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2.
《中国畜牧杂志》2019,(3)
试验旨在探讨日粮钙水平对空怀期云南半细毛羊生长性能、配种前血清生化指标和繁殖相关激素的影响,为开展空怀期云南半细毛羊营养需要量研究提供参考。选用50只体况良好、体重相近、38月龄的经产2胎空怀云南半细毛羊,随机均分为5组,分别饲喂0.40%(无外源钙)、0.45%、0.53%、0.66%、0.85%5个钙水平的日粮。预试期14d,正试期30d。结果表明:0.53%钙水平组云南半细毛羊的总增重、平均日增重、平均日采食量、耗料增重比等指标相对优于其他组;0.40%钙水平日粮组的血清钙最高,血清碱性磷酸酶、甲状旁腺素、钙、磷组间差异不显著(P>0.05);繁殖相关激素各组间表现不一,0.40%钙水平组雌二醇水平最高(P>0.05)。在日粮磷水平为0.20%水平条件下,0.53%钙水平组的空怀期云南半细毛羊表现出较好的生长性能,可为临配种前生理生化和激素水平提供较好准备;增加日粮钙水平,未见对以上指标有明显的正向增强作用,可能与日粮钙磷比失衡有关。 相似文献
3.
Mahmoud Alagawany Shaaban S. Elnesr Mayada R. Farag Ruchi Tiwari Mohd. Iqbal Yatoo Kumaragurubaran Karthik Izabela Michalak Kuldeep Dhama 《The Veterinary quarterly》2021,41(1):1
Nutraceuticals have gained immense importance in poultry science recently considering the nutritional and beneficial health effects of their constituents. Besides providing nutritional requirements to birds, nutraceuticals have beneficial pharmacological effects, for example, they help in establishing normal physiological health status, prevent diseases and thereby improve production performance. Nutraceuticals include amino acids, vitamins, minerals, enzymes, etc. which are important for preventing oxidative stress, regulating the immune response and maintaining normal physiological, biochemical and homeostatic mechanisms. Nutraceuticals help in supplying nutrients in balanced amounts for supporting the optimal growth performance in modern poultry flocks, and as a dietary supplement can reduce the use of antibiotics. The application of antibiotic growth enhancers in poultry leads to the propagation of antibiotic-resistant microbes and drug residues; therefore, they have been restricted in many countries. Thus, there is a demand for natural feed additives that lead to the same growth enhancement without affecting the health. Nutraceuticals substances have an essential role in the development of the animals’ normal physiological functions and in protecting them against infectious diseases. In this review, the uses of amino acids, vitamins and minerals as well as their mode of action in growth promotion and elevation of immune system are discussed. 相似文献
4.
不同养殖模式翘嘴鲌肌肉营养品质比较 总被引:1,自引:0,他引:1
为评价池塘与大湖不同养殖模式翘嘴鲌(Culter alburnus)肌肉营养品质差异,试验分析了商品翘嘴鲌肌肉常规营养成分、氨基酸、脂肪酸、矿物元素含量等营养指标。结果表明:大湖翘嘴鲌肌肉水分含量显著低于池塘翘嘴鲌(P<0.05),粗蛋白质含量高于池塘翘嘴鲌,差异不显著(P>0.05)。池塘与大湖翘嘴鲌肌肉,除了赖氨酸和组氨酸以外(P<0.05),绝大部分氨基酸含量均无显著性差异(P>0.05)。大湖翘嘴鲌肌肉的总氨基酸、必需氨基酸和鲜味氨基酸含量分别较池塘翘嘴鲌高出2.72%、2.87%和2.50%。根据氨基酸评分(AAS)和化学评分(CS)结果,池塘与大湖翘嘴鲌肌肉中第一限制性氨基酸均为蛋氨酸+胱氨酸,赖氨酸相对含量最高,必需氨基酸指数(EAAI)分别为68.81和69.62。池塘翘嘴鲌的棕榈油酸(C16:1)含量显著高于大湖翘嘴鲌(P<0.05),而大湖翘嘴鲌肌肉的单不饱和脂肪酸(MUFAs)、高不饱和脂肪酸(HUFAs)、必需脂肪酸(EFA)、EPA+DHA含量则高于池塘翘嘴鲌(P>0.05)。试验检测了池塘与大湖翘嘴鲌肌肉11种矿物元素,其中镁有显著差异(P<0.05),重金属元素(铬、镉、铅)含量均在限量范围以内。综上所述,大湖养殖翘嘴鲌营养品质优于池塘养殖。 相似文献
5.
