南极磷虾脂溶性成分的研究进展

南极磷虾脂类营养含量丰富:油脂提取物中二十碳五烯酸(EPA)含量高于15%,二十二碳六烯酸(DHA)含量高于9%,总磷脂含量高于20%,冰鲜的南极磷虾中总虾青素含量高于3 mg/100 g。本文总结了近年来国内外学者对南极磷虾油中的脂肪酸、虾青素、脂溶性维生素、甾醇等脂溶性成分及其功效的研究进展,以及磷虾油提取方法、多种成分稳定性的研究结果,并展望了我国开展南极磷虾脂溶性成分综合利用的前景。     

Recent advances in European sea bass and gilthead sea bream nutrition

European sea bass (Dicentrarchus labrax) and gilthead sea bream(Sparus aurata) are amongst the most important finfish speciescultured in the Mediterranean region. Production of these species isnowadays a well-controlled process, but knowledge of their nutritionalrequirements is still very limited. Nevertheless, a considerable amountof data has been accumulated in recent years, and the purpose of thispaper is to review the recent advances on the nutritional requirementsof sea bass and sea bream. The optimum protein to energy ratio of thediets of sea bass and sea bream seem to be higher than for salmonids,and there is some evidence that high dietary lipid levels have nobeneficial effects on fish performances. Although the essential aminoacid requirements were estimated by the ideal protein method, data basedon the dose-response method is only available for a few amino acids.Essential fatty acid requirements were estimated for sea bream juvenilesbut data is lacking for sea bass. Vitamin and mineral requirements ofthese species are practically unknown. Although the importance ofbroodstock nutrition on gonadal development, spawning and egg quality isrecognized, few studies were done to elucidate these aspects. The recentdevelopment of microparticulate diets for larvae will contribute to theaccurate evaluation of their nutritional requirements.     

微量元素及维生素对蜡蚧轮枝菌分生孢子的影响

通过定量地向平皿PDA培养基中添加6种微量元素和7种维生素,并接种蜡蚧轮枝菌菌株Tri-BA81进行培养研究,初筛出微量元素Mn和Ni、维生素叶酸（VM）和烟酸（VB3）对分生孢子的产生具有促进作用。对初筛出的微量元素和维生素设置不同的浓度梯度添加到单一固体基质谷子中,进行发酵筛选,结果表明,微量元素Mn和Ni的最适使用浓度均为25μg·mL-1维生素叶酸（VM）、烟酸（VB3）的最适使用浓度分别为10、1μg·mL-1     

无机盐、维生素及生长调节剂对斑玉蕈菌丝生长的影响

【目的】寻找对斑玉蕈菌丝生长有促进作用的无机盐、维生素及植物生长调节剂,为斑玉蕈液体菌种的进一步开发与利用提供参考。【方法】以斑玉蕈菌株HM-2为材料,向培养基中加入不同种类及质量浓度的无机盐、维生素和植物生长调节剂,于（23±1） ℃、空气相对湿度70%Hypsizigus marmoreus (Peck) Bigelow;inorganic salts;vitamins;plant hormones 75% 的条件下培养12 d后测定菌落直径,研究上述物质对斑玉蕈菌丝生长的影响。【结果】与不添加任何无机盐的培养基相比,0.5～2.0 g/L的 MgSO₄、NaCl和KCl对斑玉蕈菌丝生长均有一定的促进作用,且均以1.5 g/L时促进作用最大,菌落直径分别达到81.04,78.93和80.29 mm;而0.5～2.0 g/L 的CaCl₂、KH₂PO₄和0.01Hypsizigus marmoreus (Peck) Bigelow;inorganic salts;vitamins;plant hormones 0.04 g/L的ZnSO₄对斑玉蕈菌丝的生长具有不同程度的抑制作用。与不添加任何维生素的培养基相比,2.0Hypsizigus marmoreus(Peck) Bigelow;inorganic salts;vitamins;plant hormones 10.0 mg/L的烟酸、叶酸、V_B1和V_B2对斑玉蕈菌丝生长均有一定的促进作用,以2.0 mg/L叶酸的促进作用最大,菌落直径达到67.76 mm;而2.0～10.0 mg/L的V_B6对斑玉蕈菌丝生长无明显的促进和抑制作用。与不添加任何植物生长调节剂的培养基相比,2.0～10.0 mg/L的IBA、GA₃和NAA对斑玉蕈菌丝生长均有极显著的促进作用,以2.0 mg/L IBA的促进作用最大,菌落直径达到69.33 mm;而2.0～10.0 mg/L的KT与6-BA对斑玉蕈菌丝生长的促进作用相对较弱。【结论】在培养基中添加适量的MgSO₄、NaCl、KCl、烟酸、叶酸、V_B1、V_B2、IBA、GA₃和NAA,可促进斑玉蕈菌丝的生长。     

