REVIEW: Update on Vitamin Nutrition and Fortification in Dairy Cattle

Vitamins are essential to the health and well-being of commercial livestock and contribute to the nutritional value of animal products to humans. In the last 10 yr, a number of studies have been published in which varying levels of supplemental vitamins have been fed to dairy cattle, and the effects on health, reproduction, and overall performance were compared. In many cases, the results indicate that optimal levels of dietary vitamin supplementation exceed what have been considered minimal or adequate levels. Other studies have revealed previously unrecognized effects of certain vitamins, fed at levels above minimal requirements, on immune function, milk production, and in the alleviation of some toxicosis. The purpose of this paper is to review recent studies of the effects of vitamin supplementation on health and performance of dairy cattle and to provide supplementation guidelines to support optimal performance of dairy cattle under commercial conditions.     

蝇蛆的营养特性及其在畜禽生产中的应用研究进展

蝇蛆繁殖能力强、生长周期短、养殖成本低,其粗蛋白质、不饱和脂肪酸和矿物质等含量高,必需氨基酸种类较齐全,并可提取几丁质、凝集素和抗菌肽等生物活性物质,是一种优质的昆虫蛋白质饲料。研究表明,蝇蛆及其制品能够部分替代饲粮中常规蛋白质饲料,提高畜禽生长或生产性能、提升产品品质、增强机体抗氧化和免疫功能以及调节肠道菌群结构。本文综述了蝇蛆的营养特性及其应用于畜禽生产中的最新研究成果,以期为其在养殖业中的应用及进一步研究提供参考。     

Grazing management as it affects nutrition, animal production and economics of beef production

Until recently, the nutritional fate of the grazing animal has been largely ignored by both animal and range scientists despite the economic dependence of the extensive livestock industry on nutrition from grass. Of the three factors that can be manipulated to improve profit gross margin per animal, is one that is directly affected by nutrition and, hence, grazing management. The relationship between economics and grazing management may be summarized as: Gross margin = f(Animal Performance); Animal Performance = f(nutrition); Nutrition = f(grazing). Economical beef production must consider the needs of the animal and the forage plant at the same time. The health of the sward must be maintained while improving individual animal performance and simultaneously increasing stocking rate. Generally, plants that have been defoliated require a period of recovery before again being grazed. A sward is kept in a vigorous state by preventing repetitive defoliation at the one extreme, and avoiding excessive shading (mature growth) of photosynthetic material at the other. This state is best achieved where livestock grazing is controlled. For any individual paddock, periods of grazing are followed by periods that allow adequate physiologic recovery of the plants. A grazing regimen that keeps the plant in a healthy state is fortuitously also well suited to the nutritional requirements of the animal. Animals on overgrazed pastures are likely to suffer from inadequate feed intake because of deficiencies in feed quantity. Conversely, on over-rested pastures, intake deficiency results from paucity in feed quality. On most unmanaged ranges, overgrazed and over-rested plants are likely to be found side by side. By controlling duration of the rest period as well as duration of the grazing period through pasture subdivision, requirements of both the plant and the animal can be met. With artificially high economic demands placed on animal production, some form of supplementation is required in most modern livestock situations. Whereas energy is frequently the nutrient limiting production it is seldom economically feasible to supplement the grazing animal directly with energy. Protein supplementation to increase forage intake, and thus indirectly energy intake, has become standard practice in many grazing situations. When there is adequate forage with a low crude protein content (less than or equal to 7%), microbially degradable protein is the preferred choice. However, when the animals are in an energy deficient state, either through a shortage of available forage or because their requirements exceed energy intake levels, by-pass protein is required.     

Phytase and vitamin E in the feed of growing pigs: 2. Influence on carcass characteristics, meat and fat quality

