Control of phosphorus homeostasis of Atlantic salmon (Salmo salar) in fresh water     

J. Vielma  S.P. Lall 《Fish physiology and biochemistry》1998,19(1):83-93

Studies were conducted to determine the absorption, excretion and requirement of dietary phosphorus (P) by Atlantic salmon (Salmo salar). Triplicate groups of salmon parr, initial weight 15 ± 0.5±g , were fed, diets containing 4, 5, 6, 7, 8, 9, 11 and 13 mg P and 20 KJ of digestible energy (DE) per±g of diet (dry matter basis, DMB) to satiation for 16 weeks. The basal diet containing 4 mg P g^-1 (0.15 mg available P per KJ DE) was supplemented with graded levels of calcium phosphate, Ca(H₂PO₄)²H₂O to formulate the eight experimental diets. The fish were reared in fresh water at a temperature of 15 °C on a 12 h photoperiod. Vertebrae ash increased from 316 to 516 mg g^-1 fat-free dry matter with an increase in dietary P content. P requirement was estimated by using a four-parameter sigmoidal equation. The data suggests that a diet of 0.28 mg available P per KJ DE is needed for Atlantic salmon. Phosphate and calcium levels in plasma and bone increased, whereas levels of magnesium and liver cholecalciferol decreased, with an increase in dietary P.Phosphate excretion in urine and apparent availability of P were determined in deficient and replete fish. In deficient fish, the urine phosphate concentration was 0.10 mmol L^-1 before feeding and 0.25 mmol l^-1 after feeding, whereas in replete fish these concentrations were 1.09 and 5.11 mmol l^-1, respectively. The increase in urine phosphate concentration was higher in replete fish than in deficient fish, however, the apparent absorption of P was found to be significantly lower in replete fish than in deficient fish. These results suggest that similarly to terrestrial vertebrates, P homeostasis in Atlantic salmon is controlled by absorption in the intestine, conservation in the kidney and storage in the bones.  相似文献   

不规则盐度脉冲对许氏平鲉氨氮、磷排泄的影响     

侯晓飞  宋协法  葛长字  毛玉泽  于守团  叶乃好 《渔业现代化》2008,35(2):19-23

在静水系统中,骤然改变水体盐度,形成盐度脉冲;研究许氏平鲉Sebastodes fuscescens(Houttuyn)经历该脉冲后其氨氮、活性磷酸盐排泄的情况。结果表明,盐度改变后,许氏平鲉的氨氮排泄率比正常盐度(30)下呈现出不同程度的升高趋势;当盐度由30降为25和20时,随着体重增加,氨氮排泄率先增大,后又减小;当盐度由30上升为35时,氨氮排泄率随体重增加而呈下降趋势。盐度改变后,许氏平鲉的活性磷酸盐排泄率随体重增大呈先增大后减小的趋势。在同一体重下,盐度由30降至20时,活性磷酸盐的排泄率最大;盐度由30升至35时,磷的排泄率最小。方差分析表明,盐度脉冲对许氏平鲉氨氮排泄率有显著的影响(P<0.05),对活性磷酸盐排泄率的影响不显著(P>0.05)。该研究对于鱼类养殖的水质管理、养殖场的布设等有重要的指导意义。  相似文献   

Effect of Different Levels of Dietary Organic (Bioplex) Trace Minerals on Live Performance of Broiler Chickens by Growth Phases     

《The Journal of Applied Poultry Research》2008,17(1):109-115

  相似文献   

犬贾第虫包囊排出规律的研究     

喻建军  张西臣  李建华 《畜牧与兽医》2001,33(1):8-9

对自然感染贾第虫的比格犬进行粪检调查 ,结果表明犬贾第虫包囊排出呈间歇性 ,其间歇期为 7～ 8d ,排囊后 1 2～ 1 4d达到排囊高峰期 ,峰期持续 2～ 3d,排囊持续时间为 2 5～ 2 7d。用 2只幼犬进行免疫抑制接种犬贾第虫 ,接种后第 7天出现排包囊 ,排囊后 6～ 7d达到排囊高峰期 ,峰期持续 4～ 5d。受染动物出现腹泻 ,体重减轻  相似文献   

植物忍耐低磷胁迫机理的研究进展   总被引：1，自引：0，他引：1  

陈声奇  陈爱珠  周畅 《湖南农业科学》2007,(2):43-46

利用和挖掘作物自身磷高营养效率的能力,以改良作物磷营养性状,已成为植物磷素营养研究的重点和热点。论述了低磷胁迫下植物根系形态、根系分泌物以及磷的跨膜运输和体内转运等方面的适应性变化,总结了目前与磷高效营养性状有关的基因定位和克隆的研究进展,进而揭示出植物低磷胁迫忍耐机理。  相似文献   

