Effects of Altitude Change on Nutritional Quality and Elymus nutans Regularity in Qinghai-Tibet Plateau

In order to reveal the effects of different altitudes on the nutritional quality of wild forage in Qinghai-Tibet Plateau,this study used Elymus nutans as the tested plants to evaluate the changes of nutrient contents and the correlation between the nutrient contents and altitudes.Four sampling sites were set up at altitudes of 2 562,2 660,2 775 and 2 905 m with the vertical distance among each sampling point was about 100 m.The results showed that the crude protein,ash and phosphorus contents of Elymus nutans decreased significantly with an increase in altitudes.The crude protein contents decreased by 1.87 % with each 100 m increase in altitudes.The variation rule of crude protein contents with altitudes in the simulated curve was "y=–0.0187x+63.244 (R~2=0.9557)".The crude ash contents decreased by 1.77% with each 100 m increase in altitudes.The variation rule of crude ash contents with altitudes in the simulated curve was "y=–0.0177x+56.144 (R~2=0.978)".Neutral detergent fiber (NDF) and acid detergent fiber (ADF) showed an overall increasing trend with the increase of altitudes,but the most obvious increase was at 2 775 m.The contents of crude fat and Ca did not change regularly with altitudes.     

饲料型小黑麦新品系种子产量及籽粒营养价值的分析

以甘肃省临洮县种植的10份饲料型小黑麦新品系为试验材料,甘农1号小黑麦和新小黑麦5号为对照,研究了小黑麦材料的种子产量及籽粒的营养价值,采用灰色关联度法对参试材料的种子产量与营养品质进行了综合评价。结果表明:不同小黑麦材料间种子产量和营养价值均存在显著性差异,Z49的种子产量最高,达11 133.50kg/hm~2,Z48的粗蛋白含量最高,为14.04%,Z5的淀粉含量最高,为65.69%,Z35的赖氨酸含量最高,为0.46%,Z3的粗脂肪含量最高,为2.37%。综合分析表明,Z48和Z49的综合性状最佳,其关联度分别为0.713 6和0.786 4,Z19和Z23的综合表现较差。     

Evaluation of commercial catfish, tilapia and salmonid diets for growth promotion of white suckers

In an attempt to identify appropriate diets for use in intensive baitfish culture, the efficacy of three commercial diet formulations, a high-protein, high-lipid, low-carbohydrate diet [a semi-moist salmonid diet (SD)] and two low-protein, low-lipid, high-carbohydrate diets [a catfish diet (CD) and a tilapia diet (TD)] on growth performance of juvenile white suckers, Catostomus commersoni, was examined. All three diets permitted growth during the 16 week trial. The SD promoted highest growth and somatic protein and lipid deposition, whereas the CD and TD formulations promoted markedly higher accumulations of glycogen in the carcass and liver. The high hepatic glycogen content was associated with an elevated hepatosomatic index in the CD- and TD-fed groups. Plasma T3 levels were lower in the CD- and TD-fed groups, possibly a response to the low dietary protein or indicative of dietary insufficiency in these fish. Of the three diets evaluated, the SD was considered to be the best in terms of the growth performance parameters measured, and offers an economical and appropriate diet for intensive culture of juvenile white suckers.     

Physiological and biochemical parameters for egg quality determination in lake trout,Salmo trutta lacustris

The present study investigated the relationships between egg viability and ovarian fluid composition, egg physiology and egg metabolism in lake trout, Salmo trutta lacustris, to obtain biomarkers for egg quality determination. The ovarian fluid pH, protein levels and activities of aspartate aminotransferase and -d-glucuronidase were significantly correlated with egg viability expressed as the number of eyed stage embryos. Regression models demonstrated that an ovarian fluid pH between 8.44 and 8.57, protein levels below 235.56 mg 100 ml^–1ovarian fluid, aspartate aminotransferase activity below 31.65 m min^–1 l^–1ovarian fluid and -d-glucuronidase activity below 8.62 m min^–1 l^–1 ovarian fluid characterized egg batches with high viability (80%).The increase in the egg wet weight during water hardening was also significantly correlated with the number of eyed stage embryos, and egg batches with high egg viability (80%) increased in wet weight by 13% during water hardening.From the investigated metabolic parameters the number of eyed stage embryos was significantly correlated with activities of NADP-dependent isocitrate dehydrogenase (egg viability 80% at 2.07 nM min^–1 mg^–1 protein) and NAD-dependent malate dehydrogenase (egg viability 80% at 47.25 nM min^–1 mg^–1 protein), with the respiration rate (egg viability 80% at 8.71 nM min^–1 mg^–1 protein), with the ratio of NADH to NAD levels (egg viability 80% 0.872), with the levels of free, non-esterified fatty acids (egg viability 80% 72.34 g mg^–1 protein), and the ratio of non esterified to esterified fatty acids (egg viability 80% at 0.749). Also, subjective and visual control methods were described to distinguish between batches with viable and non viable eggs.     

