Free Oestrone in Adipose Tissue and its Relation to Androstenone and Skatole in Entire Male Pigs     

G Zamaratskaia  A Madej  J Babol  EJ Squires  K Lundström 《Reproduction in domestic animals》2005,40(2):156-160

Relationship between free oestrone and boar taint compounds in adipose tissue were studied in two groups of entire male pigs of different breeds. Group A consisted of 33 entire crossbred male pigs (dam Yorkshire and sire backcross Yorkshire x Wild Boar, generation seven). Group B consisted of 194 entire male pigs of crossbreeds between Swedish Hampshire (H) and Finnish Landrace (L), LH x H, H x LH, LH x LH (dam x sire). The measurements of free oestrone in adipose tissue were performed with a new method developed and validated in our laboratories. The standard curve was linear for concentrations of free oestrone ranging from 0.13 to 5.10 ng/g. The method exhibited parallelism of results between serial dilutions and a mean recovery of 97 +/- 13.7%. Intra-assay variations for samples with concentrations of free oestrone from 0.67 to 2.08 ng/g were from 9.23 to 11.94%. Inter-assay variations for the samples with concentrations of free oestrone from 0.89 to 2.96 ng/g were from 3.78 to 10.11%. The levels of free oestrone in fat from group A were well correlated with fat levels of androstenone (r = 0.66; p < 0.001) and levels of oestrone sulphate in peripheral plasma collected at the same time as the fat (r = 0.74, p < 0.001). The levels of free oestrone in fat from group B were significantly correlated to fat levels of androstenone (r = 0.68, p < 0.001) and skatole (r = 0.29, p < 0.001). In group B, age-related differences in fat levels of free oestrone, androstenone and skatole were studied. Free oestrone and skatole levels increased simultaneously at the age of 22 week (p < 0.05 for both), and androstenone levels increased at the age of 26 week (p < 0.05). It was suggested that the levels of free oestrone in adipose tissue might be used for the evaluation of hormonal status of male pigs as an alternative to plasma levels of testicular hormones. The levels of free oestrone might be involved in the regulation of skatole levels in fat as indicated by both the simultaneous increases in skatole and free oestrone levels in fat and positive correlation between skatole and free oestrone.  相似文献   

Effect of hCG Stimulation on Plasma Androstenone Concentrations and Cytochrome b5 Levels in Testicular Tissue     

G Zamaratskaia  Y Lou  G Chen  Ø Andresen  K Lundström  EJ Squires 《Reproduction in domestic animals》2007,42(1):105-108

The effect of Human chorionic gonadotropin (hCG) stimulation on the concentrations of free and conjugated androstenone in plasma was studied in 34 crossbred entire male pigs (Landrace x Swedish Yorkshire). Seventeen pigs were treated with hCG 4 days prior to slaughter and the remaining pigs were treated with sterile saline and served as controls. Blood samples were taken prior to hCG or saline injection and on the day before slaughter and analysed for concentrations of free and conjugated androstenone. Testicular tissue samples were taken at slaughter and analysed for the levels of cytochrome b5 (cyb5) protein. Here we have demonstrated for the first time that hCG stimulation causes an increase in the plasma levels of both free and conjugated androstenone. Not all animals responded in the same way to hCG treatment regarding levels of free and conjugated androstenone demonstrating that individual animals can have differences in their capacity to produce free and conjugated androstenone. We suggest that hCG treatment is a good way to determine the potential for androstenone conjugation when androstenone synthesis in the testis is high. The levels of cyb5 protein in the testis were slightly related (r=0.41, p < 0.10) to free androstenone levels in the pigs after hCG administration, although levels of cyb5 protein were not affected by hCG treatment.  相似文献   

Ultrasonographic Characteristics of Ovulatory Follicles and Associated Endocrine Changes in Cyclic Ewes Treated with Medroxyprogesterone Acetate (MAP)-releasing Intravaginal Sponges and Equine Chorionic Gonadotropin (eCG)   总被引：2，自引：0，他引：2  

