Occurrence of Eimeria species parasites on small-scale commercial chicken farms in Africa and indication of economic profitability

Abstract

Small-scale commercial poultry production is emerging as an important form of livestock production in Africa, providing sources of income and animal protein to many poor households, yet the occurrence and impact of coccidiosis on this relatively new production system remains unknown. The primary objective of this study was to examine Eimeria parasite occurrence on small-scale commercial poultry farms in Ghana, Tanzania and Zambia. Additionally, farm economic viability was measured by calculating the farm gross margin and enterprise budget. Using these economic measures as global assessments of farm productivity, encompassing the diversity present in regional husbandry systems with a measure of fundamental local relevance, we investigated the detection of specific Eimeria species as indicators of farm profitability. Faecal samples and data on production parameters were collected from small-scale (less than 2,000 birds per batch) intensive broiler and layer farms in peri-urban Ghana, Tanzania and Zambia. All seven Eimeria species recognised to infect the chicken were detected in each country. Furthermore, two of the three genetic variants (operational taxonomic units) identified previously in Australia have been described outside of Australia for the first time. Detection of the most pathogenic Eimeria species associated with decreased farm profitability and may be considered as an indicator of likely farm performance. While a causal link remains to be demonstrated, the presence of highly pathogenic enteric parasites may pose a threat to profitable, sustainable small-scale poultry enterprises in Africa.

Figure 1. Phylogeny of Eimeria species internal transcribed spacer 2 (ITS-2) sequences.

Phylogeny produced using Maximum Likelihood (ML), Neighbour Joining (NJ) and Maximum Parsimony (MP) algorithms with Eimeria species ITS-2 sequences generated here and publically available (GenBank accession numbers as shown, sequences generated here are indicated with an asterisk ‘*’). Bootstrap values shown for ML/NJ/MP respectively, n = 1000 for each.

Figure 2. Number of Eimeria species identified per farm per sampled country.

Chart demonstrating the number of farms in Ghana, Tanzania and Zambia found to host one or more Eimeria species parasites. The number presented in brackets indicates the number of farms sampled.

Figure 3. Association of Eimeria detection with economic performance of African small-scale commercial poultry producers.

The economic productivity of small-scale commercial poultry farms in Ghana, Tanzania (Tanz) and Zambia (Zamb), calculated as gross margin per bird per year ($) for broiler and layer farms (B and L respectively) and categorized by the qualitative detection of individual Eimeria species parasites. OTU-Y is not included as no sequences of this genotype were detected.