以鸭脚稗秸秆和稻草作为粗饲料对杂交奶牛常量和微量营养素利用和产奶量的影响

在印度南部,鸭脚稗秸秆和稻草是主要的粗饲料来源。因此用鸭脚稗秸秆和稻草作为粗饲料饲喂杂交奶牛来研究营养利用率、产奶量和牛奶组成。每组日粮用精料、青饲料和粗饲料以30∶45∶25的比例组成(干物质)。在为期50d的消化试验中,每7d对饲料、饲草、粪便、尿液和奶液混合采样,进行常量和微量营养素的分析。鸭脚稗秸秆含有更高的粗蛋白质、钙、磷、镁、铜、锌和钴,稻草含有更高的酸性洗涤纤维、灰分和无水硅酸。饲喂鸭脚稗秸秆的奶牛干物质、粗蛋白质、粗脂肪、中性洗涤纤维、酸性洗涤纤维和大多微量营养素(钙、磷、镁、锌、铁、锰和钴)的摄入量显著增高,并且,饲喂鸭脚稗秸秆的奶牛对干物质、粗蛋白质、粗脂肪、中性洗涤纤维、酸性洗涤纤维的消化率显著增高,钙、铜、锰、钴的肠道吸收率也显著增高。在每组日粮中,微量营养素都能满足奶牛需要量,但稻草组钙含量(0.40%)低于鸭脚稗秸秆组(0.60%)。鸭脚稗秸秆组的平均产奶量(7.0L/头)高于稻草组(6.3L/头)。奶液组成没有差异,仅有乳脂率(4.7%和4.5%),稻草组偏低。上述结果表明鸭脚稗秸秆是一种优于稻草的粗饲料,当稻草作为唯一的粗饲料饲喂奶牛时,需要额外添加钙来满足产奶需要。     

Characterization of Ca-ATPase activity in gill microsomes of freshwater mussel, Lamellidens marginalis (Lamarck) and heavy metal modulations

Freshwater mussel Lamellidens marginalis showed a Ca²⁺-stimulated ATPase activity in the microsomal fraction of gill. Mg²⁺ was also found to be an activating cation for this ATPase enzyme. Ca²⁺ ATPase showed maximal activity at 40 °C and between pH 7.5–8.0. Substrate specificity of Ca²⁺ ATPase was highest with ATP, followed by GTP and other trinucleotides such as UTP, CTP and ADP also showed some amount of hydrolysis. Ca²⁺ ATPase showed slight inhibition with ruthenium red and sodium vanadate and is insensitive to sodium azide, ouabain, oligomycin B and phenylalanine. Heavy metals like Hg²⁺, Cu²⁺ and Zn²⁺ showed 50% inhibition of Ca²⁺ ATPase activity at concentrations of 0.25 mM, 0.5 mM and 1 mM, respectively whereas Cd²⁺ and Ni²⁺ showed 39% and 28% inhibition of enzyme activity at 1 mM concentrations.     

First isolation of Tenacibaculum maritimum from wedge sole, Dicologoglossa cuneata (Moreau)

The first isolation of Tenacibaculum maritimum from wedge sole, Dicologoglossa cuneata, is reported. The pathogen was recovered from ulcers of cultured fish, from three different outbreaks. The six isolates obtained were biochemically and serologically characterized and diagnosis was confirmed by polymerase chain reaction using specific primers and partial 16S rRNA gene sequencing. The isolates constituted a homogeneous phenotypic group; however, they belong to two of the different serotypes described within this species. A virulence evaluation of the isolates using Wedge sole fry was also performed.     

A new viral epizootic of Anguilla japonica Temminck and Schlegel

Abstract. In 1969, a new kind of epizootic occurred among eels in Japan and virological investigation was initiated. A new virus designated eel virus european (EVE) was isolated and biological, cytological, serological tests and infectivity trials were carried out. In its CPE on RTG-2 cells and additionally in its biological properties and particle size, EVE was found to be similar to infectious pancreatic necrosis virus (IPNV). Serologically, EVE was similar to the ď Honnincthun, France, strain of IPNV. However, infectivity trials showed that EVE and IPNV differed; EVE killed Japanese eels Anguilla japonica but not rainbow trout fry Salmo gairdneri , while IPN virus killed rainbow trout fry but not eels. We consider EVE to be the primary agent causing the new epizootic and propose the name viral kidney disease for the resulting clinical condition.     

Fluorescence localization of epidermal cathepsins L and B in the Japanese eel

Histochemical localization of proteolytic activities in the dorsal epidermis of Japanese eel was demonstrated by fluorescent microscopy utilizing 4-methoxy-2-naphthylamide (4M$\beta$NA) derivatives as substrates and 5-nitrosalicylaldehyde as a trapping agent. Carbobenzoxy-L-phenylalanyl-L-arginyl-4M$\beta$NA (Cbz-Phe-Arg-4M$\beta$NA) and Cbz-Arg-Arg-4M$\beta$NA were used for direct detection of cathepsins L and B activities, respectively, in fresh frozen sections and unfixed cells of the eel epidermis. The fluorescing areas, where Cbz-Phe-Arg-4M$\beta$NA was hydrolyzed by cathepsin L, were shown in mucus secretory cells and club cells and broadly around skin surface. The fluorescing areas due to Cbz-Arg-Arg-4M$\beta$NA hydrolysis by cathepsin B were localized similarly in these tissues. The fluorescing intensity for both catheptic activities in mucus secretory cells was higher than that in club cells, where small fluorescing granules were distributed. These results indicate that eel cathepsins L and B are stored in epidermal secretory cells at different levels and probably serve as defense factors before or after secretion by these cells. Abbreviations: Cbz – carbobenzoxy; 4M$\beta$NA – 4-methoxy-2-naphthylamide; NSA – 5-nitrosalicylaldehyde.     

Growth and production of Pacific ocean perch (Sebastes alutus) in nursery habitats of the Gulf of Alaska

Nursery areas for juvenile fishes are often important for determining recruitment in marine populations by providing habitats that can maximize growth and thereby minimize mortality. Pacific ocean perch (POP, Sebastes alutus) have an extended juvenile period where they inhabit rocky nursery habitats. We examined POP nursery areas to link growth potential to recruitment. Juvenile POP were captured from nursery areas in 2004 and 2008, and estimated growth rates ranged from ?0.19 to 0.60 g day^?1 based on differences in size between June and August. Predicted growth rates from a bioenergetics model ranged from 0.05 to 0.49 g day^?1 and were not significantly different than observed. Substrate preferences and the distribution of their preferred habitats were utilized to predict the extent of juvenile POP nursery habitat in the Gulf of Alaska. Based on densities of fish observed on underwater video transects and the spatial extent of nursery areas, we predicted 278 and 290 million juvenile POP were produced in 2004 and 2008. Growth potential for juvenile POP was reconstructed using the bioenergetics model, spring zooplankton bloom timing and duration and bottom water temperature for 1982–2008. When a single outlying recruitment year in 1986 was removed, growth potential experienced by juvenile POP in nursery areas was significantly correlated to the recruitment time‐series from the stock assessment, explaining ～30% of the variability. This research highlights the potential to predict recruitment using habitat‐based methods and provides a potential mechanism for explaining some of the POP recruitment variability observed for this population.     

Mesohabitat associations of the threatened San Marcos salamander (Eurycea nana) across its geographic range

相似文献