中国对虾人工受精技术的研究   总被引：1，自引：0，他引：1  

孔杰  麦明 《海洋水产研究》1992,(13):1-5

首次探讨了中国对虾人工受精的方法。干法、湿法、半湿法和滴管法都可获得一定比例的受精卵,其中滴管法的受精效果最佳,最高受精率为77.8％。受精卵经过培养,能够进行正常的卵裂和胚胎发育。通过对这几种方法受精效果的分析和比较,认为,在精卵未丧失受精能力的前提下,尽可能地使精卵充分混合,才能得到较高的受精率。还对这四种方法的人工受精和自然受精对受精率的影响进行了比较和分析。  相似文献   

Effects of dietary protein levels on the growth,survival, amylase and trypsin activities in large yellow croaker,Pseudosciaena Crocea R., larvae     

Hairui Yu  Qinghui Ai  Kangsen Mai  Hongming Ma  Chantal L Cahu  José L Zambonino Infante 《Aquaculture Research》2012,43(2):178-186

A feeding trial was conducted to investigate the effects of dietary graded protein levels on the growth, survival, amylase and trypsin activities of large yellow croaker (Pseudosciaena crocea R.) larvae from 12 to 42 days after hatching (DAH). Five approximately isoenergetic microbound diets (16.65 MJ/kg diet) were formulated to contain different protein (47.1%, 52.0%, 57.1%, 62.2% and 67.5%) levels. Frozen copepods, containing 54.5% crude protein (CP), 6.0% crude lipid, 27.2% ash and 6.7% glycogen, were used as a control. Each diet was randomly fed to triplicate groups of larvae with an initial mean body weight of 1.76 ± 0.09 mg (mean ± SD) in 180 L white plastic tanks, and each tank was stocked initially with 3500 larvae. Both the survival and the specific growth rate (SGR) of large yellow croaker larvae significantly increased with increasing dietary protein level up to 57.1%, and decreased thereafter. Frozen copepods resulted in intermediate survival and low SGR compared with the other diets. Whole‐body moisture and protein of larvae were not significantly affected by the dietary protein level. In contrast, whole‐body lipid of larvae fed diet with 47.1% CP was significantly higher (P<0.05) than those from fish fed the diets containing more than 57.1% CP. Additionally, fish fed the frozen copepods had the lowest whole‐body protein and lipid. The amylase‐specific activity increased with increasing dietary carbohydrate level during the period of this experiment. However, trypsin activity was not significantly affected by the dietary protein content before 42 DAH, indicating a later onset of trypsin than amylase in the regulation of enzymatic synthesis induced by a dietary substrate.  相似文献   

Isolation and characterization of Toll‐like receptor 21 and 22 genes from Nile tilapia,Oreochromis niloticus (Linnaeus)          下载免费PDF全文

Ji‐cai Pang  Feng‐ying Gao  Miao Wang  Jin‐liang Zhao  Mai‐xin Lu 《Aquaculture Research》2017,48(7):3528-3544

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Alternative protein sources in diets for Japanese flounder Paralichthys olivaceus (Temminck and Schlegel): II. Effects on nutrient digestibility and digestive enzyme activity     

Junming Deng  Kangsen Mai  Qinghui Ai  Wenbing Zhang  Beiping Tan  Wei Xu  Zhiguo Liufu 《Aquaculture Research》2010,41(6):861-870

An 8‐week feeding trial was conducted to compare the effects of dietary protein sources on nutrient digestibility and digestive enzyme activity. Four experimental diets were formulated to contain one of the following as the sole protein source: fish meal (FM), fish protein concentrate (FPC), soy protein concentrate (SPC) and soy protein isolate (SPI). Each diet was randomly assigned to triplicate aquaria stocked with 25 Japanese flounder (Paralichthys olivaceus) each. The dry matter, crude protein and energy digestibility and individual amino acid availability of the SPC‐based diet were significantly lower than those of the other diets. The crude lipid digestibility of soy protein‐based diets was significantly lower than that of the FM‐based diet. The pepsin/protease activity was significantly higher in fish fed fish protein‐based diets compared with fish fed soy protein‐based diets. The lipase activity in fish fed the SPI‐based diet was the highest among the dietary treatments. These results indicate that P. olivaceus can effectively digest the protein from FPC and SPI (but not SPC) as well as FM. The low protein digestibility and amino acid availability of the SPC‐based diet may be related to the non‐protein compounds present in SPC, whereas the low‐lipid digestibility of soy protein‐based diets may contribute to the undigested soy protein fractions and/or the alcohol‐soluble components.  相似文献   

