|Cheng, Heng wei|
Submitted to: Poultry Science Association Meeting Abstract
Publication Type: Abstract only
Publication Acceptance Date: 6/30/2005
Publication Date: 8/20/2005
Citation: Cheng, H., Gustafson, L., Pajor, E.A., Mench, J.A. 2005. Comparative histology of duck bills following different bill trimming practices. Poultry Science Association Meeting Abstract. 84(1):82. Interpretive Summary:
Technical Abstract: Various histological staining methods have been developed to examine trauma-induced pathological changes. Each method is chosen in a tissue-dependent manner. The aims of this study were to investigate trimming-induced bill morphological changes and to test suitable staining methods for detecting traumatic neuromas. One hundred ninety-two, one-day-old Pekin ducklings were randomly assigned into 12 floor pens (3.66 X 0.91 m). The pens were divided into three groups, i.e., control, hot blade trimmed with cautery (HT), and tip-seared (TS). Six bills were randomly collected from each group when the ducks were 3 and 6 wk of age, respectively. Following fixation and decalcification, the bills were embedded in paraffin wax, and sectioned longitudinally. Alternate sections were stained with haematoxylin and eosin and Masson’s trichrome for connective tissues, and for the nerve fibers, Bielschowsky’s silver impregnation, Bodlan’s and Holm’s staining were used. Compared to the controls, although both bill trims caused connective tissue proliferation in the bill stumps, HT caused more dense tissue scars than those induced by TS. There were nerve fibers in the bill stumps trimmed by TS but not in the bills trimmed by HT (P < .01). No neuromas were found in the bill stumps following either practice. These characteristics of neuronal reactions were more clearly seen following Holm’s staining than others. These results indicate 1) trauma-induced pathological changes are dependent on the type of lesion; 2) in Pekin ducks, TS caused less morphological changes than HT, which suggests that TS may be more humane than HT; and 3) different histological methods should be used to examine different tissues, such as connective tissue vs. neuronal tissue. A further study is needed to examine the correlations between these morphological changes and pain sensations (acute and chronic) following the different bill trimming practices.