Unilateral intrauterine insemination with cryopreserved caudal epididymal sperm recovered from refrigerated canine epididymides

Canine epididymides were excised and immediately stored at 4 degrees C for 48 hr, and the qualities of caudal epididymal sperm after recovery and cryopreservation were evaluated. To confirm the fertility of the cryopreserved caudal epididymal sperm, artificial intrauterine insemination was performed. The sperm motility (61.0%) immediately after recovery from caudal epididymis stored at 4 degrees C for 48 hr was significantly lower than those of sperm stored for 0 and 24 hr (88.6 and 80.7%, respectively), but there was no significant difference after freeze-thawing (0-, 24-, and 48-hr storage groups: 27.9, 24.3, and 28.3%, respectively). The incidence of abnormal sperm immediately after recovery was significantly higher in the 24-hr and 48-hr storage groups (19.3 and 27.7%, respectively) than in the 0-hr storage group (5.6%), and a significant difference was also observed after freeze-thawing. The incidence of immature sperm with cytoplasmic droplets was significantly higher in the 48-hr storage group (18.4%) than in the 0-hr storage group (4.7%), but there was no difference after freeze-thawing. By unilateral intrauterine insemination (2x10(8) sperm), 4 of 5 bitches (80%) conceived. The above findings demonstrated that sperm motility was good even enough the incidence of abnormal sperm was high in canine epididymal sperm that were recovered from the epididymis stored at 4 degrees C for 48 hr and cryopreseved, and that artificial intrauterine insemination resulted in a high conception rate.     

Effects of Silicon on Photosynthesis of Young Cucumber Seedlings Under Osmotic Stress

Effects of silicon (Si) application on photosynthesis of solution-cultured cucumber seedlings were investigated under osmotic stress and unstressed conditions. In unstressed conditions, silicon application had no effect on growth and photosynthetic parameters. The responses of the photosynthetic parameters to abruptly imposed osmotic stress did not differ between silicon treatments. After 1 week exposure to osmotic stress, growth reduction was observed, but it was less severe in seedlings grown with silicon than in those without silicon. Although there were no differences between silicon treatments in stomatal conductance, transpiration rate, cuticular transpiration, or xylem sap exudation rate under osmotic stress, leaf intercellular carbon dioxide (CO₂) concentration was significantly lower and photosynthetic rate tended to be higher in seedlings supplied with silicon. These results suggested that the silicon-induced alleviation of growth reduction under osmotic stress in cucumber was due to amelioration of stress-induced damage of leaf tissues rather than to improvement of leaf water status.     

Molecular cloning of feline lung resistance-related protein (LRP) cDNA and its expression in a feline lymphoma cell line and adriamycin-resistant subline

Molecular cloning of feline lung resistance-related protein (LRP) was performed to evaluate the relationship between its expression level and drug resistance against chemotherapeutics. The nucleotide sequence of the coding region of feline LRP cDNA was found to be 2670-bp long and to show 84.2-92.6% homology to its human, mouse, and rat counterparts. The expression level of feline LRP mRNA was relatively high in lung, jejunum, and colon. An adriamycin (ADM)-resistant feline lymphoma subline, FT-1/ADM, showed a high level of MDR1 mRNA expression compared with parental FT-1 cells. However, no relationship was observed between the drug-resistant phenotype and the LRP mRNA expression level. Although no direct contribution of LRP to the development of the drug-resistant phenotype was observed, further investigation is advisable.     

Regulation of free glutamate content in meat by dietary lysine in broilers

Regulation of taste is important for improving meat quality and glutamate (Glu) is one of the important taste‐active components in meat. Here, the effects of dietary lysine (Lys) content on taste‐active components in meat, especially free Glu, were investigated. Fourteen‐day‐old broiler chicks (Gallus gallus) were fed on diets containing 100% or 150% of the recommended Lys content for 10 days. Concentrations of free amino acids in plasma, muscle and liver were measured. The levels of messenger RNAs (mRNAs) for enzymes related to Glu metabolism were determined in muscle and liver. The concentration of muscle metabolites was also determined. The free Glu content in muscle of chicks fed the Lys150% diet was increased by 44.0% compared with that in chicks fed the Lys100% diet (P < 0.01). The mRNA level of lysine α‐ketoglutarate reductase, which is involved in Lys degradation and Glu production, was significantly increased (P < 0.05) in the Lys150% group. Metabolome analysis showed that the Lys degradation products, muscular saccharopine, pipecolic acid and α‐aminoadipic acid, were increased in the Lys150% group. Our results suggest that free Glu content in muscle is regulated by Lys degradation. These results suggest that a short‐term feeding of high‐Lys diet could improve the taste of meat.     

