鱼类维生素C的生理功能和需要量

维生素C是鱼类所必需的微量营养成分。本文介绍了维生素C的生理功能,维生素C的剂型及不同剂型维生素C在鱼类养殖中的应用效果,鱼类维生素C缺乏临床症状以及某些鱼类的维生素C需要量。     

水产饲料中的维生素C

1 概述维生素 C 是水产饲料中必不可少的营养素。研究结果表明,同哺乳类、鸟类一样,鱼类也缺乏一种合成维生素 C 的酶,即 L-gulono-lactone 氧化酶。鱼类缺乏维生素 C 的早期症状与鳃盖骨的变化有关,一般会导致骨胶原形成机制受损,最终使鱼类脊椎变形甚至鳍背破裂。也曾有报道鱼类因缺乏维生素 C 而引起内出血和其它症状。另外,因维生素 C 可以     

鱼类饲料中的维生素C

近20年来对鱼类维生素C营养进行了深入的研究,缺乏维生素C可引起嗜眠、厌食、生长迟缓、内出血、骨骼变形、伤口愈合缓慢、抗传染力降低和死亡率高等。维生素C对保持鱼类的最佳繁育也极为重要。因此在鱼类饲料中必须添加足量的维生素C,对于提高经济效益具有重要的意义。本文对     

鱼类营养研究综述(下)

3 维生素 维生素C是鱼饲料中的一种非常重要的营养成分。虽然大多数陆上动物不需从饲料获取维生素C,但鱼类对饲料维生素C缺乏非常敏感。鱼类维生素C缺乏症已有详细报道,包括生长缓慢,体型异常(脊椎侧弯与脊椎前弯),伤口愈合减慢,对疾病、环境污染物(如亚硝酸盐、氯化烃)及抗应激能力下降(NRC,1981,1983)。为了维持正常生长和防     

鱼类最适维生素C营养及加工应用技术

<正>大多数鱼类缺乏生物合成维生素C的能力,而且即使某些鱼类能够合成维生素C,合成的数量也不足以满足自身的新陈代谢,所以在饲料的生产中     

维生素C营养与鱼类免疫

维生素C具有可逆的氧化还原形式,参与机体许多复杂的生化反应,具有多方面的生理功能。维生素C是动物正常免疫功能所必需的(周显青等,2000),是有效的免疫调节剂,在疾病预防和治疗中起着积极的作用,能增强机体的抵抗力,减少发病率。机体免疫的功能之一就是抵抗异物的侵害感染。维生素C缺乏降低鱼类对某些疾病的抵抗力。大西洋鲑鱼(Salmosalar)(Hardie等,1991)、斑点叉尾鱼回(Ictaluruspunc-tatus)(Li和Lovell,1985)日粮维生素C缺乏,病原攻击后死亡率显著升高。高剂量的维生素C摄入可提高鱼类对某些细菌性和病毒性病原体的抵抗力(Waagbo等…     

鱼类对维生素K需要量的研究进展

维生素K是一类脂溶性维生素,它在鱼类血液凝固和骨的矿化过程中发挥了重要作用。鱼类缺乏维生素K通常会导致死亡率升高、贫血、血液凝固时间延长以及肝脏和鳃发生组织病变等症状。文中论述了维生素K的生理功能,并讨论了鱼类维生素K的需要量及致毒量。     

维生素C对鱼类生长、繁殖、抗氧化和免疫的影响的研究进展

维生素是一种微量的有机物质，是保持机体健康的必要营养素。由于多数鱼类自身不能合成维生素或者合成量少，所以必须从饲料中获取。维生素C(VC)是大多数鱼类正常生长和生理功能所必需的微量营养素之一。缺乏VC会引起一系列生理功能障碍或代谢紊乱的症状，例如身体结构畸变（脊柱弯曲、眼睛、鳃和鳍等软骨的变形）、内出血、尾侵蚀、体色变黑和生长缓慢等。VC对鱼类的生长发育、伤口愈合、铁代谢、胶原的形成、应激反应和繁殖等方面发挥重要作用。文章综述了VC的生理特性、VC对鱼类生长、繁殖、抗氧化和免疫的影响以及缺乏VC对鱼类的影响，以期为VC在鱼类生产中的应用提供参考。     