Lipid oxidation is one of the the major causes of deterioration in the quality of meat and meat products. In addition to its nutrition value, meat has other aesthetic attributes, including its attractive sensory properties and therefore, lipid oxidation in meat and adipose tissue is undesirable. It can be reduced by the addition of antioxidants to feeds. Vitamin E functions is a lipid-soluble antioxidant in the cell membranes. One of the most potent forms is α-tocopherol. It is capable of quenching free radicals and thus protects susceptible cellular structures, especially polyunsaturated fatty acids in cell membranes, against oxidation and subsequent breakdown to potentially harmful, chemically reactive products (Packer and Fuchs 1993). Vitamin E supplementation above the physiological demand enhances the vitamin E concentration in tissue samples, milk and eggs (Leonhardt et al. 1997). Furthermore a positive effect on the various quality criteria of products of animal origin such as shelf life, colour, taste, etc. can be realized to meet the expectations of consumers (Asghar et al. 1991b; King et al. 1995). In another article it was demonstrated that supplementing diets with phytase had a positive effect on the digestibility of minerals such as phosphorus, calcium, iron and zinc (Gebert et al. 1999). The results indicated that dietary fat digestibility was significantly decreased due to the phytase supplementation. In addition, the α-tocopherol digestibility had a tendency to be impaired in the phytase- or vitamin E (200 p.p.m. α-tocopheryl acetate)-supplemented diets, indicating that the released minerals of the phytic acid complex could act as bi- and trivalent cations and might damage those nutrients which are susceptible to oxidation (mainly polyunsaturated fatty acids) or could use up the antioxidative vitamins in the digesta. Therefore it was of interest to investigate the effect of phytase and vitamin E (α-tocopheryl acetate) supplementation in pig diets on the carcass characteristics as well as meat and fat quality, mainly with respect to stability against oxidative destruction.     

白藜芦醇对Nrf2、NF-κB和Wnt信号通路的调控及其在动物生产中的应用

白藜芦醇(resveratrol,RES)是一种天然的非黄酮类多酚化合物,广泛存在于多种植物组织中,如葡萄、虎杖和花生等,是植物抵御病原微生物入侵和维持自身稳态的重要物质,因此也被称作植物抗毒素。RES具有良好的抗氧化、抗炎和抗菌特性,在改善动物抗逆性、提高免疫能力和维持肠道健康等方面发挥重要作用。RES通过调控核因子E2相关因子2(nuclear factor E2-related factor 2,Nrf2)-Kelch样环氧氯丙烷相关蛋白-1(Kelch-like epichlorohydrin-related protein-1,keap1)促进畜禽体内Nrf2因子的表达,提高抗氧化因子表达和抗氧化酶活性,缓解氧化应激;通过核因子-κB (nuclear factor kappa-B,NF-κB)信号通路降低机体炎性因子表达水平,减少炎症反应。在动物肠道健康方面,RES可通过调控Wnt/β-连环蛋白(Wnt/β-catenin)信号通路促进肠道上皮细胞增殖分化,改善肠道黏膜屏障完整性,促进肠道微生物定植,进而改善肠道菌群结构。在动物生产中,RES作为饲料添加剂可提高动物的生长性能,释放生长潜力,并改善畜禽产品品质。同时,RES可增强动物的免疫功能,提高其抵御病原体的能力,降低疾病的发生率。目前,RES在畜禽生产中得到广泛的研究与应用,但对其具体作用机制仍需进一步了解。作者介绍了RES调控Nrf2-Keap1、NF-κB和Wnt/β-catenin信号通路的机制,并展望了其在畜禽生产中的应用前景,以期为RES在畜禽生产中的深度应用提供理论依据。     

丝兰提取物在动物饲粮中应用的研究进展

丝兰提取物(YE)由于生理结构的特殊性,其含有的丝兰皂苷等活性成分具有吸附性,可降低畜舍氨气、硫化氢等有害气体的浓度,改善动物饲养环境,维持动物健康,还可提高动物生产性能。因此,本文就丝兰提取物的营养特点与其在反刍动物和单胃动物饲粮中的应用及对畜禽有害减排的影响进行综述,以期为丝兰提取物在动物生产中的应用提供参考。     

Effect of vitamin E supplementation on naturally acquired parasitic infection in lambs