Hepatic lesions caused by migrating larvae of Ascaris suum in chickens

Group A consisted of chickens infected with a single dose of Ascaris suum and group B of chickens infected with two successive doses. At days 1, 3, 7, 14 and 21 after the first or second infection dose, six chickens from each group were sacrificed. In both groups, larvae were recovered from the livers on days 1, 3, and 7 and lungs on days 3 and 7. No larvae were detected in chickens on day 14. Clear white lesions were noticed only on the livers from chickens of group B at day 7 but had disappeared at day 14. A comparison with group B showed mild histological changes that developed relative to the livers from group A.     

Reduction of dietary lysine increases free glutamate content in chicken meat and improves its taste

Taste is a crucial factor of meat quality, and amino acids are important taste‐active components in meat. Here, the effects of dietary lysine (Lys) content on taste‐active components in meat, especially free glutamate (Glu), were investigated. Twenty‐eight‐day‐old broilers (Gallus gallus) were fed diets with graded Lys content of 90% or 100% of the recommended Lys requirement, (according to the National Research Council, 1994 ) for 10 days. Free amino acid content in meat and sensory scores of meat soup were estimated. Free Glu content, the main taste‐active component of meat, was significantly increased by a reduction of dietary Lys. Compared with the Lys 100% group (control), free Glu concentrations of meat were increased by 35.7% in the Lys 90% group (P < 0.05). In addition, free glycine, valine, isoleucine, leucine, histidine and threonine concentrations of meat were significantly increased in the Lys 90% group (P < 0.05). Sensory evaluation of meat soup made from the Lys 100% and 90% groups indicated different meat tastes. Sensory scores of taste intensity, umami and kokumi tastes were significantly higher in the Lys 90% group. These results suggest that a reduction of dietary lysine increased free glutamate content in meat and improved its taste.     

Comparative study on hypocholesterolemic effect of Rhodopseudomonas palustris and Rhodobacter capsulatus on rats fed a high cholesterol diet

This comparative study was to investigate the hypocholesterolemic effects of dietary Rhodopseudomonas palustris and Rhodobacter capsulatus on rats fed a high cholesterol diet. Thirty male Wister–Imamichi rats were assigned to three groups and fed on either a high cholesterol diet, or a high cholesterol diet supplemented with 2.0% R. palustris or R. capsulatus for 4 weeks. Compared to the control diet, both of the R. palustris and R. capsulatus supplemented diets significantly reduced the serum cholesterol, triglycerides, low‐density lipoprotein, very low density lipoprotein cholesterol and hepatic triglycerides, but increased hepatic cholesterol in rats. In addition, both of the R. palustris and R. capsulatus supplemented diets may reduce the risk of atherosclerosis, as the ratio of high density lipoprotein cholesterol to the total cholesterol was significantly higher than in the control group (P < 0.05). Both the R. palustris and R. capsulatus supplemented diets led to an increase in the serum palmitic acid, compared with the oleic acid and linoleic acid. No significant differences were postulated between the rats fed R. palustris and R. capsulatus supplemented diets during the 4 weeks of the experimental period. Thus, the results may suggest that both R. palustris and R. capsulatus can contribute significant health benefits and seems to be feasible to investigate in future research.     

Saving Irrigation Water for Winter Wheat with Phosphorus Application in the North China Plain

Conserving irrigation water resources is a most important measure for sustainable wheat production in the North China Plain. In the present study, the effect of phosphorus (P) application for saving irrigation water was evaluated. The application of fertilizer P increased nitrogen and phosphorus uptake, shoot biomass, head number, seed number and, consequently, grain yield, and increased soil water use and seasonal evapo-transpiration. The lower the volume of irrigation water applied, the more obvious were these effects. When winter wheat was basally fertilized with 88.5 kg P₂O₅/ha and irrigated with 90 mm at the jointing stage, the highest fertilizer P use efficiency, apparent P recovery and net profit (due to irrigation and/or fertilizer P) were obtained. The results suggested that fertilizer P should be used for saving irrigation water resources in the North China Plain.     

Oral thyroxine administration mimics photoperiodically induced gonadal growth in Japanese quail

Most temperate‐zone animals are seasonal breeders. In a previous study, it was found that light‐induced hormone conversion of thyroxine (T₄) prohormone to active 3,5,3′‐triiodothyronine (T₃) in the mediobasal hypothalamus regulates photoperiodic response of gonads in Japanese quail. Here the effect of T₄ or T₃, administered in drinking water, on testicular growth in the Japanese quail kept under short days is shown. Testicular length was significantly increased in birds given T₄ at doses of 4, 8 and 10 mg/L, while any dose of T₃ had little effect on testicular growth. High doses (8 and 10 mg/L) of T₄ and T₃ resulted in high mortality and/or reduction of bodyweight. Among all of the treatment, 4 mg/L of T₄ was the most effective on photoperiodic testicular growth, which caused little reduction in bodyweight. These data provide a new conventional method for promoting gonadal growth under short days.