水产饲料中的维生素C

关于有鱼类和甲壳动物日粮中的维生素C需要，目前研究者们只对数以万计的水产动物品种中的一部分进行了检测，结果发现很多通常被人工养殖的品种，均需要由日粮提供维生素C，如鱼类均缺乏L─古洛酸糖内脂氧化酶，这种酶是细胞内V_c合成必须的酶。鱼类维生素C缺乏的早期症状与鱼鳍盖骨病变有关，一般这可归因于阻碍胶原蛋白形成的结果，最终会使鱼产生脊柱畸型（脊柱侧凸和前凸），甚至损害。也有报道缺乏V_c会造成鱼的内出血及其它病症。V_c可促进铁的吸收，因此对于预防贫血非常重要。鲇鱼日粮中大剂量V_c对于预防养殖鲇鱼疾病具有重要…     

鱼类几种常用水溶性维生素的应用研究

文章针对鱼类水溶性维生素C、维生素B1、维生素B2、维生素B6、维生素B12的需要量以及各种生理功能进行了综述,旨在为促进鱼类维生素的合理利用、水产养殖提供参考。     

Effects of vitamin A on growth performance and carcass quality in steers

Vitamin A plays a critical role in many essential life processes. In herbivores, it is either derived from plant β-carotene or directly as a dietary supplement. In cattle, vitamin A has the potential to influence various carcass traits that are sought by specific beef markets. A group of 20 Angus steers was removed from pasture and fed a low β-carotene and vitamin A cereal-based ration on a feedlot for 308 days. Ten of the steers were supplemented with vitamin A (retinyl palmitate, 60 IU of vitamin A/100 kg body weight/day) and the other ten received no supplement. The results demonstrated that restriction of vitamin A intake changed intramuscular fat deposition without changing subcutaneous fat depots. Angus steers that had been depleted of vitamin A showed increased intramuscular fat in the longissimus thoracis et lumborum (LTL) by 35% (P < 0.026) and seam fat area at the quartering site by 33% (P < 0.0273), when compared with cattle supplemented with vitamin A. There were no changes in intramuscular fat in the semitendinosus. Visually assessed marbling scores were also higher (19%; P < 0.094) in the non-supplemented, depleted group. There was no effect of vitamin A depletion on cattle growth and other meat traits (eye muscle area, meat colour, pH, meat cut weight), meat eating attributes (tenderness, cooking loss) or muscle fibre diameter. The only difference (P < 0.0177) among the meat traits was fat colour where depleted animals had whiter fat than the controls. Moreover, the fat from the vitamin A depleted group was softer with a lower melting point. We conclude that the reduced vitamin A consumption, leading to vitamin A depletion, increases intramuscular fat. On the other hand, the vitamin A depletion did not increase subcutaneous fat depth or change other meat quality traits, suggesting that marbling and these other traits are not invariably related.     

The effect of vitamin A supplementation on postnatal adipose tissue development of lambs

Vitamin A (retinoic acid) is known to be an adipogenic factor influencing both in vitro and in vivo cell development. This study aimed to determine its effect on lamb adipose tissue development during the early phase of postnatal development until 100 d of age. Male lambs (n = 24) of the Rasa Aragonesa breed were used. At birth, lambs were assigned to 1 of 2 experimental groups: 1) the control (C) group, which received feed without vitamin A supplementation, and 2) the vitamin A (V) group, which received a supplement of 500,000 IU/animal twice per week from birth to slaughter. The effect of vitamin A supplementation was studied at 16.8 +/- 0.35 kg of BW (58 +/- 0.7 d of age) and at 27.8 +/- 0.78 kg of BW (101 +/- 6.5 d of age). The variables of lamb growth, carcass, LM area, and lipid content were analyzed. To study adipose tissue development, the amount of adipose tissue accumulated, the size and number of adipocytes, and lipogenic enzyme activities (glycerol 3-phosphate dehydrogenase, fatty acid synthase, and glucose 6-phosphate dehydrogenase) of the omental, perirenal, and s.c. depots were quantified. Results showed that vitamin A supplementation had no influence on growth, carcass variables, LM area, and lipid content during lamb growth but that the number of adipocytes in the perirenal depot was 30% greater in lambs of the V group (P < 0.05) and that these lambs had smaller adipocytes in the omental and perirenal depots (P = 0.06) at 28 kg of BW (101 d of age). These results suggest that the intake of this level of vitamin A during the whole period of growth of the lambs influenced the processes of hyperplasia and hypertrophy in the different adipose depots, depending on their degree of maturity.     

