EFFECT OF SOME VITAMINS INJECTION INTO HATCHING EGGS ON PRODUCTIVE AND PHYSIOLOGICAL PERFORMANCE OF BROILERS

Abstract

The present study was carried out at the Department of Poultry Production, Faculty of Agriculture Ain Shams University during the period from March to May, 2014. The main objective was to study the effect of in ovo administration of either folic acid or vitamin D3 as well as the time of injection on embryonic development, posthatch performance, some physiological and histological traits of broiler chicks . A total of 600 eggs with average weight of 60 g were obtained from a commercial broiler breeder flock (Hubbard) at 55 weeks of age. At day 7 of incubation period, eggs were randomly divided into six groups of 100 eggs; each includes four replicates of 25 eggs. All eggs were normally incubated at 37.8°C and 65% RH in an automatic incubator. The first and the second groups were used as controls, where the 1st group was used as a negative control and received no treatment (C) and second group were injected at day 7 of incubation with 0.1 ml of distilled water/egg as solvent (S) . Eggs of the 3rd and 4th groups were injected into air cell at the 7th day of incubation with 0.1 ml of ( 500 IU) vit.D3 or folic acid 10% .The fifth and sixth groups were injected at the 14th day of incubation with the same concentrations of vit.D14 and folic acid . At the 18th day of incubation, all eggs were transferred to the hatcher and kept till hatching at 37.2°C and 70% RH. The hatched chicks from all groups were weighed and then reared under similar management, environmental and nutritional conditions. Hatchability and embryonic mortality, posthatching productive performance, carcass and muscle traits, blood constituents and histological sections in the tibiae and small intestine were investigated. The results obtained can be summarized as follows: 1- in ovo injection of broiler eggs with vitamin D3 or folic acid specially at the 7th day of incubation has no deleterious effect on hatchability (%) ,early and late embryonic mortality compared with the other groups. 2- In ovo injection with vitamin D3 and folic acid specially at the 7th day (D7 & F7) of embryogenesis decreased residual yolk sac weight followed by those injected at day 14 of incubation (D14 &F14) compared with the control groups. 3- Live body weight (LBW) of day old chicks and at 21 and DOA was significantly improved by in ovo injection with folic acid or vitamin D3 at the 7th day of embryogenesis (D7 &F7) , followed by those injected at day 14 of incubation period ( F14 & D14 ) compared with the control groups . A similar trend was also observed for body weight gain ( BWG ) at the periods from 1 to 21 ,21 to 42 and for the whole period ( 1 to 42 DOA ). 4- There is a positive effect on productive performance of broiler chicks when in ovo injection was done at the 7th day of incubation compared with in ovo injection at the 14th day. 5- In ovo injection with folic acid or vitamin D3 during embryogenesis, either at day 7 or 14 of incubation period , had significantly increased feed consumption of broilers chicks during the whole experimental period 6- Feed conversion ratio treatments was significantly improved in chicks that hatched from in ovo injected eggs at day 7 of incubation period (F7 & D7) followed with those of F14 and D14 treatments compared with the control groups during the whole experimental period. 7- Both in ovo injection with folic acid (F7 &F14) or vitamin D3 (D7 &D14) had significantly increased carcass yield of broiler chicks at marketing age (42 DOA), where hot carcass weight ,liver ,heart , gizzard and edible parts weights were significantly increased ,but abdominal fat weight was decreased , compared with control groups . 8- Breast muscles ( Pectoralis major , P. minor ) weight ,width and depth were significantly increased in chicks from folic acid treatments