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Abstract— A biotelemetry study was undertaken during spring 1995 to identify black crappie ( Pomoxis nigromaculatus ) nesting sites in two South Dakota water bodies. Individually coded ultrasonic transmitters were implanted into the body cavity of 15 adult male black crappie in each water body prior to spawning. Available habitat characteristics were recorded at 75 randomly selected sites within each water body, and habitat characteristics at nesting sites were recorded for each male black crappie believed to be nesting. Of the habitat characteristics analyzed, only substrate firmness did not differ ( P =0.79) between water bodies. In Richmond Lake, black crappie selected nesting sites with live cattails ( Typha spp.) that were protected from prevailing south winds. In Brant Lake, black crappie selected nest sites with vegetation (usually woody debris) and silty substrate that had warmer water and were protected from wind and waves. It appeared that black crappie nested in the most protected areas available. 相似文献
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Bruce KJ Karr-Lilienthal LK Zinn KE Pope LL Mahan DC Fastinger ND Watts M Utterback PL Parsons CM Castaneda EO Ellis M Fahey GC 《Journal of animal science》2006,84(6):1403-1414
This experiment was designed to evaluate the effects of selected soybean (SB) processing byproducts (gums, oil, soapstock, weeds/trash) when added back to soybean meal (SBM) during processing on the resulting nutrient composition, protein quality, nutrient digestibility by swine, and true metabolizable energy (TMEn) content and standardized AA digestibility by poultry. To measure ileal DM and nutrient digestibility, pigs were surgically fitted with a T-cannula in the distal ileum. The concentration of TMEn and the standardized AA digestibility by poultry were determined using the precision fed cecectomized rooster assay. Treatments in the swine experiment included SBM with no by-products; SBM with 1% gum; SBM with 3% gum; SBM with 0.5% soapstock; SBM with 1.5% soapstock; SBM with 2% weeds/trash; SBM with a combination of 3% gum, 1.5% soapstock, and 2% weeds/trash; SBM with 5.4% soybean oil; and roasted SB. A 10 x 10 Latin square design was utilized. The experiment was conducted at the University of Illinois, Urbana-Champaign, and at The Ohio State University, Columbus. In the swine experiment, apparent ileal DM, OM, CP, and AA digestibilities were reduced (P < 0.05) when pigs consumed the combination by-product diet compared with the diet containing no by-products. Apparent ileal digestibilities of DM, CP, and total essential, total nonessential, and total AA were lower (P < 0.05) for any diet containing by-products compared with the diet with no by-products. Apparent ileal digestibilities of DM, OM, CP, and AA were lower (P < 0.05) for the roasted SB-compared with the SB oil-containing diet. In the rooster experiment, TMEn values were greater (P < 0.05) for roasted SB compared with SBM with no by-products and increased linearly as the addition of soapstock increased. Individual, total essential, total nonessential, and total AA digestibilities were lower (P < 0.05) for roosters fed roasted SB versus SBM devoid of by-products. Gums, soapstock, and weeds/trash reduce the nutritive value of the resultant meal when they are added back during processing. 相似文献
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A Samizadeh-Yazd C N Rhodes A L Pope A C Todd 《American journal of veterinary research》1979,40(8):1107-1109
Lambs naturally infected with mixed species of Eimeria were fed monensin (30 mg/kg of feed) and aureomycin (10 mg/kg of feed) separately and in combination. An evaluation was made of the efficacy of the treatments in the suppression of oocyst production. Comparisons were made of the parasitic damage to the intestinal surface. Performance of the lambs was measured by weight gains and feed efficiency. Monensin given separately or in combination with aureomycin produced decreases in oocyst counts that were not significantly different from those in the lambs given only aureomycin. Body weight gains and feed efficiency were best in the aureomycin-treated group, and less so in the monensin-treated and the control groups. Animals fed the monensin-aureomycin combination had the poorest weight gains and feed efficiency. Scanning electron microscopy indicated that the groups fed monensin or aureomycin separately had morphologically normal intestinal surfaces. This was in contrast to the control group and the group fed the monensin-aureomycin combination, wherein there was disrupted intestinal surface morphology. 相似文献
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