Effects of high dietary vitamin A supplementation on tibial dyschondroplasia, skin pigmentation and growth performance in avian broilers

An experiment was conducted to study high dietary vitamin A on tibial dyschondroplasia, growth performance and skin pigmentation in broilers. One hundred and twenty Avian commercial broilers were randomly allotted to three treatments: group C (control group), in which broilers were fed basic diet containing vitamin A 5512IU/kg diet; group A, in which broilers were fed basic diet with addition vitamin A 35512IU/kg; group B, broilers were fed basic diet with supplement vitamin A 65512IU/kg. The experiment lasted 35d and at the end of the trial, broilers were killed and the right proximal tibiotarsi were dissected in longitudinal section for the assessment of TD incidence and TD index, skin from the same area of breast and tibia in broilers were collected to determine pigmentation. The results showed that a high level vitamin A significantly increased the rate of TD incidence and TD index, but middle level vitamin A did not have a significant effect on that. Both low and high retinoic acid decreased growth performance and skin pigmentation in broilers. It suggests that a high dietary vitamin A cause tibial dyschondroplasia in broilers, decreased growth performance and skin pigmentation. It is likely that the effect of vitamin A on TD is mediated through a depression of vitamin D status.     

Effects of injectable vitamins A, D, E and C on the health and growth rate of feedlot cattle destined for the Australian domestic market

OBJECTIVE: To examine the effects of injectable vitamins A, D and E at feedlot entry on health and growth rate and the effects of injectable vitamin C at the time of treatment for bovine respiratory disease (BRD) on cattle health. DESIGN: Systematic allocation of 2465 cattle at feedlot entry to: a commercial vitamin A, D and E preparation at the label dose rate; commercial vitamin A, D and E at twice the label dose rate; a formulation with no vitamin D, a lower concentration of vitamin A and a higher concentration of vitamin E; and the oil-based carrier alone at volumes corresponding to the above treatments. Comparisons of growth rate, disease and mortality were made between the groups at the conclusion of the feeding period. In a separate experiment, 176 cattle were alternately administered injectable vitamin C at the time of treatment for BRD, or were not injected with vitamin C, and mortality was compared between the groups. RESULTS: There were no differences between cattle administered vitamin A, D and E at feedlot entry and the controls in growth rate (P=0.11), all diseases (P=0.99), BRD (P=0.60) or mortalities (P=0.95). Cattle treated with the higher vitamin E and lower vitamin A preparation had a higher (P=0.02) incidence of anorexia than the other groups. Fewer cattle treated with 5 g of vitamin C by intramuscular injection at the time of treatment with antibiotics for BRD subsequently died (P=0.04). CONCLUSIONS: The routine injection of cattle with vitamins A, D and E at feedlot entry is unlikely to result in improvements in health and growth rate where cattle are provided with these vitamins in their diets at concentrations equal to the National Research Council recommendations. Mortality rate in cattle diagnosed with BRD may be reduced by intramuscular injection of vitamin C at the time of treatment with antibiotics.     

中华鳖对脂肪需求的研究

中华鳖是我国特种经济动物,脂肪在鱼类生长中占据举足轻重的作用,充当脂溶性维生素载体的角色。文章综合国内外文献关于中华鳖对脂肪的需求,中华鳖高脂饲料对中华鳖抗氧化能力和功能基因的影响进行综述,从中华鳖的营养和免疫学两个层面上进行研究,为中华鳖饲料中脂肪的水平和组成提供参考,以促进中华鳖养殖业的发展。     

Histological disorders related to the focal disappearance of the epiphyseal growth plate in rats induced by high dose of vitamin A

The histological disorders related to the focal disappearance of the epiphyseal growth plate were examined histochemically in the proximal tibia of rats administered a high dose of vitamin A. Animals were given 100,000 IU/100 g body weight/day of vitamin A for 5 days from 4 weeks after birth (VA rats) or given deionized water as control and sacrificed on Day 12 and 19 of the experiment. Tibiae were examined by immunohistochemistry for type I, II and X collagens, lectin-histochemistry for Helix pomatia and backscattered electron imaging. On Day 12, the abnormally developed calcified cartilage matrix was detected within the epiphyseal growth plate in VA rats. The uncalcified cartilage matrix contained type I collagen but lacked type II collagen. In addition, the eroded regions accompanied with numerous osteoclasts and osteoblasts were detected in the epiphyseal growth plate. On day 19, eroded regions penetrated the epiphyseal growth plate to result in its focal disappearances with the eroded surfaces entirely covered with bone tissue in VA rats. These findings suggested that the cartilage matrix of the epiphyseal growth plate was abnormally calcified and showed the phenotypes like bone matrix. The eroded regions of the epiphyseal growth plate seemed to be caused by the invasion of osteoclasts into the altered cartilage matrix and might develop to the focal disappearances by the modeling or remodeling due to action of osteoclasts and osteoblasts.     

