The aim of present study was to analyze the frequency of M-phase and DNA content of primordial germ cells (PGCs) just after translocation to the germinal ridge (embryos at Stages 17-20) using interactive laser cytometry. The frequency of M-phase significantly increased from 8.0 to 21.6% with advancing embryonic stage. The data of the nuclear DNA content of PGCs were presented graphically, and two peaks (first and second) were recognized in all stages. The fluorescence value of the first peak was approximately one -half that of the second one. The PGCs of the M-phase had fluorescence values similar to or greater than the second peak in all stages. These results suggest that PGCs, just after translocation to the germinal ridge, undergo a periodic change in their nuclear DNA, and that intense proliferation occurs as the embryonic stage advances.

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Fowl spermatozoa maintained vigorous movement at 30°C with or without Ca²⁺. In contrast, the motility was reversibly inhibited at 40°C without Ca²⁺, but could be immediately restored by the addition of Ca2⁺. However, the addition of verapamil, a specific Ca²⁺ channel blocker, before the addition of Ca²⁺, could not obtain fully motile spermatozoa at 40°C . Under these conditions, the intracellular free Ca²⁺ concentration was lower than that of the control (no addition of verapamil), as measured by a fluorescent Ca²⁺ indicator, fura-2. The preparations of spermatozoa without Ca²⁺ were in-cubated at 30°C, and then transferred and incubated at 40°C . After that, they were re-incubated at 30°C again. During the second incubation at 30°C, high motility was obtained, even in the presence of verapamil. The addition of Sr²⁺, which appears to stimulate the release of Ca²⁺ from the mitochondria, was also effective for the stimulation of motility at 40°C, and induced a concomitant increase in the intracellular free Ca2⁺ concentrations. These results suggest that intracellular free Ca²⁺ play a pivotal role in regulating fowl sperm motility. Furthermore, it appears that fowl sperm mitochondria have a significant role in controlling intracellular free Ca²⁺ concentrations. This mech-anism, rather than Ca²⁺ fluxes through the plasma membrane, may be involved in the temperature-dependent immobilization and restoration of fowl sperm motility.

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Localization of neuropeptides (galanin, PACAP 27 and 38) was investigated in the chicken Harderian gland by immunohistochemistry. Immunoreactivity for three peptides examined in this study was detected on nerve elements in the pterygopalatine ganglion and the gland. Pterygopalatine ganglion contained nerve cell bodies showing immunoreactivity for galanin, PACAP 27 and 38. Dot-form immunoreactivity for PACAPs was also detected around immunonegative nerve cell bodies. Galanin immunoreactivity was observed on larger nerve cell bodies and those were most commonly observed in the ganglion. Nerve fibers showing immunoreactivity for the neuropeptides were distributed in the interstitial tissue of the Harderian gland. Fine immunoreactive nerve fibers were found running beneath the capsule and between acini. No im-munoreactive nerve fibers were found contacting with epithelial cells of the collecting duct. The present data suggested that nerves containing galanin and PACAPs have a relation to the regulation of the immune function of the chicken Harderian gland.

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The plasma concentration of glucose, free fatty acid, triacylglycerol, cholesterol, albumin, protein, insulin-like growth factor-I (IGF-I) was measured in chicks (7-d-old) given diets with varying dietary protein levels (0, 10, 20, 40 and 60% protein) ad libitum for 10 days. Plasma glucose concentration decreased with rising dietary protein levels from 10 to 40%. When dietary protein levels increased from 0 to 60%, plasma cholesterol concentration decreased significantly. Plasma IGF-I concentration increased significantly with elevating dietary protein levels up to 20%, and above the level, it decreased gradually. The response of body weight change in chicks to the alteration in nutritional condition such as dietary protein levels over 10 days would be partially regulated by the change in plasma IGF-I concentration.

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The effects of hot water extract of tea (WET) on serum components, egg produc-tion, egg qualities and egg contents of laying hens were examined. Mash feeds (18.3% CP and 2, 850 kcal/kg ME) containing 0 to 0.67% of WET, having 30% catechins, were given ad libitum to laying hens for 6 weeks from 53 weeks of age.
1. The serum concentration of total lipids tended to decrease, and that of TBARS decreased significantly with increasing dietary WET.
2. Egg production, egg weight and feed intake decreased significantly with increasing dietary WET.3. Haugh unit was improved about 5∼8% by the addition of 0.17% and 0.67% WET.There were no differences in egg shell thickness nor strength of egg shell among the experimental groups.
4. The contents of crude fat and TBARS in egg yolk decreased about 10 and 16%, respectively, by addition of 0.17% WET to the diet. TBARS content in crude fat of egg yolk tended to decrease with increasing dietary WET. The fatty acid composition was not affected by the dietary WET levels.
5. The greenish yellow color of egg white disappeared in the groups fed the diet containing 0.17% or more WET.

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To investigate the effects of form and nutrition of diets for refeeding on the recovery of villi in fasted chicks, 42-day-old male White Leghorn chicks were fed rice bran (CP: 16.8%, ME: 3, 170 kcal/kg) or grower mash (CP: 18%, ME: 2, 850 kcal/kg) diets for 3, 6 or 24 hours after fasting for 10 days. After the end of each experimental period, duodenal villus height, cell area of the epithelial cells, cell mitosis in the crypt and lamina propria were compared using light microscope. Besides, surface of the villus apex was observed using scanning electron microscope.
By refeeding for 3 and 6 hours, the decreased villus height, cell area and cell mitosis in fasted chicks showed a faster recovery in rice bran group than that in grower mash group. Broad lamina propria with diffused histological components such as smooth muscle fiber, blood capillary and various kinds of cells in fasted chicks became narrow by refeeding in both groups. Rice bran group showed a narrower lamina propria than grower mash group but the latter had more activated histological components. Smooth surface of the villus apex in fasted chicks changed to a much activated rough surface by many protuberated cells in rice bran group.
By refeeding for 24 hours, the villus height, cell area and cell mitosis in grower mash group more developed than rice bran group. Lamina propria showed a broad propria with undeveloped histological components, especially, undeveloped smooth muscle fibers, in rice bran group. In grower mash group, narrow lamina propria was rich in histological components such as developed smooth muscle fibers and at the villus apex cell extrusion was frequently observed. Villus apex showed the more developed protuberances of epithelial cells in grower mash group.
These morphological alterations indicate that for the first recovery stage of villi after fasting the quickly absorbable form such as powdered diet is important rather than the nutrition of it, and that for further complete recovery stage of villi the nutritious and well-balanced diet is important.

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For eggshell fortification, oyster shell is added to layer diet. In this study, to elucidate the effects of oyster shell supplement in commercial diets on feed intake, laying performance cracked egg frequency and profit, this supplement was added throughout and during peak and late periods of egg production using Single Comb White Leghorn hens at 20 to 88 weeks of age.
Feed intake and egg mass were not influenced, but the incidence of cracked and shell-less eggs during peek production was slightly lessened by oyster shell supplementation. After 61 weeks of age, the incidence of cracked and shell-less eggs was noted to have increased with the supplementation. Profits were not significantly influenced, though there was slight decreased.
The supplement may thus be concluded to have no effect, particularly so after 61 weeks of age in the economical point of view.

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