Effects of Eimeria maxima infection doses on growth performance and gut health in dual-infection model of necrotic enteritis in broiler chickens

Abstract

The objective of this study was to investigate the effects of the different doses of Eimeria maxima (EM) oocysts on growth performance and intestinal health in broiler chickens challenged with a dual infection model of necrotic enteritis (NE) using EM and NetB+Clostridium perfringens (CP). A total of 432 fourteen-d-old male Cobb 500 broiler chickens were divided into 6 groups with 6 replicates each. The six different groups were as follows: Control, non-challenged; T0+, challenged with CP at 1 × 109 colony forming unit; T5K+, T0+ + 5,000 EM oocysts; T10K+, T0+ + 10,000 EM oocysts; T20K+; T0+ + 20,000 EM oocysts; and T40K+; T0+ + 40,000 EM oocysts. The challenge groups were orally inoculated with EM strain 41A on d 14, followed by NetB+CP strain Del-1 on 4 days post inoculation (dpi). Increasing EM oocysts decreased d 21 body weight, body weight gain, feed intake (linear and quadratic, p < 0.001), and feed efficiency (linear, p < 0.001) from 0 to 7 dpi. Increasing EM oocysts increased jejunal NE lesion score and intestinal permeability on 5, 6, and 7 dpi (linear, p < 0.05). On 7 dpi, increasing the infection doses of EM oocysts increased jejunal CP colony counts (linear, p < 0.05) and increased fecal EM oocyst output (linear and quadratic, p < 0.001). Furthermore, increasing the infection doses of EM oocysts decreased the villus height to crypt depth ratios and the goblet cell counts (linear, p < 0.05) on 6 dpi. Increasing EM oocysts downregulated the expression of MUC2, B0AT, B0,+AT, PepT1, GLUT2, AvBD3 and 9, LEAP2, and TLR4, while upregulating CLDN1, CATHL3, IL-1β, IFN-γ, TNFSF15, TNF-α, IL-10, and Gam56 and 82 on 6 dpi (linear, p < 0.05). Additionally, increasing EM oocysts decreased Pielou’s evenness and Shannon’s entropy (linear, p < 0.01). In conclusion, increasing the infection doses of EM significantly aggravated the severity of NE and exerted negative impact on intestinal health from 5 to 7 dpi.

Effects of methionine supplementation in a reduced protein diet on growth performance, oxidative status, intestinal health, oocyst shedding, and methionine and folate metabolism in broilers under Eimeria challenge

“…After 6 DPI, the birds gradually recovered from the infection, and the FI increased accordingly. The same pattern has been reported by previous studies wherein broilers were also subjected to Eimeria challenge, and the daily change in FI was monitored [ 3 , 4 , 6 , 10 ].…”

“…However, concerns have been raised due to the development of drug resistance [ 7 ] and growing public apprehension regarding antibiotic use in animal production [ 8 ]. While vaccinating birds against coccidiosis has demonstrated effectiveness, achieving successful vaccination requires exposing birds to live or attenuated oocysts to develop immunity [ 9 ], which can still lead to intestinal lesions that might potentially predispose another intestinal disease necrotic enteritis [ 10 ]. With both approaches facing limitations, the exploration of alternative strategies to mitigate the impact of coccidiosis has become necessary.…”

Effects of Artemisia annua supplementation on the performance and gut health of laying hens challenged with mixed Eimeria species

“…On day 8, the feces on the belt were thoroughly mixed within each replicate, and feces samples were collected for oocyst shedding. The oocyst counts for E. acervulina , E. maxima , and E. tenella were counted following the procedure proposed by Goo et al (2023) . In brief, 5 g of the feces was mixed in 35 mL of tap water and left to soften for 48 h at room temperature.…”