Performance and Carcass Characteristics of Broiler Chickens Fed Diets Supplemented with Graded Levels of Roxazyme G

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1 Interntionl Journl of Poultry Science 6 (5): 5-9, 2007 ISSN Asin Network for Scientific Informtion, 2007 Performnce nd Crcss Chrcteristics of Broiler Chickens Fed Diets Supplemented with Grded Levels of Roxzyme G 1 2 A.B. Omojol nd A.O.K. Adesehinw Met Science Lortory, Deprtment of Animl Science, University of Idn, Idn, Nigeri 2 Institute of Agriculturl Reserch nd Trining, Ofemi Awolowo University, P.M.B. 5029, Moor Plnttion, Idn, Nigeri 1 Astrct: The use of exogenous enzymes s feed dditives is still undergoing lot of reserch. A totl of three hundred nd sixty unsexed three week-old Aor Acre plus strin roiler chicken were rndomly llocted to four experimentl dietry tretments in completely rndomized design to evlute the effect of Roxzyme on performnce nd crcss chrcteristics of roiler chickens. The diets 1, 2,, nd 4 contined 0, 0.1, 0.2 nd 0.% enzyme supplementtion respectively. The irds were fed the experimentl diets for 5-dy period during which dt were otined on feed intke, weight gin, dry mtter digestiility (DMD) nd feed conversion rtio. At the end of the feeding tril, ten irds were scrificed per replicte to evlute crcss nd met chrcteristics. The inclusion of the exogenous enzyme did not significntly (P>0.05) improve the verge weight gin, feed intke, feed conversion rtio nd DMD. The dressing percentge of irds fed the enzyme-supplemented diets ws significntly (P<0.05) superior compred to the control. There were no significnt differences etween ll the priml cuts except the hed nd neck of the irds on the control diet tht were significntly (P<0.05) lower in weight. The inclusion of the enzyme did not (P>0.05) ffect the reltive weights of the kidney, gizzrd, hert nd the liver of ll experimentl irds. The flvour, tenderness nd juiciness scores of the met of irds fed the enzyme supplemented diets were significntly (P<0.05) higher thn the control while the colour, texture nd the overll cceptility were not significntly ffected y the inclusion of the enzyme in the diet. The Wner Brztler sher force result showed no significnt increse (P>0.05) in toughness in greement with the sensory pnel result tht djudged the met from irds fed enzyme supplemented diets s more tender (P<0.05) thn tht of the control. The rest muscle of the chickens hd higher cooking loss thn the thigh muscle while the highest (P<0.05) cooking loss ws recorded for oth muscle prts of irds rered on 0.2% enzyme supplementtion. Key words: Roxzyme, roiler chickens, growth performnce, crcss chrcteristics Introduction Feed remins the most importnt cost of niml production. The need for feed ingredients, which will reduce the cost of production, is the sis for most new ingredients tht re eing rought into limelight in livestock feed nd production reserch. This is ecuse mn nd his livestock re in competition for sic ingredients nd such ingredients re not usully produced in sufficient quntities loclly (Oluyemi et l., 1978). Therefore, vilility of feed thus ecomes the key fctor limiting poultry production. With the glol increse in the demnd for niml products s result of improved living stndrds, mny frmers tends to over stimulte their nimls with vrious sustnces such s hormones nd exogenous enzymes in order for such nimls to rech mrket weight with minimum cost within the shortest possile time. Improved efficiency of feedstuff utiliztion nd the use of wide rnge of feed ingredient currently considered inferior re likely to produce the lrgest dvnces in niml feeding. Most work with exogenous enzymes were done to evlute its effect on feed intke nd growth chrcteristics of roilers (Brener et l., 199) Supplementtion of