樟科植物提取物对断奶仔猪粪尿氮排放的影响   总被引：5，自引：0，他引：5  

潘倩  洪奇华  杨彩梅  石军  陈安国 《浙江大学学报(农业与生命科学版)》2007,33(6):656-662

为研究樟科植物提取作为脲酶抑制剂对仔猪粪尿氮排泄的影响,选取杜长大三元杂交30日龄断奶仔猪480头,按胎次、体重相近和公母基本一致分成5个处理组,分别饲喂添加不同剂量樟科植物提取物的日粮,即空白对照组Ⅰ、150 mg·kg-1组Ⅱ、300 mg·kg-1组Ⅲ、450 mg·kg-1组Ⅳ、600 mg·kg-1组Ⅴ,每个处理设3个重复,每个重复32头猪.结果表明:第Ⅳ、Ⅲ组与第Ⅰ组相比,料肉比分别降低5.67%(P＜0.01)和4.64%(P＜0.01);第Ⅳ、Ⅴ组与第Ⅰ组相比,粪样中微生物的脲酶活性显著降低(P＜0.05);第Ⅴ、Ⅳ组的尿素分解减少,总氮保持率提高,48 h后与第Ⅰ组差异均达到极显著水平(P＜0.01).樟科植物提取物的添加使血清中总蛋白含量提高、尿素氮含量降低.试验结果表明樟科植物提取物添加在断奶仔猪日粮中能够促进仔猪生长,抑制粪中脲酶活性,减少粪尿氮排泄,最佳使用剂量为450 mg·kg-1饲料(Ⅳ组).  相似文献   

Metabolism of microbial nitrogen in ruminants with special reference to nucleic acids     

Tsutomu FUJIHARA  Martin N. SHEM 《Animal Science Journal》2011,82(2):198-208

Characteristically the metabolism of microbial nitrogen (N) compounds in ruminants involves the degradation of dietary N and synthesis of microbial protein (MP), compounds including a small amount of peptides and free amino acids, which may account for 75–85% of total N and the remainder are nucleic acids (NA: DNA and RNA). Generally rumen microbes contain 10–25% NA‐N of the total N while 70–80% is in the form of RNA. This paper describes the degradation and synthesis of NA in the rumen and their fate in the lower digestive tracts. Their physiological and nutritional significance in different types of ruminant animals is also discussed. The research works on NA metabolism in ruminants has been mainly on metabolism of purines after rumen microbial digestion and absorption in the lower gut. Subsequently, the fate of absorbed purines has been intensively investigated to assess the extent of MP synthesis in the rumen. The method for predicting ruminal synthesized MP and subsequently digested MP has been proposed using urinary purine derivative (PD) excretion in sheep and cattle fed on ordinary feed. The latter approach has now been adopted for calculation of protein supply in some feeding standards, although there are still difficulties in predicting representative samples of rumen microbes, and also uncertainties in variations of non‐renal and endogenous purine losses.  相似文献   

反刍动物生产中碳、氮、磷、钾的减排问题     

高民  温雅俐  杜瑞平 《畜牧与饲料科学》2011,(9)

近年来,随着我国奶牛养殖数量和规模的不断扩大,大量的粪尿作为肥料被广泛地施用在农田里,奶牛正常的生理活动产生的大量气体（CO2和CH4）也被排放到了空气中,但是反刍动物生产中排放的这些废物却对土壤、空气和水造成了日益严重的污染,其中粪、尿和气体中的碳、氮、磷、钾元素引起的环境污染问题更是不容忽视。笔者就以上存在的问题综述了奶牛生产中碳、氮、磷和钾对环境的污染,并从营养和饲养管理上提出相应的减排技术措施。  相似文献   

日粮调节与生猪减排的研究     

许卫华  江胜滔王华江祖德  谢必峰 《饲料博览》2007,(7):10-13

为了解决养殖污染，实现生猪清洁生产，通过在猪日粮中添加合成氨基酸、复合蛋白酶、植酸酶、寡肽等复合添加剂，最终配成低蛋白日粮，在不影响猪生长性能的同时降低猪粪便中氮、磷的含量，减轻猪场治理污染的负荷，缓解养猪对环境的压力。试验结果表明，理想的试验组中，生长猪（30～60kg）和肥育猪（60—90kg）的碍增重、料肉比、干粪中N、P含量，分别为0．74kg，2.18，1.57％，0．71％和0：81kg，3．72，2．17％，0．89％。同比对照组，日增重分别提高15.6％和31．8％，其余分别降低8．79％，25．2％，33．0％和13．3％，6．5％，15.2％。减排效果明显，并且生长性能有不同程度的提高。  相似文献   

Mucus excretion and carbon turnover of endogeic earthworms   总被引：4，自引：0，他引：4  

S. Scheu 《Biology and Fertility of Soils》1991,12(3):217-220

Summary Mucus excretion of endogeic earthworms, by the body surface to burrow walls and by the intestine to casts, was investigated using uniformly ¹⁴C-labelled adult or subadult specimens of Octolasion lacteum (Örley) in laboratory incubations in soil from a beechwood on limestone. The daily loss of C due to mucus excretion from the body surface and in casts was calculated as 0.2 and 0.5% of total animal C, respectively. The C loss due to mucus excretion by subadult or adult individuals of O. lacteum is assumed to account for 63% of total C losses (including mucus excretion and respiration) of the earthworms. In a second experiment we studied the incorporation of ¹⁴C from labelled soil, again from a beechwood on limestone, into the tissue of the endogeic earthworm species Aporrectodea caliginosa (Savigny). The results of this experiment indicate the existence of two C pools, one more labile and one more stable, in earthworms. It is assumed that the C investment for respiration and mucus excretion is derived from the labile C pool of endogeic earthworms.  相似文献