Role of Thyroid Hormones, Maternal Antibodies, and Antibody Response in the Susceptibility to Colibacillosis of Broiler Genotypes Export

@article{citeulike:2529437, abstract = {The purpose of this study was to investigate whether differences in susceptibility to colibacillosis are associated with maternal antibodies, antibody response, and alterations in thyroid hormones [triiodothyronine (T3) and thyroxine (T4)] and to investigate the effect of genotype on the changes in T3 and T4 during challenge and antibody response. A challenge experiment was executed in 2 trials. Per trial, 24 chicks per genotype were challenged, and 20 chicks per genotype were controls. At 7 d of age, challenged chicks were intratracheally inoculated with 0.3 mL of Escherichia coli O78K80 and controls with 0.3 mL of PBS. All chicks were euthanized at 14 or 15 d. Thyroid hormone plasma concentrations and E. coli-specific antibody titers (AB) were measured at 7 d (T3 d7, T4 d7, and ABd7) and 14 or 15 d (change from 7 to 14 or 15 d was analyzed: {Delta}T3, {Delta}T4, and {Delta}AB). Susceptibility was defined based on mortality, lesions, growth retardation, and eating behavior. There was a significant effect of challenge on T3 d7; probably due to eating pattern in association with circadian rhythm. The challenge group was suggested to have functional hypothyroidism relative to the control group, indicating metabolic changes due to the challenge, and it was indicated that an antibody response was elicited. Differences in susceptibility were not significantly related to differences in T3 d7, T4 d7, {Delta}T3, or {Delta}T4 or to maternal antibodies (ABd7), but the antibody response tended to increase (decreasing {Delta}AB) with increasing susceptibility. There were indications of genetic variation in T4 d7, {Delta}T4, ABd7, and {Delta}AB, but there was no observed effect of genotype on {Delta}T3 and {Delta}T4 during challenge or on the antibody response. Further, there were indications that selection for growth traits has resulted in alterations in {Delta}T4 due to challenge, as indicated by a lower {Delta}T4 in the challenge group relative to the control group for more intensively selected genotypes as opposed to a higher {Delta}T4 for less intensively selected genotypes.}, author = {Ask, B. and Decuypere, E. and van der Waaij, E. H.}, citeulike-article-id = {2529437}, citeulike-linkout-0 = {http://ps.fass.org/cgi/content/abstract/85/12/2141}, citeulike-linkout-1 = {http://view.ncbi.nlm.nih.gov/pubmed/17135670}, citeulike-linkout-2 = {http://www.hubmed.org/display.cgi?uids=17135670}, day = {1}, journal = {Poult Sci}, keywords = {chicken, colibacillosis, thyroid}, month = {December}, number = {12}, pages = {2141--2148}, posted-at = {2008-03-13 19:53:44}, priority = {2}, title = {Role of Thyroid Hormones, Maternal Antibodies, and Antibody Response in the Susceptibility to Colibacillosis of Broiler Genotypes}, url = {http://ps.fass.org/cgi/content/abstract/85/12/2141}, volume = {85}, year = {2006} }

TY - JOUR ID - citeulike:2529437 L3 - citeulike-article-id:2529437 N2 - The purpose of this study was to investigate whether differences in susceptibility to colibacillosis are associated with maternal antibodies, antibody response, and alterations in thyroid hormones [triiodothyronine (T3) and thyroxine (T4)] and to investigate the effect of genotype on the changes in T3 and T4 during challenge and antibody response. A challenge experiment was executed in 2 trials. Per trial, 24 chicks per genotype were challenged, and 20 chicks per genotype were controls. At 7 d of age, challenged chicks were intratracheally inoculated with 0.3 mL of Escherichia coli O78K80 and controls with 0.3 mL of PBS. All chicks were euthanized at 14 or 15 d. Thyroid hormone plasma concentrations and E. coli-specific antibody titers (AB) were measured at 7 d (T3 d7, T4 d7, and ABd7) and 14 or 15 d (change from 7 to 14 or 15 d was analyzed: {Delta}T3, {Delta}T4, and {Delta}AB). Susceptibility was defined based on mortality, lesions, growth retardation, and eating behavior. There was a significant effect of challenge on T3 d7; probably due to eating pattern in association with circadian rhythm. The challenge group was suggested to have functional hypothyroidism relative to the control group, indicating metabolic changes due to the challenge, and it was indicated that an antibody response was elicited. Differences in susceptibility were not significantly related to differences in T3 d7, T4 d7, {Delta}T3, or {Delta}T4 or to maternal antibodies (ABd7), but the antibody response tended to increase (decreasing {Delta}AB) with increasing susceptibility. There were indications of genetic variation in T4 d7, {Delta}T4, ABd7, and {Delta}AB, but there was no observed effect of genotype on {Delta}T3 and {Delta}T4 during challenge or on the antibody response. Further, there were indications that selection for growth traits has resulted in alterations in {Delta}T4 due to challenge, as indicated by a lower {Delta}T4 in the challenge group relative to the control group for more intensively selected genotypes as opposed to a higher {Delta}T4 for less intensively selected genotypes. IS - 12 JF - Poult Sci EP - 2148 TI - Role of Thyroid Hormones, Maternal Antibodies, and Antibody Response in the Susceptibility to Colibacillosis of Broiler Genotypes VL - 85 SP - 2141 KW - chicken KW - colibacillosis KW - thyroid AU - Ask, B AU - Decuypere, E AU - van der Waaij, EH PY - 2006/12/01/ UR - http://ps.fass.org/cgi/content/abstract/85/12/2141 ER -