الفهرس 
TABLE OF CONTENTS
HousingOnly 14 pages are availabe for public view
 |  | from | 118 |  |  |
| | | from | 118 | | |
Abstract
This experiment was carried out at Poultry Research Farm of Poultry Production Department, Faculty of Agriculture, Assiut University, Assiut, Egypt during the period from January, 2016 to April, 2016.
Theexperimentaimedtostudytheeffectofearlyfeedingofnewlyhatchedbroilerchicksimmediatelyafterhatchongrowthperformanceandcarcassquality.
Atotalnumberof300ArborAcreseggswereincubatedandthe hatchedchickswereclassified into threecategories:
d. Earlyhatched:thathatchedtill 479 hrs of incubation.
e. Midterm hatched: that hatched between 479 and 485 hrs ofincubation.
f. Latehatched:thathatchedafter485 hrsof incubation
Sixty chicks from each category were taken, wing banded and weighedindividuallyanddivided intotwo unequalgroups:
group 1: 15 chicks were left in the hatcher without feed (control)
group 2: 45 chicks were divided into 3 replicates (15 chicks each) and moved immediately to floor pens, where they got feed and water (ad libitum).
Therefore, therewere four groups(45chickseach):
Group1(control):hadaccessto water only for3 days,thenfedstarterdiet
Group2 (Early hatched):hadaccessto pre-starterdiet for 3 days,then fedstarterdietGroup3 (Midtermhatched):hadaccessto pre-starter diet for2 days,then fedstarter dietGroup4 (Latehatched):hadaccessto pre-starterdiet for oneday,then fedstarter diet
Thepre-starterdietconsisted of 15%eggpowder,1%oil,20%glucose,and64%water
Startingfromthe fourthdayof age,allchicks werefedcommercialstarterdiet for 2weeksfollowed withgrowerdiet for2 weeksthen finisherdiet for2 weeks
Theparametersstudied in this experimentwerebodyweight,body weightgain,feedconsumption,andfeedconversionratio.Carcasstraits were also studied at two ages: 4 weeks and 6 weeks.
Theobtainedresultscould be summarizedas follows:
A. The effect of early feeding on growth performance
1- Chicks of treatment 2 (early hatched, EH) had significantly the highest live body weight through the 6 weeks compared to the other treatments. Also, chicks of treatment 3 (midterm hatched, MH) had significantly higher live body weight through the 6 weeks than treatment 1 (control , C) and treatment 4 (late hatched group, LH). Moreover, chicks of treatment 4 (late hatched , LH) had significantly higher live body weight at 1,2,4,6 weeks of age than treatment 1(C); however, there was no significant difference between LH and ( C) treatments at 3,5 weeks of age.
2- The results reveal that chicks of treatments 2 (EH) and 3 (MH) had significantly higher BWG than that of treatments 1 (C) and 4 (LH).. However; chicks of treatment 4 (LH) had significantly higher BWG than treatment 1 (C) at 4,6 wks. of age. Also, chicks of treatment 2 (EH) had the highest BWG through the 6 weeks period as compared to the other treatments. Moreover, chicks of treatment 3 (MH) had significantly higher BWG than treatment 1 (C) and treatment 4(LH). Also, treatment 2 (EH) had significantly higher BWG than treatment 1 (C), treatment 3 (MH), and treatment 4 (LH) through (0- 2) , (3-4) , (5- 6), (0- 4), (0- 6) wks. of age.
The results also reveal that chicks of treatment 3 (MH) had significantly higher BWG than treatment 1(C) and treatment 4 (LH) through (0- 2) , (3-4) , (5- 6), (0- 4), (0- 6) wks. of age. Besides, chicks of treatment 4 (LH) had significantly higher BWG than treatment 1 (C) at all periods except at (5-6) wks. of age.
In general, the effect of early feeding on body weight gain was in favor of treatment 2 than 1,3 and 4, and in favor of treatment 3 than 1,4 and in favor of treatment 4 than treatment 1.
