Abstract
1. An experiment was designed to evaluate the effect of different doses of oocysts of Eimeria acervulina on intestinal absorption and skin deposition of xanthophylls (XAs) in broilers.
2. A total of 192 broiler chickens were randomly assigned to 4 groups: an uninfected control group and three groups inoculated with either 1 × 102, 1 × 104 or 1 × 105 sporulated oocysts of E. acervulina by gavaging at 21 d. There were 4 replicate pens (2 male and 2 female) per group.
3. Plasma xanthophyll (PX) and skin yellowness (SY) were measured in live birds weekly. At 42 d of age, SY was measured in the breast and abdomen after chilling and in the breast 24 h post-processing on refrigerated carcasses.
4. In general, in all challenged treatments, and for the duration of the study, the average PX decreased by 0.02 μg/ml (R2 = 61.6%) for every 1000 inoculated oocysts, whereas PX increased by 1.26 μg/ml/d in uninfected birds.
5. The average SY in live birds from 21 to 42 d of age decreased by 0.019 b*/every 1000 oocysts administered, while SY of uninfected controls increased by 0.57 b*/d. It was also noted that in all treatments females had a greater SY (6.17 b*) than males for the duration of the study. The SY of the breast and abdomen was correlated (r = 0.76) in chilled carcasses. Breast SY in 24 h refrigerated carcasses was greater in the control group and for female birds.
6. Oocyst excretion was different between inoculated treatments only on 7 d post-inoculation (PI). Coccidia lesion scores in the duodenum averaged 1+ in infected birds and 2+ in birds given the highest oocyst dose.
Acknowledgements
The authors gratefully acknowledge the excellent technical assistance of Cheryl A. Lester and Howard Lester. Particular thanks go to Dr. Manuel Quiroz-Pesina (Vepinsa S. A. de C.V.) for providing the natural yellow pigment. Funding was from Programa de Apoyo a la Superación del Personal Académico (PASPA), Dirección General del Personal Académico (DGAPA) de la Universidad Nacional Autónoma de México (UNAM).