The relationship of readily decomposable organic matter of the paddy soil to its colloidal complexes

The soil nitrogen of paddy soil is found to exist in the form of organic and inorganic nitrogen. In general, the content of inorganic nitrogen is so low that it is mainly occupied by organic nitrogen. Such soil organic nitrogen is characterized by large resistance to decomposition by soil microorganisms, and so its mineralization occurs to a small extent in most cases. However, as revealed by M. Shioiri¹⁾ and T. Harada et al. ^2,3), by some appropriate treatment of paddy soil, a part of soil organic nitrogen becomes decomposed by microorganisms and mineralized under flooded condition. Among various treatment, for example, are Presented the followings: (1) air-drying of soil Prior to flooding; (2) raising the soil temperature during the flooded condition; (3) raising the soil reaction (pH 9.0) by addition of weak alkali solution; (4) the addition of neutral salts such as Nafiuoride, Na-phosphate, Na-oxalate etc., which make soil humus peptizable.     

Studies on the organo-mineral colloidal complexes of paddy soil (Part 2) Humus contained in G1 of the degraded paddy soil

Regarding paddy soil colloids as the so-called “organo-mineral colloidal complexes” of A. F. Tyulin, the authors separated the colloidal fractions after his method, and reported the characrzstics of each fraction, and content of humus and some characteristics thereof in the previous paper¹⁾.     

Phosphorus (P) Uptake mechanisms of crops grown in soils with low P status

In our previous studies, pigeonpea (Cajanus cajan L.), groundnut (Arachis hypogaea L.), and rice (Oryza sativa L.) were found to have a higher ability to take up Fe- or Al-bound phosphorus (P) than soybean (Glycine max L.) and sorghum (Sorghum bicolor L.). Phosphorus absorption characteristics like I _max, K _m, C _min, and Fe^III reduction activity of roots, and root exudates in various crops were examined with a view to analyzing the mechanisms of P uptake. Phosphorus uptake ability was largely unrelated to variations in I _max, K _m, C _min, and Fe^III reduction activity of roots. Phosphorus-solubilizing activity in anionic fractions of root exudates was detected in pigeonpea but not in rice or groundnut. Malonic acid was the major component followed by oxalic and piscidic acid. These organic acids were able to release P from FePO₄ and A1PO₄. The higher P uptake ability of pigeonpea in soils with low P fertility presumably depends on the secretion of such organic acids from roots.     

Causes of low seed set in white clover (Trifolium repens L.)

A field experiment was conducted to clarify the factors responsible for poor seed set in four white clover ( Trifolium repens L.) cultivars. Although the mean number of ovules per floret was 5·18–5·29, the average number of seeds per floret was found to be only 1·23-1·82. A stainclearing technique was used to examine the cytoplasmic state of the embryo sac in intact, unfertilized, mature ovules and it was found that 28–33% of ovules per carpel were sterile. The abortion rate of fertilized ovules and immature seeds (7 days after pollination) ranged between 32 and 34%. Beyond this period, it was observed that only a very small proportion of the total seeds were lost. The observation of high pollen fertility and a high pollen load strongly suggests that poor pollination does not account for the reduced number of seeds per floret. A 'nutrient competition' hypothesis was proposed for high ovule sterility and post-fertilization abortion of developing seeds.     

Equine sarcoid of the glans penis with bovine papillomavirus type 1 in a miniature horse (Falabella)

A 23-year-old Falabella gelding kept in Tochigi, Japan, for more than 20 years presented with a recurrent mass of the glans penis that was first noticed about a year earlier. Partial phallectomy was performed with no adjunctive therapy for local regrowth of the mass. The horse was euthanized 3 months after surgery for urinary retention due to suspected regrowth. The resected mass affected the genital and urethral mucosa of the glans penis, and was diagnosed as equine sarcoid by histopathology and identification of bovine papillomavirus (BPV) DNA. Phylogenetic analysis of the BPV genome of the sarcoid showed high sequence homology to BPV type 1 (BPV-1) from Hokkaido, Japan, suggesting a geographical relationship for BPV-1 in Japan.     

