Loss Of Water Balance Research Articles

Duration of Zearalenone Exposure Has Implications on Health Parameters of Lactating Cows.

There is a limited research focus on evaluating the detrimental effects of prolonged zearalenone (ZEN) intake on dairy cows' health under controlled conditions. This experiment was conducted to evaluate whether the length of exposure to a ZEN-contaminated total mixed ration (TMR) at a level of 9.45 mg per day can negatively influence animal health parameters, such as milk composition, rumen and fecal fermentation, and the chewing activity of lactating dairy cows. For this experiment, we used 18 lactating Simmental cows that were fed a diet of 60% forage and 40% concentrate (on dry matter basis) for 26 consecutive days. The first 4 days were for adaptation prior to the first sampling day (day 0). The sampling events took place on day 0 (baseline) without ZEN, followed by day 1, day 7, day 14, and day 21 (with toxin). Dry matter intake (DMI) and ruminating chews per minute increased on the third week of ZEN inclusion; meanwhile, ruminating, eating, and drinking times were not affected. Most milk composition variables were also unaffected. Rumen fluid osmolality increased on day 21 and total short-chain fatty acids (SCFA) of ruminal fluid decreased on day 7. Fecal SCFA increased on day 21 and the acetate-to-propionate ratio increased from day 1 onwards, showing the influence of toxin intake. Animal health parameters, like heart rate, respiratory rate, and body temperature, were negatively influenced by ZEN intake, all increasing consistently on days 4 and 6, 9 and 12, and 16 and 18, respectively. The liver enzyme glutamate dehydrogenase decreased in response to ZEN intake on day 7. A total daily ZEN intake at the level of 9.45 mg did not show detrimental effects on DMI. Nevertheless, certain health parameters were negatively affected, including body temperature, respiratory rate, and heart rate, starting from the 7th day of ZEN intake, with additional signs of possible loss of water balance on the last sampling day.

Evapotranspiration and runoff in a forest watershed, western Japan

AbstractA Note has been published for this article in Hydrological Processes 18(4) 2004, 825. Both water and heat balances were studied in a conifer plantation watershed in south‐west Japan, within the warm‐temperate East Asia monsoon area. Forest cover in the watershed consists mainly of Japanese cedar (Cryptomeria japonica) and Japanese cypress (Chamaecyparis obtusa) plantations. Precipitation and runoff have been observed since 1991, so evapotranspiration can be compared with the water balance. Two meteorological observation towers were built to monitor evapotranspiration in the watershed. The annual average precipitation, amount of runoff and losses were 2166, 1243 and 923 mm, respectively. The evapotranspiration (latent heat flux) agreed well with the water balance losses. The average annual evapotranspiration at the tower built in the centre of the watershed was 902 mm; evapotranspiration at the other tower, further upslope, was 875 mm. The observed evapotranspiration was 39% to 40% of the average precipitation (2166 mm). The mean net radiation was c. 2·6 GJ m−2 year−1, and is considered a representative value of the net radiation (Rn) in coniferous plantations in this region. This region is classified in the humid zone based on the ratio of net radiation (Rn) to the energy required to evaporate the rainfall (λR). The mean annual evaporation of canopy‐intercepted water was 356 mm or about 15% of the average precipitation. Copyright © 2003 John Wiley & Sons, Ltd.

Studies on corresponded-relations between plant characters and cultivation methods. III. Comparison of water balance in plants at transplanting among millets.

Some experiments on transpiration and water absorption were conducted to determine the different rooting ability of millets at the time of transplanting from the viewpoint of water balance in the plant. This report also contains work on the effect of seedling quality on rooting. These experiments were done during the period from 1978 to 1981. The results obtained were as follows: 1. Transpiration rate per leaf arca was the highest in Japanese barnyard millet and the lowest in sorghum under the condition of water culture. Among the seedlings from the nursery bed filled with volcanic soil, however, Italian millet showed the highest transpiration, and the low values were seen in common millet and Japanese barnyard millet (Table 1). 2. The reason why Italian millet was subject to losing water balance in the plant at transplanting time, compared with finger millet were as follows: (1) Water content of the plant organs was lower in Italian millet and its transpiration rate was higher. This might be due to the higher stomata density per leaf area. (2) Top/Root ratio of Italian millet is extremely high and it becomes still higher by unavoidable cutting of roots at the time of transplanting. This results in a considerable decrease in water absorption by roots, although Italian millet has high water absorption rate and high level of bleeding water per root dry matter weight. This decrease in water absorption compared to a higher transpiration rate of leaves may result in losing water balance in Italian millet. On the other hand, finger millet had lower water absorption and also lower bleeding water level per root dry matter weight. But this crop had a high water content in its plant organs and a lower ratio of Top/Root. Therefore, the water balance can be kept in the plant. In the case of sorghum, ablility of water absorption and bleeding was low and the water balance in the plant may be kept with lower water contents because of its lower transpiration rate due to fewer stomata per leaf area. Japanese barnyard millet and common millet showed a similar tendency to finger millet and Italian millet, respectively (Table 2 and 3, Figs. 4-5). 3. To understand the effect of seedling quality on taking root, the rooting ability of seedlings grown at different fertilizer levels was investigated. New roots were more numerous in the seedlings of the standard fertilizer plot than the non-fertilizer application plot. The longest root was found in the seedling of the non-fertilizer plot. In the high fertilizer plot, only finger millet could produce more roots. Two weeks after transplanting, plants from the standard level plot showed greater growth, whereas common millet, Japanese barnyard millet and Italian millet displayed less growth at a higher level of fertilizer than the standard level (Table 4 and 5). From the above results, the higher Top/Root ratio is likely to cause taking root to fail at transplanting mainly due to damage of roots by pulling seedlings from the nursery bed, and the resultant decrease of water absorption by roots and loss of water balance in the plant can be seen. Therefore, especially the direct sowing type plants such as Italian millet and common millet are not suitable for transplanting. As to the effect of seeding quality on taking root, the seedings grown at the standard fertilizer levels generally showed good growth with many newly-emerged roots. But with a higher fertilizer level, all the millets except finger millet could not attain desirable growth.

The water relations of Maidenhair fronds treated with silver nitrate

The wilting of cut fronds of Maidenhair fern ( Adiantum raddianum cultivar ‘Decorum’) after less than 2 days in DI water was associated with a rapid reduction in water potential, loss of water balance, and a sharp decline in the rate of water conduction through the stem. AgNO 3 vase solutions maintained water potential, water balance and turgidity of the fronds for up to 2 weeks by simultaneously reducing water loss from the pinnae and maintaining water conductivity of the rachis.