研究了广西右江河谷地区芒果中农药残留现状,并做了人群的膳食风险评估,旨在为芒果农产品的农业主管部门监管提供科学依据。在右江河谷产区采集99份芒果样品,对样品中107种农药残留进行分析检测,并运用点评估方法对农药残留膳食摄入风险进行评估。结果表明,芒果的检出农药类型上,以甲氧基丙烯酸酯类杀菌剂为主,检出率高达61.61%;累计检出20种农药残留,样品检出率为80.80%,其中吡唑醚菌酯检出率最高,达到46.46%;按照GB 2763-2021判定,超标数量达到14份,占总样品数量的14.14%,吡唑醚菌酯和氯氟氰菊酯两种农药超标;检出农药对成人和儿童的慢性膳食摄入%ADI在0.00 -2.43 %之间,其中氯氟氰菊酯、联苯菊酯对儿童的急性膳食摄入%ARfD分别为101.82%、136.16 %,所有检出农药对成人的急性膳食摄入%ARfD均小于100 %。广西右江河谷地区芒果中多农药组分残留情况明显,吡唑醚菌酯和氯氟氰菊酯需要重点监测关注;儿童对芒果中摄入氯氟氰菊酯和联苯菊酯的农药残留急性膳食有一定的暴露风险,成人对芒果中检出的所有农药急、慢性膳食暴露风险极低。 相似文献
6.
In this study, the effect of immature wheat flour (IWF) on the fermentation activity of lactic acid bacteria (LAB) and on the nutritional quality properties of bread were evaluated. IWF was added in the as the ratio of 10g/100g in sourdough fermentation medium, and the fermentation activity (total LAB, pH, titration acidity (TA), and total reducing sugar (TRS)) of LAB cultures was monitored. Additionally, some physical quality characteristics (specific volume, texture profile and colour value), estimated glycaemic index (eGI), rapidly digestible starch (RDS), slowly digestible starch (SDS), and the total dietary fibre content of sourdough bread were determined. According to the statistical test, it was revealed that the IWF addition stimulated LAB growth and increased their fermentation activity. The pH of the fermentation medium decreased from 6.57 to 3.50, and TA raised from 0.13% to 1.2% in 48 h. The highest TRS content was determined in IWF enriched sourdough samples, and as a result of this, the eGI of sourdough bread increased. Compared to the control sample, the SDS and total dietary fibre content were higher in IWF added sourdough bread, and a positive correlation was noted between these two components. IWF utilisation of sourdough bread formulation increased the hardness value by nearly 50%. 相似文献
7.
铁氧化物与硅酸盐矿物是土壤中最重要、最活跃的固相组分,它们之间的交互作用直接影响土壤物理化学特性,可有效地调控土壤(类)重金属的迁移、转化。本文以铁氧化物和硅酸盐矿物胶结过程中的一些表观特征变化为出发点,从宏观、表观到微观综述了二者交互作用的界面特性和机理、交互作用前后对土壤砷的固定与释放机制等内容。本文阐明层状硅酸盐与铁氧化物通过多种化学作用而发生表面复合,其中静电作用是作用力之一,带负电荷的硅酸盐与带正电荷的铁氧化物在静电引力的作用下迅速结合,在胶体表面双电层上形成二元团聚体;形成的二元团聚体可改变土壤矿物的表面积和孔性结构、表面电化学特性和物理性质。同时,铁氧化物-硅酸盐复合物表面的活性基团可以通过内层络合共氧的方式将土壤中AsO_4~(2-)络合,形成单核或双核表面络合物而固定砷。复合物对AsO_4~(2-)的吸附能力介于铁氧化物和硅酸盐矿物之间,并更接近铁氧化物的表面吸附特性。本文旨在为土壤砷的原位固定提供理论支撑。 相似文献
8.
