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肖培弘 《畜牧兽医科技信息》2003,19(11):55-55
北方地区冬季冰封期长(达 150d以上),水温低(约为1℃～3℃),越冬池塘的溶氧量成为鱼类安全越冬的重要因素。越冬池塘中的溶氧状况主要取决于耗氧和产氧两个方面。耗氧是指水中生物的呼吸和有机物的氧化等。产氧是指水生维管束植物(某些沉水植物)及浮游植物的光合作用。生物增氧就是根据具体情况,创造一切有利条件,促进冰下浮游植物的生长、繁殖并在光合作用中产生氧气。生物增氧可改善水质、满足鱼类呼吸的需要,有利于鱼类安全越冬。 相似文献
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池塘正确使用增氧机的技术要点 总被引：2，自引：0，他引：2
一、增氧机的种类和功能 (一)叶轮式增氧机 具有增氧、搅水、爆气等综合作用,适用于水深1米以上的大面积池塘增氧,是目前最多采用的增氧机。 (二)水车式增氧机 具有良好的增氧及促进水体流动的效果,适用于淤泥较深,面积1.5～3.8亩的池塘使用。 (三)射流式增氧机 增氧动力效率超过水车式,充气、喷水等形式的增氧结构简单,能形成水流,搅拌水体。射 相似文献
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水产品在人类日常饮食生活中占据着较高的地位,尤其经过社会持续进步和人民要求的不断严格,水产养殖技术也获得前所未有的进步。不过,关于池塘养鱼中的病虫害问题还是无法完全遏制,长期放置无疑会令水产品养殖户面临沉重的经济损失压力。在此类背景下,笔者决定联合池塘清洁和消毒、种苗消毒、科学放养、投喂药饵等途径,探讨论证新时代下我国池塘养鱼病虫害的具体防治手段,希望能够为有关养殖主体带来希望。 相似文献
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池塘养鱼常见水质问题及解决方法 总被引：1，自引：0，他引：1
池塘养鱼中水质的优劣直接关系到养殖效益的好坏,除了有足够的水量外,更要具务相应的水质条件。论文对池塘养鱼水质指标、水色标准、水色辨别等方面做了总体概述,对池塘养鱼生产中常见的pH异常,氨氮偏高,亚硝酸盐过高,溶解氧浓度,硫化氢过高,蓝藻等问题及其发生的原因、来源、危害以及解决办法进行了解析,以期为做好水质管理,争取高产提供依据。 相似文献
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D. I. Ayoade E. Kiarie B. A. Slominski C. M. Nyachoti 《Journal of animal physiology and animal nutrition》2014,98(3):569-577
Gaining a detailed knowledge on the impact of a feedstuff on pig growth and physiological responses is critical for its effective utilization. Thus, the purpose of this study was to investigate the effect of distillers dried grains with solubles derived from co‐fermentation of wheat and corn (wcDDGS) on performance, carcass and visceral organ weights, whole‐body O2 consumption and heat production (HP) in growing barrows. The experimental diets were as follows: corn–soybean meal diet (Control), Control + 15% wcDDGS and Control + 30% wcDDGS. In Exp. 1, 48 pair‐housed pigs of average BW 18.6 ± 1.5 kg (mean ± SD) were allotted to the 3 diets (n = 8). Pigs had free access to water and feed for a 28‐day period during which ADG and ADFI were calculated weekly. Thereafter, 1 pig/pen was killed to measure carcass and visceral organ weights. Overall, wcDDGS linearly decreased (p < 0.05) ADFI and ADG but had no effect on G:F (p > 0.10). The ADFI was 1.55, 1.45 and 1.36 kg/day for diets containing 0, 15 and 30% wcDDGS respectively; corresponding values for ADG were 0.79, 0.75 and 0.67 kg/day respectively. A linear decline (p = 0.01) in eviscerated hot carcass weight was observed as dietary wcDDGS increased. In Exp. 2, 18 pigs of average BW 20.4 ± 2.4 kg (mean ± SD) were individually housed in metabolism crates and fed the 3 diets (n = 6) at 550 kcal ME kg BW?0.60day for a 16‐day period followed by measurement of O2 consumption using an indirect calorimeter. Diet had no effect (p > 0.10) on whole‐body O2 consumption and HP. In conclusion, increasing wcDDGS content in growing pig diets linearly reduced ADFI, ADG and eviscerated hot carcass weight but had no effect on G:F, visceral organ weights or HP. 相似文献
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Yoshimitsu Ouchi Vishwajit S. Chowdhury John F. Cockrem Takashi Bungo 《Animal Science Journal》2021,92(1):e13632
Avian uncoupling protein (av-UCP) is a key protein for thermoregulation in poultry. A single nucleotide polymorphism (SNP) in the av-UCP gene has been reported in chickens. The purpose of the current study was to clarify the association between this av-UCP gene mutation and thermoregulation in chickens. Wild and mutant type chicks for the av-UCP gene SNP (g. 1270 of the av-UCP gene exon 3 with C to T substitution and amino acid substitution) were exposed to high ambient temperature. Rectal temperature, radiation temperature on the body surface, and the expression of heat dissipation behavior (wing drooping and panting) during heat exposure were measured. In addition, oxygen consumption rate in the thermoneutral zone in wild and mutant type chicks was measured. Changes in wing temperature during heat exposure in wild-type chicks were lower than those in mutants. The latency of continuous wing drooping during heat exposure in wild-type chicks was shorter than in mutant chicks. It was also found that the SNP in the av-UCP gene caused reduced oxygen consumption. These results suggest that the av-UCP gene mutation affects thermoregulation, especially heat production, in chickens. 相似文献
