共查询到20条相似文献，搜索用时 15 毫秒
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1. The proline disappearance from the jejunal and ileal lumen of chickens aged from 1 day to 15 weeks were studied using a perfusion method "in vivo”.
2. A decrease in proline transport was observed from younger to older animals. The 2 intestinal segments showed different behaviours, the 1‐day and 1‐week‐old animals showed the same value in the jejunum, whereas in the ileum a progressive decrease in proline transport was observed from the first week of life.
3. The differences observed in the 2 segments could be attributed to the different rates of growth of the jejunum and ileum with age; the jejunum showed a peak of growth in the second week of life whereas the ileum showed a peak of growth in the first week. Proline transport in the jejunum decreased until the fifth week and remained constant thereafter. 相似文献
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Twenty-four hearts of Brown Leghorn ranging in age from newly hatched to adult were investigated histologically to elucidate the topographical disposition of the entire cardiac conducting system. Through this study, the bird's heart was found to have the same specialized conducting system as that of mammals. Moreover, in addition to this system, the nodus truncobulbaris and the fasciculus truncobulbaris were reported in detail, and the anulus atrio-ventricularis dexter was confirmed. These peculiar nodes and bundles of the bird's heart are discussed in comparison with the mammalian cardiac conducting system. 相似文献
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大豆肽对蛋鸡肠道菌群的影响试验 总被引：4，自引：0，他引：4
本试验通过蛋鸡饲养试验,研究了大豆肽对蛋鸡肠道常驻菌群调节的影响。结果表明:添加大豆肽可以促进嗉囊、空肠、盲肠、直肠乳酸菌的增殖,与对照组相比乳酸菌数量增加10倍以上,差异极显著(P<0.01);添加大豆肽明显抑制大肠杆菌、好氧菌总数的增加,与对照组相比细菌数量下降10倍以上,差异显著。大豆肽可以作为良好的蛋鸡肠道菌群调节型饲料添加剂。 相似文献
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S E Solomon 《British poultry science》1975,16(3):255-258
The isthmus extends from the aglandular zone, which delimits it from the magnum, to the tubular shell gland, which to the naked eye is marked by a distinct colour change from off-white to brown. 2. The surface epithelium comprises three cell types, ciliated, non-ciliated and mitochondrial, of which only the non-ciliated cells contribute towards the carbohydrate moiety of the shell membranes. 3. The gland cells are distinctive, containing granules of variable electron density, variations also occurring within individual granules. 4. Although two types of gland cell have been observed, they may merely represent different phases of development. 5. In the type 1 cell, the rough endoplasmic reticulum and Golgi complex are typical of the normal protein secreting cell; in the type 2 cell the RER is sparse, dilated and filled with intracisternal granules while the Golgi complex is likewise distended. 相似文献
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1. A new integrating method of assessing the proportions of cortical and medullary tissue in the avian adrenal gland is described and statistically evaluated. 2. It is shown that a single "central" section of the adrenal gland will suffice to obtain accurate results. 3. Each section was projected on to a grid of about 2500 intersection points and the ratio of points falling on cortical or medullary tissue was determined. 4. Applications of this method to normal fowls showed that there were significant breed, sex and, particularly, age differences in the cortico-medullary ratio of the fowl's adrenal glands. 相似文献
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Chicks were handled for 5 min twice daily for five consecutive days per week over a three-week period. The control birds were not handled once they had been allotted to their brooders. The growth rate of the treated birds was significantly decreased. There was no adrenal hypertrophy; the concentration, but not the content, of adrenal cholesterol was significantly increased. Plasma glucose, FFA and cholesterol concentrations were similar in the groups at the end of the experiment. The lipolytic response of the handled birds to a further stimulus of handling was significantly greater than that of unhandled birds experiencing novel handling stimulus. There was also a significant decrease in the concentration of corticosterone in the plasma of the handled birds but not in the unhandled group. There was thus no evidence of habituation. 相似文献
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1. Conventional or gnotobiotic chicks, when injected from 1 d to 3 weeks of age with adrenocorticotrophic hormone (120IU/kg, three times weekly), showed a depressed growth rate, adrenal hypertrophy and depletion of cholesterol form the adrenal glands. 2. Feeding a diet supplemented with aureomycin (10 mg/kg) did not have any consistent ameliorating effect on the response of the stressed bird as judged by the above parameters. 3. It was found that treating germfree chicks with five daily injections of sterile milk on days 3 to 7 did not depress growth rate at any time, nor could differences in adrenal size or cholesterol stores be detected at the end of the 21-d experimental period. The responses were not modified by feeding an aureomycin-supplemented diet. 相似文献