Tanino associado a ácidos orgânicos em dietas para frangos de corte desafiados por E. maxima

Abstract

The objective of this study was to evaluate whether condensed tannin from black wattle (Acacia mearnsii), isolated or combined with organic acids (propionic, butyric, tributyrin, and formic), affects the performance, health, and intestinal microbiome, carcass characteristics, meat quality, and litter quality of broilers challenged with Eimeria maxima. A total of 1,064 male Ross broiler chicks were used, distributed in a completely randomized design with seven treatments, eight replicates, and 19 birds per experimental unit. The treatments consisted of negative control (NC, without performance-enhancing feed additives), positive control (PC, with the combination of performance enhancers avilamycin, nicarbazin, and maduramycin), diet containing black wattle tannin (CNT), and diets containing tannin associated with propionic (CNTProp), butyric acid (CNTBut), tributyrin (CNTTrib), and formic acid (CNTForm). The diets were formulated to cover the pre-starter, starter, grower, and finishing phases. At 14 days of age, all birds were given 0.5 mL of a concentrated suspension with 50,000 sporulated oocysts of E. maxima via oral gavage. The CNTProp and CNTBut treatments increased the birds’ weight gain in the growth and finishing phases, with lower average feed consumption for the CNTProp group. In contrast, the CNTTrib treatment increased average feed consumption and weight gain in all phases, similar to the positive control treatment. At 21 days of age, CNTProp reduced the incidence of footpad lesions, while at 42 days, CNTForm had a higher proportion of birds without lesions. The inclusion of additives in the diet increased triglyceride levels and showed a greater tendency for creatine phosphokinase activity at 28 days of age, while aspartate aminotransferase activity was higher for CNTBut, CNTTrib, and CNTForm. In general, the inclusion of isolated tannin and tannin associated with organic acids reduced jejunal morphometry and reduced the alpha diversity of the cecal microbiome. Acetic and butyric acid concentrations increased with the inclusion of CNTBut, CNTTrib, and CNTForm. Bacteria of the genus Catenibacillus (species C. scindens) were identified only in the cecum of birds that received CNTTrib. Bone parameters were influenced by the additives, indicating an improvement in bone quality in the birds. In general, carcass and cut yield with the inclusion of additives was similar to the positive control, and lipid oxidation of meat was reduced 24h postmortem when CNTTrib and CNTForm were supplied, while CNT was effective in reducing oxidation 24 hours and 30 days postmortem. No differences were observed between treatments for body temperature, enzyme activity (trypsin and chymotrypsin), egg count per gram of feces, digesta pH, meat quality characteristics, and litter quality variables. In conclusion, the CNTProp, CNTBut, and CNTTrib treatments were the most efficient in safely and effectively replacing performance enhancers, showing favorable results for zootechnical performance, production efficiency index, and viability, with CNTBut, CNTTrib, and CNTForm also improving the footpad lesion index.