酸奶发酵剂菌种的产香物质及发酵特性研究

对分离自不同来源的国内外直投式发酵剂和酸奶中的13株保加利亚乳杆菌和14株嗜热链球菌在乳中的产酸特性、产生乙醛能力、产生双乙酰能力及产黏特性,总结了保加利亚乳杆菌和嗜热链球菌对不同酸奶品质的影响.结果表明,嗜热链球菌的前期产酸速度比保加利亚乳杆菌的快,发酵酸乳后产酸主要由保加利亚乳杆菌发酵引起;主要风味物质乙醛由保加利亚乳杆菌发酵产生、双乙酰由嗜热链球菌发酵产生;嗜热链球菌的产粘特性明显高于保加利亚乳杆菌的;嗜热链球菌和保加利亚乳杆菌中,菌株S5、S7、S9、S10、LB5、TK1适宜加工凝固型发酵酸乳;菌株S5、S11、L9、L2、L1、L8、L6适宜生产风味型酸奶.为筛选优良菌株、研制开发优良酸奶及发酵乳饮料发酵剂提供理论指导.     

隆林山羊与努比亚山羊杂交对后代生产性能和肉品质影响的研究

为了促进广西隆林山羊杂交改良技术的应用,提高隆林山羊的生产效益,本研究以努比亚山羊、隆林山羊及努隆杂交F1代（努比亚山羊♂×隆林山羊♀）为研究对象,所有山羊都在相同水平下进行饲养管理,选取3个群体共205只山羊,分别对1、3、6月龄山羊的生产性能及体尺指标进行测定,选取6只6月龄的父母代及杂交F1代进行屠宰,取其背最长肌进行肉品质分析。结果表明,努隆杂交F1代经产母羊的产羔率、羔羊成活率与父母代差异不显著（P>0.05）,初生重、不同月龄体尺指标与父母代差异极显著（P<0.01）,努隆杂交F1代宰前活重、胴体重、净肉重、屠宰率、净肉率较隆林山羊都有显著提高（P<0.05）,肌肉粗蛋白质含量、肌内脂肪含量、必需氨基酸、风味氨基酸、游离脂肪酸与父母代均有不同程度的提高。因此,努比亚山羊在改善隆林山羊体型、生长速度和肉品质上综合表现良好。     

海南省高校图书馆服务体系现状调查与发展对策

通过对海南省8所高校图书馆的主要服务项目及基本状况进行调查,提出了持续改进服务水准所面-]名的问题,阐明了高校图书馆今后应着眼于更深层次的服务资源配置、平台搭建、绩效评估等问题,以提升高校图书馆的整体服务效益.     

Effects of varying dietary compositions using common feed ingredients on growth and feed efficiency of pond‐raised channel catfish Ictalurus punctatus (Rafinesque)

Two experiments were conducted to evaluate various ingredient combinations in a 28% or 32% protein diet for optimum performance of channel catfish Ictalurus punctatus. All diets contained soybean meal and corn, but with or without cottonseed meal, wheat middlings or fish meal (FM). Channel catfish fingerlings were stocked into 0.04 ha earthen ponds at 18 530 fish ha^?1. Fish were fed one of eight diets once daily to apparent satiation for two growing seasons. Results demonstrated that the dietary ingredient composition used had significant effects on fish performance, but magnitude of differences was relatively small. Overall, diets containing FM resulted in greater weight gain (Experiments 1 and 2) and lower feed conversion ratio (Experiment 1) than fish fed all‐plant diets. However, certain combinations of plant ingredients provided the similar fish growth as some diets containing FM. There were no significant differences in weight gain between fish fed soybean meal–corn or soybean meal–corn–wheat middlings‐based diets with cottonseed meal or FM. The use of wheat middlings in the diet had no significant effects on fish production characteristics.     

Channel catfish,Ictalurus punctatus,nutrition in the United States: A historical perspective

Although a concerted effort in catfish nutrition research in the United States did not begin until the late 1950s/early 1960s, the genesis of both the catfish industry and catfish nutrition research is rooted in studies conducted early in the 20th century. Thus, a historical view delineating the progression of channel catfish, Ictalurus punctatus, nutrition from 1900 to the present is given. Notable nutrition research programs, as well as significant events and accomplishments, will be examined.     