Gastrointestinal nematode infections cause substantial economic losses in pasture-based sheep farming worldwide. Host nutritional status has been identified as a key component of immune function. While vitamin E supplementation is known to have broad-spectrum effects on immune function in livestock, to our knowledge, there are no reports on the effect of vitamin E supplementation on trichostrongylid parasite infections in lambs. This study evaluated the effect of parenteral vitamin E supplementation on naturally acquired parasite infection in lambs. Twenty-seven spring lambs were sequentially assigned to receive injections of vitamin E (15 or 30 IU D-α-tocopherol/kg body weight (BW) or placebo, every two weeks, from birth to 28 weeks of age. Blood was collected at weeks 0, 2, 4, 8, 12, 16, 20, 24, and 28 to determine serum α-tocopherol concentration. Once the youngest animal reached 15 weeks of age all lambs were dewormed and grazed together on a pasture known to be contaminated with trichostrongylid larvae. Fecal egg count and blood packed cell volume (%) were determined on each lamb immediately prior to deworming and for the first seven weeks of pasture infection. Lambs were euthanized when they reached 28 weeks of age for determination of parasite worm burdens. Vitamin E supplementation at 30 IU/kg BW increased serum α-tocopherol over that of placebo (P<0.001) however, there was no effect of vitamin E supplementation on liver (P=0.804) or muscle (P=0.16) α-tocopherol content. There was no effect of vitamin E supplementation on fecal egg counts, packed cell volume, worm burden or nematode species distribution. Nematode genera identified were Haemonchus (30%), Trichostrongylus (42%), Nematodirus (27%), Strongyloides sp. (<1%), and Aonchotheca sp. (<1%). These results indicate that biweekly injections of vitamin E at 15 and 30 IU d-α-tocopherol/kg BW, had no effect on parasitological parameters used in the study to assess gastrointestinal nematode infection.     

Beneficial impacts of bee pollen in animal production,reproduction and health

Bee pollen (BP) is one of the most useful therapeutic products favoured by natural medicine scientists because of its possible nutritional and medical applications. It exhibits many impacts such as antimicrobial, immunostimulating, antioxidants and hepatoprotective. Furthermore, BP has some useful therapeutic features in numerous pathological situations such as its impact to normalize wound healing. Based on previous literatures, the level of BP supplement in livestock and poultry ranged from 0.1 to 20 g/kg diet. This variation depends on the species, physiological status, age and purpose of addition; so far generally, it accepted to use the level with no side effects. It has been observed that BP enhanced growth performance, immunity responses and blood variables and had hypoglycaemic activity by reducing the lipid in the blood and carcass. Also, BP contains more nutrients, which stimulate faster differentiation and proliferation of the cells of immune system of birds. Therefore, the present review recommends that BP supplementation (up to 20 g/kg diet) had possible beneficial impacts, antioxidants and protective activities on most of the production, productive and health patterns of livestock.     

大豆异黄酮对畜禽抗氧化机能的影响及其作用机制研究进展

近年来,大豆异黄酮的抗氧化功能受到人们广泛关注。本文介绍了大豆异黄酮对猪、鸡抗氧化机能的影响,并从淬灭自由基、减轻DNA氧化损伤,抑制脂质过氧化、增强抗氧化酶基因表达和抗氧化酶活性、增加抗氧化蛋白表达及螯合金属离子等方面对大豆异黄酮的抗氧化机制进行了综述。     

Effect of vitamin E supplementation on the health and fertility of dairy cows: a review

The currently recommended intake of vitamin E for dairy cows is based on the prevention of nutritional myopathy, a calf disease. However, it is likely that the vitamin E requirement of the modern dairy cow is very different from that of a calf. This review of the literature investigates the effect of vitamin E supplementation on the health and fertility of the dairy cow. Supplementation of high levels of vitamin E (at least 1000 iu per day) during the dry period and early lactation can reduce the incidence of mastitis, possibly because of an increase in immune system activity and function, but there appears to be little benefit of supplementation on infectious diseases other than mastitis. The evidence for a response in the reproductive system is more equivocal. In herds with a history of selenium deficiency and a high incidence of retained fetal membranes, supplementation, in conjunction with selenium, can reduce retention, but the evidence for an effect of supplementation on other reproductive diseases, such as cystic ovarian disease and metritis, is based on a very limited number of cases. The literature suggests that the current recommendations for vitamin E are inadequate. In particular, it suggests that the current linking of requirement to dry matter intake is incorrect, because vitamin E requirement is probably at its highest when intake is at its lowest However, the majority of the data on which this conclusion is based, come from North America where cows will encounter significantly different levels of oxidative stress from cows in the EU.     

