Chronic heat stress and Salmonella enteritidis challenge in Japanese quail: immune effects in adult and transgenerational consequences

GIAYETTO, O.; VIDELA, E. A.; LABAQUE, M. C.; MARIN R. H.; NAZAR, F N

Congreso; 2018 PSA Latin American Poultry Scientific Conference; 2018

Stressful events during productionsuch as routine vaccination protocols and high environmental temperatures are commonchallenges for poultry species. Chicks? prenatal environment can be influencedby these events, inducing trans-generational effects. This study evaluated whetheran immune challenge and a chronic heat stress (CHS) exposure on adult Japanesequail can modulate later immune responses and whether those effects can be reflectedin their offspring. Eighty adults were inoculated with inactivated Salmonella enteritidis (challengeinitiated at 115 days of age) and then exposed to a CHS along 9 days (between 121 to 129 days ofage) by increasing the environmental temperatures from 25 to 34 °C duringthe daylight hours. A 2x 2 factorial experimental design was used and 4 treatments groups (20 birdseach) were therefore defined: Non Challenged-Non Stressed, Challenged-NonStressed, Non Challenged-Stressed and Challenged-Stressed. Between 125 and 130 daysof age, eggs were collected and incubated. Newly hatched chicks (n=82) wereidentified according to their parental treatments. Percentage of inflammation, Heterophil/Lymphocyte (H/L) ratio andantibody titers against sheep red blood cells (SRBC) were evaluated both inadults and their offspring. In adults, compared to controls, stressed groupsshowed a reduced percentage of inflammation (P<0.001) and an elevated H/L (p=0.02),regardless of the challenge. No differences between groups were found in SRBCtiters. In offspring, the percentage of inflammation was elevated (p=0.03) andthe SRBC titers were reduced (P=0.02) in chicks whose parents were stressed, independentlyof the challenge. The H/L ratio of the chicks did not differ between groups. Theimmune challenge had no impact on the selected variables either on the adultquails or in their offspring, suggesting that all groups (stressed or not) werecapable of dealing with the vaccine challenge. On the other hand, the CHS affectedthe immune response both in the adults and in their offspring which could haveimportant welfare and productive implications.