Effect of in-ovo probiotic administration on growth performance, immune response and antioxidative properities of broilers

Abstract

This study was carried out at Poultry Production Farm, Faculty of Agriculture and Veterinary Medicine, Qassim University, to investigate the effect of in-ovo probiotic administration and probiotic dietary supplementation on growth performance, immune response and antioxidative properities of broilers. A total of 1500 fertile eggs (Ross 308) were injected in-ovo with two levels of probiotic (500 and 1000 cfu) and control (without injection), in the air cell prior of hatching (i.e., 3 days before hatching). Of which 1200 (400 of each group) hatched unsexed day old broiler chicks were used in probiotic dietary supplementation experiment. Probiotic dietary supplementation treatments consisted of 2 groups of probiotic (control and 200 g probiotic/ ton of diet fed to the grown chicks), in a complete random factorial design of 6 treatments (3 groups of in-ovo probiotic injection x 2 groups of probiotic dietary supplementation). The numbers of chicks located in each pen (20 chick/ pen) were placed in each one square meter (1m2 ) of the pen using wire mesh partitioning. Main results of the present study could be summarized as follows: Growth related body weights (g), feed consumption (g), feed conversion ratio (FCR), and mortality rate (%): 1. No significant differences in growth performance throughout the whole experiment for groups fed probiotic supplemented diets. 2. Group injected in-ovo with 500 cfu probiotic owned with highly significant difference a heavier body weight at fourth week of age. 3. Both groups injected with 500 and 1000 cfu probiotic in-ovo owned significantly the heaviest body weights at the sixth week of age. 4. Heavier body weights at 6 week were exhibited by group in-ovo injected with 500 cfu of probiotic. 5. Insignificant differences in feed consumption and feed conversion ratios, whether in groups injected in-ovo, or dietary probiotic supplementation groups. 6. Mortality rates were decreased by probiotic in-ovo injection or probiotic dietary supplementation comparing with control group. Carcass dissection: 1. No significant differences were decreased in carcass, leg quarter, thigh, drumstick, liver, heart and breast muscle percentages (%) among experimental groups against control groups. 2. Half back showed highly significant superiority in group in-ovo injected with 1000 cfu probiotic. Insignificant differences for group supplemented with dietary 200 g probiotic/ ton comparing with control group. 3. Significant differences in favor of group supplemented with dietary 200 g of probiotic/ ton of diet for gizzard (%), while unremarkable differences were observed among groups injected with in-ovo probiotic (500 and 1000 cfu) and control group. 4. Spleen (%) was significantly higher in control group comparing with in-ovo injected groups. Insignificant variation for spleen (%) between control group and dietary supplemented group. Heamatological parameters: 1. No significant differences were observed in blood components (Heamoglobin, Red blood cells, Heamatocrit and Platelets) among various levels of probiotic in-ovo injection (500 and 1000 cfu) and dietary supplemented groups (200 g/ ton) compared to control groups. Blood plasma analysis: 1. No significant differences between dietary supplementation with 200 g probiotic/ton diet and control group in blood plasma parameters (T. protein, Albumin, calculated globulin, cholesterol, triglyceride and HDL). 2. Insignificant variations among in-ovo injected groups with probiotic (500 and 1000 cfu) comparing with control group for plasma albumin and HDL levels. 3. Highly significant differences between control and 1000 cfu in-ovo probiotic injected groups for plasma albumin, and significant differences for globulin level. 4. A significant superiority in cholesterol and triglyceride levels in group injected with 500 cfu probiotic in-ovo, while group injected with 1000 cfu probiotic in-ovo owned the lowest level of cholesterol. Immune response: 1. Insignificant differences were noted between control group and probiotic dietary supplementation with 200 g probiotic/ ton, in all immune response figures including (response to injection with PHA-P, Immunoglobulin profile, and specific response against NDV). 2. No significant differences were observed in response to injection with PHA-P (toe web swelling) after 24 and 48 hours of injection for groups in-ovo injected with probiotic. 3. Insignificant variations among tested groups for IgA and IgY were observed. 4. Groups injected in-ovo with 500 or 1000 cfu of probiotic recorded highly significant distinction in comparison with control group regarding IgM figure. 5. Highly significant supremacy was recorded for group injected in-ovo with 500 cfu probiotic in terms of response to Newcastle disease virus (NDV). Antioxidative status 1. No significant differences for total antioxidant capacity and lipid peroxide were noted among treated groups, comparing with control groups. Bacterial count 1. Highly significant differences at 3 days of age in gut total bacterial count, TBC; counts of Bacillus, Bac. and Salmonella, Sal. for both groups injected in-ovo, or dietary supplementation with probiotic. 2. Control group (T1) had lower TBC, Bac. and E. coli comparing with in-ovo supplementation group with 500 cfu probiotic (T2) and 1000 cfu (T3) at 3 days of age, while Sal. count was meaningfully lower for T3 at the same age. 3. A noteworthy variances were observed regarding gut microbial count (TBC, Bac., E. coli., and Sal.) at 2 weeks old among treated groups, in addition that T1, T2 and T3 groups have lower Bac., E. coli, and Sal. counts, Consecutively. 4. Insignificant variations among in-ovo probiotic injected groups in TBC. Control group didn’t supplemented with probiotic in feed (T4) recorded significantly lower TBC and Bac. at the same age (14 days). On the contrary, group in dietary supplementation with 200 g probiotic/ ton feed (T5) showed considerably lower E. coli, and Sal. counts compared to control (T4) group. 5. At 5 weeks of age (35 days), gut bacterial count revealed highly significant differences among tested groups of probiotic. T1 and T4 had lower figures of TBC (slight significance) and Bac. While, from the other hand, T3 and T5 groups had significantly lower E. coli and Sal. counts. 6. Regarding microbial count in meat at slaughter time (6 weeks); T2 group had significantly lower TBC and Sal. counts, associated with T3 as for the later count (Sal.). While T3 alone recorded highly notable differences lower E. coli counts. T5 had significantly lower meat TB, E. coli, and Sal. counts. 6 From these results it could conclude that using probiotic, whether as in-ovo injection or as dietary supplementation, for broiler chicks could generally improve growth rate, profitable carcass cuts, lymphoid organs, blood plasma constituents, immunity response and gut microbial count, as a consequence of its valuable impact on the survival of useful microorganisms and reserving the balance of normal micro-flora populations located in the bird gut. In addition, probiotics have pharmaceutical effect against bacteria and viruses invasion, besides being safe and natural cultivated as feed component itself, reducing feed cost dramatically and maintain the efficiency of feed and meat shelf-life for a long time without a degradation resulted from chemical components reactions of feed additives in feed and meat.