Purulent Necrotic Dislocation of the Hip Joint Associated with Umbilical Infection in a Foal

A 42-day-old heavy draft horse fell into sudden astasia. Significant swelling and heat sensation of the left femoral region were observed. Because of a friction sound in the left hip, we supposed that the hip joint was dislocated or the hip bone was fractured. Computed Tomography (CT) examination showed that the left hip joint was dislocated and the left femoral head was disjunct. We carried out a pathological autopsy, and made a diagnosis of the foal as fracture of the hip bone and femoral head with suppurative umbilical arteritis. Pathologic changes in the umbilical artery and hind leg were completely unilateral, suggesting that left umbilical arteritis spread to the blood circulation, causing arthritis and dislocation of the hip bone.     

Effect of bilateral cecal ligation on use of dietary energy in growing chickens

In order to determine the role of the cecum on energy use in growing chickens, metabolizability of the dietary energy and energy expenditure were examined in the week following bilateral ligation and washing out of the cecum. Apparent metabolizable energy (AME) values were 14.30 and 13.69 kJ/g air‐dry matter for sham‐operated and cecally ligated chickens, respectively. These values were found to be significantly different (P < 0.05). Although AME intake and fasting heat production were decreased by cecal ligation, the distribution of AME (measured as fasting and feeding heat production, as well as heat increment and energy retention, as a proportion of AME intake) was not affected. These results suggest that the cecum helps chickens extract AME from corn‐soybean type diets with little, if any, effect on AME use, based on the present study of growing chickens in the week following cecal ligation.     

Role of sodium bicarbonate on the initiation of sperm motility in the Japanese eel

ABSTRACT:   In order to find out the role of sodium bicarbonate (NaHCO₃) on the initiation of sperm motility in the Japanese eel Anguilla japonica , interactions were investigated between NaHCO₃ and various reagents (K⁺ channel blocker 4-aminopyridine [4-AP], ammonium chloride [NH₄Cl], sodium acetate and calcium chloride [CaCl₂]) that could regulate internal factors (intracellular K⁺, intracellular pH [[pH]_i] and intracellular Ca²⁺) in sperm motility. Contradictory effects of NaHCO₃ were observed (i.e. an inhibitory effect when 4-AP was absent and a promoting effect when 4-AP was present). Sodium bicarbonate inhibited the initiation of sperm motility in the Japanese eel. However, NaHCO₃ restored the motility of immotile sperm that 4-AP inhibited. The inhibitory effect of NaHCO₃ disappeared with the addition of NH₄Cl, which raised [pH]_i, but the promoting effect was not affected by [pH]_i. Although NaHCO₃ recovered motility in the presence of 4-AP, this recovery was also observed with the addition of CaCl₂ instead of NaHCO₃. In the initiation of sperm motility in the Japanese eel, two roles for NaHCO₃ are suggested: an inhibitory role relating to the regulation of [pH]_i and a promoting role relating to the uptake of another initiation factor, which could be Ca²⁺.     

The relationship between plasma leptin concentrations and the distribution of body fat in crossbred steers

The objective of the present study was to examine the relationship between plasma leptin levels and fat distribution in crossbred steers. Twenty-four crossbred steers (Japanese Black × Holstein) were used in this study. Six steers belonged to the growing phase (11 months of age), and 18 steers to the finishing phase (from 21 to 28 months of age). Plasma leptin levels correlated positively with body fat weight ( r  = 0.807, P  < 0.01), body fat percentage ( r  = 0.802, P  < 0.01), visceral fat weight ( r  = 0.807, P  < 0.01), visceral fat percentage ( r  = 0.780, P  < 0.01), subcutaneous fat weight ( r  = 0.745, P  < 0.01), subcutaneous fat percentage ( r  = 0.734, P  < 0.01), intermuscular fat weight ( r  = 0.793, P  < 0.01), intermuscular fat percentage (0.775, P  < 0.01), renal fat weight ( r  = 0.694, P  < 0.01), renal fat percentage ( r  = 0.642, P  < 0.01), subcutaneous fat thickness ( r  = 0.755, P  < 0.01), intermuscular fat thickness ( r  = 0.721, P  < 0.01), beef marbling score ( r  = 0.706, P  < 0.01) and the crude fat content of Musculus longissimus thoracis ( r  = 0.592, P  < 0.01). The location of fat deposits did not affect the correlation values. However, when steers were divided into growing ( n  = 6) and finishing ( n  = 18) groups, there was no significant correlation between plasma leptin levels and the carcass characteristics related to fat deposition (fat weight, fat percentage, carcass traits) in either group. These results suggest that plasma leptin levels in crossbred steers positively correlate with body fat content and carcass traits when these parameters vary widely.