||Comparison of Breaking Strength and Shell Thickness as Evaluators of Eggshell Quality.
Bennett, J. K. ;
Ringer, R. K. ;
Bennett, R. S. ;
Williams, B. A. ;
Humphrey, P. E. ;
||Corvallis Environmental Research Lab., OR. ;Northrop Services, Inc., Corvallis, OR. ;Michigan State Univ., East Lansing. ;Oregon State Univ., Corvallis. Dept. of Forest Products.
Sulfur organic compounds ;
Breaking strength ;
Bobwhite quail ;
Biological effects ;
||Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy.
||The shell quality of eggs produced by northern bobwhite (Colinus Virginianus) dosed with sulfanilamide was evaluated by a compression breaking strength test and by the shell thickness measurements that are used in the U.S. Environmental Protection Agency avian reproduction test to determine the effect of a chemical substance on eggshells. The relative sensitivities of the two methods in detecting shell quality changes in sulfanilamide-treated quail were compared by relative response ratios, calculated as treatment period response divided by pretreatment values. The ratios demonstrated a clear shell weakening response and a less apparent shell thinning response. Significant differences in shell thickness of eggs from sulfanilamide-treated hens and those from control hens were not demonstrated (alpha = 0.32 and 0.34), although highly significant differences in shell strength were demonstrated (alpha <0.0001). Scanning electron micrographs of weak shells of normal thickness revealed abnormal ultrastructure, usually poorly formed mammillae. Obtaining both shell thickness and shell strength information may provide better means to evaluate a chemical's effect on shell quality.
||Pub. in Environmental Toxicology and Chemistry, v7 p351-357 1988. Prepared in cooperation with Northrop Services, Inc., Corvallis, OR., Michigan State Univ., East Lansing, and Oregon State Univ., Corvallis. Dept. of Forest Products.
|NTIS Title Notes
||Reprint: Comparison of Breaking Strength and Shell Thickness as Evaluators of Eggshell Quality.
||57Y; 57Z; 98E
||PC A02/MF A01