营养因素对比目鱼形变的影响

比目鱼是海水鱼中的一大类,包括鲆科、鲽科、鳎科3科。鲆科中常见的有牙鲆、斑鲆、花鲆;鲽科中常见的有高眼鲽、石鲽、木鲽和油鲽;鳎科中最常见的是舌鳎。比目鱼成鱼两只眼睛在同侧,但刚孵化出来的小比目鱼的眼睛生在两侧,在鱼体长到大约3cm长的时候,比目鱼的眼睛开始发生移位,一侧的眼睛向头的上方移动,渐渐地越过头的上缘移到另一侧,直到接近另一只眼睛时才停止。正常着色的比目鱼,有眼面呈褐色或棕褐色,无眼面呈白色。但是,人工养殖的比目鱼常大量出现着色异常的个体。这些鱼通常售价较低,且放流时易被敌害捕食,成活率低,这是比目鱼养殖…     

碱性矿物质对比目鱼生长性能、养分消化率和非特异性免疫的影响

文章旨在评估一种商品复合碱性矿物质对比目鱼生长性能、养分消化利用及非特异性免疫的影响.试验选择平均初始体重为(144.06±0.17)g的比目鱼900条,随机分为3组,每组5个水族箱,每个水族箱饲养60条.对照组饲喂基础日粮,处理组日粮分别在基础日粮中添加2和4?mg/kg碱性矿物质,试验持续105?d.结果:随着日粮...     

维生素E和氯化汞对比目鱼生长性能和汞生物学蓄积的交互作用

本研究进行6周的饲养试验,评估维生素E(VE)和汞对比目鱼生长性能和汞生物学蓄积的影响。试验采用2×3因子设计,将360条比目鱼随机分到6组,每组3个重复,每个重复20条鱼。对照组饲喂基础日粮,处理组分别在基础日粮中添加100、200 mg/kg VE、15 mg/kg汞、15 mg/kg汞+100 mg/kg VE、15 mg/kg汞+200 mg/kg VE。结果显示,日粮添加汞显著抑制比目鱼的增重、特定生长率、饲料效率和蛋白效率(P<0.05),而VE显著改善增重(P<0.05)。汞和VE对试验期间比目鱼的存活率无显著影响(P>0.05)。日粮补充VE对比目鱼粗脂肪、水分有一定影响。VE显著降低肌肉、肝脏和肾脏汞含量(P<0.05),但日粮添加汞降低了组织VE含量(P<0.05)。汞显著降低了比目鱼机体二十碳五烯酸和二十二碳六烯酸含量(P<0.05),补充VE后显著改善了机体亚麻酸和二十碳五烯酸含量(P<0.05)。结果表明,日粮中添加VE对比目鱼生长发育具有促进作用,同时有降低无机汞在机体蓄积的潜在作用。     

影响禽蛋蛋黄着色的影响因素

本文针对老百姓对禽蛋蛋黄颜色的一系列误解,从蛋黄着色的机理开始深入探讨,讨论了品种、饲料原料、添加剂、疾病与用药等影响蛋黄品质的各种因素,最后推荐了10种常用的天然蛋黄增色剂,以期对实际生产给予指导.     

影响卵黄着色的因素

卵黄的颜色对消费者很重要，一般消费者喜欢金黄色到橙色的卵黄，而卵黄的色泽来源于产蛋鸡饲料中天然或全成的烃基类胡萝卜素，它是脂质样的化合物，主要由植物、微生物和甲壳类（虾、螃蟹等）产生。分析式决定了烃基类胡萝卜素的色泽是黄色或是红色。影响卵黄着色的因素有遗传，饲养方式，脂质和抗氧化剂、维生素A高水平的钙、抗生物质和药物等。     

类胡萝卜素着色的影响因素

色泽是衡量食品质量好坏的一个感觉指标,所以广大养殖户便把饲料对动物产品的着色能力作为评价饲料质量优劣的标准之一。当前饲料生产者通过在畜禽饲料中添加着色剂来满足广大养殖户的这一要求。其中类胡萝卜素作为一种经济高效的着色剂而受到生产者的青睐,但如果     

影响蛋壳颜色的因素

在蛋鸡的生产实践中,养殖户常常会遇到蛋壳颜色变浅的现象,并抱怨饲料厂提供的饲料有问题。另外,蛋壳颜色也是影响鸡蛋消费的原因之一。在不同地区,受传统习俗的影响,较白壳蛋,人们对红壳蛋有着偏爱。产生蛋壳颜色的主要色素是棕色原卟啉,由母鸡蛋壳腺中的氨基乙酰丙酸合成的。     

营养因素对肉质的影响

阐述了肉质的评价指标,并对影响肉质的营养因素进行了详细的分析,提出了提高肉质的方法     

A preliminary study of dietary protein requirement of juvenile marbled flounder (Pseudopleuronectes yokohamae)

