Response of broiler chickens to addition of bacitracin methylene disalicylate and roxarsone to diets containing halofuginone.

Studies were conducted at six locations over a 7-yr period to evaluate the response of broiler chickens to bacitracin methylene disalicylate (BMD) and roxarsone in the presence of diets containing 3 ppm halofuginone/kg feed. Treatments consisted of a 2 x 2 factorial arrangement with 0 or 55 mg BMD and 0 or 50 mg roxarsone/kg feed. These additives were fed beginning with day-old chicks and were removed 6 days before termination of the study, which varied in length from 48 to 56 days among locations. Body weights were significantly improved (P less than .05) by the addition of either BMD or roxarsone with a significant interaction (P less than .05) between BMD and roxarsone. Roxarsone improved body weights only in the presence of BMD. Feed utilization was significantly (P less than .05) improved by addition of either BMD or roxarsone, with no interaction between the two products.

The addition of fowlpox and pigeon pox vaccine to Marek's vaccine for broilers.

Laboratory and field studies indicated that a cell-culture fowlpox vaccine was effective and safe when administered subcutaneously to day-old broiler chicks in combination with cell-associated Marek's vaccine without compromising the latter. Pox vaccines of chick embryo origin evaluated similarly provided excellent protection, although they caused local musculature swelling when injected into muscle rather than under the skin. No muscle swelling followed improper vaccination with the cell-culture fowlpox vaccine.