Effect of Early Feeding of Finishing Rations on the Subsequent Performance of Broilers A. L. PALAFOX

Transcription

1 Effect of Early Feeding of Finishing Rations on the Subsequent Performance of Broilers A. L. PALAFOX

2 'rechnical PROGRE:SS REPORT NO, 152 DECEMBER 1966 HAWAII AGRICLJL'rUHAL E:XF'ERIMENT ST'ATION COLLE:GE; OF THOPICAL AGRICULT'URE: UNIVE:HSITY OF' HAWAII Honolulu, Hawaii Effect of Early Feeding of Finishing Rations on the Subsequent Performance of Broilers A. L PALAFOX* Data on the effect of feeding low concentrations of protein in the diet of starting broiler chicks and on their subsequent growth to market age is limited. Hoberts and Carrick (1942) found that broiler chicks receiving a 20 percent diet up to 6 weeks of age and then a 16 percent protein diet from 6 to 12 weeks grew as rapidly as those receiving 20 percent protein during the entire period. Douglas and Harms (1960) lowered the protein content of the diet of broiler chicks from 23 percent to 21 percent at 5 weeks with no s urru n cant effect on growth. The present study deals with the effects of early feeding of finisher diets on the performance of New Hampshire cockerels and Brown Ledbrest x Arbor Acres sexed chicks. *Mr. A. I". Palafox is Assistant Poultry Scientist at the Hawu i i Agricultural Experiment Station and Assistant Professor of Poultry Science, College of Tropic a l Agriculture, University of Hawaii.

3 TABLE 1. Composition of diets used

4 T he birds which died durin g th e first 2 days of t he study were repl a ced. It was ass umed th at morta lity occ urring durin g th is time was nat ca us ed by trea tment. T he da ta were s ta tis tically analyz ed ac cordi ng to Duncan' s multiple ra nge tes t (1955) and Kra mer's mod ificati on of t he mult iple range test for group mea ns of unequa l re plicat ions (1956). Result s and Dis cus s ion T ab le 2 s ummarize s the da ta obtained with New Hamps hire cocker els. Six -wee k and 9-week body weights were significantly a ffected by tr eatment. Coc kere ls whi ch wer e fed the 16 pe rcent prote in di et s tarting at 1 day of ag e were s ignificantly lighter than thos e fed the same diet at 3 wee ks, at 6 weeks, and those fed the 20 perce nt protei n diet from 1 day of age t o the e nd of the experi ment. Six-week bod y we ights of th e birds in tr ea tme nt 2 we re s ignifi cantly ligh ter tha n those in trea tme nt 4. Howev er, at 9 weeks no s ignificant di fference betwee n the same treatmen ts were found. TAB LE 2. Summa ry of data obtained with New Hampshire cockerels, Experiment 1 1 T reatment 2, We igh t, 6 we eks ; g m b 774 bc 812 c We ig ht, 9 weeks; g m b 1334 b 1385 b Feed, 9 weeks; lb Feed / gai n; 9 we e ks I Mea ns on t he some hori zonta l line be ar ing 0 d ifferent pos tscript le tter a re s ign ifi c ant Iy d iher ent at the 5 percent le ve I of prob a b i iity. 2 T hre e re p lica t e groups, 10 bird s each. 3Trea t me nt 1-16% pro tein 1 doy t o 9 wee ks T reatme n t 2-20% protein 1 da y t o 3 we eks 16% protein 3 wee ks to 9 we e ks Treatm e nt 3-20% pro t e in 1 d a y 10 6 weeks 16% protein 6 weeks to 9 weeks T rea t me n t 4-20% pro tein 1 day to 9 weeks.

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6 3. in E"o"rin"u't cbtc av"rage fi gur e s

7 2 3..

8 or weeks. This was true even average were not different among treatrnents we uzht s at Feed in this to Differe nces among treatments E:viscerated Grades and purposes of s tatistical the ficant difference among means. Further UU(U~Y"')I'" and different. fed the for scores which were to those observed difference was due treatments and 4. The ost treatment. This difference between starter diet made the total which were fed broiler re ce rvma the showed

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10 TAB LE 5. of dcro obtained with brai Experiment 2 Treotment 4 2 Weight, 3 weeks; gm We 6 weeks ; gm Weight, 9 weeks lb Feed, 9 weeks; lb. a in v i s c ero t e d grade s c or e-' C1 Cost of feed per pound gain; cents Cost of feed/bird 9 weeks; cents Selling pr i 9 weeks; cents" Average return; cenrs? Morta Iit y Means on the same horizontal line bearing different postscript letter are signifi cantly different at the 5 percent level of probability. 2Eviscerated grade score: Grades A, S, and C were given scores of 3,2, and 1, respectively. 3 Morto Iity per 30 birds in each treatment. 4Treatment 1 - Treatment 2 - Treatment 3 - Treatment 4 - Finisher diet started at 3 weeks Finisher diet started at 4 weeks Finisher diet started at 5 weeks Finisher diet started at 6 weeks. "Calculations bosed on 32 cents per pound live weight charged to State Poultry Processors. 6Average return: Selling price per bird less cost of feed per bird.

11 Ha~7'\..,...h'l_~ cock- 9 weeks of cockerels fed a percent 3 weeks and then to a 16 7'\0..'... 01"'1" finisher diet not ""''Ii"... n'li"'1non I"I'lT different from those fed the diet for 6 or 9 weeks. feed feed for birds fed the broiler starter ration before were fed finisher ration. were 5, or 6 At 9 and 4.28 to 4.45 In of feed. Eviscerated carcass Nine-week-old broiler 7.46 to 7.77 I.1Vl.lUUiO. ments, I.1VILl..l.l\..li:J'I consumed among treat- The cost of feed to a broiler nnt'""vo.1"ol to cents, whereas the average for cents. of at 9 weeks for Brown Leuorest... '-'''..'''''.1...:7 avel~a.grea to cents, whereas the to cents. ""''''',..''' At 9 the average return over feed cost less cost for cockerels from to cents, whereas the range was from to cents for Broilers which were fed the l"'1n'1'.,,..t,01'' diet at weeks the return, fed 6 weeks. +,n'''''''... L1_ diets be fed as over-all of 11

12 LITERATURE CITED 1. Douglas, C. R., and R. H. Harms Effects of varying protein and energy levels of broiler diets during the finishing period. Poultry Sci. 39: Duncan, D. B Multiple range and multiple F tests. Biometrics 11: Kawano, and C. Oumi Report on analysis of commercial feeds. Hawaii Agr. Expt. Sta. Bull pp. 4. Kramer, C. Y Extension of multiple range tests to group means of unequal number of replications. Biometrics 12: National Research Council Nutrient requirements of poultry. National Academy of Sciences. Publication Roberts, R. E., and C. W. Carrick Influence of starting rations on subsequent growth. Poultry Sci. 21: 477. UNIVERSITY OF HAWAII COLLEGE OF TROPICAL AGRICULTURE HAWAII AGRICULTURAL EXPERIMENT STATION HONOLULU, HAWAII THOMAS H. HAMILTON President of the University C. PEAIRS WILSON Dean of the College and Director of the Experiment Station G. DONALD SHERMAN Associate Director of the Experiment Station