An 8-week feeding trial was conducted to determine the optimal dietary protein level for juvenile marbled flounder. Five semi-purified test diets were formulated to contain different protein levels (CP) including 42.7%, 47.4%, 53.3%, 58.8%, and 64.5% (dry matter), named as CP42.7, CP47.4, CP53.3, CP58.8, and CP64.5, respectively. Five hundred and twenty-five juveniles (6.0 ± 0.1 g) were randomly distributed into 15 tanks (300 L tanks), resulting in 35 fish per tank (n = 3 tanks). Fish were fed the test diets 5 times per day until satiation. The CP58.8 resulted in the highest gain in weight and the best efficiency in feed utilization among the tested protein levels (P < 0.05). Fish fed the CP58.8 diet showed significantly higher whole-body protein and lipid contents than the fish that were fed the other diets (P < 0.05). Fish fed the CP53.3, CP58.8, and CP64.5 diets showed a significantly higher dorsal-muscle lipid content than the fish that were fed the CP42.7 and CP47.4 diets (P < 0.05). The one-slope straight broken-line regression analysis on the results of the thermal growth coefficient and feed conversion ratio indicated that the estimated optimum dietary protein level was 58.8%. Taken together, it is suggested that the dietary protein level of 58.8% is optimal for better growth and high efficiency in feed utilization for the juvenile marbled flounder.     

Effects of multiple environmental and nutritional factors in laying hens

1. A large experiment on multiple factors and levels of those factors was carried out to test the hypothesis that in production experiments responses can be measured separately and then applied as if interactions are rare.

2. Significant interactions of any order were indeed found to be rare, except for the interaction between temperature and dietary protein content.

3. Responses to temperature, light intensity, protein content and feeding system were reasonably consistent with earlier reports.

4. The rarity of interactions validates the use of a previously‐published additive model.     

营养成分对基因表达的调控

<正>目前,我国动物营养学的研究是在机体水平上研究各种营养素对机体的作用,在机体内研究吸收、代谢与平衡等。随着分子生物学的发展及其在动物营养学上的应用,从分子水平上弄清养分的代谢规律,准确确定动物群体及个体的营养需要,掌握养分摄入过量及缺乏的后果,预防和治疗营养代谢疾病以及解决其它营养问题将成为可能。尤其是同基因工程技术相结合,从分子水平来解释各种营养素对机体的作用机制、动物机体的生理病理变化等问题,这也是动物营     

Identification and characterization of Japanese flounder, Paralichthys olivaceus interferon-stimulated gene 15 (Jf-ISG15)

Previously, using cDNA microarray analysis, we demonstrated that an EST clone of Japanese flounder (Paralichthys olivaceus) with homology to mammalian interferon-stimulated gene 15 (ISG15) was strongly induced by treatment with DNA vaccine encoding the glycoprotein gene of Hirame rhabdovirus (HIRRV). In this study, we conducted molecular cloning and expression analysis of the Japanese flounder ISG15 (Jf-ISG15). Jf-ISG15 encoded two exons. The first exon was non-coding, while the second exon encoded a protein of 158 amino acids. The coded protein has two tandem ubiquitin-like domains with a carboxyl-terminus conjugation motif “LRLRGG”. Phylogenetic analysis revealed an evolutionary relationship among Jf-ISG15, mammalian and fish ISG15 orthologues. The interferon-stimulated response element (ISRE) sites were conserved among DNA sequences of Jf-ISG15 and mammalian ISG15 promoter regions. An RT-PCR analysis of healthy tissues showed that Jf-ISG15 mRNA was notably strongly expressed in gills, PBLs and spleen. Expression of Jf-ISG15 was strongly induced by poly-I:C treatment in head-kidney cells, peripheral blood leukocytes (PBLs) and spleen cells, and by HIRRV infection in kidney of juvenile fish suggesting that Jf-ISG15 plays a role in fish antiviral response.     

孕酮和雌二醇对绵羊精子体外获能的影响

试验探讨孕酮和雌二醇对绵羊精子体外获能和顶体反应的影响。将绵羊精子分别加到含不同浓度孕酮(1、10和100μmol/L)和雌二醇(1、10、和100μmol/L)的输卵管合成液(SOF)中,作用不同时间后分别取出部分精子样本进行金霉素荧光染色(chlortetracycline,CTC),通过精子与CTC结合染色的不同类型来评定孕酮和雌二醇对绵羊精子的作用。结果表明:雌二醇对绵羊精子体外获能和顶体反应都没有显著的促进作用(P>0.05);一定浓度的孕酮和雌激素组合抑制绵羊精子体外获能和顶体反应的发生(P<0.05)。     

Gene expression profile of HIRRV G and N protein gene vaccinated Japanese flounder, Paralichthys olivaceus during HIRRV infection

The glycoprotein (G protein) gene, but not the nucleocapsid protein (N protein) gene, of the hirame rhabdovirus (HIRRV) was previously shown to be highly effective in inducing a protective immune response in Japanese flounder (Paralichthys olivaceus) when used as a DNA vaccine. Our previous cDNA microarray analysis demonstrated that interferon-stimulated genes (ISGs) were strongly induced by the HIRRV G protein gene (pHRV-G) but not by the N protein gene (pHRV-N). However, the molecular basis for the difference in protective immunity between pHRV-G- and pHRV-N-vaccinated fish during HIRRV infection is still unclear. In this study, we use a DNA microarray to analyze differences of gene expression in pHRV-G- and pHRV-N-vaccinated fish during HIRRV infection. Microarray analyses showed substantial difference in gene expression patterns during HIRRV infection between fish vaccinated with pHRV-G and pHRV-N. In addition, genes having homology to mammalian T cell activation-related genes were up-regulated in the HIRRV G protein-vaccinated group.