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C.?W.?ChanEmail author J.?K.?Schueller W.?M.?Miller J.?D.?Whitney J.?A.?Cornell 《Precision Agriculture》2004,5(6):601-616
The accuracy and interaction among global positioning system (GPS) horizontal accuracy, differential GPS (DGPS) sampling frequencies and machine delay times of a hypothetical variable rate applicator for nitrogen (N) fertilizer application based on an application map in Florida citrus were studied. Parameters studied included: five GPS horizontal accuracy levels, two levels of DGPS horizontal accuracy, two DGPS sampling frequencies and two machine delay times. Two integrated models were developed which documented the effects of the parameters. Machine delay time was the most important factor and GPS horizontal accuracy was the second most important. 相似文献
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The objective of this study was to investigate the response of 16 different genetic sources of corn (Zea mays L.) to lime and P application on a low pH and P Parsons silt loam soil in the greenhouse. A highly significant lime x P interaction was found for both dry matter production and P concentration. Phosphorus increased both dry matter production and P content of plant tissues with or without lime application. However, liming produced a detrimental effect when P was applied but no effect when no P was applied. Corn genetic sources showed a highly significant interaction with P treatment, but not with lime for both dry matter production and P concentration. The results suggest that improvement in corn growth could be achieved in a low P soil environment by genetic selection. 相似文献
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Two experiments were conducted to determine the effects of including distiller's dried grains with solubles in nursery diets on growth performance, and to establish maximum inclusion rates for corn distiller's dried grains with solubles originating from modern, "new-generation" ethanol plants (built since 1990). Ninety-six crossbred pigs (BW = 6.18 +/- 0.14 kg) were blocked by gender and ancestry, and pigs within each block were randomly assigned to one of six dietary treatments (four pigs/pen, four pens/dietary treatment) in each of two growth performance experiments. Dietary treatments provided 0, 5, 10, 15, 20, or 25% distiller's dried grains with solubles during Phases 2 and 3 of a three-phase nursery feeding program for early-weaned pigs. Pigs in Exp. 1 were slightly older (19.0 vs. 16.9 d of age) and heavier (7.10 vs. 5.26 kg) at the beginning of the experiment compared to pigs in Exp. 2. All pigs in both experiments were provided a commercial pelleted Phase 1 diet for the first 4 d after weaning and were then switched to their respective experimental Phase 2 diets, which were fed for 14 d, followed by their respective Phase 3 experimental diets, which were fed for a subsequent 21-d feeding period. Experimental diets were formulated to contain equivalent apparent ileal digestible lysine (1.35 and 1.15%), apparent ileal digestible methionine + cystine (0.80 and 0.65%), ME (3,340 and 3,390 kcal/kg), calcium (0.95 and 0.80%), and total phosphorus (0.80 and 0.70%) within Phases 2 and 3, respectively. Overall growth rate, ending body weight, and feed conversion were similar among pigs regardless of dietary distiller's dried grains with solubles level for both experiments. In Exp. 1, feed intake was not affected by dietary treatment (P > 0.10). In Exp. 2, however, increasing the level of distiller's dried grains with solubles linearly decreased feed intake (P < 0.02) during Phase 2 and tended to decrease voluntary feed intake (P < 0.09) over the length of the experiment. These results suggest that the corn distiller's dried grains with solubles used in this study can be included in Phase 3 diets for nursery pigs at dietary levels of up to 25% without negatively affecting growth performance after a 2-wk acclimation period. Including high levels of corn distiller's dried grains with solubles in diets for pigs weighing less than 7 kg in BW, however, may negatively influence feed intake and growth. 相似文献
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Whitney D. DeGroot 《The Canadian veterinary journal. La revue veterinaire canadienne》2014,55(1):1253-1254
A 2-year-old cat was presented with acute onset seizures, tremors, and hypersalivation. Permethrin toxicity was diagnosed based on a history of recent flea treatment. Measures were taken to minimize further absorption of permethrin, and methocarbamol and intravenous lipid emulsion were used to control tremors. The cat recovered and was discharged within 42 h. 相似文献
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Hannah J. Munro Lesley Berghuis Andrew S. Lang Laura Rogers Hugh Whitney 《Canadian journal of veterinary research》2014,78(2):140-144
Feline immunodeficiency virus (FIV) and feline leukemia virus (FeLV) are retroviruses found within domestic and wild cat populations. These viruses cause severe illnesses that eventually lead to death. Housing cats communally for long periods of time makes shelters at high risk for virus transmission among cats. We tested 548 cats from 5 different sites across the island of Newfoundland for FIV and FeLV. The overall seroprevalence was 2.2% and 6.2% for FIV and FeLV, respectively. Two sites had significantly higher seroprevalence of FeLV infection than the other 3 sites. Analysis of sequences from the FeLV env gene (envelope gene) from 6 positive cats showed that 4 fell within the FeLV subtype-A, while 2 sequences were most closely related to FeLV subtype-B and endogenous feline leukemia virus (en FeLV). Varying seroprevalence and the variation in sequences at different sites demonstrate that some shelters are at greater risk of FeLV infections and recombination can occur at sites of high seroprevalence. 相似文献