The experiment was conducted on 350 one day old straight run broiler chicks consisting of seven treatment groups having ten replicates with five chicks each soybean meal was replaced with alternate protein meal (APM) viz. Guar meal (GM), Rapeseed meal (RSM) and Cotton seed meal (CSM) each at 3 (total 9 percent) and 6 percent level (total 18 percent) with or without the supplementation of Non starch polysaccharide (NSP) hydrolyzing enzymes. The 3 percent APM containing diet was supplemented with two levels of the NSP hydrolyzing enzymes i.e. (xylanase, ß-D-glucanase, cellulase, mannanase and pectinase @ 3200, 4000, 1520, 8000, and 3200 IU/kg (1X concentration) and 6400, 8000, 3040, 16000 and 6400 IU/kg (2X concentration) respectively. Similarly the 6 percent APM containg diet was supplemented with two levels of the NSP hydrolyzing enzymes i.e. (xylanase, ß-D-glucanase, cellulase, mannanase and pectinase @ 3200, 4000, 1520, 8000, and 3200 IU/kg (1X concentration) and 6400, 8000, 3040, 16000 and 6400 IU/kg (2X concentration) respectively . The 3 % APM diet supplemented with NSP hydrolyzing enzymes at 1X and 2X levels had shown significantly higher body weight gain (BWG) compared with that of control. However, the 6% APM control diet has witnessed significantly lower BWG throughout the experimental period. Similarly, the 6 % APM diet supplemented with 2X NSP hydrolyzing enzymes has not shown any significant differences in BWG throughout the experimental period. Feed intake was significantly higher (P<0.05) in 6 % APM control diet followed by 3 % APM control diet. Supplementation of NSP hydrolyzing enzymes at 1X and 2Xlevels influenced the FCR (P<0.05) of broilers.
Poultry ration consist of cereals and vegetable based protein sources. These ingredients consist of 10-75% of non-starch polysaccharides (NSP) (Choct, 2011). The NSP in cereals form a part of the cell wall structure and in vegetable proteins, especially legumes, play a role as an energy storage material. Poultry being simple stomach cannot digest complex nutrients like non-starch polysaccharides Supplementation of poultry diet with fiber hydrolyzing enzymes does enhance utilization of the complex carbohydrate moiety (Choct, 2006). Because of increase in World’s population and the decline in its food reserve, a more efficient conversion of agro industrial by-products including those rich in NSP, into high quality food is a major area of research today. Soybean meal (SBM) is being used as sole protein source in recent years which contains about 20% NSP (Malathi and Devegowda, 2001). Similarly, other major ingredients used in broiler and layer diets i.e., maize and rice bran contains 9 and 25% NSP, respectively (Malathi and Devagowda, 2001) half of which is cellulose as reported by (Saunders, 1986). The NSPs are insoluble (cellulose) and soluble (β-glucose, arabinoxylan, arabinogalactose, xyloglucon etc). The soluble NSPs have the property to immobilize water in its matrix by forming loose gel network which is responsible for increased viscosity, there by depressing the digestibility of fats, proteins and starch. These NSPs impair activity of endogenous enzymes by reducing the contact intensity between nutrients and enzymes, which results in sticky and moist droppings.
Nowadays, the cost of soybean meal is increasing day by day and because of this the poultry farmers are looking for the alternate protein meals (APM) like- guar meal (GM, protein 33-45%), rapeseed meal (RSM, protein 38-43 %) and cotton seed meal (CSM, protein 40-42%). However, the non-starch polysaccharide (NSP) contents of GM, RSM and CSM are very high (78%, 36.2 and 36.7) respectively. The NSPs can be hydrolyzed with the supplementation of NSP hydrolyzing enzymes. Feed enzymes have been incorporated to improve the nutritive value of poultry diets has become common practice in many countries due to use of feed ingredients containing higher proportion of NSP. However, chicken does not secrete NSP hydrolyzing enzymes to breakdown NSPs present in most of raw materials of plant origin (Close, 1996). Poultry being simple stomached, do not produce enzymes like cellulase, hemicellulase, xylanase and β-glucanase which are required for the digestion of cell wall components of plant material. Inadequate or non-availability of certain enzymes in the digestive tract of chicken reduces their utilization. Enzymes added in the diet break the polymeric chain of fibrous material more effectively, thereby reducing the gut viscosity and improve their nutritive value (Smits and Annison, 1996). Hence to resolve this issue the supplementation of the substrate specific NSP hydrolyzing enzyme combination has been taken as an alternative tool. Hong et al. (2002) found that the use of an enzyme cocktail improved the digestibility of corn-soybean based diets.