贮存时间和方法对乳猪袋装流质饲料中维生素和微生物含量影响研究初报

为开发袋装流质饲料,将自来水和哺乳乳猪全价配合粉料按4:1比例装入蒸煮袋内后用封口机封口,浸泡40min后立即将蒸煮袋放入温度为90℃的蒸饭箱内在常压下用蒸汽蒸煮40min,并分别测定第1、15和30d哺乳乳猪袋装流质饲料中的维生素和微生物含量;另外,将哺乳乳猪袋装流质饲料开袋后分别放在猪场内和冰箱内(6℃),测定第24h后袋内哺乳乳猪流质饲料微生物含量。结果表明:蒸煮和延长贮存时间会降低袋装流质饲料中维生素的含量,同时蒸煮可有效杀灭饲料中的微生物,但随着贮存时间的延长,有些微生物的活性增强。     

仔猪阶段对维生素的营养需要

仔猪阶段的营养是猪的所有成长阶段中,最复杂最难以掌握的一个阶段.若是维生素营养供给不合理,会直接造成仔猪生长缓慢,并出现腹泻,死亡率极高,最终导致中大猪阶段的生长慢,出栏时间大大延长.文章对仔猪阶段对维生素的营养需要做了探讨.     

Efficacy of vitamin E + selenium and vitamin A + D + E combinations on oxidative stress induced by long-term transportation in Holstein dairy cows

The aim of this study was to evaluate the stress response to long-term transportation and to analyze the effects of vitamin A + D + E and vitamin E + selenium administrations on oxidative stress induced by long-term transportation in Holstein dairy cows. Control group (n = 10) received 0.9% saline (placebo), Group I (n = 10) received vitamin A + D + E, and Group II (n = 10) received vitamin E + selenium. After the transport, adrenaline levels were high in all groups (P < 0.05). Noradrenaline level was low in Group I (P < 0.05) and tended to be low in Group II. Mean levels of serum cortisol decreased significantly in all groups (P < 0.05) when comparing pre-transport data with post-transport data. Glucose levels increased in Control group (P < 0.05) and in Groups I and II (P < 0.01). The malondialdehyde level significantly increased in the Control group (P < 0.05) after the transport and the levels were lower in Group I (P = 0.076) and Group II (P < 0.05) than in the Control group. As a result, vitamin E + selenium and vitamin A + D + E have been determined to prevent lipid peroxidation and oxidative stress, associated with long-term transportation stress in cattle.     

Quantifying the dietary niacin requirement of the Indian catfish, Heteropneustes fossilis (Bloch), fingerlings

