维生素A、D对肉鸡钙、磷代谢的影响

本试验旨在研究维生素A、D对肉鸡钙、磷代谢的影响。采用4×4完全随机试验设计,将384只8日龄健康艾维茵雄性肉鸡称重后随机分为16个处理组,每个处理组设3个重复,每个重复8只。其中,VA设4个添加水平,分别为1500、3000、15000和45000IU/kg日粮;VD设4个添加水平,分别为500、1250、2500和5000IU/kg日粮,共构成16个处理组的试验日粮。结果表明:日粮VA水平对肉鸡钙、磷代谢有显著的影响,日粮VA为45000IU/kg时,肉鸡胫骨灰分含量、胫骨矿化度及血清AKP活性相对于1500、3000IU/kgVA组显著下降(P<0.01或P<0.05),胫骨磷含量显著增加(P<0.05),胫骨钙含量趋于增加(P>0.05);日粮VA水平为15000IU/kg时,胫骨钙含量、血清AKP活性有降低的趋势,胫骨磷含量趋升高。日粮VD水平在500～5000IU/kg范围内,对肉鸡的胫骨灰分含量、胫骨钙、磷含量、胫骨矿化度及血清AKP活性无显著影响(P>0.05),但随着VD添加剂量的增加,血清钙、磷含量呈一次线性增加,胫骨钙含量呈二次曲线上升趋势。日粮VA为15000IU/kg时,肉鸡VA临界过量;日粮VA为45000IU/kg时,肉鸡VA过量。日粮VD水平在500～5000IU/kg范围内,对肉鸡的钙、磷代谢无显著影响。     

维生素D在动物营养中的应用研究

维生素D2主要存在于植物性饲料中,如麦角和酵母;而维生素D3则主要由存在于动物的皮肤、血液、神经和脂肪组织中的7脱氢胆固醇在紫外线照射下生成。维生素D2与维生素D3对哺乳动物的活性基本相同;对于包括家禽在内的鸟类,维生素D3的活性远高于D2,前者约为后者的20～40倍;奶牛维生素D2的效价可能只有维生素D3的1/2～1/4。近年来,对活性维生素D的研究有了进一步的认识,逐渐发现活性维生素D除具有经典的钙磷调节作用以外,还参与调节许多细胞的代谢过程,对机体的免疫功能、生殖等方面均有着十分重要的意义。作者就近年来国内外对维生素D在动…     

乳牛口服过量维生素A对维生素D3及钙磷代谢的影响

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－     

日粮铝与维生素D3对肉用仔鸡生长和钙,磷代谢的互作效应

为了估测日粮铝(硫酸铝)与维生素D_3对肉鸡生长性能和Ca、P代谢的互作效应,作者将1日龄向用仔鸡(公)分成6个日粮处理组,即在玉米—大豆粉为主的基础日粮(含Ca0.88％、有效 P0.45％,未添加维生素D_3)中添加0或0.2％铝(AI),0、100或200ICU/kg维生素D_3。试验结束时,测定饲喂0.2％和无AI 日粮组鸡平均体增重(328g:545g)、采食量(611g:784g)、增重饲料比(54％:68％)、血浆无机 P(4.2mg/dL:6.7mg/dL)。显然,0.2％Al日粮组的几项指标均低于无AI日粮组。日粮维生素 D_3水平从 0提高到 100ICU/kg时,可以改善这四项指标,但如果将维生素D_3水平提高到 200ICU/kg时却不能使其效果进一步改善。AI与维生素D_3对体增重、采食量及饲料利用率有明显的互作效应,但对血浆P则没有。在不同维生素D_3水平条件下,日粮AI均可引起肉仔鸡的体增重和采食量明显下降。维生素D_3可引起血浆总Ca水平的明显上升,但AI则不能。日粮维生素D_3水平的提高并不能完全缓解AI的负效应。     

日粮铝和维生素D对肉仔鸡的生长和钙磷代谢的影响

本实验就日粮铝和维生素Ｄ间的相互作用对肉用仔公鸡的生长和钙磷代谢的影响进行了研究。采用复因子实验设计，在仔鸡基础饲料（玉米－大豆，含钙０．８８％，有效率０．４５％，不添加ＶＤ３）中添加０、０．２％的铝和０、１００、２００ＩＣＵ／ｋｂ的ＶＤ３。四十只一日龄鸡平均分配于四个试验笼中，用于各日粮处理。与不饲喂铝的鸡相比，饲喂０．２％铝者平均增重（３２８对５４５ｇ）、采食量（６１１对７８４ｇ）、肉料比（０     

