排序方式： 共有27条查询结果，搜索用时 109 毫秒
1.
2.
水温 饵料 投饵率对河蟹生长和饵料转化率的影响 总被引：3，自引：0，他引：3
在实验室条件下研究了水温、饵料和投饵率对河蟹生长的影响。结果表明,在10～26℃水温范围内,河蟹对不同饵料的摄饵率和特定生长率均与水温呈正相关关系;相比之下,用配饵投喂,河蟹对温度的变化较为敏感,但配饵的饲养效果明显次于螺蛳。随着水温的升高,当螺蛳的投饵率由半饱增至全饱时,河蟹的湿重生长率增长不明显,而体蛋白量则增加了13%～28%。在适温范围内,适当降低投饵率可提高饵料转化率和蛋白质利用率,可是蟹体蛋白量的增加则明显下降。 相似文献
3.
首先提出并讨论了饲料资源量的主体部分就是饲料能量总量及饲料蛋白质总量的问题。然后,用相关及回归方法筛选出了牛代谢能及粗蛋白质指标。在此基础上,建立了对饲料资源的品质和数量进行判断的蛋能结构指数及蛋能丰度指数体系。 相似文献
4.
HPLC法测定饲料中的炔雌醇 总被引：1，自引：1，他引：0
为了制定中国适用于饲料中炔雌醇的高效液相色谱(HPLC)测定的标准方法。本研究通过添加回收方法,以三大类饲料基质（配合饲料、浓缩饲料、添加剂预混料）的代表样品为研究对象,建立了HPLC法测定饲料中炔雌醇的方法,即以乙腈-0.025%磷酸(1:1,v/v)组成混合提取液,超声辅助提取,经液液萃取和C18固相萃取净化后,以反相液相色谱荧光法测定。实验结果表明：该方法线性范围0.05~5 mg/L,线性相关系数0.9992;检出限浓度0.04 mg/kg（添加剂预混料为0.06 mg/kg）,定量限浓度0.1 mg/kg（添加剂预混料为0.2 mg/kg）;配合饲料在0.05、0.25、0.5 mg/kg添加水平的回收率和精密度分别为83%~87%和5.9%~7.0%;三大类饲料平均回收率在81%-86%,相对标准偏差（RSDs）实验室内为3.3%~9.6%,实验室间为5.7%~6.6%。该方法操作简单、环保、灵敏,适用于各类饲料样品中炔雌醇的快速筛查。 相似文献
5.
The study aimed to assess the nutritive value of 10 feeds (grains and forages) commonly used in horse nutrition in Mexico, on the basis of their chemical composition, in vitro organic matter digestibility (IVOMD) and in vitro gas production measurements with or without the supplementation of Saccharomyces cerevisiae (SC) at 4 mg/g DM. Fecal inoculum was obtained from 4 adult English Thoroughbred horses fed on restricted amount of concentrate and oat hay ad libitum. Substrates tested were: 6 concentrates (corn gluten meal, soybean meal, steam-rolled corn, steam-rolled barley, oat grain, and wheat bran) and 4 roughages (soybean hulls, corn stover, alfalfa hay, and oat hay). Gas production (GP) was recorded at 2, 4, 6, 8, 10, 12, 14, 24, 48, and 70 hours using the pressure transducer technique. Some ingredient × yeast interactions were observed (P ≤ .020) for the asymptotic GP and GP at 48 and 70 hours of incubation. Yeast addition increased (P < .001) the asymptotic GP of concentrates compared to roughages. Concentrate feeds had higher (P < .05) GP and lower (P < .001) rate of GP compared to roughages without yeast. From 24 to 70 hours of incubation, forages with or without yeast had lower (P < .05) GP compared to concentrates supplemented with SC. Forages had higher fermentation pH compared to concentrates but lower (P < .05) metabolizable energy, IVOMD, and microbial protein production compared to concentrates. Supplementation with SC increased (P < .05) the asymptotic GP of oat grain, soybean meal, soybean meal, steam-rolled barley, steam-rolled corn, wheat bran, corn stover, and oat hay, without affecting the rate of GP or lag time of oat grain, soybean meal, wheat bran, corn stover, and oat hay. Moreover, supplementation with SC increased (P < .05) metabolizable energy, IVOMD, and microbial protein production of steam-rolled barley, wheat bran, and corn stover, without affecting (P > .05) the fermentation of other feeds. Supplementation with SC improved fermentation of feeds with higher effects on concentrates compared to roughages. It was concluded that although SC mainly improves concentrate utilization by horses, it also improves fiber digestion when used on high-roughage diets fed to horses. 相似文献
6.
Eleni Mente Graham J. Pierce Maria Begoña Santos Christos Neofitou 《Aquaculture International》2006,14(5):499-522
While marine aquaculture has grown rapidly, so have concerns regarding the environmental impacts caused by the industry. In particular, increasing discharges of solid and dissolved fish excretions, nutrients and therapeutic chemicals have coincided with greater public awareness of the possibility of environmental damage. This has stimulated a number of criticisms, drawn from a wide spectrum of interests, ranging from the use of natural fish stocks to produce fish meal for aqua feeds to the effects of enhanced nutrient input on the coastal marine environment. The present study reviews available information on the environmental effects of feeding practices in salmonid aquaculture in Europe. Accumulation of waste food and fish faecal material results in changes in the sediment under fish cages, characterized by a low redox potential, high content of organic material and accumulation of nitrogenous and phosphorous compounds. Although significant environmental impacts have been reported in the literature at distances of up to 100 m from the cages, in general such impacts are reported to be localized to within 20–50 m around the cages. For farmed salmon and trout, mass balance models have been developed for nitrogen and phosphorus, indicating that 50% of the nitrogen and 28% of the phosphorus supplied with the food is wasted in dissolved form. The maximum nutrient release can be estimated from the hydrographic conditions in the immediate vicinity of the farm, such as water volume, tidal water exchange and currents. At present production levels, improvements in the feeding efficiency and feed quality of aquafeeds could reduce waste and consequent environmental impacts. 相似文献
7.
8.
益康XP酵母培养物在养殖业上的应用 总被引：5，自引：0，他引：5
就益康XP的组成、作用机理以及在畜禽和水产养殖中的应用情况进行了综述,表明益康XP在奶牛饲料中每天每头添加60g,日均产奶量增加;在仔猪和妊娠母猪饲料中分别添加0．25％和0．5％可提高仔猪的初生重和日增重;在蛋鸡饲料中添加0．1％或0．15％可提高其产蛋性能;在虾饲料中添加0．5％,可提高其产量和存活率。 相似文献
9.
10.
本研究建立了饲料中玉米赤霉醇类药物的UPLC-MS/MS分析方法。饲料样品经乙腈水溶液提取,离心后提取液经多功能净化柱净化,氮气吹干,用乙腈+乙酸水溶液（50：50,V/V）溶解, UPLC-MS/MS分析。结果显示,6种玉米赤霉醇类药物在5.0～50.0 g/kg浓度范围内线性关系良好, r≥0.999。以单一饲料、浓缩饲料、配合饲料和预混料等为添加基质,其回收率在65.8%～104.6%,检出限为5.0 g/kg。本方法灵敏度高、专属性好、操作简单、结果可靠,可满足饲料中玉米赤霉醇类药物的分析检测。 相似文献