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1.
StudyoftheLaserLightEffectonImprovingSheepSemenQuality¥YUEWenbin;LIUWenzhong(DepartmentofAnimalShanxiAgricultutalUniversity,S...  相似文献   
2.
Abstract

Naturally produced methane shows different δ13C-values with respect to its origin, e.g., geological or biological. Methane-production of ruminants is considered to be the dominant source from the animal kingdom. Isotopic values of rumen methane—given in literature—range between ?80‰ and -50‰ and are related to feed composition and also sampling techniques. Keeping cows, camels and sheep under identical feed conditions and sampling rumen gases via implanted fistulae we compared δPDB 13C-values of methane and CO2 between the species. Referring to mean values obtained from 4 or 5 samples at different times of 11 animals (n = 47) we calculated δPDB 13C-medians resulting in small but not significant differences within and significant differences between the species for CO2 and methane. The δPDB 13C-differences between methane and CO2 were statistically equal within and also between the species. Therefore a linear regression of methane values on CO2 is appropriate and leads to: δPDB 13C(methane)‰ = 1,57 * δPDB 13C(CO2)‰-47‰ with a correlation coefficient of r = 0,87.  相似文献   
3.
Five hybridomas stably secreting monoclonal antibodies (McAbs) to androstenedione were prepared by using artificially synthesized androstenedione-11α-succinyl conjugate with bovine serum albumin (BSA) as antigen. These McAbs showed slightly high cross-reactivity with testosterone (8.1—12.3%) and estrone (0.8—2.5%) and high affinities ranging from 2.0×10~7 to 2.8×10~8 L/M. They were all of the IgG_1 subclass. Xinjiang finewool ewes which were passively immunized with McAbs had higher circulating levels of progesterone (P) and luteinizing hormone (LH) than those of control ewes in two oestrous cycles and these changes led to increased ovulation rate and twin lambs born in young ewes.  相似文献   
4.
In der Welt fallen jährlich ca. 2 Milliarden t Getreidestroh an, die nur partiell für die Fütterung genutzt werden, weil seine Verdaulichkeit gering ist. Durch verschiedene chemische und physikalische Methoden ist seit den neunziger Jahren des vorigen Jahrhunderts versucht worden, die Verdaulichkeit des Strohs zu erhöhen (Übersicht Flachowsky [1]). 1962 berichteten Pritchard u. a. [2] über den Aufschlußeffekt von Gamma-Strablen bei Stroh.  相似文献   
5.
Sheep on the island of North Ronaldsay (Orkney, UK) feed mostly on seaweed, which contains high concentrations of dimethylated arsenoribosides. Wool of these sheep contains dimethylated, monomethylated and inorganic arsenic, in addition to unidentified arsenic species in unbound and complexed form. Chromatographic techniques using different separation mechanisms and detectors enabled us to identify five arsenic species in water extracts of wool. The wool contained 5.2 ± 2.3 µg arsenic per gram wool. About 80% of the arsenic in wool was extracted by boiling the wool with water. The main species is dimethylarsenic, which accounted for about 75 to 85%, monomethylated arsenic at about 5% and the rest is inorganic arsenic. Depending on the separation method and condition, the chromatographic recovery of arsenic species was between 45% for the anion exchange column, 68% for the size exclusion chromatography (SEC) and 82% for the cation exchange column. The SEC revealed the occurrence of two unknown arsenic compounds, of which one was probably a high molecular mass species. Since chromatographic recovery can be improved by either treating the extract with CuCl/HCl (CAT: 90%) or longer storage of the sample (CAT: 105%), in particular for methylated arsenic species, it can be assumed that labile arsenic–protein‐like coordination species occur in the extract, which cannot be speciated with conventional chromatographic methods. It is clear from our study of sheep wool that there can be different kinds of ‘hidden’ arsenic in biological matrices, depending on the extraction, separation and detection methods used. Hidden species can be defined as species that are not recordable by the detection system, not extractable or do not elute from chromatographic columns. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   
6.
Recent advances in the structural biology of chondroitin sulfate chains have suggested important biological functions in the development of the brain. Several studies have demonstrated that the composition of chondroitin sulfate chains changes with aging and normal brain maturation. In this study, we determined the concentration of all glycosaminoglycan types, i.e. chondroitin sulfate, dermatan sulfate, keratan sulfate, heparan sulfate, hyaluronan and chondroitin in cerebrum, cerebellum and brainstem of young sheep brain. In all cases, chondroitin sulfate was the predominant glycosaminoglycan type, comprising about 54-58% of total glycosaminoglycans, with hyaluronan being present also in significant amounts of about 19-28%. Of particular interest was the increased presence of the disulfated disaccharides and dermatan sulfate in cerebellum and brainstem, respectively, as well as the detectable and measurable occurrence of chondroitin in young sheep brain. Among the three brain areas, cerebrum was found to be significantly richer in chondroitin sulfate and hyaluronan, two major extracellular matrix components. These findings imply that the extracellular matrix of the cerebrum is different from those of cerebellum and brainstem, and probably this fact is related to the particular histological and functional characteristics of each anatomic area of the brain. Copyright (c) 2008 John Wiley & Sons, Ltd.  相似文献   
7.