Effects of dietary lipid level on growth,fatty acid composition,digestive enzymes and expression of some lipid metabolism related genes of orange‐spotted grouper larvae (Epinephelus coioides H.)          下载免费PDF全文

Songlin Li  Kangsen Mai  Wei Xu  Yuhui Yuan  Yanjiao Zhang  Huihui Zhou  Qinghui Ai 《Aquaculture Research》2016,47(8):2481-2495

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Effects of Feeding Levels on Growth Performance, Feed Utilization, Body Composition, and Apparent Digestibility Coefficients of Nutrients for Grouper Epinephelus coioides Juveniles   总被引：1，自引：0，他引：1  

Zhi  Luo Yong-Jian  Liu  Kang-Sen  Mai Li-Xia  Tian Xiao-Ying  Tan Jin-Fang  Shi 《Journal of the World Aquaculture Society》2006,37(1):32-40

An experiment was conducted to determine effects of feeding levels on growth performance, feed utilization, body composition, and apparent digestibility coefficients (ADCs) of nutrients for juvenile grouper Epinephelus coioides (initial weight, 10.31 ± 0.36 g). Grouper were fed a practical diet from 0 (starvation) to 3.5% (at 0.5% increments) body weight per day (bw/d) for 8 wk. ANOVA indicated that growth performance, feed utilization, body composition, and ADCs of dry matter, protein, and energy were significantly (P < 0.05) affected by feeding levels. Survival was the lowest for the starvation group and for fish fed a ration of 0.5% bw/d. Final mean body weight, weight gain (WG), specific growth rate, and metabolic growth rate increased with feeding rate from 0 to 2.5% bw/d (P < 0.05) and showed no significant differences above the level (P > 0.05). Feed conversion rate was significantly lower at a feeding level of 2.0% bw/d than above and below the level (P < 0.05). Protein efficiency ratio was markedly highest at the 2.0% bw/d ration level (P < 0.05). Lipid contents of whole body, muscle, and liver increased with increasing feeding rates from 0 to 3% bw/d and showed a slight decline at the feeding level of 3.5% bw/d. Protein contents of whole‐body composition, muscle, and liver remained relatively stable with the different ration amount with the exception of fish fed a ration of 0.5% bw/d, at which grouper possessed significantly lower body protein concentration (P < 0.05). Condition factor, viscerosomatic index, and hepatosomatic index were the lowest for fish fed 0.5% bw/d and tended to increase with the increasing feeding levels. ADCs of dry matter, protein, and energy decreased with increasing feeding levels from 0 to 2.5% bw/d and then remained relatively constant over the level. Based on the broken‐line regression analysis using WG data, the optimum and maintenance feeding levels for grouper were 2.5% bw/d and 0.25% bw/d, respectively.  相似文献   

