The objective of Exp. 1 was to compare the effects of virginiamycin (VM; 0, 175, or 250 mg x animal(-1) x d(-1)) and monensin/tylosin (MT; 250/ 90 mg x animal(-1) x d(-1)) on ruminal fermentation products and microbial populations in cattle during adaptation to an all-concentrate diet. Four ruminally cannulated, Holstein steers were used in a 4x4 Williams square design with 21-d periods. Steers were stepped up to an all-concentrate diet fed at 2.5% of BW once daily. Ruminal pH, protozoal counts, and NH3-N and VFA concentrations generally were unaffected by VM or MT. Mean counts of Lactobacillus and Streptococcus bovis were lower (P<.05) for VM-treated compared with control or MT-treated steers. Both VM and MT prevented the increase in Fusobacterium necrophorum counts associated with increasing intake of the high-concentrate diet observed in the control. The objective of Exp. 2 was to compare the effects of VM and MT on ruminal pH, L(+) lactate and VFA concentrations, and F. necrophorum numbers during carbohydrate overload. Six ruminally cannulated Holstein steers were assigned randomly to either the control, VM (175 mg/d), or MT (250 + 90 mg/d) treatments. Acidosis was induced with intraruminal administration of a slurry of ground corn and corn starch. The VM and MT premixes were added directly to the slurry before administration. Carbohydrate challenge induced acute ruminal acidosis (pH was 4.36 and L (+) lactate was 19.4 mM) in controls by 36 h. Compared with the controls, steers receiving VM or MT had higher (P<.05) ruminal pH, and the VM group had a lower (P<.05) L (+) lactate concentration. Fusobacterium necrophorum numbers initially increased in VM- and MT-administered steers. In the control steers, F. necrophorum was undetectable by 36 h. Virginiamycin seemed to control the growth of ruminal lactic acid-producing bacteria and, therefore, has the potential to moderate ruminal fermentation in situations that could lead to rapid production of lactic acid.

Nutrient element concentrations and grain quality were assessed in spring wheat grown under elevated CO 2 concentrations and contrasting levels of tropospheric ozone at different nitrogen supply rates at several European sites. Carbon dioxide enrichment proved to affect nutrient concentrations in a complex manner. In green leaves, all elements (with exception of phosphorus and iron) decreased. In contrast, effects on the element composition of grains were restricted to reductions in nitrogen, calcium, sulphur and iron. Ozone exposure resulted in no significant effects on nutrient element concentrations in different tissues in the overall analysis. The nitrogen demand of green tissues was reduced due to CO 2 enrichment as shown by reductions in the critical leaf nitrogen concentration and also enhanced nitrogen use efficiency. Reductions in the content of ribulose-bisphosphate carboxylase/oxygenase and repression of the photorespiratory pathway and reduced nitrogen allocation to enzymes driving the photosynthetic carbon oxidation cycle were chiefly responsible for this effect. Thus, nitrogen acquisition by the crop did not match carbon acquisition under CO 2 enrichment. Since crop nitrogen uptake from the soil was already completed at anthesis, nitrogen allocated to the grain after anthesis originated from vegetative pools-causing grain nitrogen concentrations to decrease under CO 2 enrichment (on average by 15% when CO 2 concentrations increased from 360 to 680 mmol mol−1). Correspondingly, grain quality was reduced by CO 2 enrichment. The Zeleny value, Hagberg value and dry/wet gluten content decreased significantly with increasing [CO 2 ]. Despite the beneficial impact of CO 2 enrichment on growth and yield of C 3 cereal crops, declines in flour quality due to reduced nitrogen content are likely in a future, [CO 2 ]-rich world.