The effect of humidity on sheep wool during irradiation by an accelerated electron beam was examined. Each of the samples with 10%, 53%, and 97% relative humidity (RH) absorbed a dose of 0, 109, and 257 kGy, respectively. After being freely kept in common laboratory conditions, the samples were subjected to batch Co(II) sorption experiments monitored with VIS spectrometry for different lapses from electron beam exposure. Along with the sorption, FTIR spectral analysis of the wool samples was conducted for cysteic acid and cystine monoxide, and later, the examination was completed, with pH measuring 0.05 molar KCl extract from the wool samples. Besides a relationship to the absorbed dose and lapse, the sorptivity results showed considerable dependence on wool humidity under exposure. When humidity was deficient (10% RH), the sorptivity was lower due to limited transformation of cystine monoxide to cysteic acid. The wool pre-conditioned at 53% RH, which is the humidity close to common environmental conditions, demonstrated the best Co(II) sorptivity in any case. This finding enables the elimination of pre-exposure wool conditioning in practice. Under excessive humidity of 97% RH and enough high dose of 257 kGy, radiolysis of water occurred, deteriorating the sorptivity. Each wool humidity, dose, and lapse showed a particular scenario. The time and humidity variations in the sorptivity for the non-irradiated sample were a little surprising; despite the absence of electron irradiation, relevant results indicated a strong sensitivity to pre-condition humidity and lapse from the start of the monitoring.  相似文献   
8.
Moxidectin (MXD) is an antiparasitic drug used extensively in veterinary clinics. In this study, to develop a new formulation of MXD, a thermosensitive gel of MXD (MXD-TG) was prepared based on poloxamer 407/188. Furthermore, the gelation temperature, the stability, in vitro release kinetics and in vivo pharmacokinetics of MXD-TG were evaluated. The results showed that the gelation temperature was approximately 27 °C. MXD-TG was physically stable and can be released continuously for more than 96 h in vitro. The Korsmeyer–Peppas model provided the best fit to the release kinetics, and the release mechanism followed a diffusive erosion style. MXD-TG was released persistently for over 70 days in sheep. Part of pharmacokinetic parameters had a difference in female and male sheep (p < 0.05). It was concluded that MXD-TG had a good stability, and its release followed the characteristics of a diffusive erosion style in vitro and a sustained release pattern in vivo.  相似文献   
9.
Liquid chromatographic methods were used for the detection of ochratoxin A (OTA) and its metabolites ochratoxin alpha (OTalpha), 10-hydroxy OTA (10-OHOTA), 4R-hydroxy OTA (4R-OHOTA) and the ethyl ester of OTA (OTC) in in vitro samples, obtained with Caco-2 cell culture experiments and in in vivo urine samples from sheep. A high-performance liquid chromatography method with fluorescence detection (HPLC-FLD) and a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method were developed and validated for the detection of OTA and its metabolites OTalpha, 10-OHOTA, 4R-OHOTA and OTC, which was used as internal standard. The LOD/LOQ values for OTalpha, 4R-OHOTA and OTA were 0.63/2.11, 0.99/3.31 and 0.84/2.81 microg/L, respectively, for the HPLC-FLD method and 0.98/3.28, 1.11/3.72 and 0.88/2.96 microg/L, respectively for the LC-MS/MS method. Within-day and between-day precision were both <12% for the HPLC-FLD method, and <10% for the LC-MS/MS method. The recovery of OTA and its metabolites ranged between 71 and 111% for the HPLC-FLD method and between 79 and 110 % for the LC-MS/MS method. In the first experiment only OTA was added to the Caco-2 cells while in the second experiment 3-methylcholanthrene (3MC) was also present in the cell culture systems. Besides OTA, which was recovered in all the samples, an unknown compound was also observed in the second experiment. When 3MC was added, the results showed that the OTA concentration in the basolateral samples was decreased by 50%. The methods were also implemented for the analysis of urine samples of sheep, fed increasing amounts of OTA. With the HPLC-FLD method it could be concluded that the concentration of OTA and OTalpha increased according to ingested amounts of OTA, with OTalpha being the most abundant compound. The results obtained with the LC-MS/MS method confirmed these results. Copyright (c) 2008 John Wiley & Sons, Ltd.  相似文献   
10.
The purpose of this study is to investigate the potential effects of 5-hydroxytryptophan (5-HTP) duodenal perfusion on melatonin (MT) synthesis in the gastrointestinal (GI) tract of sheep. 5-hydroxytryptophan is a precursor in the melatonin synthetic pathway. The results showed that this method significantly increased melatonin production in the mucosa of all segments in GI tract including duodenum, jejunum, ileum, cecum and colon. The highest melatonin level was identified in the colon and this indicates that the microbiota located in the colon may also participate in the melatonin production. In addition, portion of the melatonin generated by the GI tract can pass the liver metabolism and enters the circulation via portal vein. The current study provides further evidence to support that GI tract is the major site for melatonin synthesis and the GI melatonin also contributes to the circulatory melatonin level since plasma melatonin concentrations in 5-HTP treated groups were significantly higher than those in the control group. In conclusion, the results show that 10–50 mg of 5-HTP flowing into the duodenum within 6 h effectively improve the production of melatonin in the GI tract and melatonin concentration in sheep blood circulation during the day.  相似文献   
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