A Length–Weight Relationship for Pond‐raised Hybrid Catfish Fingerlings

A length–weight relationship was developed for pond‐raised hybrid catfish fingerlings, Ictalurus punctatus × Ictalurus furcatus. A total of 4663 fish were sampled ranging from 20 to 240 mm total length. Predicted weight (g) from length (mm) is based on the equation: Y = 0.000017311X^2.868474309 (r² = 0.996) where Y is the estimated individual fish weight and X is measured total length. The predicted values generated by this model differ from, but follow the same general trends seen with channel catfish, I. punctatus, fingerlings and can be used as a baseline for the development of a length–weight table for hybrid catfish fingerling production.     

Performance of Alternative Diets Containing Solvent‐Extracted Distillers Dried Grains with Solubles Compared to Traditional Diets for Pond‐Raised Channel Catfish,Ictalurus punctatus,and Hybrid Catfish,Ictalurus punctatus × Ictalurus furcatus

Two concurrent pond studies were initiated in April 2011 to evaluate feeds containing solvent‐extracted distillers dried grains with solubles (SE‐DDGS) in both 28 and 32% protein catfish feeds. Channel catfish, Ictalurus punctatus, were stocked in multiple‐batch production ponds at the University of Arkansas at Pine Bluff (UAPB) and hybrid catfish, ♀ Ictalurus punctatus × ♂ Ictalurus furcatus, in single‐batch production ponds at the National Warmwater Aquaculture Center (NWAC), Mississippi State University, Stoneville, Mississippi, USA. The experimental design was a 2 × 2 factorial with two protein levels (32 and 28% protein), with and without 20% SE‐DDGS. Fish were fed once daily to apparent satiation, and managed similarly to a commercial farm for 186 d at UAPB and 172 d at NWAC. For channel catfish, two‐way ANOVA showed significant effects of both protein level (28% being better than 32%) and protein source (20% SE‐DDGS diets being better than traditional diets) on yield, survival, total diet fed, and feed conversion ratio (FCR), due primarily to effects on the understocked fingerlings. Partial budget analysis suggested that the 28% protein diet with the 20% SE‐DDGS was preferred economically for the prevailing feed costs. For hybrid catfish, two‐way ANOVA did not show significant differences in total diet fed, yield, survival, and processing yields, but use of SE‐DDGS resulted in a lower FCR. Results showed that both channel and hybrid catfish can utilize 20% SE‐DDGS in the diet without adversely affecting production or processing characteristics.     

青海省酸牦牛奶中明串珠菌分离及其耐酸特性研究

从青海省部分牧区采集的32份牦牛酸乳样中,经形态学特征及生理生化特性分析,获得10株明串珠菌属菌株,分别鉴定为:Leu.mesenteroide subsp.dextranicum二株,Leu.lacti四株,Leu.paramensenteroide三株,Leu.mesen-teroides subsp.mesenteroide一株。并经耐受pH值3.09-3-2和Leu.paramensenteroides QH4-3-1两株菌呈现较强的耐酸性,为今后的明串珠菌耐酸性特征的进一步研究奠定了基础。     

Effects of Various Dietary Carotenoid Pigments on Fillet Appearance and Pigment Absorption in Channel Catfish, Ictalurus punctatus

A study was conducted to evaluate effects of various carotenoids on skin and fillet coloration and fillet carotenoid concentration in channel catfish, Ictalurus punctatus. For 12 wk, juvenile catfish were fed one of six experimental diets containing no supplemental carotenoid or 100 mg/kg of one of following carotenoid additions: β‐carotene (BCA), lutein (LUT), zeaxanthin (ZEA), canthaxanthin (CAN), and astaxanthin (AST). Visual yellow color intensity score was highest for fish fed LUT, followed by ZEA, AST, and CAN, and lowest for fish fed basal and BCA diets. Skin and tissue Commission Internationale de I’Eclairage yellowness value was the highest in fish fed LUT, followed by fish fed ZEA, AST, and CAN, and lowest for fish fed basal and BCA diets. Fish accumulated the supplemental carotenoids in muscle tissues, but concentrations of different carotenoids in the tissue varied greatly. Approximately 30% of the LUT added was converted to echineone; no conversion was observed among other supplemental carotenoids. Results from the present study indicate that channel catfish can accumulate yellow pigments LUT and ZEA and red or pink pigments CAN and AST in the flesh, resulting in yellow coloration. The yellow pigment BCA does not appear to deposit in skin or flesh at levels sufficient to alter the coloration.