Materials and Methods
The present experiment was undertaken on 350 day old ven-cobb straight run broiler chicks consisting of seven treatment groups having ten replicates five birds each. The housing and management of experimental birds was similar to all groups. The experiment was specifically designed keeping in view the replacement of soybean meal as protein source from the broiler diet with the alternate protein sources viz. guar meal (GM), rapeseed meal (RSM) and cotton seed meal (CSM) each at two different levels as alternate protein source was supplemented at 3 (total 9 percent) and 6 percent level (total 18 percent) at Iso-caloric and Iso-nitrogenous levels.
The experiment was a stepping stone to derive a suitable NSP hydrolyzing enzyme combination for the alternate protein sources so as to utilize the low cost alternate protein meals in broiler diet to make the diet economically viable. The pure NSP hydrolyzing enzymes were procured from Advanced Bio- Agrotech Limited, Pune, India. The activity of xylanase, ß-d-glucanase, cellulase, mannase and pectinase was 160000, 200000, 1000000, 200000 IU/g, and 150000 respectively. A total of seven experimental diets were formulated and details are presented in Table 1. The ingredient and nutrient composition of the experimental diets is given in Table 3. However the concentrations of the NSP hydrolyzing enzymes are given in Table 2.The data obtained from the experiment were subjected to appropriate statistical analysis using Statistical Package for Social Sciences (SPSS) software and comparison of means was tested using Duncan’s multiple range tests (Duncan’s, 1955).
Table 1: Details of Broiler Diets
|Diet||Dietary Group||Metabolizable Energy (kcal/kg diet)|
|I||Control corn – soybean meal diet without NSPHE||2950||3050||3150|
|II||Control diet 3 percent alternate proteins (GM,RSM and CSM each 3 percent) (i.e. total 9 percent) level without NSPHE||2950||3050||3150|
|III||3 percent alternate proteins (GM, RSM and CSM each 3 percent) level NSPHE 1 X||2950||3050||3150|
|IV||3 percent alternate proteins (GM, RSM and CSM each 3 percent) level with NSPHE 2 X||2950||3050||3150|
|V||Control diet with 6 percent alternate proteins(GM,RSM and CSM each 6 percent) (i.e. total 18 percent) level without NSPHE||2950||3050||3150|
|VI||Control diet with 6 percent alternate proteins (GM,RSM and CSM each 6 percent) level with NSPHE 1 X||2950||3050||3150|
|VII||Control diet with 6 percent alternate proteins (GM,RSM and CSM each 6 percent) level without NSPHE 2 X||2950||3050||3150|
Table 2: Details of the NSP Hydrolyzing Enzyme Concentrations
|APM (GM, RSM, CSM (each @ 3 % level total 9 %)|
|Percentage of Enzyme||Xylanase (IU/kg)||β-D-glucanase (IU/kg)||Cellulase (IU/kg)||Mannanase (IU/kg)||Pectinase (IU/kg)|
|APM (GM, RSM, CSM (each @ 6 % level total 18 %)|
Table 3: Ingredient Composition of Broiler Diets
|Ingredient (g/kg)||Pre Starter||Starter||Finisher|
|Diets||Standard||3 % APM||6 % APM||Standard||3 % APM||6 % APM||Standard||3 % APM||6 % APM|
|Trace mineral mix1||0.10||0.10||0.10||0.10||0.10||0.10||0.10||0.10||0.10|
|CSM 36 %||0.00||3.00||6.00||0.00||3.00||6.00||0.00||3.00||6.00|
|Nutrient Composition (calculated)|
|Available P (%)||0.45||0.45||0.45||0.40||0.40||0.40||0.38||0.38||0.38|
1Trace mineral provided per kg diet: manganese, 120mg; Zinc, 80mg; Iron, 25mg; Copper, 10mg; Iodine,1mg; and Selenium, 0.1mg. 2 Vitamin premix provided per kg diet: Vitamin A, 20000IU; Vitamin D3, 3000IU; Vitamin E, 10mg; Vitamin K,2mg; 3 Riboflavin, 25mg; Vitamin B1, 1mg; Vitamin B6, 2mg: vitamin B12, 40mcg and Niacin, 15mg
Results and Discussion