diets of monogstric nimls (pig nd poultry) with exogenous enzymes hs een incresingly investigted nd pplied during the pst decde s mens of enhncing nd incresing the effectiveness of nutrient utiliztion (Acmovic, 2001). With the wide use of enzymes it ecme impertive to evlute the effect of such dditive on the finl product, s this is relevnt to the helth nd well eing of the consumer. Addition of enzymes hs een shown to improve weight gin nd feed conversion efficiency in roiler chicks ut its effect on met qulity ttriutes hs to e evlute hence the purpose of this reserch work. Mterils nd Methods A totl of three hundred nd sixty (60) unsexed three week-old Aor Acre plus strin of roiler chicken were rndomly llotted to four dietry tretments in completely rndomized design. The four dietry tretments were 0, 0.1, 0.2 nd 0.% enzyme supplementtion respectively. Ech dietry tretment 5

2 Tle 1: Gross composition of experimentl diets Dietry level of Rozxyme G Ingredients (Kg) Mize Groundnut cke Fish mel Whet offls Plm kernel cke Di-Clcium phosphte Minerl Vitmin premix Roxzyme G? Methionine Lysine Common slt (NCl) Plm oil ws replicted thrice. The growth nd performnce study lsted 5 dys. At the end of the growth nd performnce study, dry mtter digestiility ws determined in 7-dy tril using eighteen irds of similr weight per tretment (six per replicte). Tens irds were rndomly selected from ech replicte t the end of the feeding tril nd were scrificed to evlute the crcss nd met chrcteristics. The irds were strved of feed for 16 hours weighed nd slughtered. The slughtered irds were properly led, defethered nd eviscerted. The eviscerted irds were dissected nd ll internl orgns nd externl offls (hed, shnk nd neck) were crefully removed. The hot crcsses were weighed to otin the dressed weight nd lter chilled efore priml cuts were mde nd the weight tken (Omojol et l., 2004) Percentge cooking loss: Smples of known weight were tken from the rest nd thigh muscles of ech crcss nd cooked in moist-het to n internl o temperture of 72 C. The wter relesed fter cooking nd cooling ws mnully seprted nd the weight of the cooked met tken to otin the cooking loss. Cooking loss = [weight of smple efore cooking weight fter cooking] / [Weight efore cooking] x 100 Sher force determintion: The ojective evlution of tenderness ws performed using the modified Wrner Brztler sher force procedure (Bouton nd Hrris, 1978). Met smples from the rest nd thigh muscles o were cooked to n internl temperture of 72 C. The cooked smples were llowed to cool to room temperture. Three cores of 0.5cm dimeter were removed from ech cooked met smple. Ech core ws shered t three loctions prllel to the orienttion of the muscle fire. Wter holding cpcity: This ws determined in triplicte y the press method (Tsi nd Ockermn 1981). Approximtely 5.0g of smple ws weighed into 9cm whtmn No 1 filter pper nd pressed etween two 10.2 x 10.2 cm plexi glsses t pproximtely 5.2kg/cm for 1 minute,. The re of free wter ws mesured using compenstory plnimeter (Plnix 5000, Tmy Technics, Inc., Tokyo, Jpn) nd percentge free wter ws clculted sed on smple weight nd moisture content (Tsi nd Ockermn, 1981) while percentge ound wter or wter holding cpcity (WHC) ws clculted s 100% minus free wter %. Tste pnel evlutions: A totl of twenty trined individuls were used. The pnelists were mle (n=9) nd femle (n=11) nd rnged in ge from 27 to 5 yers. The pnelists were rndomly llocted to the four tretments. The pnelists were mde to rte ech of the three replicte of met smples. Equl ite size from ech tretment were coded nd served in n odourless plstic plte. Ech smple ws evluted independent of the other. The pnelists rted the smples on ninepoint hedonic scle for colour, flvour, tenderness, texture, juiciness nd overll cceptility. Sttisticl