RESPONSE OF GROWING PULLET CHICKENS TO DIETARY INCLUSION OF PHYTOGENICADDITIVES (ORANGEORLEMONPEEL)AND THE IMPLICATION OF PHYTASE SUPPLEMENTATION.

Abstract

ABSTRACT

Thetransitionoftheglobalpoultryindustryawayfromantibioticsasgrowthpromotershas intensified interest in the use of phytogenic feed additives as safe and sustainable alternatives. However, primary feed ingredients and some phytogenic additives contain anti-nutritive factors, particularly phytates observed to limit nutrient bioavailability and increaseenvironmental pollutionthroughexcretion,highlightingthenecessity ofincluding phytase,anenzymecapableofhydrolyzingphytates,toenhancenutrientutilizationoffeed. Thisstudyevaluatedtheresponseofgrowingpulletstodietaryinclusionofphytogenicfeed additives(orangeorlemonpeels)withorwithoutphytasesupplementation.Atotalof640 4-week-oldIsaBrowngrowingpulletswereassignedtoeightdietarytreatmentsina4 x2 factorialarrangement, eachwithfourreplicates containing 20birds.Treatments werebasal diet(PC-),basaldietwithoutbonemealandlimestone(NC-),NCwithlemonpeel(NCLP- )andNCwithorange peel(NCOP-)at1g/kgfeedallwithout phytase, beingtreatments 1 to4,and thesamerespective dietswithphytasesupplementationconstituting treatment 5 to8(PC+,NC+,NCLP+andNCOP+respectively).Datacollectedongrowthperformance, nutrient digestibility, blood profiles, calcium (Ca) and phosphorus (P) metabolism, and early egg characteristics of growing pullets were subjected to analysis of variance using IBMSPSS (21).Growth performance parameters did not vary significantly (P >0.05) at the main and interaction effects of both phytogenic feed additives and phytase supplementation.Thereweremarkedimprovementsincrudefibreandashdigestibility observedinchickensfedNCOP(67.85,71.130a)comparedwithNC(61.47,62.87%)atthe maineffectofphytogenic additives, whilephytase supplementationresulted in increased ash digestibility from 61.69 to69.75%. For the interaction effect, the highest crude fibre andashdigestibilityvaluesof68.29%and79.85%,respectively,wererecordedfor

chickens on NCOP+ diet, whereas for the same parameters, the least values of60.21% and 40.17%, respectively, were observed inchickens fed NC- diet. The main effect of phytase supplementationsignificantlyincreased (P <0.05) some blood parameters such asalbumin (35.68g/L),totalprotein(10.89g/dL),andglobulin(73.34 g/L).PulletsontheNCOP+diet recordedthehighestalbumin(39.73g/L)andtotalprotein(11.45 g/dL).Forthemaineffect, SuperoxideDismutaselevelswerehigher(157.05U/mLand141.00U/mL)inbirdson NCLPandNCOPdiets,respectively,whileMalondialdehydelevelswerelower(67.20 Mmol/Land67.46 Mmol/L)forthesamegroupofbirds.Phytasesupplementation significantlyimproved (P < 0.05) calcium bioavailability (2.62 mg/dL), while phosphorus levels remained constantat 0.10 mg/dLacross treatments.Shell thicknessincreasedfrom 0.96mmto1.41mmforthemain effectofphytasesupplementation,andalbuminwidth was highest (54.85 mm) inbirdsonNCOP dietscompared toNCLP diets(49.25mm).The study concluded that there was an improvementin nutrient digestibilityand blood profileofgrowingpulletbirdsfeddietswithphytogenicfeedadditiveandphytasewithoutnegative impact ongrowth andfirsteggquality.