The body weight gain was significantly higher (P<0.05) in control diet T1 and 3% APM supplemented with 1X and 2X HC throughout the three phases of experimental period. The 3% APM diet supplemented with NSPHE @ 1X and 2X T3 and T4, 6% APM diet supplemented with 1X NSPHE T6 have shown significantly higher (P<0.05) BWG during the prestarter phase. 3 % APM control diet had shown comparatively better BWG (P<0.05) than that of T5 and T7, which have shown significantly poor BWG (Table 4). During the starter phase, the BWG was significantly higher (P<0.05) in T1, T3 and T4 compared with T2, T6, T7 and T5. The starter phase BWG was significantly lower in the T5 followed by T7. The finisher phase BWG was significantly better (P<0.05) amongst the treatment groups T1, T2, T3, T4 and T6 compared with T5 and T7. The treatment T5 comprising of 6 % APM control had shown poor BWG during the finisher phase, which was followed by T7 comprising of 6 % APM + 2X NSPHE (Table 4).
Table 4: Effect of supplementation of non starch polysaccharide hydrolyzing enzymes in diets containing APM (GM,RSM,CSM) each at 3 and 6 % levels on body weight gain(g)of broilers (0-42 days)
|T2||3% APM Control||288.7b||727.1bc||1,017.6a||2,048.9ab|
|T3||3% APM + 1X HC||336.4a||798.4a||999.4a||2,134.2a|
|T4||3% APM + 2X HC||331.1a||772.8ab||995.5a||2,099.4a|
|T5||6 % APM control||260.9c||641.0d||874.4b||1,776.3c|
|T6||6 % APM + 1X HC||326.2a||722.7bc||925.9ab||1,974.7b|
|T7||6 % APM + 2X HC||267.3c||689.3cd||877.1b||1,833.7c|
Values bearing different superscripts within a columns differ significantly (P<0.05)
The findings are in accordance with Abbas et al. (1998) revealed that NSP enzyme supplementation to fibrous diet improved the growth rate of broilers. Zanella et al. (1999) investigated the effect of a commercial enzyme cocktail containing xylanase, protease and amylase on performance of broilers fed a corn-soybean meal based diet. Enzyme supplementation improved BWG. Hanumantha Rao et al. (2003) reported that the supplementation of enzyme cellulase, xylanase, amylase, protease and phytase individually to maize soybean based diets, significantly (P<0.05) improved BWG of broilers at 42 d. Lazaro et al. (2003) also reported that enzyme supplementation improved performance of birds fed rye lets. Edwin et al. (2004) concluded significant increase in fifth week BWG (P <0.01) of the Japanese quail supplemented with NSP hydrolyzing enzymes. Olukosi et al. (2007) and Gao et al. (2007) reported improved BWG with enzyme supplementation. Cowieson and Ravindran (2008b) who concluded that enzyme supplementation in broilers fed maize based diets varying in nutrient density improved weight gains of the birds (P<0.001), Berwal et al. (2008) observed feed intake (P<0.05) in broilers fed diets with higher crude fibre levels supplemented with enzyme. Dinani et al. (2010) reported that enzyme supplementation is beneficial for growth performance of growing quails. Mohammad et al. (2010) reported that supplementation of 0.1% (Avizyme) 1100 (xylanase and β-glucanase 300 U/g) to barley based finisher diets improved weight gains. Larhang and Torki (2011) reported that inclusion of different levels of guar meal (0, 4 and 8%) and commercial enzyme (0 and 0.05% of Natuzyme) resulted highest BW and BWG. Narasimha et al. (2013c) concluded that supplementing sub-optimal energy diets with NSP enzymes along with synbiotics and phytase improved BWG, FCR. Rama Rao et al. (2014) reported that inclusion of GM 200g/kg diet with incremental level of enzyme supplements resulted (P<0.05) increased BWG compared to GM 200g/kg diet without enzyme. Santhi et al. (2014) conducted an experiment to find out the effect of supplementation of exogenous cellulase through feed in turkeys up to eight weeks. Nikam et al. (2016) concluded that supplementing NSP hydrolyzing enzymes to Corn soybean meal based diets has influenced the BWG of the broilers.
