2019 journal article
Blackhead Disease: Recovery of Layer Flock After Disease Challenge
JOURNAL OF APPLIED POULTRY RESEARCH, 28(3), 755–760.
author keywords: Histomonas meleagridis; blackhead disease; layer pullets; egg production
TL;DR:
While there was no long-term effect of blackhead infection on layer productivity under laboratory conditions, H. meleagridis persisted in the flock, providing a reservoir for infection.
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UN Sustainable Development Goal Categories
3. Good Health and Well-being
(Web of Science)
5. Gender Equality
(Web of Science)
Source: Web Of Science
Added: September 30, 2019
SUMMARY Blackhead disease, caused by the protozoan Histomonas meleagridis, is commonly found in layer pullets raised on the floor. We examined the effects of blackhead disease during the pullet-rearing period and on subsequent productivity during the first 8 wk of the laying cycle. Treatments were (1) uninfected controls and (2) H. meleagridis -infected pullets, with 4 replicate pens/treatment, 32 pullets/pen (Hy-LineW-36). Pullets in the challenge treatment were infected with H. meleagridis on day 18. Four birds/pen were necropsied on days 23 and 28 for lesion scores and day 176 for detection of H. meleagridis. Hens were moved to individual layer cages on day 120 and observed daily for feed consumption, date of first lay and egg production parameters. Pullets were positive for signs of blackhead disease in 83%–90% of infected birds necropsied on days 23 and 28, with average cecal lesion scores of 2.5 and 2.9. No liver lesions were observed. On day 176, 40% of infected birds were positive for H. meleagridis in the ceca. During the laying cycle, there were no significant differences (P ≤ 0.05) between treatments in terms of date of first lay, hen-day egg production, egg weight, feed conversion, egg mass/hen, or other reproduction measurements. These results showed that while there was no long-term effect of blackhead infection on layer productivity under laboratory conditions, H. meleagridis persisted in the flock, providing a reservoir for infection.