Plant-derived essential oil products, in general, are considered minimum-risk pesticides and are exempt from Environmental Protection Agency registration under section 25(b) of the Federal Insecticide Fungicide and Rodenticide Act. However, many of the plant-derived essential products available to consumers (homeowners) have not been judiciously evaluated for both efficacy and plant safety. In fact, numerous plant-derived essential oil products labeled for control of arthropod pests have not been subject to rigorous evaluation, and there is minimal scientific information or supporting data associated with efficacy against arthropod pests. We conducted a series of greenhouse experiments to determine the efficacy and phytotoxicity of an array of plant-derived essential oil products available to consumers on arthropod pests including the citrus mealybug, Planococcus citri (Risso); western flower thrips, Frankliniella occidentalis (Pergande); twospotted spider mite, Tetranychus urticae Koch; sweetpotato whitefly B-biotype, Bemisia tabaci (Gennadius); and green peach aphid, Myzus persicae (Sulzer). Although the products Flower Pharm (cottonseed, cinnamon, and rosemary oil) and Indoor Pharm (soybean, rosemary, and lavender oil) provided > 90% mortality of citrus mealybug, they were also the most phytotoxic to the coleus, Solenostemon scutellarioides (L.) Codd, plants. Both GC-Mite (cottonseed, clove, and garlic oil) and Bugzyme (citric acid) were most effective against the twospotted spider mite (> or = 90% mortality). However, SMC (canola, coriander oil, and triethanolamine), neem (clarified hydrophobic extract of neem oil), and Bug Assassin (eugenol, sodium lauryl sulfate, peppermint, and citronella oil) provided > 80% mortality. Monterey Garden Insect Spray, which contained 0.5% spinosad, was most effective against western flower thrips with 100% mortality. All the other products evaluated failed to provide sufficient control of western flower thrips with < 30% mortality. In addition, the products Pest Out (cottonseed, clove, and garlic oil), Bang (Pipereaceae), and Fruit & Vegetable Insect Spray (rosemary, cinnamon, clove oil, and garlic extract) had the highest flower (transvaal daisy, Gerberajamesonii [H. Bolus ex Hook.f]) phytotoxicity ratings (> or = 4.5 of 5) among all the products. None of the plant-derived essential oil products provided sufficient control of sweetpotato whitefly B-biotype or green peach aphid 7, 14, and 21 d after application. Furthermore, the products Bug Assassin (eugenol, sodium lauryl sulfate, peppermint, and citronella oil) and Sharpshooter (sodium lauryl sulfate and clove oil) were phytotoxic to the poinsettia, Euphorbia pulcherrima Willd. ex Klotzsch, plants. This study is one of the first to quantitatively demonstrate that commercially available plant-derived essential oil products vary in their effectiveness against certain arthropod pests stated on the label and are phytotoxic.

A comparison of hedonic scales and just-about-right (JAR) scales is needed because data in previous studies using JAR scales suggest that predicted optimum levels of ingredients often are not the same as the levels in products that currently are sold successjully. Thus, in this research, consumers tested lemonade varying in sugar concentrationkom 6% to 14%, using ( I ) a JAR scale formed by boxes or a line and (2) a hedonic box-type scale. Predicted "optimum" levels of sweetness for the lemonade and differences in liking for the formulations were determined. The JAR line and box scales gave similar predicted optimal results (9.2% and 9.4% sucrose, respectively), which were significantly lower than the hedonic scale results ( I 0.3% sucrose). In a preference test, consumers significantly preferred the 10.3% sugar lemonade over the 9.3% concentration, indicating that, based on paired preference testing, the hedonic scale resulted in better prediction of optimal sweetness than the JAR scale.

A two-part study determined the effectiveness of gum-based rinses with or without oil for alleviating residuals of a bitter (0.8 g/L caffeine solution) and an astringent (Ig/L alum solution) stimuli in serial responses using a sip and spit method. In Experiment I , rinsing with deionized water was compared to rinsing with 0.3% xanthan gum in water alone or with 5 % corn oil and 0.55% carboxymethyl cellulose (CMC) in water alone or with 5 % or 10% corn oil. The 0.3% xanthan gum and 5% corn oil mixture resulted in the highest stimulus intensity difference before and a f e r rinsing, whereas 0.55% CMC had a value of nearly zero for residual effect. Results of a two-alternative forced choice test used in Experiment 2 indicated that both were equally effective for reducing bitterness residuals, but 0.55% CMC solution resulted in the lowest (j~ =0.007) residual effect for astringency. Therefore, the 0.55 % CMC rinse was considered an effective interstimulus rinse to use for assessing both bitterness and astringency in model solutions. '