COALMINERS — A novel system in studying chronic inflammation in chickens

     

Modern poultry broiler production strives for the maximum live weight, which can contribute to chronic intestinal inflammation and broader metabolic syndromes. There is thus a need to establish realistic models that help the industry. Several challenge models have been proposed by the scientific community and these include biological agents or pathogens, chemicals, reused litter, and, more recently, different non-starch polysaccharides. However, they all lack the realism of true live production. Here, we propose a novel approach termed COALMINERS (ChrOnic intestinAl infLamMatIoN modEl under real faRming conditionS), in which mini-wired pens (high level of replication) are placed inside a commercial facility so that the birds under study have the same cumulative environmental production exposure. A gradient of intestinal challenges can be created by varying degrees of exogenous nutritionally induced stressors. In one experiment, the mean bacterial enteritis (BE) score, as defined in the literature, was statistically higher in the COALMINERS group (when corn was replaced with wheat) versus the actual farm diet and a “clean” experimental setting (the latter 2 groups, standard corn-soy diets) at d 21 and d 28 (3.75, 2.13, and 2.25, and 3.25, 1.88, 1.00, respectively; n = 8; P < 0.01). More importantly, the BE scores were reduced proportionally (~13%) over time only in the COALMINERS and real-farm environments, whereas the complete recovery in the experimental setting may reflect the lack of “cumulative production pressure” under such controlled conditions. In another COALMINERS iteration, aiming to study related mechanisms, the drop from a “high” (d 21–28) to a “low intensity” (d 29–35) natural heat stress (mean temperatures: ~10°C and ~5°C higher than breeder standards, respectively) resulted in significant reduction in intestinal oxidative stress expressed as MDA (~25%; P < 0.01). However, 2 inflammatory (IFN-γ) and immune (sIgA) markers increased significantly (~36% and 40%, respectively, n = 8; P < 0.01). The COALMINERS approach offers a novel system for studying chronic inflammation in chickens and addresses the needs of modern poultry production.

Key Words: Novel, model, chronic, intestinal, inflammation.