The Effect of Vitamin E on The Toxicity of Cadmium in Cadmium-Sensitive Staphylococcus Aureus

The effect of vitamin E on the toxicity of cadmium (Cd) in Cd-sensitive Staphylococcus aureus 3719– was studied. The addition of vitamin E into the liquid growth medium resulted in a shortened lag phase of growth in Gd-stressed S. aureus 3719–. It is suggested that the decrease observed in the length of the lag phase is due to the antioxidative effect of vitamin E which indicates that Cd together with hydrogen peroxide produced by the bacterium may induce an oxidative damage in staphylococcal cells.     

Heat stress decreases plasma vitamin C concentration in lactating cows

Heat stress causes oxidative stress, which decreases plasma levels of vitamin C, an antioxidative vitamin in pigs and poultry. We investigated the plasma vitamin C concentration in lactating cows exposed to a hot environment temperature. In the first experiment, plasma vitamin C concentrations of 8 lactating cows were measured in summer and autumn. The concentration was found to be significantly lower in summer. The second experiment was performed using 4 lactating cows in a crossover design. The ambient temperature was set at 18 °C in the control treatment and at 28 °C in the heat-stressing treatment. Milk yields and feed intake tended to be lower in the stressing than control treatment. Rectal temperature and respiration rate were significantly (P < 0.05) higher in the heat-stressing treatment. The plasma vitamin C concentration was significantly (P < 0.05) lower in the heat-stressing period. These results indicate that heat stress decreases the plasma vitamin C concentration. Dietary supplementation with vitamin C may be beneficial for lactating cows in hot weather.     

Vitamins a, e and selenium blood levels in the fat cow syndrome

Blood plasma analyses for vitamins A, E and selenium were performed from calving to five weeks of lactation in 29 cows. Twelve of the 29 cows had fat cow syndrome. The healthy cows had significantly higher (P<0.01) plasma vitamin A (40 μg/dL) and vitamin E (5 μg/mL) levels than the cows with fat cow syndrome (29 μg vitamin A/dL and 3 μg vitamin E/mL). At parturition, vitamin A level in plasma was low (25 μg/dL) but increased progressively thereafter (up to 51 μg/dL) in healthy cows, whereas cows with fat cow syndrome had lower levels of vitamin A, bordering on deficiency. The possible role of vitamin E in the alleviation of fat cow syndrome by affecting oxidation-reduction reactions in the liver is discussed. Significant (P<0.01) difference was not observed in selenium blood plasma level (35 ng/mL) between the two groups of cows or in another random group of 12 cows clinically affected by fat cow syndrome.     

A comparison of the effects of parenteral and oral administration of supplementary vitamin E on plasma vitamin E concentrations in dairy cows at different stages of lactation

As a result of research conducted in the US, recommendations for dry cow vitamin E intakes have increased seven fold there, however there has been no change to recommendations in the UK. As part of a larger study comparing the impact of existing UK and new US recommended vitamin E intakes on the health and fertility of commercial dairy cows in the UK, a study was set up to investigate the effect of route of supplementation and stage of lactation, over a 21 day period, on the response to mega-supplementation of cattle receiving supposedly adequate vitamin E. The study assessed the response of dry, peak lactation and mid lactation cows to in-feed or parenteral vitamin E supplementation (7 animals per treatment/lactation stage group) by measuring plasma and milk vitamin E concentrations, blood glutathione peroxidase (GSH-Px) activity and milk yields over a 21 day period. Plasma vitamin E concentrations were significantly influenced by a time, stage and treatment interaction (P = 0.046). Both dry and lactating animals had significantly higher plasma vitamin E concentrations at some time points in the parenteral supplemented cows compared to the in-feed supplementated animals (P ≤ 0.011 and P < 0.01, respectively). Milk vitamin E concentrations did not significantly differ between lactation stages but treatment had a significant effect on concentrations (P < 0.008) when lactation stage was removed from the model. There was no significant difference in milk yield between treatment groups. A significant relationship between plasma and milk vitamin E concentrations was only found in the parenterally supplemented cows (r = 0.435, P < 0.001). In cattle with intakes greater than the ARC recommendations, measurement of plasma vitamin E concentration may be of limited value in determining whether there has been a response to supplementation. The relationship between plasma and milk vitamin E concentrations is too poor for milk vitamin E concentrations to be used as a proxy for plasma vitamin E.