K. HAMRE A. SRIVASTAVA I. RØNNESTAD A. MANGOR-JENSEN & J. STOSS 《Aquaculture Nutrition》2008,14(1):51-60
The current best practice intensive culture of larval Atlantic cod includes feeding rotifers from onset of exogenous feeding until 25–30 days after hatching. These larvae grow considerably slower and develop higher frequencies of deformities than larvae reared in semi‐extensive systems, using copepods as feed. The present study compares the micronutrient concentrations in rotifers with those of copepods, with the aim of identifying nutrients that may be limiting for normal growth and development of cod larvae. An additional criterion used is the nutrient requirements given for fish in general, by NRC (1993) , as nutrient requirements of cod remains to be determined. Rotifers were fed on four different diets, consisting of baker's yeast with cod liver oil (3.3 : 1 dry weight (DW)/v), baker's yeast with Algamac 2000TM (3.5 : 1 DW), baker's yeast with live algae Chlorella (4.1 : 1 DW), and Culture Selco 3000TM (CS). CS was a complete commercial diet for rotifers while the other diets are considered as based on raw ingredients. Compared with copepod nutrient levels, rotifers grown on yeast‐based diets supplemented with either cod liver oil, Algamac 2000 or Chlorella were apparently sufficient for covering the requirements in cod larvae for all the B‐vitamins, except thiamine. Rotifers cultured on the CS diet also had sufficient amounts of thiamine. Of the minerals, only calcium and magnesium were sufficient, using this criterion while iron was on the borderline. However, with reference to the requirements given for larger fish ( NRC 1993 ), only thiamine, vitamin A, manganese, selenium and perhaps copper, appear too low in the rotifers cultured without extra micronutrient supplementation. The other nutrients were present at levels intermediate between copepod and fish requirement levels. This study suggests that it is necessary to develop enrichment techniques to produce rotifers with sufficient amounts of all micronutrients. Such techniques will also be important tools for determining which nutrients are present at levels below the actual requirements in cod larvae. 相似文献
9.
测定分析并评价了养殖曼氏无针乌贼( Sepiella maindroni)白色卵膜(WEM)的营养成分。结果表明,WEM (鲜样)中水分、粗灰分、粗蛋白和粗脂肪的质量分数分别为92.34%、1.76%、5.28%和0.34%。WEM(干样)中氨基酸(AA)总量为55.53%,其中必需氨基酸(EAA)总量为19.85%;必需氨基酸与非必需氨基酸(NEAA)的比值为65.6%,构成比例符合 FAO/ WHO 规定的优质蛋白质标准;鲜味氨基酸( DTAA)总量为29.53%。WEM的第一限制性氨基酸为苯丙氨酸+酪氨酸(Phe + Tyr),必需氨基酸指数(EAAI)为38.03。脂肪酸中多不饱和脂肪酸(PUFA)占19.21%。矿物质含量丰富,尤其以磷(P)质量分数最高(1423.2 mg·kg -1)。结果表明,WEM 营养组分较为全面,与野生黑色卵膜(BEM)的营养成分进行对比分析发现,在氨基酸组成、必需氨基酸和无机元素质量分数等方面存在差异,这种差异是否是导致白化受精卵孵化率降低的关键因素有待进一步研究。 相似文献
10.
This study investigated the influence of different dietary protein/carbohydrate ratios on activities of enzymes involved in the amino acid metabolism as well as on growth performance and body composition of Nile tilapia (Oreo- chromis niloticus). Fish were fed semi-synthetic diets differing in their protein/carbohydrate ratio. The diets were formulated to be isolipidic and isoenergetic (on the basis of metabolizable energy). Fish were reared individually. After a prefeeding phase, tilapia were randomly assigned to three groups and were fed the experimental diets at a relatively low level. The study lasted 9 weeks. Proximate composition, gross energy content, and activities of aspartate aminotransferase (ASAT) and alanine aminotransferase (ALAT) in the liver of fish were determined. While the mean growth rate and feed conversion efficiency did not differ significantly among the feeding groups, the body composition showed significant differences. The dietary protein/carbohydrate ratio had no significant effect on the protein and energy gain, but the lipid gain was significantly higher in tilapia fed the low-protein diet. The activities of ASAT and ALAT per gram of liver and per gram of soluble protein were significantly increased in fish fed the high-protein diet. There was a significant positive correlation between the activities of ASAT and ALAT. The activities of both enzymes in the liver were significantly higher in fish with a higher protein gain. Measuring the activities of enzymes involved in the amino acid metabolism can provide more information about the metabolic utilized dietary protein. 相似文献