维生素A、D对肉鸡钙磷代谢相关激素水平的影响

试验旨在研究维生素A、D对肉鸡钙磷代谢相关激素水平的影响。采用4×4完全随机试验设计,将8日龄健康艾维茵雄性肉鸡384只称重后随机分为16个处理组。每个处理组设3个重复,每个重复8只鸡,试验期5周。其中,维生素A设4个添加水平,分别为1 500、3 000、15 000和45 000 IU/kg日粮。维生素D设4个添加水平,分别为500、1 250、2 500和5 000 IU/kg日粮。结果表明,45 000 IU/kg维生素A组的肉鸡血清BGP含量相对于1 500 IU/kg维生素A组有显著的降低趋势(P=0.08);随着日粮维生素A水平的增加(1 500～45 000 IU/kg),血清CaBP浓度呈趋于显著的一次线性降低趋势(P=0.092),血清维生素D3与CT含量也呈现降低趋势(P=0.12,P=0.18),其中,以15 000、45 000 IU/kg维生素A组较低,尤以45 000 IU/kg维生素A组最低;血清PTH含量呈显著的一次线性增加(P=0.029)。随着日粮维生素D水平的增加,血清维生素D3含量呈趋于显著的一次线性增加趋势(P=0.093),血清BGP浓度也呈一次线性增加趋势(P=0.14);其中,以2 500和5 000 IU/kg时较高,5 000 IU/kg时最高。由此可知,日粮维生素A过量引起肉鸡骨骼钙磷代谢发生障碍与血清CaBP浓度的降低及PTH浓度的增加有关,也与过量维生素A对维生素D的拮抗作用有关。     

维生素A、E对肉鸡骨骼钙、磷代谢的影响

试验选用1日龄健康艾维茵肉鸡384只称重后随机分为16个处理组,每个处理组设3个重复,每个重复8只,试验期为6周,采用4×4(VA×VE)完全随机试验设计,研究了日粮中添加不同水平维生素A(1 500、3 000、15 000和45 000 IU/kg)和维生素E(5、15、150和1 500 IU/kg)对肉鸡骨骼钙磷代谢的影响。结果表明,随日粮维生素A水平的增加,肉鸡的胫骨钙浓度呈显著一次线性降低(P<0.05),血清AKP活性与胫骨磷浓度呈一次线性降低趋势(P<0.10),而且45 000 IU/kg维生素A组的肉鸡血清AKP活性、胫骨的灰分与钙含量均显著降低(P<0.05),胫骨矿化度趋于降低(P<0.10)1;5 000 IU/kg维生素A组的上述各项指标均呈不同程度地降低。随日粮维生素E水平增加,血清钙含量与胫骨矿化度呈显著一次线性增加(P<0.05),胫骨钙含量呈显著的一元二次增加(P<0.05);而且1 500 IU/kg维生素E组的肉鸡胫骨矿化度有显著的增加趋势(P<0.10)。日粮维生素A水平在1 500～45 000 IU/kg范围内,维生素E水平在5～1 500 IU/kg范围内,维生素A、E在肉鸡的钙、磷代谢方面均无明显的互作效应存在。过量的维生素A对肉鸡钙、磷代谢有显著的负面影响,日粮维生素A水平为45 000 IU/kg时,提示肉鸡维生素A过量;日粮维生素A水平为15 000 IU/kg时,提示肉鸡维生素A临界过量。日粮中添加较高剂量的维生素E(1 500 IU/kg),可引起肉鸡骨骼强度呈增加趋势,对肉鸡的钙、磷代谢有一定的促进效果。     

提高日粮维生素D3水平对鸡蛋的维生素D3、钙、磷含量及蛋品质的影响

试验旨在研究日粮中添加不同水平的维生素D3(VD3)对芦花鸡蛋中VD3、钙、磷含量及蛋品质的影响.选择252只40周龄健康状况良好的芦花鸡,随机分为7组,每组36只.对照组芦花鸡饲喂基础日粮(VD3水平为3600 IU/kg),试验组在基础日粮中增加不同水平的VD3(VD3水平分别为6600、9600、15600、27...     

Interactions of calcium, phosphorus, magnesium and vitamin D that influence their status in domestic meat animals

Known and possible interactions between Ca, P, Mg, parathyroid hormone (PTH), calcitonin (CT), vitamin D and its metabolites, and interactions of each of these with other factors plus complexities and possible variations between and within domestic animal species, such as age, sex, physiologic state (i.e., pregnancy, lactation and growth) and diet, make Ca, P and Mg metabolism extremely dynamic and complex. Many advances have been made in understanding these interactions and how each of these factors is controlled, secreted or metabolized within the body. Some interactions among these factors are discussed in detail, mostly with a view to understanding mechanisms by which homeostasis of Ca, P and Mg is maintained. Also, three of the major diseases of mineral metabolism of cattle (milk fever, grass tetany and wheat pasture poisoning) provide excellent models to study the complex soil, plant and animal interrelationships among Ca, P, Mg and the factors that influence and control the ultimate utilization of these minerals in animals. These diseases are used to illustrate some of the interactions among many of the factors that influence Ca, Mg and P metabolism in domestic animals.     

