C. L. Quarles

Protection of Chicks Against E. coli Infection by Dietary Supplementation with Vitamin E

Summary Dietary supplementation of 150–300 mg vitamin E (dl-α-tocopheryl acetate)/kg gave increased protection against a relatively moderate (25–30% mortality) E. coli infection. A correlative 2-3-fold increase in log2 antibody titer against the E. coli indicates that increased chick survival was in part immunologic. We thank Hoffmann La Roche, Inc., for supplying the vitamin E and for the vitamin E assays of the diets.

Effect of Poultry Litter Treatment? (PLT?) on Death Due to Ascites in Broilers

The purposes of this study were to determine the effect of Poultry Litter Treatment (PLT) on levels of litter moisture, litter nitrogen, atmospheric ammonia, and death due to ascites. Data were collected from chicks raised in containment conditions that resembled commercial settings. The ascites death rate (5.9%) in broiler chicks on PLT-treated litter was significantly (chi 2 = 15.5, df = 1, P = 0.0001) lower than that (31.5%) in broiler chicks raised on untreated litter. Likewise, atmospheric ammonia levels in pens that had been treated with PLT were significantly (P < 0.05) lower than those in pens that received no treatment. Under the conditions of the present study, litter moisture and litter nitrogen levels were not different (P > 0.05) among treatments at any sample interval.

Anticoccidial efficacy of diclazuril in broilers under simulated natural conditions in floor pens.

Anticoccidial efficacy of diclazuril given for 42 to 49 days of age was evaluated in broiler chickens. Mortality from coccidiosis in unmedicated controls averaged 12.90% for six experiments. Treatment with diclazuril at 0.5, 1.0, and 1.5 ppm reduced coccidiosis mortality to 1.41%, 0.85%, or 0.63%, respectively, and reduced average total lesion scores by 78%, 81% or 82%, respectively. The final live weight and feed conversion at 49 days of age was significantly improved by treatment with diclazuril at all levels. Comparisons in some trials suggested that 1.0 ppm of diclazuril was equal or superior to the other anticoccidial drugs. There was no evidence that diclazuril harmed performance, even when given at 1.5 ppm.

Efficacy of maduramicin against ionophore-tolerant field isolates of coccidia in broilers

Maduramicin ammonium was given at 2.5-8 ppm in the feed to broilers experimentally infected with coccidia recently isolated from broiler farms where ionophores had been used for several years. Infection pressure varied from mild to severe in five trials: mortality in unmedicated controls ranged from 0 to 59%, intestinal lesion scores were high, and weight gain was depressed by the infections. The cultures of Eimeria were partly resistant to ionophores: birds medicated with monensin at 100-121 ppm had only modest reductions in lesion scores and incomplete protection against weight loss or mortality. Control of infections by maduramicin was significant at 4 ppm but best at 5-7 ppm. Maduramicin was more effective than monensin or narasin, but about the same as salinomycin, in reducing lesions and mortality and in protecting performance. Maduramicin was well tolerated within the dose range of 5-7 ppm.