Effects of different dietary protein and lipid levels on growth, feed utilization and body composition of red porgy (Pagrus pagrus) fingerlings

Two feeding trials were conducted to determine the minimum dietary protein level producing maximum growth, and the optimum protein to energy ratio in diets for red porgy (Pagrus pagrus) fingerlings, respectively. In the first trial, six isoenergetic diets were formulated with protein levels ranging from 400 to 650 g kg^?1 in increments of 50 g kg^?1, and fed for 11 weeks to 2.8 g average initial weight fish. Weight gain, specific growth rate and feed efficiency were significantly higher with diets containing higher protein levels, when compared with dietary levels below 500 g kg^?1. The highest protein efficiency ratios were obtained in fish fed 500 g kg^?1 dietary protein. The minimum dietary protein level producing maximum fish growth was found to be 500 g kg^?1. In the second trial, 15 g average initial weight fish were fed for 12 weeks, six diets containing three different lipid levels (100, 150 and 200 g kg^?1) combined with two protein levels (450 and 500 g kg^?1). Weight gain values increased when dietary lipids increased from 100 to 150 g kg^?1, with a further decrease for 200 g kg^?1 lipids in diets; the lowest fish growth being supported by 200 g kg^?1 dietary lipids. Fish growth was significantly higher when dietary protein increased from 450 to 500 g kg^?1. There was no evidence of a protein‐sparing effect of dietary lipids. Liver protein and lipid contents were low when compared with other fish species. All diet assayed produced high liver glycogen accumulation. The recommended protein and lipid levels in diets for red porgy fingerlings were 500 and 150 g kg^?1, respectively.     

Managing soil quality for humanity and the planet

Rather than a human-centric, the basic strategy of achieving Sustainable Development Goals must be focused on restoring and sustaining planetary processes. The urgency of meeting the demands of the humanity must be reconciled with the necessity of enhancing the environment. Increasing and restoring soil organic matter content of the degraded and depleted soils is critical to strengthening planetary processes.     

不同加工方式的南极大磷虾粉营养品质评价

对3种加工方式的南极大磷虾（Euphausia superba）粉（磷虾粉A为冷冻运回中国,冻干;磷虾粉B为捕捞现场蒸煮加工,未添加抗氧化剂;磷虾粉C为捕捞现场蒸煮加工,添加抗氧化剂）的营养品质进行分析和评价。结果显示,3种磷虾粉中粗蛋白占干物质的质量分数为61.73%~68.48%,氨基酸总量（AA）为51.46%~66.32%,10种鱼虾必需氨基酸总量（EAA）为23.69%~31.78%,多不饱和脂肪酸总量（PUFA）占脂肪酸总量的44.05%~52.74%,EPA和DHA占脂肪酸总量的38.55%~46.38%。其中磷虾粉C的AA、EAA、EAAI值、SRC值、PUFA、EPA和DHA的质量分数均高于磷虾粉A和B。磷虾粉C的粗蛋白质量分数高,氨基酸组成合理,多不饱和脂肪酸丰富,具有最高的营养价值。

     

转红色荧光蛋白基因唐鱼与非转基因唐鱼肌肉营养成分的分析和比较

对含有外源基因的转红色荧光蛋白基因唐龟(简称:转基因唐鱼)和同胞家系中不含有外源基因唐鱼(简称:非转基因唐鱼)肌肉中的一般营养成分、游离氨基酸和脂肪酸的组成和含量进行分析和比较.结果表明:转基因唐鱼肌肉水分、粗蛋白含量粗灰分含量高于非转基因唐鱼,粗脂肪含量低于非转基因唐鱼,但差异均不显著(P>0.05);转基因唐鱼和非...     

Protein Hydrolysate from Visceral Waste Proteins of Bolti Fish (Tilapia nilotica): Chemical and Nutritional Variations as Affected by Processing pHs and Time of Hydrolysis

The main objective of the current work was to evaluate the proximate chemical composition and nutritional quality of amino acids of protein hydrolysates from viscera of Tilapia nilotica fish. The results of amino acid composition showed that all hydrolysates contained sufficient and/or excessive amounts of both essential and nonessential amino acids, with appreciable values of essential amino acid/nonessential amino acid ratio (0.77 to 1.59) and essential amino acid/total amino acid ratio (43.35 to 61.35). All protein hydrolysates had a high content of the flavor enhancer amino acids. The lowest values of essential amino acids were found for phenylalanine and methionine with chemical scores ranging from 0.04 to 0.77 and 0.09 to 1.06, respectively, except for 18 h hydrolysates. The protein efficiency ratio had values greatly exceeding 2.0, which is considered a high quality. On the other hand, the levels of sugar and ash contents ranged from 2.69 to 3.32 g L^?1 and 0.48 to 2.1%, respectively, with 9.2 to 14% dry matter. Mineral composition showed that sufficient amounts of calcium, sodium, potassium, magnesium, and iron were present. The results suggest that the studied hydrolysates are appropriate for use in balanced human or animal diets.     

仔稚鱼的极性脂——磷脂研究进展

总结了饲料磷脂对仔稚鱼在成活率、生长、抗御外部压力的耐受性以及畸形鱼发生率等方面的重要作用。饲料中缺乏磷脂对仔稚鱼的影响比对幼鱼的影响更明显 ,仔稚鱼饲料中的磷脂含量应高于幼鱼饲料中磷脂的含量。仔稚鱼对饲料磷脂中的磷脂酰胆碱和磷脂酰肌醇的需要量占饲料的 1%～ 3% (干重 )。用磷脂作为必需脂肪酸和能量的来源在仔稚鱼中的消化率高于中性脂的消化率。饲料磷脂可以增强仔稚鱼体内的脂类运输能力