微量元素在毛皮动物中的应用及其调控毛皮品质的研究进展

微量元素作为毛皮动物生长发育过程中必需的营养素,对提高生产性能具有重要意义。文章综述了微量元素在毛皮动物中的生理功能、生产中的应用以及有机、无机形式的添加效果,重点阐述了其调控毛皮品质的研究进展,以期为进一步的研究和应用提供参考。     

Effects of biological type of beef steers on vitamin D, calcium, and phosphorus status

Feedlot steers (n = 36) from three biological types (Bos indicus, Bos taurus-Continental, and Bos taurus-English) were used to determine the Ca, P, and vitamin D3 status of feedlot cattle. The USDA yield and quality grade traits were measured at slaughter, and the concentrations of vitamin D3 (VITD) and the metabolites 25-hydroxyvitamin D3 (25-OH D) and 1,25-dihydroxyvitamin D3 (1,25-(OH)2 D) were determined in LM, liver, kidney, and plasma. Plasma and muscle Ca and P concentrations also were determined. Biological type of cattle affected a number of carcass traits. Carcasses from Bos taurus-English cattle had more marbling, resulting in higher quality grades (P < 0.05). Carcasses from Bos taurus-Continental cattle had lower calculated yield grades (P < 0.05) than did carcasses from cattle in the other biological types. In general, differences in carcass traits resulting from biological type were consistent with other reports. Plasma and LM Ca and P concentrations were not affected (P = 0.06) by biological type of cattle, indicating that Ca and P homeostasis is a conserved trait across the different types of cattle. Plasma VITD and 25-OH D concentrations were not affected (P = 0.41) by biological type, whereas plasma 1,25-(OH)2 D concentration was lower (P < 0.05) in Bos taurus-English cattle than in Bos taurus-Continental and Bos indicus cattle. Liver VITD and 25-OH D were not affected by biological type (P = 0.76), but liver 1,25-(OH)2 D concentration was greater (P < 0.05) in Bos indicus cattle than in Bos taurus-Continental cattle. Kidney vitamin D metabolite concentrations were not affected by biological type of cattle (P = 0.21). Muscle VITD concentration was greater (P < 0.05) in Bos taurus-English cattle than in the other two biological types, and muscle 25-OH D concentrations were greater (P < 0.05) in Bos taurus-English cattle than in Bos indicus cattle. Muscle 1,25-(OH)2 D concentration was less (P < 0.05) in the Bos taurus-Continental cattle than in the other two biological types. Cooking eliminated vitamin D metabolite differences among the biological types. Our results suggest that Bos indicus cattle had greater 1,25-(OH)2 D (the biologically active form) in tissues, and greater 1,25-(OH)2 D plasma concentrations than Bos taurus cattle. Thus, the need for VITD supplementation and optimal levels of Ca and P in feedlot diets might differ between Bos indicus and Bos taurus cattle.     

Seasonal changes in serum calcium, phosphorus, and vitamin D concentrations in llamas and alpacas

OBJECTIVE: To evaluate the interaction of season and age on serum calcium, phosphorus, and vitamin D3 concentrations in llamas and alpacas. ANIMALS: 23 clinically normal llamas and 7 alpacas. PROCEDURES: Animals were assigned to 1 of the 3 following groups on the basis of age at the start of the study: adult (age, > or = 24 months; n = 8), yearling (> 12 but < 20 months; 5), and neonate (< 6 months; 17). Twelve serum samples were obtained at monthly intervals. Calcium, phosphorus, and vitamin D3 concentrations were measured, and the calcium-to-phosphorus concentration (Ca:P) ratio calculated. Effect of season and age on each of these variables was determined. RESULTS: Vitamin D3 concentrations varied significantly as a function of season; the highest and lowest concentrations were detected September through October and February through March, respectively. The seasonal decrease in vitamin D3 concentration was significantly greater in neonates and yearlings, compared with adults. Serum phosphorus concentration decreased as a function of age, with the most significant seasonal change detected in the neonate group. The Ca:P ratio in neonates varied between 1.1 and 1.3 except during winter months when it increased to > or = 2.0. CONCLUSIONS AND CLINICAL RELEVANCE: Mean vitamin D3 concentration varied by > 6 fold in neonatal and yearling llamas and alpacas and > 3 fold in adult animals as a function of season. These results support the hypothesis that seasonal alterations in vitamin D3 concentrations are a key factor in the development of hypophosphatemic rickets in llamas and alpacas.     