However the findings are conflicting compared with Mohammad Akbari Gharaei et al., 2012) who reported that inclusion of GM (0, 3, 6 and 9 %) and β – mannanase enzyme (0 and 0.05 %) were not significant on weight gain. Mishra et al. (2013) reported that live weight of guar korma fed group was inferior to SBM fed ones and that mannanase supplementation did not revert this effect. Narasimha et al. (2013a) reported that non-starch polysaccharide enzymes with or without prebiotics had no effect on BWG of broilers. The prestarter phase had shown significantly better (P<0.05) feed intake in the group fed with 3 % APM diet supplemented with 1X and 2X NSPHE. However 3% APM containing diet and 6 % APM supplemented with 1X NSPHE had also shown significantly higher (P<0.05) feed intake during prestarter phase and was comparable with T3, T4and T5. During prestarter phase, the feed intake in control diet (T1) and NSPHE @ 2X (T7) showed significantly low feed intake. The starter phase showed significant difference (P<0.05) in the feed intake in the 6 % APM control diet (T5) compared with rest of the diets. The standard control diet (T1) has also shown significantly higher (P<0.05) feed intake but was statistically comparable with T2, T3, T4, T7 and T6 (P<0.05). The diets with 3 % APM (T2) and 3 % APM with 1X (T3) and 2 X (T4) NSPHE and (T6) had shown comparable feed intake which was significantly higher (P<0.05) compared with (T7). The diet (T7) has shown significantly poor feed intake during the starter phase. In finisher phase, the feed intake was significantly higher (P<0.05) among the 3 and 6 % APM fed control (T2 and T5) compared with rest of diets i.e. T1, T3, T4, T6and T7. The 6 % APM diet supplemented with NSPHE @ 2X (T7) concentration has also shown significantly higher feed intake (P<0.05) (Table 5).
The results are supported by Nadeem et al. (2005) who reported that by supplementing NSP degrading enzymes at higher concentrations (1X HC and 2X HC) to low energy diets resulted in higher feed intake during overall period compared to basal corn-soy control. Cowieson et al. (2010) observed higher feed intake in low energy deficient corn-soy diet (P<0.01) supplemented with NSPHE alone or in combinations in broilers compared to standard diet. Mirakzehi et al. (2010) reported that diet based on soybean meal which was replaced by enzyme treated RSM (0.03%) had similar overall feed intake to control diet. Ramesh and Chandrasekaran (2011) reported increased feed intake in low nutrient density diets supplemented with exogenous enzymes in Babcock male broiler chicks. Nikam and Reddy (2015) concluded that supplementing NSP hydrolyzing enzymes to Corn soybean meal based diets @ 1X higher concentration has influenced the feed intake of the broilers.
Contrary to the present findings several other workers Narasimha Rao (1998) reported no significant effect of enzyme supplementation. Edwin et al. (2004), Hanna et al. (2008) and Cowieson and Ravindran (2008a) also reported no effect of exogenous enzyme supplementation on feed intake in broilers.
