Effects of option mitigating ammonia volatilization on CH4 and N2O emissions from a paddy field fertilized with anaerobically digested cattle slurry

A lysimeter experiment was carried out to evaluate the effects of the NH₃ volatilization mitigation by adding anaerobically digested cattle slurry (ADCS) alone, with wood vinegar (WV) or with a higher level of floodwater (HFW), on emissions of CH₄ and N₂O from a paddy soil planted with fodder rice. We have carried out the following treatments: (1) chemical fertilizer, (2) ADCS, (3) ADCS + WV, and (4) ADCS + HFW; the height of floodwater was 10 cm in the latter treatment, and it was 3 to 4 cm in the other treatments just before fertilizer applications. Nitrogen fertilizer rate added to soil in each treatment was 30 g NH₄⁺–N m⁻² (split in one basal and two top-dressing additions). Ammonia volatilization in the ADCS treatment was 2.7 g NH₃–N m⁻² throughout the growing season, and it was significantly reduced by 79% and 55% in the ADCS + WV and ADCS + HFW treatments, respectively. The total amount of CH₄ emitted in the ADCS treatment in the growing season was not significantly enhanced by the mitigation of NH₃ volatilization either by adding wood vinegar or by increasing the height of the floodwater. Negligible N₂O emissions were observed in all treatments during the growing period.     

Salsolinol is present in the bovine posterior pituitary gland and stimulates the release of prolactin both in vivo and in vitro in ruminants

The aims of the present study were to determine whether salsolinol (SAL), a dopamine-related compound, is present in the bovine posterior pituitary (PP) gland, and to clarify the effect of SAL on the secretion of prolactin (PRL) in ruminants. SAL was detected in extract of bovine PP gland using high-pressure liquid chromatography with electrochemical detection (HPLC-EC). A single intravenous (i.v.) injection of SAL (5 and 10mg/kg body weight) significantly and dose-dependently stimulated the release of PRL in goats (P<0.05). Plasma PRL levels reached a peak 10min after the injection, then gradually returned to basal values in 60-80min. The PRL-releasing pattern was similar to that in response to sulpiride (a dopamine receptor antagonist). The intracerebroventricular (i.c.v.) injection of 1mg of SAL had no significant effect on the release of PRL in calves, however, 5mg significantly stimulated the release (P<0.05) with peak values reached 30-40min after the injection. Moreover, SAL significantly stimulated the release of PRL from cultured bovine anterior pituitary cells at doses of 10(-6) and 10(-5)M, compared to control cells (P<0.05). Taken together, our data clearly show that SAL is present in extract of the PP gland of ruminants, and has PRL-releasing activity both in vivo and in vitro. Therefore, this endogenous compound is a strong candidate for the factor having PRL-releasing activity that has been previously detected in extract of the bovine PP gland.     

Effects of urinary excretion of nitrogen, potassium and sodium on urine volume in dairy cows

Data of 50 balance measurements were collected from dry and lactating Holstein cows to clarify the effects of urinary excretion of nitrogen (N), potassium (K) and sodium (Na) on urine volume in cows. In dry cows, orchardgrass silage, timothy hay, alfalfa silage and corn silage were offered to meet the TDN requirement. Orchardgrass silage or alfalfa silage diets were offered in switch back trials in lactating cows. There were no relationships between urinary excretion and plasma concentrations of K or Na in cows, but urinary N excretion increased with the increase of plasma urea nitrogen. There was positive correlation between urinary excretion and urinary content of Na, but urinary K contents increased rapidly by 1.3% with the increasing urinary K excretion and thereafter remained almost constant. The increasing urinary K and N excretion enhanced urine volume in cows, but urine production in cows was accurately estimated from the regression equation of urine K excretion on urine volume. Urine volume was not affected by urinary Na excretion. These results suggest that the increase of urine volume in cows affected by the increasing urinary excretion of K and N may be due to the maintenance of urine or plasma osmolality.     

Evaluation of coproantigen diagnosis for natural Echinococcus multilocularis infection in red foxes.

The validity of a coproantigen ELISA for Echinococcus multilocularis was evaluated by comparison of three diagnostic methods; autopsy, egg examination and the ELISA. Of 71 foxes, 39 were found to be infected with the cestode at autopsy. The overall mean of worm burdens was 3,451, but the number varied (1-34,522). The ELISA could detect 94.9% (37/39) of the worm positives and there were no false-positives. Two false-negatives were infected with 1 and 4 cestodes, whereas 3 cases with similar worm burdens (2, 4 and 6 worms) were diagnosed as positives. This indicates the detection limit of the assay may be equivalent to less than 10 (in the worm burden). On the other hand, egg examination showed low sensitivity (43.6%, 17/39). These results suggest the ELISA has a potential to replace for the conventional methods.     

Histopathology and physiopathology of gastric mucous hyperplasia in rats heavily infected with Taenia taeniaeformis.