X Liu  Q Dai  EJ Hart  DMW Barrett  NC Rawlings  RA Pierson  PM Bartlewski 《Reproduction in domestic animals》2007,42(4):393-401

The aim of this study was to assess the ultrasonographic characteristics of ovulatory follicles in cyclic Western White Face ewes (December) that had received intravaginal sponges containing medroxyprogesterone acetate (MAP; 60 mg) for 12 days, with or without an injection of 500 IU of equine chorionic gonadotropin (eCG) at sponge removal. We hypothesized that quantitative echotextural attributes of the follicles in ewes treated only with MAP would differ from those in MAP/eCG-treated ewes, reflecting the increased antral follicular growth and secretory function under eCG influence. Digital images of ovulatory follicles obtained at 0 and 24 h after MAP sponge removal and at 24 h before ovulation in the eCG-treated (five ewes, 13 follicles) and control (six ewes, 9 follicles) animals, were subjected to computerized analyses. The mean diameter of ovulatory follicles increased (p < 0.001) 24 h after eCG treatment. The mean pixel intensity and heterogeneity of the follicular antrum (p < 0.001), as well as mean pixel intensity of the follicular wall and perifollicular ovarian stroma (p < 0.05), were greater in eCG-treated animals compared with control ewes 24 h after sponge removal and at 24 h before ovulation. Mean serum concentrations of oestradiol-17beta tended to increase (p = 0.06) 24 h after eCG treatment and the eCG-treated ewes exceeded (p < 0.05) control animals in progesterone concentrations from days 9-15 after ovulation. Our results support the hypothesis that large antral follicles in eCG-treated ewes exhibit distinctive echotextural characteristics. Follicular image attributes in eCG-treated ewes appear to be indicative of the changes in follicular morphology and secretory activity caused by the administration of the exogenous gonadotropin, which has both FSH- and LH-like activities.  相似文献   

Interspecific variation in xylem vulnerability to cavitation among tropical tree and shrub species     

Lopez OR  Kursar TA  Cochard H  Tyree MT 《Tree physiology》2005,25(12):1553-1562

In tropical moist forests, seasonal drought limits plant survival, productivity and diversity. Drought-tolerance mechanisms of tropical species should reflect the maximum seasonal water deficits experienced in a particular habitat. We investigated stem xylem vulnerability to cavitation in nine tropical species with different life histories and habitat associations. Stem xylem vulnerability was scored as the xylem water potential causing 50 and 75% loss of hydraulic conductivity (P50 and P75, respectively). Four shade-tolerant shrubs ranged from moderately resistant (P50=-1.9 MPa for Ouratea lucens Kunth. Engl.) to highly resistant to cavitation (P50=-4.1 MPa for Psychotria horizontalis Sw.), with shallow-rooted species being the most resistant. Among the tree species, those characteristic of waterlogged soils, Carapa guianensis Aubl., Prioria copaifera Griseb. and Ficus citrifolia Mill., were the most vulnerable to cavitation (P50=-0.8 to -1.6 MPa). The wet-season, deciduous tree, Cordia alliodora (Ruiz and Pav.) Oken., had resistant xylem (P50=-3.2 MPa), whereas the dry-season, deciduous tree, Bursera simaruba (L.) Sarg. was among the most vulnerable to cavitation (P50=-0.8 MPa) of the species studied. For eight out of the nine study species, previously reported minimum seasonal leaf water potentials measured in the field during periods of drought correlated with our P50 and P75 values. Rooting depth, deciduousness, soil type and growth habit might also contribute to desiccation tolerance. Our results support the functional dependence of drought tolerance on xylem resistance to cavitation.  相似文献   

Synchronous climate changes in antarctica and the north atlantic     

EJ Steig  EJ Brook  JWC White  CM Sucher  ML Bender  SJ Lehman  DL Morse  ED Waddington  GD Clow 《Science (New York, N.Y.)》1998,282(5386):92-95