Vitamin E Biochemistry and Function: A Case Study in Male Rabbit

Vitamin E supplementation has become a common procedure to promote growth and health and improve the qualitative characteristics of farm animals. It has been demonstrated to be an efficient strategy for improving their reproductive function. Germ cells are particularly vulnerable to oxidative damage and may thus require additional antioxidant protection. The aim of this review is to give a comprehensive overview of the current knowledge of the biochemistry and physiology of vitamin E; successively, the effect of this compound on the reproductive activity of rabbit buck is accurately described. In particular, this review examines studies on the effects of animal age, dose and duration of vitamin E supplementation, as well as the co-supplementation with selenium, vitamin C and polyunsaturated fatty acids. Several investigations have shown beneficial effects in bucks supplemented with vitamin E levels higher than the standard dietary requirement (50 mg/kg) particularly when the semen is stored. However, the exact dietary intake of vitamin E should be decided according to specific tissue needs for the individual vitamin E forms and the specific saturation markers.     

Nutritional applications and beneficial health applications of green tea and l-theanine in some animal species: A review

Green tea (Camellia sinensis) is a popular herbal plant with abundant health benefits, and thus, it has been used as a potent antioxidant for a long time. Based on the available literature, the diversity and the availability of multifunctional compounds in green tea offer its noteworthy potential against many diseases such as liver and heart diseases, inflammatory conditions and different metabolic syndromes. Owing to its bioactive constituents including caffeine, amino acids, l -theanine, polyphenols/flavonoids and carbohydrates among other potent molecules, green tea has many pharmacological and physiological effects. The effects of green tea include anti-oxidative, anti-inflammatory, anti-arthritic, anti-stress, hypolipidaemic, hypocholesterolaemic, skin/collagen protective, hepatoprotective, anti-diabetic, anti-microbial, anti-infective, anti-parasitic, anti-cancerous, inhibition of tumorigenesis and angiogenesis, anti-mutagenic, and memory and bone health-improving activities. Apart from its utilization in humans, green tea has also played a significant role in livestock production such as in dairy, piggery, goatry and poultry industries. Supplementation of animal feeds with green tea and its products is in line with the modern concepts of organic livestock production. Hence, incorporating green tea or green tea by-products into the diet of poultry and other livestock can enhance the value of the products obtained from these animals. Herein, an effort is made to extend the knowledge on the importance and useful applications of green tea and its important constituents in animal production including poultry. This review will be a guideline for researchers and entrepreneurs who want to explore the utilization of feeds supplemented with green tea and green tea by-products for the enhancement of livestock production.     

植物提取物添加剂在动物营养中的应用及其机制的研究进展

植物提取物添加剂具有提高动物生产性能、无残留和无抗药性的特点,能够为畜禽养殖业高效生产安全、健康、营养的食品提供保证.本文综述了植物提取物添加剂的抗菌和抗氧化作用,并总结了其在猪禽上的应用研究和影响其使用效果的因素.     

The vitamin E distribution in serum, liver, adipose and muscle tissues in the pig during depletion and repletion

This study was designed to examine the storage capacity for vitamin E in liver, adipose tissue and skeletal muscle of growing pigs during a period of supplementation and of depletion. Therefore, biopsy specimens of these tissues and samples of serum were frequently taken from 7 pigs throughout the experimental period. After a 7-week period on a diet highly supplemented with vitamin E (405 mg/kg), a significant increase (p less than 0.001) in the concentration of this vitamin was observed in all tissues sampled. The highest level (102.9 +/- 26.2 mg/kg) was observed in the liver. After 2 days of depletion the concentration of vitamin E in the liver had fallen by 80%, whereas the concentration in the fat and muscle remained unchanged during 1 week of depletion. The serum vitamin E value rose significantly (p less than 0.001) after 1 week on the supplemented diet and then remained at about 7 mg/l throughout the supplementation period and decreased (p less than 0.001) after 2 days on a nonsupplemented diet. Generally, the serum vitamin E levels among growing pigs are between 2 and 3 mg/l. The results show that the serum and liver values were correlated when the serum level was within this range. Moreover, it is clearly demonstrated that the concentrations of vitamin E in serum and liver reflect the immediate nutritional status of the animal, whereas the vitamin concentrations in adipose and skeletal muscle tissue reflect its long-term nutritional history.     

