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E Axnér C Linde Forsberg Correction added after online publication April : from CL Forsberg to C Linde Forsberg 《Reproduction in domestic animals》2007,42(3):282-291
Knowledge about normal ranges in semen quality and the association between sperm morphology and fertility in felids is limited. The aims of this retrospective study were to (1) define a normal spermiogram in cats; (2) evaluate possible effects of season, age and breed on sperm morphology; and (3) evaluate the relationship between sperm morphology and fertility. Semen samples collected by electroejaculation from 52 cats were evaluated for sperm morphology. The cats constituted two groups: a general population of cats (n = 48) and cats examined because of poor breeding records (n = 4). The general population was divided into household (n = 20), pedigree (n = 19) and colony cats (n = 9) and into three age classes, <12 months, 12-59 months and >or=60 months. The median percentage of normal spermatozoa in the general population was 44.0% (range 1.0-91.0%). Criteria were tentatively set for what was considered a normal spermiogram. The mean percentage of normal spermatozoa was higher during February to July than during August to January (p < 0.05). Pedigree cats had a lower mean percentage of normal spermatozoa than did household cats (p < 0.05). Age had no effect on the percentage of normal spermatozoa but was positively correlated with the percentage of proximal droplets. Of the cats with <40% normal spermatozoa (n = 19), all those with known breeding records (n = 11) had produced litters. The four cats examined because of poor breeding results had higher percentages of different sperm abnormalities than tentatively stipulated for the normal spermiogram. In two of these cats both sperm morphology and fertility changed over time. 相似文献
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RT NORRIS CL McDONALD RB RICHARDS MW HYDER SP GITTINS GJ NORMAN 《Australian veterinary journal》1990,67(7):244-247
In the first of 2 experiments, a simulated voyage was conducted to examine the effects of various treatments on bodyweight change and feeding frequency of inappetant sheep at the end of lot-feeding (non-feeders). The treatments, applied during simulated shipping, were: normal quantities of feed and length of troughs; extra trough length; extra feed. Adult Merino wethers (n = 108) were used in each treatment. A voyage to the Middle East was then conducted to establish whether shipboard mortality could be reduced by separating non-feeders (n = 305) from feeders (n = 5,620) late in the feedlot hase and housing the groups separately aboard ship. A control group of non-feeders (n = 215) mixed with feeders (n = 5,732) was used for comparison. Bars (marker bars), containing a coloured dye, were attached to feed troughs to mark sheep that fed. Most non-feeders (82%) began eating when placed in shipping pens in both studies. However, there was no significant difference in percentage of sheep that fed between non-feeders given extra trough length or extra feed compared with non-feeders given standard management at any stage of simulated shipping. There was no significant difference in mean bodyweights between treatment groups on days 1, 8 and 15 of simulated shipping. Differences in bodyweight on d 22 were probably associated with different levels of gut fill. Death rates were not significantly different in separated and control groups (1.1%, 0.9%, P = 0.6) in the voyage of 14 d to the Middle East.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
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Four levels of vegetative competition were used to quantify the growth of loblolly and shortleaf pines (Pinus taeda L. and P. echinata Mill.) in naturally regenerated, even-aged stands on the Upper Coastal Plain of southeastern Arkansas, USA. Treatments included: (1) no competition control, (2) woody competition control, (3) herbaceous competition control, and (4) total control of nonpine vegetation. After pines became established from natural seeding, herbicides were used to control herbaceous plants for 4 consecutive years and woody plants for 5 consecutive years. Even though 89% of crop pines on untreated check plots were free-to-grow 11 years after establishment, crop pines on vegetation control plots were larger (P<0.001) in mean dbh, total height, and volume per tree. From age 5 through 11 years, crop pine diameter growth increased on woody control plots and decreased on herbaceous control plots because of hardwood competition in the latter treatment. At age 11, crop pine volume production averaged 207 m3/ha on total control plots, 158 m3/ha on herbaceous control plots, 130 m3/ha on woody control plots, and 102 m3/ha on untreated check plots. 相似文献
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Effect of Oil Overlay on Inhibition Potential of Roscovitine in Sheep Cumulus‐Oocyte Complexes 下载免费PDF全文
LF Crocomo WC Marques Filho CMV Ulian NS Branchini DT Silva CL Ackermann FC Landim‐Alvarenga SD Bicudo 《Reproduction in domestic animals》2015,50(3):410-416
Inhibitors of cyclin‐dependent kinases, as roscovitine, have been used to prevent the spontaneous resumption of meiosis in vitro and to improve the oocyte developmental competence. In this study, the interference of oil overlay on the reversible arrest capacity of roscovitine in sheep oocytes as well as its effects on cumulus expansion was evaluated. For this, cumulus‐oocyte complexes (COCs) were cultured for 20 h in TCM 199 with 10% foetal bovine serum (Control) containing 75 μm roscovitine (Rosco). Subsequently, they were in vitro matured (IVM) for further 18 h in inhibitor‐free medium with LH and FSH. The culture was performed in Petri dishes under mineral oil (+) or in 96 well plates without oil overlay (?) at 38.5°C and 5% CO2. At 20 and 38 h, the cumulus expansion and nuclear maturation were evaluated under stereomicroscope and by Hoechst 33342 staining, respectively. No group presented cumulus expansion at 20 h. After additional culture with gonadotrophins, a significant rate of COCs from both Control groups (+/?) exhibited total expansion while in both Rosco groups (+/?) the partial expansion prevailed. Among the oocytes treated with roscovitine, 65.2% were kept at GV in the absence of oil overlay while 40.6% of them reached MII under oil cover (p < 0.05). This meiotic arrest was reversible, and proper meiosis progression also occurred in the Control groups (+/?). So, the culture system without oil overlay improved the meiotic inhibition promoted by roscovitine without affecting the cumulus expansion rate or the subsequent meiosis progression. 相似文献
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Genotypic relatedness and antimicrobial resistance of Staphylococcus schleiferi in clinical samples from dogs in different geographic regions of the United States 下载免费PDF全文
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De Graef V Foubert I Smith KW Cain FW Dewettinck K 《Journal of agricultural and food chemistry》2007,55(25):10258-10265
The objective of this study was to gain insight into the role of trans fatty acids in determining the crystallization behavior and texture of palm-based confectionery fats. Therefore, the isothermal crystallization behavior of two series, each of three fats, one trans-containing and one trans-free, was examined by pNMR, DSC, and rheology. Furthermore, the hardness of these samples was examined at three different storage times at 10 degrees C. All of the trans free samples showed a two-step crystallization at 10 degrees C which is hypothesized to be an alpha-mediated beta' crystallization for two of the samples and a fractionated crystallization in the beta' polymorph for the third, while the trans-containing fats crystallized in a single step, probably a direct beta' crystallization. The trans-containing fat series clearly crystallized faster than the trans-free fat series and also yielded higher hardness values at all storage times investigated. The presence of trans fatty acids seems to reduce the effect of compositional variations on the crystallization process. For the trans free fats, chemical composition was much more critical in determining the crystallization rate, the SFC, and the final hardness value. 相似文献
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Field experiments were conducted to ascertain if trawling utilizing electrical currents was an effective method of harvesting crawfish.Results suggest that catch efficiency relative to vegetation density is more dependent upon trawl mechanical ability than on relative crawfish abundance. Catch is also dependent upon trawling speed, water depth and time of trawling. Trawling consistently yielded higher catches per area than did conventional traps. Unmarketable individuals and mortality were no different for the two gear types.Trawling could be an effective supplemental harvesting method, but additional work needs to be performed to alleviate electrical and mechanical problems before economic efficiency can be realistic. 相似文献