A growth study was conducted to determine the dietary niacin requirement of the Indian catfish, Heteropneustes fossilis (Bloch), fingerlings (Mean weight 9.41 ± 0.18 g). Semi‐purified diets with five levels (0, 5, 10, 20 and 40 mg kg^?1 diet) of supplemental niacin were fed to H. fossilis for 15 weeks. Each diet was fed to three replicate groups of fish. Results indicated that the highest (P < 0.05) weight gain was for the fish fed the diet supplemented with 20 mg niacin kg^?1, followed by fish fed the diets with 40, 10 and 5 mg niacin kg^?1, and the lowest in fish fed the unsupplemented control diet. Patterns of specific growth rate (SGR) and protein efficiency ratio (PER) were similar to those of the weight gain. Survival of fish fed the control diet and niacin‐supplemented diet was 58% and 91–100% respectively. Niacin deficiency signs such as anaemia, anorexia, lethargy and skin haemorrhage were observed in fish fed the control diet. The haematocrit values (Ht) were higher (P < 0.05) in fish fed the diets supplemented with niacin than in fish fed the control diet. The hepatosomatic indexes (HSI) of fish fed with or without niacin‐supplemented diets were not significantly (P > 0.05) different from each other. Both body protein and lipid content were higher (P < 0.05) in fish fed the diet supplemented with 20 and 40 mg niacin kg^?1, respectively, than those fish fed other diets. The niacin content in liver significantly (P < 0.05) reflected the supplementation level in the diet and ranged from 29.11 to 40.31 mg g^?1 tissue. The associated liver niacin content for growth was about 47 μg g^?1 tissue. Quadratic regression analysis showed that the dietary niacin requirement for maximal growth of H. fossilis under these experimental conditions was about 25 mg kg^?1 diet.     

Theoretical evaluation of risk for nutritional deficiency with caloric restriction in dogs

Background: Risk of nutrient deficiency in dogs during caloric restriction is not currently known, while obesity is a growing concern.

Objectives: To determine nutrients that might require further evaluation for the risk of deficiency during caloric restriction.

Animals and methods: Five commercially available canine diets, representing a range of caloric density (2900–4240?kcal/kg metabolizable energy), were assessed for potential nutrient inadequacy if fed to a hypothetical overweight dog. Caloric density and typical nutrient analysis for protein, amino acids, fat, fatty acids, minerals, and vitamins were obtained from the manufacturer. Nutrient intake was calculated using ideal body weight for caloric intakes including 87, 79, 70, 61 and 52?kcal/kg^0.75 and compared with National Research Council recommended nutrient allowances (NRC-RA) for ideal weight.

Results: No diets were less than NRC-RA when compared to NRC-RA (/1000?kcal). The five evaluated diets varied in terms of which nutrients were less than NRC-RA and the degree of restriction required for this to occur. All diets had at least one essential nutrient less than NRC-RA at 79?kcal/kg^0.75/day and multiple nutrients less than NRC-RA at 70?kcal/kg^0.75/day. Choline and selenium were the nutrients most often affected by caloric restriction but others were less than the NRC-RA with caloric restriction.

Conclusions: Further research is needed to determine actual nutrient requirements in overweight dogs, and whether clinical nutrient deficiencies actually arise in vivo.

Clinical importance: Weight loss plans for overweight dogs (particularly those with very low-energy requirements) should include consideration for nutrient adequacy.     

Serum Vitamin E Concentration of Horses on Different Vitamin E Supplementation Levels

Abstract

The influence of vitamin E supplementation on blood serum vitamin E concentration as well as the seasonal variation of serum vitamin concentration was investigated. Forty horses were divided into a control and three vitamin E supplementation (experimental) groups. The levels of the vitamin E supplementation in the three experimental groups were 1, 3 or 5 mg/kg body weight (bwt) per day. The vitamin was dosed orally. The supplementation was started either at the beginning or in the middle of the indoor (winter) feeding period. There was seasonal variation in the serum vitamin E content; the serum vitamin concentration increased during the grazing and decreased during the indoor feeding period. The basal feeding and a daily supplement of 1 mg/kg bwt were not adequate to maintain or increase the serum vitamin E concentration during the indoor feeding period in an exercising horse. The minimum daily intake of vitamin E would seem to be greater than 1.5 mg/kg bwt. It is suggested that a daily supplement of 3 to 5 mg/kg bwt may be required by horses in training to increase the serum vitamin E levels. This amounts to 1500–2500 mg/day for a horse weighing 500 kg. Supplementation should be started at the beginning of the indoor feeding period.