nlysis: All dt otined were sujected to nlysis of vrince procedures (SAS, 1999) nd where sttisticl significnce ws oserved, the mens were compred using the Duncn s Multiple Rnge (DMR) test. The SAS computer softwre pckge ws used for ll sttisticl nlysis (SAS, 1999) Results nd Discussion The result of the performnce study is shown in Tle 2. The inclusion of RoxzymeG did not significntly (P>0.05) improve the verge weight gin, feed intke, feed conversion rtio nd dry mtter digestiility (DMD). The highest feed intke ws recorded in the tretment with 0.2% RoxzymeG inclusion. Beyond the 0.2% enzyme level there ws slight depression in feed intke. A similr trend ws oserved in the verge weight gin (g/dy) nd DMD lthough, in this instnce the plteu ws reched in the 0.1% enzyme supplemented diet. The result otined in this study contrdicted tht of Iyyi nd Yhy (1999) where they used polyscchridse enzyme. The lck of significnt improvement in performnce otined in this study might e due to the fct tht the feed used ws rich in nutrient composition nd will therefore support mximum performnce without supplementtion with exogenous enzyme. In most cses, the exogenous enzymes re known to improve feed intke nd utiliztion of high fire diets nd diets rich in non-strch polyscchride (Fkorede, 1997) which, prt from eing resistnt to the digestive enzymes, lso reduce the digestiility of other dietry components like proteins nd hence reduce the performnce of the niml. The dressing percentges otined in this present study were 72.8, 75.70, nd for 0, 0.1, 0.2 nd 6

3 Tle 2: Performnce of roiler finisher fed grded levels of Roxzyme G Dietry level of Rozxyme G Prmeters Averge feed intke (g/dy) 101.1± ± ± ±7. Averge weight gin (g/dy) 18.79± ± ± ±2.15 Dry mtter digestiility (%) 67.61± ± ± ±4.11 Feed Conversion rtio 2.67± ± ± ±0.14 Dressing (%) 72.8± ± ± ±4.54,=Mens long the sme row with similr superscripts re not significntly (P>0.05) different from ech other. Tle : Reltive weight of crcss prt nd orgns of irds fed grded levels of Rozxyme G Dietry level of Rozxyme G Prmeters Dressing percentge 72.8± ± ± ±4.54 Cut up prts (%) Hed 2.41± ± ± ±0.10 Neck 4.65± ± ± ±0.11 Brest 19.26± ± ± ±1.65 Bck 1.52± ± ± ±.12 Wing 8.02± ± ± ±2.17 Thigh 11.01± ± ± ±1.86 Drum stick 10.2± ± ± ±1.80 Internl orgns % Kidney 0.17± ± ± ±0.15 Gizzrd 2.56± ± ± ±0.10 Her 0.47± ± ± ±0.02 Liver 2.54± ± ± ±0.07,=Mens in the sme row with similr superscript re not significntly (P>0.05) different from ech other. 0. percent enzyme supplemented rtions respectively. rnged from 5.71 to 6.75 s ssessed on nine-point The dressing percentges were higher thn the rnge of hedonic scle. Although, the colour rting improved s otined y Omojol et l. (2004). The high the level of enzyme inclusion incresed, however, this dressing percentge prt from the effect of enzyme ws not significnt (P>0.05). supplementtion might e due to the high nutritive profile of the experimentl diet. The dressing percentge Flvour: Rw met hs little odour nd only lood like of the irds fed the enzyme-supplemented diets ws tste. Cooking is necessry to develop the flvour. significntly superior (P<0.05) compred to the control. Mstiction reks down the fire mtrix nd relese It ws noticed tht s the enzyme level incresed eyond flvour-juices nd the voltile rom components into the 0.2% inclusion there ws slight drop in the the mouth. The result of this work showed tht the met dressing percentge. hrvested from diets with exogenous enzyme gve etter The result of the reltive weight of crcss prt nd flvour index (P<0.05) nd s the level of the exogenous orgns of the irds re shown in Tle. The weight of enzyme incresed, the flvour perception incresed. the rest, ck, wing, thigh nd the drumstick were not There ws no significnt difference (P>0.05) etween