Effects of Subclinical Mycotoxin Exposure and Coccidial Challenge on Growth Performance, Body Composition, Gut Health, and Egg Production During Pullet-to-Layer Transition Period

Authors: PANERU, DEEPENDRA - University Of Georgia; SHARMA, MILAN - University Of Georgia; SHI, HANYI - University Of Georgia; GOO, DOYUN - University Of Georgia; LEE, JIHWAN - University Of Georgia; Shanmugasundaram, Revathi; KIM, WOO KYUN - University Of Georgia

Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 4/28/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: n/a

Technical Abstract: A study was conducted to investigate the combined effects of subclinical mycotoxin exposure and coccidial challenge on pullets (Hy-Line W36, n = 288) during the pullet-to-layer transition (15-22 weeks of age). Using randomized complete block design, four treatments were organized in 2 × 2 factorial arrangement with six replicates of 12 birds per replicate. Birds received either non-contaminated or mycotoxin-contaminated diets (1.3 mg/kg deoxynivalenol, 56 µg/kg zearalenone, 0.06 mg/kg total fumonisins) starting from 15 weeks of age and were either unchallenged or challenged orally with mixed Eimeria species (125,000 E. acervulina, 25,000 E. maxima, and 25,000 E. tenella oocysts/mL) at 18 weeks of age (0 DPI: days post-Eimeria inoculation). Growth performance, gut permeability, body composition, intestinal lesions, and egg production were recorded following coccidial challenge. Statistical analysis employed two-way ANOVA to assess main and interaction effects. Coccidial challenge significantly reduced the body weight (BW) by 5.71% (P < 0.001) and feed intake (FI) by 34.96% (P < 0.001) from 0 to 6 DPI compared to unchallenged birds. BW and FI recovered gradually in challenged birds, with significant differences observed until 21 DPI (BW, P = 0.006; FI, P < 0.001) but no significant differences by 29 DPI (BW, P = 0.099; FI, P = 0.964). Ingestion of mycotoxins did not affect BW, but FI was numerically lower in challenged birds fed mycotoxin than ones fed the control diet. Gut permeability was significantly increased (P < 0.001) by coccidial challenge on 5 DPI, and this increase was further numerically exacerbated in the birds fed mycotoxin. Coccidial challenge reduced the bone mineral density (P = 0.011), body fat percentage (BFP, P < 0.001) and body tissue mass (P < 0.001) on 6 DPI compared to unchallenged birds. BFP tended to be higher in the birds fed mycotoxin (P = 0.083) than in birds fed control diet on 14 DPI. Antagonistic trends (P = 0.073) were observed in BFP with the interaction of mycotoxin and coccidiosis on 14 DPI. Intestinal lesions were more frequent and intense in the challenged birds fed mycotoxin than in those fed control diet. The presence of mycotoxin in the feed delayed the age of first lay by 6 days, whereas coccidial challenge delayed by 10 days. There was no significant interaction between mycotoxin and coccidiosis on the age at first lay. In conclusion, subclinical mycotoxin exposure delayed the first egg production and exacerbated the negative effects of coccidial challenge on gut health and body composition during the pullet-to-layer transition period. Keywords: mycotoxin, coccidiosis, pullet-to-layer transition, gut health, egg production