Calcium anacardate and citric acid in starter diets for pullets reared on the floor

The objective of this study was to evaluate the effects of combinations of calcium anacardate (CaA) and citric acid (CA) in the diet of layers between the 1st and 8th weeks of age, reared on the floor. A total of 960 1-day-age chicks were used in a completely randomized design with 8 treatments and 6 replicates with 20 birds per treatment. The treatments consisted of two control diets, negative (no additives) and positive (with anticoccidial additive-salinomycin), and 6 diets with the combinations: 0.25% CaA + 0.25% CA; 0.50% CaA + 0.25% CA; 0.50% CaA + 0.50% CA; 0.75% CaA + 0.25% CA; 0.75% CaA + 0.50% CA; and 0.75% CaA + 0.75% CA. Performance, intestinal morphometry, blood biochemical parameters and bone quality were assessed. Birds fed the diet containing salinomycin showed lower feed intake, average weight at 8 weeks and weight gain, with no influence of the treatments on feed conversion and uniformity. There was no influence of the treatments on the morphometry parameters in the duodenum, however, it was observed that in the jejunum and ileum, the birds fed diets containing the different combinations of CaA + CA had the lowest crypt width values. The addition of CaA + CA reduced the concentration of uric acid in the blood and the treatment with salinomycin affected bone quality. Therefore, the use of salinomycin is not recommended for layers in the growth phase, while the combination of 0.25% CaA + 0.25% CA can be used safely for these animals.