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With their growth, it is important to consider how alliances will impact the beef industry in the future. Alliances have the potential to make sweeping changes to cattle production, live and feeder cattle marketing, food safety protocols, use of government grades and standards, ownership structure, supply chain management, wholesale and retail product marketing, risk management, and many other industry activities. In an effort to address these issues, this article addresses the following questions: What is an alliance? What has motivated their proliferation? What have we learned from alliances? What aspects of alliances affect their likelihood of success or failure? What is the future of alliances? Are they a fad or a long-term evolving industry structural change?  相似文献   
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The experiment was conducted to investigate the effects of trace amounts of antibiotic on growth performance, diarrhea, systemic immunity, and intestinal health of weaned pigs experimentally infected with an enterotoxigenic Escherichia coli. Weaned pigs (n = 34, 6.88 ± 1.03 kg body weight [BW]) were individually housed in disease containment rooms and randomly allotted to one of the three dietary treatments: nursery basal diet (CON) and two additional diets supplemented with 0.5 or 50 mg/kg carbadox to the nursery basal diet (TRA or REC), respectively. The experiment lasted 18 d with 7 d before and 11 d after the first E. coli inoculation. The E. coli F18 inoculum was orally provided to all pigs with a dose of 1010 colony-forming unit (CFU)/3 mL for three consecutive days. Fecal and blood samples were collected on day 0 before inoculation and days 2, 5, 8, and 11 postinoculation (PI) to test the percentage of β-hemolytic coliforms in total coliforms and complete blood cell count, respectively. Sixteen pigs were euthanized on day 5 PI, whereas the remaining pigs were euthanized at the end of the experiment to collect the jejunal and ileal mucosa and mesenteric lymph node for gene expression and bacterial translocation, respectively. Pigs in REC had greater (P < 0.05) final BW and lower (P < 0.05) overall frequency of diarrhea compared with pigs in the CON and TRA groups. Pigs in TRA had the lowest (P < 0.05) average daily gain and feed efficiency from day 0 to 5 PI, highest (P < 0.05) percentage of β-hemolytic coliforms in fecal samples on days 2 and 5 PI, and greatest (P < 0.05) bacterial colonies in mesenteric lymph nodes on day 11 PI compared with pigs in the CON and REC groups. Pigs in TRA had the greatest (P < 0.05) neutrophils on day 5 PI and higher (P < 0.05) white blood cell counts and lymphocytes than other groups on day 11 PI. Pigs in TRA had the greatest (P < 0.05) serum C-reactive protein on days 2 and 5 PI and serum tumor necrosis factor-α on day 5 PI, compared with pigs in the CON and REC groups. Pigs fed REC had increased (P < 0.05) mRNA expression of zona occludens-1 (ZO-1) and occludin (OCDN) and reduced (P < 0.05) interleukin-1 beta (IL1B), interleukin-6 (IL6), and tumor necrosis factor-alpha (TNFA) in ileal mucosa on day 5 PI, compared with the CON, whereas TRA upregulated (P < 0.05) mRNA expression of IL1B, IL6, and cyclooxygenase-2 (COX2) in the ileal mucosa on day 11 PI, compared with the REC. In conclusion, trace amounts of antibiotic may exacerbate the detrimental effects of E. coli infection on pig performance by increasing diarrhea and systemic inflammation of weanling pigs.  相似文献   
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Doušová  B.  Machovič  V.  Koloušek  D.  Kovanda  F.  Dorničák  V. 《Water, air, and soil pollution》2003,149(1-4):251-267
Arsenic is of increasing environmental concern due to risk to plants, animal and human health. In aqueous systems arsenic is dominated by the AsV oxyanions H2AsO4 - and HAsO4 2- under oxidizing conditions. The possibility to remove arsenic from aqueous solutions, using sorption processes, was studied with both inorganic and organic-based sorbents. Both of tested inorganic sorbents, calcined synthetic hydrotalcite and calcined natural boehmite, were acceptable for removal of AsV compounds from aqueous systems at laboratory temperature (20 °C) and neutral pH due to their crystal structure changes. They were able to remove more than 70% of AsV compounds from aqueous solution at low sorbent-solution ratios (1 g L-1 and 2.6 g L-1, respectively) and relatively high concentration of AsO4 3- ions in the initial solution (about 2.10-3 mol L-1). Humic acid-type sorbents (i.e. pure humic acid and oxihumolite) efficiences remined low even at increased sorbent-solutionratios (about 20 g L-1) and significantly lower concentrations of As in the initial solution. At higher pH values (about 9), the sorption process slightly improved due to solubility of humic substances in alkaline solutions. The sorption increment did not exceed 50% of the initial As content. These results were confirmed by infrared spectroscopy. Both the original calcined and the sorbed inorganic sorbent samples show significant As-O vibrations, while in spectra of original and sorbed oxihumolite no significant As-O vibrations were observed, due to negligible content of sorbed As compounts.  相似文献   
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