Table 5: Effect of supplementation of non starch polysaccharide hydrolyzing enzymes diets containing APM (GM,RSM,CSM) each at 3 and 6 % level on phase wise feed intake (g) of broilers (0-42 days)
|T2||3% (APM) Control||501.4ab||1,308.6bc||2,147.4a||3,957.4b|
|T3||3% APM + 1X HC||514.0a||1,324.8bc||1,884.6c||3,723.4c|
|T4||3% APM + 2X HC||508.9a||1,304.0bc||1,843.0c||3,655.9c|
|T5||6 % APM control||511.3a||1,425.4a||2,221.8a||4,158.5a|
|T6||6 % APM +1X HC||494.1ab||1,323.2bc||1,884.4c||3,701.7c|
|T7||6 % APM + 2X HC||464.8c||1,270.0c||1,993.3b||3,728.1c|
Values bearing different superscripts within a column differ significantly (P<0.05)
The FCR during the pre starter period was significantly (P<0.05) in birds fed with standard control diet (T1) (Table 6).The phase wise FCR was comparable among the diets T3, T4 and T6and was found to be significantly better (P<0.05) compared with T2, T7 and T5 .The prestarter phase had shown poor FCR in the diets with 3 and 6 % APM control. However it was statistically comparable with T7.The starter phase FCR was significantly better (P<0.05) in the treatment T3compared with other treatments. However it was statistically comparable with T1, T2, T4 and T5except T3 the FCR was statistically comparable among all the treatments. The diets T6 and T7 had significantly poor FCR during starter phase. The finisher phase FCR was significantly better (P<0.05) in the 3 % APM diet supplemented with NSPHE @ 2X concentration (T4) compared with rest of the treatments. The diets T1, T2, T3 and T7 has also shown significant improvement (P<0.05) in FCR compared with T5 and T6. The diet T5 had witnessed poor FCR during finisher phase supplementation of NSP hydrolyzing enzymes at 1X and 2X concentrations has influenced the FCR (P<0.05) during overall period (0-42) days (Table 6). Supplementation of NSP enzymes at 1X and 2X levels influenced the FCR (P < 0.05) during overall period (0-42) days. The findings of this experiment were supported by Saleh et al. (2005) who reported the feed conversion ratio was significantly improved in enzyme fed diets. Meng and Slominski (2005), Wang et al. (2005) also reported similar findings with feed conversion ratio (FCR) of chickens in energy deficient diet. Song et al., 2010 and Mohammad et al., 2010 reported better FCR with enzyme supplementation. Narasimha et al. (2013a) concluded that FCR improved with addition of NSP enzymes alone or in combination with prebiotics. Rama Rao et al. (2014) reported that inclusion of GM 200g/kg diet with incremental level of enzyme supplements resulted (P<0.05) lower FCR. Santhi et al. (2014) conducted an experiment to find out the effect of supplementation of exogenous cellulase through feed in turkeys up to eight weeks. The findings of the study indicated significantly improved feed efficiency in the enzyme supplemented groups. Nikam et al. (2016) concluded that supplementing NSP hydrolyzing enzymes to Corn soybean meal based diets has influenced the FCR of the broilers reared on sub-optimal diets.
These findings are not in accordance with Naqui and Nadeem (2004), Olukosi et.al. (2007), Garipoglu et al. (2006), Gao et al. (2007) and Berwal et al. (2008)
Table 6: Effect of supplementation of non starch polysaccharide hydrolyzing enzymes diets containing APM (GM,RSM,CSM) each at 3 and 6 % level on phase wise feed efficiency of broilers (0-42 days)
|T2||3% (APM) Control||1.60c||1.74ab||1.94ab||1.87b|
|T3||3% APM + 1X HC||1.47ab||1.67a||1.89ab||1.74a|
|T4||3% APM + 2X HC||1.48ab||1.69ab||1.86a||1.74a|
|T5||6 % APM control||1.60c||1.82ab||2.22c||1.98c|
|T6||6 % APM + 1X HC||1.45ab||1.85b||2.04b||1.87b|
|T7||6 % APM + 2X HC||1.54bc||1.85b||1.95ab||1.83b|
Values bearing different superscripts within a column differ significantly (P<0.05)
The NSP hydrolyzing enzyme combinations consisting of xylanase, ß-D-glucanase, cellulase, mannanase and pectinase @ 1X i.e. 3200, 4000, 1520, 8000, and 3200 IU/kg respectively and @ 2X concentration i.e. 6400, 8000, 3040, 16000 and 6400 IU/kg respectively has resulted in improved performance of the broilers with respect to body weight gain, feed intake and feed conversion ratio when alternate protein meals viz. guar meal (GM),rapeseed meal (RSM) and cotton seed meal (CSM) were incorporated each at 3 and 6 % levels in the broiler diets.