A Comparative Review of Vitamin E and Associated Equine Disorders

Vitamin E is a primary chain‐breaking antioxidant that prevents cyclic propagation of lipid peroxidation. Across species, vitamin E is essential for normal neuromuscular function by acting as a potent antioxidant, as well as by modulating the expression of certain genes, inhibiting platelet aggregation and stabilizing plasma membranes. This review focuses on vitamin E structure, absorption, metabolism, current equine dietary recommendations, the interplay between antioxidants and exercise, a discussion of the necessity of vitamin E supplementation in the horse above the Nutritional Research Council (NRC) 2007 requirements, and a review of equine diseases that are associated with a vitamin E deficiency. Particular emphasis is placed on the proteins involved in vitamin E absorption, transport, and metabolism as potential candidates for vitamin E‐associated diseases across species.     

植物多酚的抗氧化机理及其在动物生产中的应用

肉及肉制品在加工及贮藏过程中易发生氧化而导致品质下降，在动物日粮中添加植物多酚可抑制脂肪及蛋白质氧化，进而提高肉及肉制品在加工及贮藏过程中的氧化稳定性。植物多酚因具有酚羟基结构而具有清除自由基的抗氧化作用，可提高动物机体及肉制品中抗氧化酶的活性，还可激活Nrf2/ARE信号通路从而提高肉制品在加工及贮藏过程中的抗氧化能力。将植物多酚添加到畜禽日粮中，可促进动物对饲料中营养物质的消化吸收，提高其生产性能，且可提高动物机体的抗氧化酶活性及总抗氧化能力，降低畜禽产品中丙二醛的含量，提高产品的质量，延长产品的货架期。文章介绍了植物多酚，包括黄酮类、酚酸类、非黄酮类化合物及其代表性化合物的结构，并阐述了其抗氧化性机理及其在动物生产中的应用，旨为研究利用植物多酚提高肉制品的氧化稳定性、安全性提供理论参考。     

维生素E在饲草及畜产品中的应用研究

摘要：维生素E作为一种具有抗氧化作用、安全无毒的食品添加剂,已被广泛用于各种加工产品中。本研究阐述了维生素E的抗氧化机理,从牧草维生素E含量及其影响因素、饲草维生素E对肉奶脂质氧化稳定性品质的提高、动物油脂保存期延长与维生素抗氧化性的关系3个方面综述了维生素E抗氧化的有效性,也从中比较了各生育酚抗氧化能力的大小与环境温度和浓度等因素的相关性,以便于人们更好地了解和利用生育酚。     

万寿菊的生物活性及其在动物生产中的应用研究

万寿菊中主要含有叶黄素、黄酮、精油和α-三联噻吩等活性成分,具有抗炎、抗氧化、抑菌杀虫等生物活性.万寿菊在动物生产中具有提高机体免疫力和生产性能、改善畜产品品质等重要作用.文章对万寿菊的生物活性及其在动物生产中的应用进行综述,旨在为万寿菊的进一步开发利用提供参考.     

Dietary green tea polyphenols do not affect vitamin E status,antioxidant capacity and meat quality of growing pigs

Supplementation of pigs with vitamin E, the most important lipid-soluble antioxidant, has been shown to improve meat quality and animal health. Previous studies in cultured cells and laboratory animals indicate synergistic effects between polyphenols and vitamin E. The present feeding trial was undertaken to investigate the effects of dietary green tea polyphenols (GTP) on vitamin E status, antioxidative capacity and parameters of meat quality in growing pigs. Eighteen castrated, crossbred, male pigs received a flavonoid-poor diet based on corn starch, caseinate and rapeseed oil with a total vitamin E content of 17 IU/kg diet over a period of 5 weeks. This basal diet was supplemented with green tea extract to provide daily doses of 0 (control), 10 and 100 mg GTP/kg body weight. Dietary supplementation of growing pigs with GTP did not affect serum, liver, lung and muscle vitamin E (α- and γ-tocopherol) concentrations, plasma antioxidant capacity (ferric reducing ability of plasma, trolox equivalent antioxidant capacity) or parameters of meat quality including meat temperature, pH, conductivity, colour and drip loss. In conclusion, supplementation of pig diets with green tea catechins is not associated with improved antioxidant status and meat quality under practice-oriented conditions.     

富硒动物产品的研究进展

硒是人体和动物必需的微量元素,具有重要的生理功能。硒能预防心血管疾病、抗肿瘤、维持免疫系统功能。本文就硒的生理功能,富硒产品开发的必要性,有机硒对动物产品硒富集的影响以及开发富硒动物产品存在的问题进行简要综述。