3- Thechicks of EHgroup hadsignificantlyhigherFC than MH,LHand Cgroups at 1,2,3,4,5 and 6 wks. ofage. Also,chicks ofMHgroup hadsignificantlyhigherFC thanLHand Cgroupsat1,2,3,4,5 and 6wks. of age. Moreover, chicks of LHgroup had significantlyhigher FC than C group at2,3,4 and 5 wks. of age.Theresults also show that chicks of EHgroup had significantlyhigherFCthanC, MH,LHgroups through (0- 2), (3-4), (5- 6), (0-4) and (0- 6)wks. of age.Also, chicks ofMH group had significantlyhigherFC than C,LHgroupsthrough(0-2),(3-4), (5- 6),(0- 4) and (0-6)wks. ofage.Besides,chicks of LHgrouphad significantlyhigherFC thanC groupthrough (0-2),(3-4) , (5-6),(0- 4) and (0- 6)wks. of age.
Ingeneral, the effectof earlyfeedingonfeedconsumptionwas in favor oftreatment 2 than treatments 1,3 and 4 , followedbytreatment3than treatments 1 and 4, and finallyof treatment 4 thantreatment 1.
4- TherewasasignificantdifferenceinFCRamonggroupsthrough0-6wks.ofage,whereasEHgroupwasthebestandCgroupwastheworst.However,therewasnosignificantdifferenceinFCRbetweenEHandMHthrough0-4wks.ofage, whereas FCR of EHandMH groups wasthebestandCgroupwasthe worst.
Ingeneral, theeffectofearlyfeedingonfeedconversionratiowasinfavoroftreatment2than1,3 and 4,andinfavoroftreatment3than1 and 4,andinfavoroftreatment 4 thantreatment1.
B. The effect of early feeding on carcass quality
1- Theresultsrevealthatat28daysofage,chicksofEHgrouphadsignificantlythehighestLBWandcarcass,gizzard, intestineweightandintestinelengthcomparedtotheothergroups.Also,chicksofEHgrouphadsignificantlyhigherliverweightthanCandLHgroup;however,nosignificantdifferencewas detected between LHand C groups.Moreover,chicksofMHgrouphadhigherLBWandcarcass,gizzardandintestineweightcomparedtoCandLHgroups,whilenosignificantdifferencewasdetectedinliverweightandintestinelengthbetweenCandLHgroups.
2- At42daysofage,theresultsshowthatchicksofEHgrouphadsignificantlythehighestLBW,carcass,heart,gizzard,liver,giblets,leg, femur,drumstick,breast,back,wing,totalfatweightandthepercentageofdressedcarcassandgizzard.Also,thechicksofMHgrouphadsignificantlyhigherLBWandcarcass,liver,giblets,leg,femur,drumstick, breast, back, wing weightand the percentageofdressedcarcassandfeatherthanCandLHgroups.
3- The gizzardand intestine weight(IW)in treatment 2 increasedby61.8 and 11.6 %; respectivelyat 4 wks. ofage,and by41.9 and 16.2%;respectivelyat 6 wks. of age.Theintestine length(IL)increasedonlyin treatment 2at 4 wks. ofage by11.6%. This increase inILwas not detectedat 6 wks. of agein anytreatment.
4- The ratiobetweenIWandILincreasedin treatments 2 and 3compared with thecontrol. This increase was more pronounced in treatment 2 (38.5and 19.7 % at 4 and 6wks. of age ; respectively).TheratiobetweenIWandILreflects the thickness of intestinein eachlength unit. This ratioindicatedthatfeedingofearlyhatchedchicks was more pronounced onIW than onIL,whichmayresultedfrommorethickness ofintestines of earlyfed chicks.
5- Basedontheobtainedresults,itmaybeconcludedthatearlyfeedingofhatchedchicksstartingfromthefirsthoursafterhatchhas a positiveandsignificanteffectonbody weightgain,feedefficiency,importantcarcassparts(breastandlegs),and on development ofgastrointestinaltract.