Differential immune response to Eimeria maxima infection in fast‐ and slow‐growing broiler genotypes

Abstract

Very little has been reported comparing resistance to coccidiosis in fast or slow growing broilers, the latter of which are becoming more prevalent in the broiler industry. We examined mRNA expression in the intestines of fast and slow growing broilers following Eimeria infection. We show that by day 13 post‐infection (d pi) with 2500 or 7000 oocysts of Eimeria maxima, slower‐growing (Ranger Classic) broilers significantly (P < 0.01) upregulated expression of proinflammatory cyclooxygenase genes (LTB4DH, PTSG1 and PTSG2) above that detected in fast growing (Ross 308) broilers. Expression of CD8α mRNA was downregulated in Ross 308 at day 6d pi with either 2500 or 7000 oocysts of E maxima (P < 0.05), compared to uninfected controls, but was not differentially expressed in Ranger Classic. CD4 genes were not differentially expressed in either chicken line infected with either infectious oocyst dose at d6 pi, compared to uninfected controls. However, at d13 pi, CD4 expression was significantly upregulated in both chicken lines infected with either infectious oocyst dose, compared to uninfected controls (P < 0.05) but this was significantly greater in Ranger Classic broilers compared to Ross 308 (P < 0.05). At d13 pi, expression of CD3 chains (required for T lymphocyte activation) was significantly increased in Ranger Classic compared to Ross 308, infected with either oocyst dose (P < 0.05‐0.01). Expression of IL‐2 and IL‐15 mRNA, required for T lymphocyte proliferation was also significantly upregulated, or maintained longer, in Ranger Classic broilers compared to Ross 308. These differences in immune response to E maxima corresponded with a reduction in E maxima genome detected in the intestines of Ranger Classic compared to Ross 308.

Ileal and cecal microbiota response to Salmonella Typhimurium challenge in conventional and slow-growing broilers

“…Moreover, the concern for improved animal welfare has allowed slow-growing commercial broiler Frontiers in Physiology frontiersin.org breeds to become recognized by well-informed consumers (Lusk, 2018). Previous research has compared characteristics between slow-growing and conventional broilers related to differences in behavior (Bokkers and Koene, 2003;Çavuşoğlu and Petek, 2019), gene profile (Cui et al, 2012;Hu et al, 2013), carcass traits (Mikulski et al, 2011;Singh et al, 2021), or immune response (Williams et al, 2013;Giles et al, 2019), while a limited number of studies have compared slow-growing and conventional breeds in their intestinal microbiota and the interaction of the microbiota with a separate factor such as the addition of a feed additive or pathogen challenge. Therefore, the purpose of this study was to investigate the ileal and cecal microbiota response to Salmonella challenge in both conventional and slow-growing broilers.…”

Use of black soldier fly and house fly in feed to promote sustainable poultry production

“…Slow-growing broilers experience better welfare (Vissers et al, 2019), due to lower daily weight gain and altered morphological conformation, improved walking abilities (Corr et al, 2003;Wallenbeck et al, 2016), and higher active behaviour (Wallenbeck et al, 2016;Wilhelmsson et al, 2019). Moreover, slow-growing broilers exhibit lower mortality rates (Dixon, 2020) and similar (Sakkas et al, 2018) or improved immune responses (Giles et al, 2019).…”