MORPHOLOGIC CHARACTERISTICS OF OVIDUCTS FROM HENS PRODUCING EGGS OF DIFFERENT HAUGH UNITS CAUSED BY GENETICS AND BY FEEDING VANADIUM AS DETERMINED WITH COMPUTER SOFTWARE-INTEGRATED DIGITIZING TECHNOLOGY

Magnum and isthmus morphologic characteristics (surface epithelium hei ght, fold height and diameter, and periodic acid-Schiff-positive area and surface epithelium cells) of stained 6-mu m tissue sections were m easured by light microscopy, with data acquisition using a digitizing tablet interfaced to a microscope and to a personal computer with morp hometric-dimensional software. Tissues were obtained from Leghorn laye rs in two separate experiments in which production of eggs with low an d high Haugh unit (HU) values was induced by either genetic selection or by feeding V. Eggs produced by these hens had HU differences betwee n the high and low groups of 11 to 14 units (both experiments, P = .00 01) and had a greater volume of thick albumen fraction in high-HU grou ps (both experiments, P = .0001). The computer software-integrated dig itizing system enabled rapid measurements of multiple characteristics. In the genetic lines, higher magnum fold height and magnum and isthmu s surface epithelium height were detected at moderate significance (al l at P < .05) in the tissues of the layers producing high-HU eggs than in tissues from the low-HU line. Other morphologic variables were not different between genetic lines. In response to feeding V, none of th e morphological characteristics were affected, although magnum fold he ight approached difference at P < .07. Based on the observations in th ese two experiments, magnum fold height may be a further important fac tor related to egg albumen condition, in addition to surface epitheliu m height. It appears, however, that layers producing eggs of considera bly different HU values, due in these experiments to genetics or V fee ding can have magnum or isthmus morphological characteristics that are indistinguishable, or only moderately different, as detected by integ rated digitizing technology.