Effect of probiotics, organic acids or their mix on the growth performance of starting cockerels

Two hundred and eighty eight 3 weeks old cockerels (127.9±6.5 g) were randomly assigned to 7 treatments for a 42 days feeding trial. A basal diet (whithout additives) was formulated (maize, soybean meal, groundnut cake and wheat bran). Probiotic (Lactobacillus acidophilus, Saccha-romyces cerevisae and S. boulardii) was added to the basal diet at the expense of wheat bran at 0, 0.05 and 0.1% in diets I, II and III. Organic acids (formic and propionic) replaced the wheat bran at 0, 0.2 and 0.4% in diets I, IV and V. A mix of probiotics+acidifier replaced the wheat bran at 0.0+0.0, 0.05+0.2, and 0.1+0.4% in diets I, VI and VII. Increasing feed additive did not affect to final body weight, body weight gain, protein efficiency ratio and feed/gain ratio of starting chicken. Aditives at lower or upper levels of inclusion exert no influence on most performance criteria except on feed intake which was higher in birds fed a mix of probiotics and organic acids on diets VI and VII. Final body weight was highest on diet VI (711) and lowest on diet I (661), while feed/gain ratio was highest on diet VII (4.1) and lowest on diet III (3.8).