ffected significntly (P>0.05) y the exogenous enzyme the mens of ll tretments with the exogenous enzyme inclusion in the diet. Aprt from the hed nd the neck while the control diet gve the lest (P<0.05) vlue. The tht were significntly ffected (P<0.05) y enzyme flvour perception is function of the cooking loss nd inclusion, the weight of the other orgns were not the wter holding cpcity (Tle 5). The lower the ffected y the tretment. The result otined in this cooking loss the more juicy the met tends to e. As study followed similr trend tht ws reported y Iyyi shown in tle 5, the cooking loss in oth the rest nd nd Yhy (1999). thigh met reduced s the enzyme level incresed nd this ers n inverse reltionship with the wter holding Tste pnel evlution: The result of tste pnel cpcity, this might proly e the reson for the trend evlution is shown in Tle 4. oserved in the flvour rtings. Juiciness of met is directly relted to the intrmusculr Colour: Colour is n importnt indictor of qulity of lipids nd moisture content of the met (Cross et l., fresh or cooked met, s such the ppernce of met 1986). In comintion with wter, the melted lipids influences the consumer cceptnce of the met (Vn constitute rooth which when retined in the met is Oeckel et l., 1999). The tste pnel scores for colour relesed upon chewing. Tle 4 showed the men 7

4 Tle 4: Sensory evlution of roiler met fed grded levels of Rozxyme G Dietry level of Rozxyme G Prmeters Colour 5.67± ± ± ± 0.2 Flvour 5.71± ± ± ± 0.20 Tenderness 5.75± ± ± ± 0.20 Texture 6.00± ± ± ± 0.9 Juiciness 5.21± ± ± ± 0.9 Overll cceptility 6.± ± ± ± 0.22,= Mens in the sme row with similr superscripts re not significntly (P>0.05) different from ech other. Tle 5: Physicl properties of rest nd thigh muscles of roiler chicken fed rtions supplemented with Rozxyme G Dietry level of Rozxyme G Prmeters Cooking loss % Brest 6.40± ± ± ± 2.99 Thigh 4.9± ± ± ± 2.80 Sher force (Kg/cm ) Brest 1.2± ± ± ± 0.0 Thigh 1.27± ± ± ± 0.09 Wter holding cpcity % Brest 6.64± ± ± ±.11 Thigh 62.71± ± ± ± 2.25,= Mens in the sme row with similr superscripts re not significntly (P<0.05)different. rting for juiciness. The lest score of 5.21 ws otined in the tretment with no enzyme supplementtion while vlues of 6.42, 6.04 nd 6.29 were otined for the 0.1, 0.2, nd 0.% enzyme supplementtion respectively. Similr resons dduced for the result otined for flvour might e lso responsile for the juiciness score otined. Tenderness score followed similr trend s otined for juiciness nd flvour. The lest score for tenderness ws otined from the irds on the control diet. Tenderness is regrded s the most importnt sensory ttriute ffecting met cceptility (Cross et l., 1986; Quli, 1990; Wrkup et l., 1995). As stted y Quli (1990) nd Smulders et l. (1991), met tenderiztion is multifctoril process dependent on numer of iologicl nd environmentl fctors. The utiliztion of the exogenous enzyme incresed the degree of tenderness (P<0.05) s ssessed y the tste pnelists. The result otined under the sensory evlution ers resemlnce with the ojective result otined through Wrner Brtzler sher force (WBSF) except tht the result of the WBSF ws not significntly different (P>0.05) from ech other. Despite the nonsignificnce, the vlues decresed s the enzyme level incresed, indicting tht less force ws required to sher through the met s the enzyme level incresed. Texture nd the overll cceptility were not ffected y the exogenous enzyme supplementtion. The texture rting however improved with n dditionl 0.1 percent enzyme inclusion in the rtion while the vlues otined for the control in the overll cceptility rting ws the lest The result of the cooking loss, sher force, wter holding cpcity nd the therml shortening re reported in Tle 5. The cooking loss from the thigh muscle were slightly lower thn the vlues otined for the rest muscle in ll the dietry tretments. There ws however, no sttisticl difference etween vlues otined for the rest nd thigh muscle from irds on the control tretment nd tretment with 0.1% enzyme supplementtion. Vlues of 6.40,4.12, nd 1.45% were otined for the rest muscle in tretments with 0, 0.1, 0.2 nd 0.