Effects of dietary calcium, available phosphorus and vitamin D on growth rate, food utilisation, plasma and bone constituents and calcium and phosphorus retention of commercial broiler strains

1. The effects of different dietary concentrations of calcium (Ca), available phosphorus (AP) and vitamin D (D) on 5- to 16-day growth performance, and aspects of calcium and phosphorus (P) metabolism of chickens from three commercial strains were studied in two experiments. 2. Increasing dietary Ca reduced weight gain, tibia Ca and P content and increased plasma total Ca, Ca consumption and excretion, whilst dietary Ca at 32 g/kg increased tibia Ca:P ratio, plasma ionized calcium and reduced plasma P, tibia ash, P excretion, excreta moisture and Ca retention. 3. Increasing dietary AP reduced plasma total and ionized Ca and excreta moisture and increased P consumption and excretion, plasma P and tibia ash. 4. The addition of vitamin D increased plasma total and ionized Ca, tibia Ca:P ratio and reduced plasma sodium and P concentrations. 5. Strains differed in their tibia contents of Ca and Ca:P ratios, in response to Ca, AP and vitamin D diets whilst they differed in Ca excretion and excreta moisture caused by feeding either dietary Ca or AP. 6. It was concluded that dietary Ca, AP, vitamin D and strain of broiler chickens influenced the metabolism of Ca and P and that, as a consequence, the tolerance to high dietary Ca. A lean strain of chickens tolerated high dietary calcium better than its fat counterparts.     

Serum vitamin D,calcium, and phosphorus concentrations in ponies,horses and foals from the United States and Thailand

Vitamin D is essential in calcium and phosphorus regulation, bone physiology, cell proliferation and epithelial integrity. Literature on vitamin D in growing horses is sparse, and the effect of age on vitamin D has not been evaluated in equids in the United States or in tropical countries. The goal of this study was to determine if there was an effect of age on serum 25(OH)D₃ concentrations in equids in the US (Ohio/Kentucky) and Thailand (Chiang Rai and Kanchanaburi) during the same time of the year. Blood samples were collected from healthy ponies (n = 21) and Thoroughbred foals (n = 13), yearlings (n = 10), and horses (n = 20) in Thailand and from Thoroughbred foals (n = 10) and horses (n = 17) in the US. Serum concentrations of 25(OH)D₃, calcium and phosphorus were measured.In both countries, serum 25(OH)D₃ concentrations were lower in foals than in yearlings and adult horses. Serum 25(OH)D₃ concentrations were higher in horses than in ponies in Thailand, but were not different between horses from either country. Calcium concentrations were not different between groups or location. In both countries, phosphorus concentrations were higher in foals than in older groups; however, were not different between ponies and horses. This study shows that independent of geography there are age-related differences in 25(OH)D₃ concentrations in horses and further confirms that 25(OH)D₃ concentrations are lower in horses compared to other species. The information will serve as the basis for future clinical studies and to help understand better the pathophysiology of equine disorders associated with calcium and phosphorus dysregulation.     

维生素A和维生素D对动物基因表达的影响

本文在介绍维生素A和维生素D营养生理功能的基础上,综述了维生素A和维生素D对相关基因表达的调控及其主要机制。     

Effects of dietary calcium, phosphorus, calcium: phosphorus ratio and vitamin K on performance, bone strength and blood clotting status of pigs

Three factorial experiments were conducted to evaluate the effects of various Ca:P ratios (1:1, 2:1 and 3:1) in diets having deficient (.3%), adequate (.6%) and excess (.9%) levels of dietary P on rate and efficiency of gain and bone strength of 192 pigs from 18 to 40 kg BW. A corn-soybean meal diet fortified with minerals and vitamins (but not vitamin K) was fed. Levels of Ca and P were achieved by adjusting the amounts of dicalcium phosphate and ground limestone in the diet. The corn was free of detectable mycotoxins. A hemorrhagic condition occurred in Exp. 1 in pigs fed the higher dietary Ca levels; all eight of the pigs fed 2.7% dietary Ca died of internal hemorrhage within the initial 28 d of the experiment. Vitamin K (5 mg menadione [as menadione dimethylpyrimidinole bisulfite]/kg) was added to half of the diets of the remaining animals and the experiment was continued for an additional 14 d. Prothrombin and whole blood clotting times were increased (P less than .01) in pigs fed high Ca without vitamin K but were normal in pigs fed high Ca with added vitamin K. Similar trends in clotting times occurred in a second experiment. A third experiment was conducted to determine whether the addition of vitamin K could reverse the hemorrhagic condition induced by feeding high dietary Ca for 28 d. As in the other two experiments, clotting times were increased (P less than .01) in pigs fed high Ca and no vitamin K. Addition of vitamin K after 28 d resulted in a return to basal prothrombin values by d 50. In regard to the original objectives, increasing the Ca:P ratio from 1:1 to 2:1 or 3:1 tended to reduce rate and efficiency of gain at all levels of P. Increasing the Ca:P ratio to 2:1 resulted in increased bone strength only when P was at or above the dietary requirement.