饲料中添加肽聚糖对大黄鱼生长和非特异性免疫力的影响   总被引：2，自引：0，他引：2  

张春晓  麦康森  艾庆辉 《水产学报》2008,32(3):411-416

以初始体重(30.8±1.33)g的大黄鱼(Pseudosciaena crocea)为研究对象,探讨饲料中添加肽聚糖对其生长和非特异性免疫力的影响.分别向每千克基础饲料中添加0(对照组)、100、500mg肽聚糖,配制出3种等氮等能的实验饲料,进行为期8周的摄食生长实验.实验在海水浮式网箱(1.5m×1.5m×2.0m)中进行,每个处理设3个重复,每个重复放养40尾.实验采取饱食投喂方式,每天投喂2次(05:00和17:30),实验期间海水水温为27.5～30.5℃,盐度为29～33,溶解氧含量在7mg·L-1以上.饲喂实验结束后测定实验鱼的生长及相关的免疫学指标,同时每网箱取10尾实验鱼转入室内300L水族箱内进行攻毒实验.实验结果表明,饲料中添加肽聚糖显著影响大黄鱼的成活和生长.当饲料中添加100和500mg·kg-1肽聚糖时,成活率(分别为95.8%和95.0%)显著高于对照组(88.3%).当饲料中添加100和500mg·kg-1肽聚糖时特定生长率(分别1.44%·d-1和1.41%·d-1)显著高于对照组(1.12%·d-1)(P<0.05).饲料中添加肽聚糖实验组大黄鱼血液白细胞吞噬活力和血清溶菌酶活力显著高于对照组(P<0.05),且添加肽聚糖的两实验组之间差异不显著;而血清替代补体途径活力则随着饲料中肽聚糖添加水平的增加而显著提高(P<0.05).哈维氏弧菌攻毒实验结果表明,饲料中添加肽聚糖实验组的累积死亡率(分别为25.0%和25.7%)显著低于对照组(64.3%)(P<0.05).因此,饲料中添加适宜含量的肽聚糖可显著提高大黄鱼生长率和非特异性免疫力,肽聚糖可以作为一种安全高效的口服免疫增强剂应用于大黄鱼的养殖生产.  相似文献   

基于Kinect相机的苹果树三维点云配准   总被引：4，自引：0，他引：4  

郑立华  麦春艳  廖崴  文瑶  刘刚 《农业机械学报》2016,47(5):9-14

为建立具有真实彩色信息的果树三维点云形态结构模型,用Kinect相机获取不同视角下果树的原始三维点云,针对传统最近点迭代算法对待配准点云的空间位置要求苛刻的问题,提出了改进的点云配准算法。首先通过归一化对齐径向特征算法搜寻点云关键点,并使用快速点特征直方图描述子计算关键点处的特征向量。然后根据求得的特征向量估计2片点云关键点之间的空间映射关系,再基于随机抽样一致性算法提纯映射关系并完成点云的初始配准。最后利用最近点迭代算法完成点云的精确配准。实验结果表明,通过在最近点迭代算法前增加点云初始配准算法,有效地提高了点云配准的准确性和稳定性,能够对任意初始位置的2片点云进行准确匹配,平均配准误差为0.7 cm。  相似文献   

山东菏泽地区草地贪夜蛾发生为害情况     

高庆刚  高俊平  路迈  张冬菊 《安徽农业科学》2022,50(2):142-146

在2019和2020年调查了菏泽地区草地贪夜蛾的发生和为害情况。通过形态学和分子生物学方法鉴定明确了菏泽地区的草地贪夜蛾物种。利用灯诱和性诱监测成虫、田间调查监测幼虫,连续2年的数据表明,草地贪夜蛾在8月中旬左右迁飞至菏泽地区,选择低于大喇叭口期的玉米上产卵为害;成虫监测方面,性诱效果显著高于灯诱。上述结果表明,草地贪夜蛾成功入侵山东菏泽地区,虽然害虫种群密度和发生为害面积小,但有扩张的趋势,后续应在山东菏泽地区继续加强对草地贪夜蛾的监测预警。  相似文献   

橡胶林钾素研究进展   总被引：2，自引：0，他引：2  

邢慧  蒋菊生  麦全法 《热带农业科学》2012,32(4):42-48,56

综述国内外橡胶林钾素相关研究,指出在橡胶林生态系统中,钾的来源途径主要包括土壤、降水、枯枝落叶归还和人工施肥等,输出途径主要为采胶、采种、淋溶损失和水土流失,针对当前胶林系统内钾素养分失衡的现状,对橡胶林钾素循环进行系统动态模拟研究,实现养分循环理论研究与指导施肥的有机结合仍是今后研究的重点。  相似文献