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Single layer centrifugation (SLC) has been shown to select the most robust spermatozoa from the ejaculate in several species. Here the effects of SLC prior to freezing on various parameters of frozen‐thawed bovine sperm quality are reported. Semen from 8 bulls was layered on top of a species‐specific colloid, Bovicoll. After centrifugation for 20 min at 300 g, the resulting sperm pellet was resuspended in OPTIXcell® (IMV Technologies, l′Aigle, France); the SLC‐selected sperm samples and uncentrifuged controls were frozen. On thawing, all sperm samples were analysed for membrane integrity, production of reactive oxygen species, mitochondrial membrane potential (MMP) and chromatin integrity. The SLC‐treated samples had a higher percentage of live, superoxide‐positive spermatozoa than uncentrifuged samples (27.9 ± 5.1% versus 21.7 ± 6.7%; p = .03). They had a higher proportion of spermatozoa with high mitochondrial membrane potential than uncentrifuged samples (55.9 ± 8.2% versus 40.5 ± 15.1%; p = .03) and also a lower proportion of spermatozoa with low mitochondrial membrane potential than non‐treated samples (42.0 ± 8.5% versus 55.9 ± 14.4%; p = .04). No significant effects of treatment were found for membrane integrity or chromatin integrity. The effect of bull was significant on the proportions of dead, superoxide‐positive spermatozoa and live, hydrogen peroxide‐negative spermatozoa, as well as on membrane integrity, but it was not significant for mitochondrial membrane potential or chromatin integrity. These results suggest that SLC selects the most metabolically active bull spermatozoa from the rest of the population in normal ejaculates; the pattern of reactive oxygen species production may be different in SLC‐selected spermatozoa compared to unselected samples. 相似文献
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池塘内循环流水养殖模式对黄颡鱼生长性能、形体指标、血清生化指标及肌肉营养成分的影响 总被引：1，自引：0，他引：1
为了综合评价池塘内循环流水养殖(IPA)模式在黄颡鱼养殖中的应用效果,选取IPA模式、常规池塘养殖(UPA)模式和野生环境(WE)下的黄颡鱼各50尾为研究对象,在养殖322 d后对其生长性能、形体指标、血清生化指标及肌肉营养成分差异进行比较。结果显示:1) IPA组黄颡鱼的成活率显著高于UPA组(P<0.05),但增重率和特定生长率略低于UPA组(P>0.05)。2) IPA组和WE组黄颡鱼的肥满度、肝体指数和脏体指数显著低于UPA组(P <0.05); IPA组的肥满度显著高于WE组(P<0.05),而肝体指数和脏体指数2组间差异不显著(P>0.05)。3) IPA组和UPA组血清中总蛋白含量显著低于WE组(P<0.05); IPA组血清中总胆红素、碱性磷酸酶、总胆汁酸和总胆固醇含量显著低于UPA组(P<0.05); IPA组血清中γ-谷氨酰基转移酶和谷草转氨酶活性显著高于WE组(P<0.05); IPA组血清中肌酐、葡萄糖含量显著低于UPA组(P<0.05)。4) IPA组和WE组肌肉中粗脂肪含量显著低于UPA组(P<0.05),但粗蛋白质含量显著高于UPA组(P<0.05); IPA组肌肉中氨基酸总量显著高于UPA组(P<0.05),而显著低于WE组(P<0.05); IPA组必需氨基酸和鲜味氨基酸总量显著高于UPA组(P <0.05); 3组黄颡鱼肌肉中第一限制性氨基酸均为苯丙氨酸+酪氨酸,且IPA组和WE组的必需氨基酸指数显著高于UPA组(P<0.05); IPA组和WE组黄颡鱼肌肉中n-3多不饱和脂肪酸(PUFA)和二十碳五烯酸(EPA)+二十二碳六烯酸(DHA)含量显著高于UPA组(P<0.05),且饱和脂肪酸总量显著低于UPA组(P<0.05)。由此得出,IPA组黄颡鱼具有较高的成活率,较好的体形,其肌肉营养品质优于UPA组黄颡鱼,且健康状况也优于UPA组黄颡鱼,但仍差于WE组黄颡鱼。因此,应进一步优化IPA的环境条件(如流速因子、养殖密度等)以及人工配合饲料配方以迎合消费者对于黄颡鱼营养和味道的需求。 相似文献
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Deborah S. Greco Rod A.W. Rosychuk Gregory K. Ogilvie Lynn M. Harpold Camilla H. Van Liew 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1998,12(1):7-10
Thirty adult, client-owned dogs were diagnosed with hypothyroidism based on history, physical examination findings, hematologic and biochemical abnormalities, thyrotropin (TSH) response testing, endogenous canine thyrotropin (cTSH) concentration, or both, and total serum thryoxine concentration. All dogs received levothyroxine (L-thyroxine) at an initial dose of 22 μg/kg PO sid in either a tablet (13 dogs) or chewable form (17 dogs). Energy expenditure of each dog during apparent rest was estimated with an open-flow indirect calorimetry system by determining the rates of carbon dioxide production and oxygen consumption. Energy expenditure of apparent rest (EE) was lower in untreated hypothyroid dogs compared with reference values for EE. After treatment with L-thyroxine, EE of the hypothyroid dogs was significantly ( P < .05) higher than pretreatment values. 相似文献
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在水产养殖中良好的水质是保证鱼类正常生长的基础,对于促进水产养殖效益的提高具有至关重要的作用。本试验采用复合枯草芽孢杆菌微生态制剂产品,对鲤鱼养殖池塘水质状况的影响进行观察。结果发现,在养殖过程中泼洒复方枯草芽孢杆菌制剂,在不使用任何调水剂条件下,透明度高于未使用组10~20cm,且藻类丰富、微囊藻少,pH维持在7左右,氨氮、硫化物和亚硝酸盐基本稳定,水质得到了优化。 相似文献