Central Greenland ice cores provide evidence of abrupt changes in climate over the past 100,000 years. Many of these changes have also been identified in sedimentary and geochemical signatures in deep-sea sediment cores from the North Atlantic, confirming the link between millennial-scale climate variability and ocean thermohaline circulation. It is shown here that two of the most prominent North Atlantic events-the rapid warming that marks the end of the last glacial period and the Bolling/Allerod-Younger Dryas oscillation-are also recorded in an ice core from Taylor Dome, in the western Ross Sea sector of Antarctica. This result contrasts with evidence from ice cores in other regions of Antarctica, which show an asynchronous response between the Northern and Southern Hemispheres.  相似文献   

Diversity,abundance, and size structure of bivalve assemblages in the Sipsey River,Alabama     

Wendell R. Haag  Melvin L. Warren Jr 《水产资源保护:海洋与淡水生态系统》2010,20(6):655-667

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Evaluation of parameters affecting switchgrass tissue culture: toward a consolidated procedure for <Emphasis Type="Italic">Agrobacterium</Emphasis>-mediated transformation of switchgrass (<Emphasis Type="Italic">Panicum virgatum</Emphasis>)     

Chien-Yuan Lin  Bryon S. Donohoe  Neha Ahuja  Deborah M. Garrity  Rongda Qu  Melvin P. Tucker  Michael E. Himmel  Hui Wei 《Plant methods》2017,13(1):113

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Mechanism for lactate-color stabilization in injection-enhanced beef     

Kim YH  Hunt MC  Mancini RA  Seyfert M  Loughin TM  Kropf DH  Smith JS 《Journal of agricultural and food chemistry》2006,54(20):7856-7862

In two experiments, the relationship between metmyoglobin (MMb) reduction and lactate to pyruvate conversion with concomitant production of reduced nicotinamide adenine dinucleotide (NADH) via lactic dehydrogenase (LDH) was investigated. In experiment 1, nonenzymatic reduction of horse MMb occurred in a lactate-LDH-NAD system. Exclusion of NAD+, L-lactic acid, or LDH resulted in minimal MMb reduction. Increasing NAD+ and L-lactic acid concentrations increased reduction. In experiment 2, beef strip loins (longissimus lumborum muscle) were injected with combinations of potassium lactate, sodium tripolyphosphate, sodium chloride, and/or sodium acetate. Steaks were packaged in high-oxygen (80% oxygen/20% carbon dioxide) modified-atmosphere packaging and stored for 2-9 days and then placed in a fluorescent-lighted, open-top display case for 5 days at 1 degrees C. Enhancing loins with 2.5% potassium lactate significantly increased LDH activity, NADH concentration, MMb-reducing activity, and subsequent color stability during display. These research results support the hypothesis that enhancing beef with lactate replenishes NADH via increased LDH activity, ultimately resulting in greater meat color stability.  相似文献   

Emerging technologies and the safety and health of farming people     

Myers ML 《Journal of agricultural safety and health》2006,12(3):179-180

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Farm management factors associated with bulk tank somatic cell count in Irish dairy herds     

PT Kelly  K O'Sullivan  DP Berry  SJ More  WJ Meaney  EJ O'Callaghan  B O'Brien 《Irish veterinary journal》2009,62(Z4):S45

The relationship between bulk tank somatic cell count (SCC) and farm management and infrastructure was examined using data from 398 randomly selected, yet representative, Irish dairy farms where the basal diet is grazed grass. Median bulk tank SCC for the farms was 282,887 cells/ml ranging from 82,209 to 773,028 cells/ml. Two questionnaires were administered through face-to-face contact with each farmer. Herd-level factors associated with bulk tank SCC were determined using linear models with annual somatic cell score (i.e., arithmetic mean of the natural logarithm of bulk tank SCC) included as the dependent variable. All herd level factors were analysed individually in separate regression models, which included an adjustment for geographical location of the farm; a multiple regression model was subsequently developed. Management practices associated with low SCC included the use of dry cow therapy, participation in a milk recording scheme and the use of teat disinfection post-milking. There was an association between low SCC and an increased level of hygiene and frequency of cleaning of the holding yard, passageways and cubicles. Herd management factors associated with bulk tank SCC in Irish grazing herds are generally in agreement with most previous studies from confinement systems of milk production.  相似文献