% enzyme supplementtion respectively while the vlues of 4.9, 2.0, 24.8 nd 27.0% were otined from the thigh muscle of similr tretments. The sher force vlue is n indiction of the degree of toughness or tenderness. The higher the vlue otined the tougher the met. Vlues of 1.2, 1.22, 1.14 nd 1.12 kg/cm were otined for the rest muscles of irds from the control, 0.1, 0.2 nd 0.% enzyme supplemented rtions respectively. Like in the cse of cooking loss slightly lower vlues were otined for the thigh muscles from similr dietry tretments. The WHC incresed in oth muscles with dietry enzyme supplementtion. In the rest muscle the WHC decresed slightly s the level of enzyme in the diet incresed ut in the thigh muscle, pek ws reched t the level of 0.2% enzyme inclusion. Conclusion: The effect of the enzyme Roxzyme G used in this study ws not pronounced on the performnce chrcteristics since the rtion formulted ws dequte to support the performnce of the irds without 8

5 the ddition of such enzyme. However, trits of economic importnce s the dressing percentge incresed with enzyme supplementtion. The crcss cuts up were not significntly ffected y supplementtion of the rtion with exogenous enzyme. The physicl properties such s the cooking loss, sher force vlue nd WHC were ffected y the dietry tretment. It ws lso oserved tht the flvour, juiciness nd tenderness were mong the eting qulities tht were significntly improved y the exogenous enzyme inclusion in the diet. The texture, colour nd overll cceptility were however not significntly (P>0.05) ffected y the inclusion of the enzyme in the diet. References Acmovic, T., Commercil Appliction of Enzyme Technology for Poultry Production. World s Poult. Sci. J., 57: Bouton, P.E. nd P.V. Hrris, Fctors Affecting Tensile nd Wrner-Brtzler Sher Vlues of Rw nd Cooked Met. J. Texture Studies, 9: Brener, A.W., W.K. Guenter, R.R. Mrqurdt nd B.A. Rotter, 199. Effect of B-glucnse/pentosnse Enzyme Supplementtion on the Performnce of Chicken nd lying hens fed Whet, Brley, Nked ots nd Rye diets. Cn. J. Anim. Sci., 7: Cross, H.R., P.R. Qulnd nd S.C. Seldemn, Muscles s Food Ed. P. P. J. Bechtel Acdemic Press F. L.P., Fkorede, T., Effect of Rozxyme Enzyme on the Performnce of Lyers Mintined on 40% Whet nd 45% Corn offls Diets. B.Sc. Disserttion University of Idn. Iyyi, E.A. nd B.A. Yhy, Performnce of Broilers Mintined on Diets Supplemented with Commercil Polyscchridse Enzyme in the Tropics. Trop. Anim. Prod. Invest., Oluyemi, J.A., A.S. Arf nd H. Hems, Influence of snd nd grit on performnce of turkey poult fed on diets contining different concentrtions of protein. Br. Poult. Sci., 19: Omojol, A.B., A.O.K. Adesehinw, H. Mdu nd S. Atth, Effect of Sex nd Slughter Weight on Broiler Chicken Crcss. J. Food Agri. Environ., 2: Quli, A., Post-mortem Chnges in Muscles Tissue. J. Muscles Foods, 1: SAS, SAS/ STAT User s Guide (relese 6.0) Sttisticl Institute Crry, North Cnoline. Smulders, F.J.M., R. Vnlock nd G. Ellelenoom, In: The Europen Met Industry in the 1999 s Ed. F.J.M. Smulders. Audet Nijmogen, pp: Tsi, T.C. nd H.W. Ockermn, Wter Holding Mesurement of Met. J. Food Sci., 46: Vn Oeckel, M.J., N. Wrrmnt nd L.V. Bookque, Mesurement nd prediction of pork colour. Met Sci., 52: Wrkup, C.C., S. Mrie nd G. Hrrington, Expression of Tissue Proteinses nd Regultion of Protein Degrdtion s Relted to Met Qulity Ed. A. Quli, D., Demeyer nd F. J. M. Smulders. Eccemst. Ultrechit. The Netherlnds, pp: