首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 406 毫秒
1.
One-day-old poults fed a vitamin D3-deficient diet were examined for clinical, biochemical, and morphological changes at 14 days of age. Changes in these parameters were compared at 15.5 and 17 days of age after one of the following vitamin D-replacement therapies was provided: water-soluble vitamin-mineral packs that contained vitamin D3; vitamin D3 in the feed; or vitamin D, 1,25-dihydroxyvitamin D3 in the feed. The vitamin D3-deficient poults were lame and had significant decreases in weight gain and in longitudinal skeletal growth. None of the therapies alleviated all these changes, but clinical lameness subsided in poults provided 1,25-dihydroxyvitamin D3. Calcium concentrations were significantly improved by all therapies. Treatment with vitamin D3 in the feed and water significantly increased 25-hydroxyvitamin D3 concentrations in vitamin D-deficient poults. The growth plate zones, with the exception of the mineralized hypertrophied zone, were all increased in length and not modified by treatment. However, the mineralized hypertrophied zones in the 1,25-dihydroxy-vitamin D3 group and the group receiving vitamin D3 in the water were comparable to that in the controls on day 15.5.  相似文献   

2.
Structural changes in bone, parathyroid, and ultimobranchial body were examined in three groups of chicks fed a vitamin D-deficient diet; one group was treated with vitamin D3 and another with 1,25(OH)2D3. Diets were fed from day of hatching until 5 weeks old, when deficient chicks were near death due to hypocalcemic tetany, loss of fat and muscle, and marked bone deformities. In deficient chicks, parathyroid mass increased linearly to 7.5 times normal at 5 weeks. Parathyroid cells were irregular and vacuolated, with few granules. 1,25(OH)2D3 had normal parathyroids until the fifth week, when parathyroid mass increased greatly. There were few differences in length of growth cartilage, but marked changes in length of metaphyses. Deficient chicks had metaphyses nearly five times longer than vitamin D3-treated chicks. Metaphyses in chicks given 1,25(OH)2D3 were twice as long as those of vitamin D-treated chicks at 5 weeks. Both osteoblasts and osteoclasts were more numerous in deficient chicks. These studies suggest that vitamin D3 is more effective than 1,25(OH)2D3 in preventing parathyroid and bone lesions of vitamin D deficiency.  相似文献   

3.
乳牛口服大量β-胡萝卜素对维生素D3及钙磷代谢的影响   总被引:1,自引:0,他引:1  
6头健康成年荷斯坦乳牛被随机均分为2组。试验组牛第1周每头口服β-胡萝卜素23.0g,以后每周每头口服11.5g,对照组不做任何处理。试验期共8周。结果表明,试验组乳牛血清钙及无机磷水平呈下降趋势;血清维生素D3活性代谢产物25-OH-D3和1,25-(OH)2-D3均呈现明显下降;至第5周末,血液β-胡萝卜素水平最高,25-OH-D3水平下降非常明显。据此认为,乳牛对β-胡萝卜素的吸收存在一阈值,大剂量的β-胡萝卜素进入机体,可能直接干扰维生素D3的羟化,使其活性代谢产物呈下降趋势,但由于吸收阈值的存在,其对维生素D3和骨骼钙磷代谢的干扰作用可得到一定程度的减缓。  相似文献   

4.
From June 1994 to June 1996, 18 fledgling American crows (Corvus brachyrhynchos brachyrhynchos) from multiple locations on Long Island, New York, were presented with signs of metabolic bone disease characterized by folding fractures of the proximal tibiotarsus. Plasma alkaline phosphatase levels were elevated, and the calcium/phosphorus ratio and 25-hydroxycholecalciferol (25-(OH)D3) levels were decreased. The histopathologic diagnosis was parathyroid hyperplasia and generalized osteodystrophia fibrosa. A diet low in bioavailable calcium and/or vitamin D3 was the probable cause. Also, exposure to xenobiotics could have contributed to the depression of 25-(OH)D3 levels.  相似文献   

5.
Aged laying hens at oviposition were given four levels of dietary vitamin D3 and three levels of 1,25-dihydroxyvitamin D3 (1,25[OH]2D3) to determine the effects of the additives on the medullary and endosteal bone. Oxytetracycline hydrochloride labeling and histomorphometry of undecalcified sections were used in the determination of changes in medullary bone and endosteal surface of mid-diaphyseal tibiotarsal bones. Treatment with 1,25(OH)2D3 increased mineralized medullary bone area, endosteal surface length, amount of tetracycline labeling in medullary and endosteal bone, total number of osteoclasts on endosteal and medullary bone, and appositional rate of mineralizing bone. Vitamin D3 increased mineralized medullary bone area and total tetracycline labeling in endosteal bone but decreased endosteal mineral apposition rate. Medullary bone matrix with no mineral was observed only in the group receiving neither supplement. These areas were much larger than typical osteoid seams usually seen in trabecular bone. Both 1,25(OH)2D3 and vitamin D3 were effective in stimulating bone formation and retention of mineral within medullary bone matrix at oviposition.  相似文献   

6.
维生素D的免疫功能   总被引:2,自引:0,他引:2  
维生素D是动物所必需的营养素,除对钙和骨代谢具有重要影响外,对免疫系统也有重要作用。1,25(OH)2维生素D3是维生素D的活性形式,1,25(OH)2维生素D3的生物学效应是由维生素D3受体(VDR)介导的。淋巴细胞、单核细胞、巨噬细胞等免疫细胞都有VDR的表达,这表明,维生素D对免疫系统功能有重要调节作用。  相似文献   

7.
8.
Day-old broiler chicks were fed a vitamin D-deficient diet for 30 days. Gross, microscopic, and radiographic examinations of the proximal tibiotarsus were done at 2, 3, and 4 weeks of age. In 2-week-old chicks, there was variable lengthening and disorganization of the proliferating-prehypertrophied zone (P-PHZ), resorption of cartilage spicules in the degenerating hypertrophied zone and primary spongiosa, and lengthening of bone spicules in the secondary spongiosa; many bone surfaces were lined with increased osteoid. In 3-week-old chicks, there was a tendency for the P-PHZ to decrease in relative length and for cartilage spicules to increase in length. In 4-week-old chicks, however, there was marked lengthening of the P-PHZ, resorption of cartilage spicules, and replacement of the metaphysis with irregularly oriented islands of woven bone, osteoid, and loose fibrous connective tissue.  相似文献   

9.
1. Young chicks were used to evaluate the efficacy of 2 new vitamin D3 analogs relative to 1alpha-hydroxycholecalciferol (1alpha-OH D3) for their ability to improve the bioavailability of phytate-bound phosphorus (P) when added to P-deficient maize-soyabean meal diets that were superadequate in cholecalciferol. 2. Both 20-epi-19-nor-1,25-(OH)2 D3 and 20-epi-19-nor-1alpha-OH D3 were observed to have phytate-P releasing activity, as measured by bone ash responses. 3. However, the bioactivity of the 2 new analogs differed when compared with 1alpha-OH D3. The 20-epi-19-nor-1alpha-OH D3 analog had a lower (P 0.05) phytate-P releasing activity (45%) than either 1alpha-OH D3 or 20-epi-19-nor-1,25-(OH)2 D3, which did not differ. 4. A dietary concentration of 10 to 15 mug/kg 1alpha-OH D3 was found to optimize phytate-P utilisation in 2-week-old chicks.  相似文献   

10.
1. A series of 5 trials was conducted with Cobb chickens in order to determine the effect of 25-hydroxycholecalciferol (25OHD3) on their performance and bone development under adequate Calcium (Ca) and Phosphorus (P) supplementation, and under moderate dietary restriction of Ca and P. Formulated beadlets of 25OHD3, trade name HY-D (IsoGen, Naperville, IL, USA) were used as the 25OHD3 source. 2. Five to 10 microg of cholecalciferol (vitamin D3) or 25OHD3/kg diet were sufficient to ensure normal body weight (BW) and bone ash in chickens under continuous lighting. The two materials had similar effects on BW and bone ash. 3. In one out of the three experiments, 25OHD3 increased BW and BW gain, while in the others it had a similar effect to that of vitamin D3, or even a slight negative effect in a trial conducted on the floor, in which the diets were supplemented with the D sources at 75 microg/kg. The effects of both D sources on bone ash and on the severity or frequency of tibial dischondroplasia were similar. 4. 25OHD3 restrained the effect of moderate dietary P restriction, but not of Ca restriction, on BW gain and bone ash in 22-d-old chickens. This effect could not be explained by an higher P bioavailability in the 25OHD3-fed chickens.  相似文献   

11.
An osteodystrophy with features of both rickets and fibrous osteodystrophy was diagnosed in growing pigs housed indoors and fed on a diet deficient in vitamin D. Affected pigs were severely lame and preferred to remain recumbent. At necropsy, the long bones had reduced breaking strength and in one five-month-old pig the articular surfaces of both proximal humeri were indented due to collapse of subchondral bone. Microscopic changes in the bones included prominent osteoclastic activity in the proximal metaphyses, variable myelofibrosis, trabecular microfractures, and focal thickening of the hypertrophic zone in some growth plates. Treatment consisted of an injection of Vitamin D3, addition of dicalcium phosphate to the diet for 18 days and long-term supplementation of the diet with fat-soluble vitamins. This is the first report of an osteodystrophic disease in pigs in New Zealand.  相似文献   

12.
Cholecalciferol (Vitamin D3) and its metabolites participate in the regulation of Ca and P metabolism in vertebrates. The intermediate (6,7-cis-precalciferol) is formed by a photoreaction at wave length of 250-310 nm from 7-dehydrocholecalciferol in skin tissues. Vitamin D3, 1,25(OH)2 D3 and other metabolites, previously known to be synthesized only in mammalians and avians, have been detected also in plants. The influence of the UV light (6 hrs radiation with 254 nm) in the calcinogenic activity of T. flavescens and N. veitchii was tested. The extracts of the plants were administered to rachitic chicks in two research models: "Alimentation without Vitamin D" and "Strontium added Alimentation". After 25 days the extracts were administered (per os) and the serum was analyzed to determine the level of Ca, P and alkaline phosphatase. The results were compared with those obtained in chicks with standards of vitamin D3, 1,25(OH)2 D3, T. flavescens and N. veitchii not irradiated and also with T. flavescens that has grown in Rio Grande do Sul/Brazil.  相似文献   

13.
Adult laying hens were fed diets deficient in phosphorus, calcium, calcium and phosphorus, and vitamin D3 to determine their effects on bone histology and parathyroid gland size. The phosphorus deficient diet caused an insignificant decrease in parathyroid size while the other diets caused significant increases. A considerable amount of individual variation in medullary bone volume and osteoid seam width was observed in all groups but, despite this, the calcium, calcium and phosphorus and vitamin D3 deficient diets clearly resulted in increased osteoid. Birds receiving diets deficient in calcium and phosphorus, and in vitamin D3 for longer periods were observed to have partially or completely resorbed medullary bone. Osteodystrophia fibrosa was noted in vitamin D3 deficient birds which had no follicular activity.  相似文献   

14.
One-day-old poults were placed on litter on which poults had previously developed diarrhea, increased mortality, stunting, and malabsorption. Gross, microscopic, and morphometric evaluations of the proximal tibiotarsal growth plate, along with analysis of plasma calcium, phosphorus, and 25-hydroxyvitamin D3 concentrations, were conducted for 3 weeks to determine the development and character of skeletal lesions. Poults developed enteritis with diarrhea and dehydration. Body weights and shank lengths were significantly decreased. Plasma 25-hydroxyvitamin D3 concentrations were significantly decreased. Plasma calcium was significantly decreased on day 8. Plasma phosphorus concentrations were significantly increased on day 8 and were significantly decreased on days 15, 18, and 22. Growth plates narrowed on days 8 and 11 and expanded on days 15, 18, and 22. The proliferating-prehypertrophy zone significantly decreased in length on days 11, 18, and 22, and significantly increased in length on day 15. The unmineralized hypertrophy zone was significantly increased in length on days 15, 18, and 22. The mineralized hypertrophy zone was significantly decreased in length on all days. Skeletal lesions during the poult malabsorption syndrome evolved from an early osteoporotic lesion associated with hypocalcemia to a rachitic lesion associated with depleted vitamin D and hypophosphatemia.  相似文献   

15.
An osteodystrophy with features of both rickets and fibrous osteodystrophy was diagnosed in growing pigs housed indoors and fed on a diet deficient in vitamin D. Affected pigs were severely lame and preferred to remain recumbent. At necropsy, the long bones had reduced breaking strength and in one tive-month- old pig the articular surfaces of both proximal humeri were indented due to collapse of subchondral bone.

Microscopic changes in the bones included prominent osteoclastic activity in the proximal metaphyses, variable myelofibrosis, trabecular microfractures, and focal thickening of the hypertrophic zone in some growth plates.

Treatment consisted of an injection of Vitamin D3, addition of dicalcium phosphate to the diet for 18 days and long-term supplementation of the diet with fat-soluble vitamins. This is the first report of an osteodystrophic disease in pigs in New Zealand.  相似文献   

16.
乳牛口服过量维生素A对维生素D3及钙磷代谢的影响   总被引:9,自引:0,他引:9  
从北京郊区某农场选取10头健康成年黑白花乳牛,随机分为试验(5头,每周每头口服维生素A100万单位)和对照(5头,不作任何处理)两组。8周以后检测发现,试验组血清钙和无机磷水平呈下降趋势;尾椎骨皮质变薄,密度下降,呈现骨质吸收现象;血清碱性磷酸酶显著下降(P<0.05);其活性代谢产物25-羟维生素D3(25-OH-D3)极显著下降(P<0.01);1,25-二羟维生素D3[1,25-(OH)2-  相似文献   

17.
At early ages, added dietary ascorbic acid did not affect growth or femur mineralisation of poults. In poults after 8 and 12 weeks, femur mass was reduced by 3000 mg ascorbic acid per kg diet. 2. Plasma calcium and magnesium were not influenced differently by 1000, 4000 and 16,000 IU vitamin A/kg diet, but plasma phosphorus was decreased by the 16,000 level. 3. Vitamin A at 1000 or 16,000 IU/kg diet reduced growth in both sexes to 12 weeks of age compared with the NRC recommended 4000 IU/kg diet. In males, the growth retardation continued to 18 weeks. 4. Vitamin A at 16,000 IU/kg reduced femur development as measured by femur weight to body weight or to femur length ratios.  相似文献   

18.
A suspected inherited form of rickets was diagnosed in Corriedale sheep on a commercial sheep farm in Marlborough. Affected lambs were normal at birth but showed a reduced growth rate and a range of skeletal abnormalities, including both varus and valgus deformities and a characteristic dip in the shoulder region. Up to 20 affected lambs had been born on the property over the last two seasons. Skeletal lesions in affected lambs included swollen costochondral junctions, moderate to marked thickening of physes in long bones, and collapse of weakened subchondral bone, particularly in the proximal humerus. These lesions, together with the microscopic changes, strongly suggested a diagnosis of rickets. Affected lambs were hypocalcaemic and hypophosphataemic, consistent with a deficiency of vitamin D.

Vitamin D assays revealed significantly higher 1,25(OH) vitamin D concentrations in affected lambs than in controls, suggesting a defect in the vitamin D receptor as the likely mechanism. DNA testing revealed that 4/10 Corriedale rams used during the previous season had sired affected lambs. Studies aimed at confirming the genetic nature of the disease and the mechanism are continuing at Massey University.  相似文献   

19.
This research was performed to evaluate the utility of several serum and urine parameters as well as bone ash and plasma parathormone assay to diagnose and monitor diet-related osteopenia in growing pigs. Five diets were tested as follows: calcium-deficient, phosphorus-replete; moderate-deficiency of calcium and phosphorus; marked deficiency of calcium and phosphorus; calcium replete, phosphorus deficient; and vitamin D deficient. Parameters monitored included serum calcium and phosphorus as well as ratios of urine calcium to creatinine, phosphorus to creatinine, calcium to phosphorus, and percent fractional excretions of calcium and phosphorus. Plasma parathormone (PTH) levels were monitored in 2 of 3 experiments. Osteopenic bone differences at necropsy were evaluated by bone density, percent ash, ash per milliliter bone, calcium per milliliter bone, and phosphorus per milliliter bone. Marked change in urine mineral parameters, especially the calcium-to-phosphorus ratio, typically occurred within 1 to 2 days of treatment and preceded significant change in serum mineral or plasma PTH by 2 to 3 weeks. When monitored, plasma PTH levels were elevated following treatment, which confirms the hyperparathyroid state induced by the test diets. Significant differences in bone mineralization between control and treatment diets at necropsy were generally observed. The results of this study indicate that the analysis of urine minerals offers an early, noninvasive technique to investigate diet-associated osteopenic disease in growing pigs, which can be supported further by bone mineral analysis at postmortem using techniques herein described. Several urine mineral reference intervals for application to field investigations are included. Research into application of similar techniques to evaluate calcium and phosphorus homeostasis in pigs of all ages, including gestating and lactating gilts and sows, appears warranted.  相似文献   

20.
Vitamin D is involved in calcium metabolism as well as bone and shell quality, and is therefore important to broiler breeders. In this research we investigated the effects of maternal dietary 25-OH vitamin D3 on broiler breeder egg quality and hatchability, as well as on progeny bone mineral density and performance. In a field study, all hens were fed 3,000 IU of vitamin D3 (D) per kilogram of complete feed; in addition half of the hens also received 34.5 µg of 25-OH vitamin D3 per liter in the drinking water (25OHD). Eggs from each treatment group were incubated and hatched; chicks were fed a common diet and grown to 41 d of age. Eggs from hens in the 25OHD treatment had a nearly 30% reduction in early embryo mortality. However, a larger egg size resulted in greater chick BW for the D chicks, although this did not affect broiler production performance. Broilers from the maternal 25OHD treatment had a lower FCR during the grower phase. Unexpectedly, chick plasma 25-OH vitamin D3 was only greater for the maternal 25OHD treatment at 4 d of age, but not at hatch, 2, 6, 8, 10, 12, or 14 d of age. Maternal vitamin D3 source did not affect progeny 41-d bone mineral density. Maternal 25-OH vitamin D3 had a protective effect on the growing embryo, reducing early embryonic mortality, with minimal effects on progeny performance and bone mineral density to processing at 41 d of age. The previously reported effects of 25-OH vitamin D3 on increasing broiler performance and breast yield seem to be dependent on supplementation of the broiler diet; a carry-over effect of maternal supplementation is insufficient to achieve these effects.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号