Cochlosoma in turkey poults: Timing matters
The time of infection with C. anatis in turkey poults affects growth performanceThe flagellated protozoan parasite, Cochlosoma anatis, is a widespread turkey pathogen in the eastern United States. Infection commonly results in flock non-uniformity, runting, diarrhea, and depression with high morbidity and relatively low flock mortality. The cause of non-uniformity in affected flocks is suspected to be a construct of individual responses to infection.
Justin Lowery, a graduate student at North Carolina State University, and fellow researchers at North Carolina State University and the University of Georgia, undertook a study to understand the impact of infection time on growth performance and uniformity in turkey poults. The results of the research were presented at the 2023 International Poultry Scientific Forum.
In the study, 200 1-day-old poults were evenly placed in 20 isolation cages (10 birds/cage) with 5 cages assigned to each treatment: 0, 7 and 14 days of age infection with a non-infected control, Lowery said.
He explained that at the time of challenge, each bird was orally gavaged with ~500,000 C. anatis cells except the non-infected group, then grown to 28 days of age, he said. Individual bodyweights were recorded throughout the trial at days 0, 14, 21 and 28, with feed intake measured at day 28.
Also, at day 28, 2 birds per cage were orally gavaged with 4mg/kg FITC-d and their blood collected one hour later to assess intestinal permeability via FITC-d blood concentration. All data analysis used SAS 9.4 with a statistically significant p-value <0.05, he said.
Lowery noted that this study showed elevated mortality associated with earlier infection, evidenced by significantly higher mortality throughout the study in poults infected on in day 0 and day 7 compared to the non-infected group and the group infected on day 14 (P=0.0007).
Bodyweight gains between all groups revealed significantly lower values in poults infected at day 0 compared to those infected at days 7 and 14, with all infected poults having significantly lower gains than non-infected poults (P=0.0008), Lowery said. There was a trend toward a decrease in uniformity relating to earlier time of infection (P=0.0648), he added.
Overall, feed conversion ratio and gut permeability were not significantly altered between any of the treatment groups, Lowery said.
The researchers concluded that the time of infection with C. anatis in turkey poults appears to have severe impacts on growth performance. Furthermore, the time of infection may also be a contributing factor in non-uniformity in addition to individual effects of the disease as growth seems to be stunted soon after infection onset.