Rats heavily infected with larval Taenia taeniaeformis show hyperplasia of the gastric mucosa accompanied by mucous cell proliferation, increase in the level of intragastric pH and hypergastrinemia. Sixty one rats were divided into 2 groups designed as infected (36 rats) and control (25 rats) group. These rats were examined with time course of the infection histopathologically and physiopathologically, during 14-112 days postinfection (DPI). In the infected rats, gastric mucosal hyperplasia began to be observed at 56 DPI, and the structural disturbance of zymogenic units in the corpus and mucous units in the antrum had increased with time. However, the degree of these changes in the antrum was weaker than those in the corpus. Alcianblue and/or PAS-positive cells increased in their numbers with time, and 4 types of cells other than typical surface mucous cell and mucous neck cell were observed by electron-microscopy. However, zymogenic and parietal cells decreased in their number after 56 DPI. Further, the infected rats showed changes in the serum concentration of alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen, glucose and total protein. Some similarities with Menetrier's disease were discussed.     

Comparison of methanotrophic bacteria, methane oxidation activity, and methane emission in rice fields fertilized with anaerobically digested slurry between a fodder rice and a normal rice variety

Methane oxidation activity (MOA), methanotrophic bacteria (MOB), and CH₄ emission in a paddy field fertilized with anaerobically digested slurry were compared between two varieties: a fodder rice variety Leaf star (LS) and a normal rice variety Kinuhikari (KN). Average MOA and MOB per unit dry root were significantly higher in KN (7.1?μmol?g^?1 CH₄?g^?1 dry root h^?1 and 3.7?×?10⁷ MPN?g^?1 dry root, respectively) than in LS (4.3?μmol?g^?1 CH₄?g^?1 dry root h^?1, 2.1?×?10⁷ MPN?g^?1 dry root), although MOA in the rice root per whole plant was not significantly different since root biomass of LS (1.5?g dry root plant^?1) was significantly higher than that of KN (1.2?g dry root plant^?1). MOA in the soil ranged from 0.031 to 0.087?μmol?g^?1 CH₄?g^?1 dry soil h^?1, but there were no significant differences in both depths (0–5 and 5–15?cm) between the two rice varieties. MOA in the rhizosphere soil was significantly different between the rice varieties at flowering, but not at tillering. Methane emission in the field was lower and MOA and MOB in the rice root were higher in LS than in KN at tillering, but the reverse results were found at flowering and maturity stages. Total CH₄ emission during a growing period was not significantly different between LS (27.4?±?16.9?g CH₄?m^?2) and KN (24.0?±?19.5?g CH₄?m^?2). There was a significant negative relationship between CH₄ emission and rice root MOB (P?<?0.01) or MOA (P?<?0.05) and significant positive relationship was observed between root MOA and MOB (P?<?0.01). This study revealed that choice of rice variety might be an important environmental issue in paddy cultivation since it can influence MOA and MOB in rice root and rhizosphere soil which relate with CH₄ emission.     

Maximum prey size estimation of longtooth grouper,Epinephelus bruneus,using morphological features,and predation experiments on juvenile cannibalism

In fish culture, cannibalism, which induces critical damage, is separated into two types: type I, which occurs in early larval stages when size heterogeneity is low; and type II, which starts in later larval and/or early juvenile stages following type I when size heterogeneity is high. In type II, the cannibal's maximum prey size is limited by its gape size relative to the prey fish body size. Ratios of prey to cannibal body size changes are associated with allometric factors and feeding behaviour with growth. In a previous study on grouper, the maximal prey size was estimated morphologically (i.e., the relationship between gape size and body height). This method is very simple and useful; however, it does not consider allometric factors and feeding behaviour changes; therefore, it probably causes a large estimation error. To overcome this, we present a new method for estimating maximal prey size to determine the size ranges for size grading of longtooth grouper, Epinephelus bruneus, juveniles using predation experiments. It is shown that grouper type II cannibalism is affected by two factors; in early juvenile stages by morphology and in later (TL over 50 mm) by prey size selectivity.     

Textural quality of cooked potatoes: II. Relationship of steam cooking time to cellular strength of cultivars with similar and differing solids

The relationship of steam cooking time with cellular strength of cultivars Chieftain, Kennebec, Russet Burbank and White Rose was compared within and among solids concentrations. Nitrogen fertilization had no discernible effect on cell wall strength. Cell strength of Kennebec and Russet Burbank was similar regardless of solids concentration or cooking time. However, cell strength of Chieftain and White Rose differed with solids concentration and cooking time. Knowledge of cell strength and its characteristics with cooking time appear important for understanding the differences in textural quality that exists between cultivars.     

Oil content of French fries as affected by blanch temperatures,fry temperatures and melting point of frying oils

The oil content of par-fried frozen French fries prepared by two methods, conventional and freeze-leached, was not affected by blanch temperatures when blanched for 15 minutes. Melting points of the frying oil did affect the oil content of par-fried French fries. The differences were variable and could not be explained by melting point alone. Blowing the potato strips with ambient air after the par-fry and cooling below the melting point of the frying oil had no effect on the oil content of the frozen product. Contrary to previous reports, the oil content of the French fries increased significantly as the par-frying temperature was increased from 160.0 to 185°C (320 to 365°F) with the greatest increase occurring between 171.1 and 185.0°C (340 and 365°F). The French fries par-fried 1 min at 171.1 and 185.0°C (340 and 365°F) were judged to have identical quality after finish frying 3 minutes at 185.0°C (365°F). A lower par-fry temperature or possibly a shorter par-fry time at the higher temperature would be an advantage to the processor who could use less oil and energy without adversely affecting the quality of the final consumable product.