Aditivo simbiótico em substituição a bacitracina de zinco em dietas para aves poedeiras na fase de recria

• Autor(a) principal: RIBEIRO, Apolônio Gomes
• Data de Publicação: 2021
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UFRPE
• Texto Completo: http://www.tede2.ufrpe.br:8080/tede2/handle/tede2/8911
• topic: Nutrição animal; Aditivo simbiótico; Galinha poedeira; CIENCIAS AGRARIAS::ZOOTECNIA

The study evaluated the effects of supplementation of symbiotic based on Saccharomyces cerevisiae, Bifidobacterium bifidum, Bacillus subtilis, Enterococcus faecium, Lactobacillus acidophilus, glucans, and mannans in diets of laying hens in the rearing period, replacing zinc bacitracin. A total of 684 pullets (Dekalb White strain), from 6 to 10 (R1), 11 to 15 (R2), and total period (6 to 15) weeks of age were distributed in a completely randomized design with 5 treatments, 8 repetitions of 18 birds, except for the reference treatment, which had 6 repetitions. The treatments were composed of two base diets: the first one was based on corn and soybean meal (RD); the second one was based on corn and soybean meal plus meat and bone meal (MBM); and three other diets based on MBM, added 0.05% of Zinc Bacitracin (BacZn) supplied from R1, 0.1% of symbiotic (Simb-C) supplied from R1, and the last one Simb-C supplied from R2 (Simb-R). It was evaluated the performance, hematology, serum biochemistry, weight of immune system organs (thymus, spleen, and bursa of Fabricius), digestive system (liver, pancreas, and intestine), and length measurement (intestine and cecum). The data were analyzed by variance analysis and the means were compared by Orthogonal Contrast (P < 0.05). The contrasts were: C1 - RD vs MBM; C2 - MBM vs BacZn; C3 - BacZn vs Simb-C; C4: BacZn vs Simb-R. Birds fed RD had lower results (P = 0.008; 0.026; <0.001) for feed conversion throughout the analyzed period. Birds fed BacZn had highest mean for BW (P = 0.012) and WG (P = 0.017) compared to those fed Simb-R (6 to 10 weeks) and higher WG (P = 0.030) compared to MBM (6 to 15 weeks), not differing (P = 0.551) from those fed Simb-C. For organ weights and lengths, the effects (P = 0.012) were observed for Bursa in the C4, with the highest mean for Simb-R. Birds fed the MBM diet obtained higher values (P = 0.023; 0.033; 0.003) for thymus weight, liver, and cecum length compared to BacZn. The animals fed BacZn had lower cecum weight compared to the Simbiotics diest (P = 0.003; 0.023). These results reflect an improvement in the immune system response and serum levels: alkaline phosphatase, GGT, globulin, and TGP through the modulation of the microbiota when the birds were submitted to BacZn and Symbiotic diets. The use of the symbiotic additive for laying hens has achieved its purpose in replacing the antibiotic zinc bacitracin as an additive. When used from the starter phase, it is even possible to obtain better results for some serum biochemistry variables.