Effect of synthetic gizzerosine on growth, mortality, and gizzard erosion in broiler chicks.

Two experiments were conducted to determine the dose-dependent response of synthetic DL-gizzerosine (GIZZ) on the growth, mortality, and gizzard erosion (GE) of male broiler chicks. In a short-term experiment (7 days duration), 4-day-old chicks were fed diets supplemented with 20 levels of GIZZ (from 0 to 18 ppm) in three trials. In a long-term experiment (28 days duration), day-old chicks were fed diets supplemented with eight levels of GIZZ (from 0 to 1 ppm) in two trials. The GE scores, growth and mortality were measured. In the short-term experiment, GE scores of groups fed incremented levels of GIZZ increased rapidly up to 3 ppm of supplemental GIZZ. Weight gain was unaffected until the 1-ppm GIZZ supplementation level was reached, but scores were linearly depressed with increasing increments of dietary GIZZ thereafter. The first mortality occurred at 2 ppm dietary GIZZ, and the mortality rate increased with higher dietary GIZZ levels. In the long-term experiment, the GE scores also increased with increasing increments of supplemental GIZZ. Growth rates of birds fed supplemental GIZZ levels from 0 to .9 ppm were almost the same; growth rate declined at 1.0 ppm GIZZ. Mortality first appeared at .8 ppm supplemental GIZZ. It is suggested that the recommended concentration of GIZZ in practical diets should be less than .4 ppm (L-form).