean by PSM was not significantly influenced by birds during the finisher phase and overall period. This leads to a non-substantial change in FCR as well. the current result in agreement with Ani and Okeke, (2011) indicated there is no change in PER and FCR between 0, 6.5, 13.0, 19.5, 26.0 and 32.5% roasted PSM. This strongly indicates that broiler finishers’ diet at 26% and 27% toasted PSM, may be incorporated into broiler finisher diets without any deleterious effect on the growth performance of broiler birds. On contrary, Ahmed et al. (2006) indicated that soaked PSM at 0, 50, 100, and 150 g/kg of inclusion in the broiler diet were not different in EER among treatments. However, in the current study, the PER and MER were not significantly different at higher substitution levels. The difference in results is due to a reduction in antinutritional factors (oxalate, tannic acid, etc.) which affect the metabolizable energy (ME) and protein or nitrogen retention in chicks which might be minimized due to the processing of pigeon pea by toasting.

 

CONCLUSIONS AND RECOMMENDATION

 

As the levels of PSM replacement increase greater than 30% the feed intake of bird decline. Broilers BW gain and ADG were significantly influenced by 20% and 30% PSM replacement for SBM. Therefore, Toasted PSM at 20% and 30% levels was suitable to be used in broiler diets as a source of protein without any adverse effect on the growth performance of broiler birds. However, further research is needed to determine the optimum level PSM with different processing methods to achieve the optimum growth performance and effects on carcass yield and qualities of meat.

 

ACKNOWLEDGMENTS

 

The authors are grateful to Wolaita Zone Livestock and Fishery Resource Office and Wolaita Sodo University for their financial support. They are also highly indebted to ATVET College for their collaboration and facilitation.

 

NOVELTY STATEMENT

 

Pigeon pea seed is a superb supply of protein for chicken feeding. unfortunately, Its have an anti-nutritional element that limits its usage with the aid of using chicken. There are lots of remedies are to be had to reduce those anti-nutritional effects, from this heat treatments are one of them and it appears the best way to overcome this problem. however, the extent of substitution of the soybean meal by pigeon peameal in the ration still does not exceed 10 and 20% of replacements. The present study provides a recommended level of replacement of soybean meal by toasted Pigeon peameal.

 

AUTHOR’S CONTRIBUTION

 

Both authors collect the necessary data and write up the article.

 

Conflict of interests

The authors have declared no competing interest.

 

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