Artificial burrow preference by the Japanese crayfish Cambaroides japonicus

SUMMARY: Preference for artificial burrows by the endangered Japanese crayfish species Cambaroides japonicus was studied to improve its cultivation. The occupation of artificial burrows, which were made from straight polyvinyl chloride pipes of different internal diameters ( Y , mm), by crayfishes of different total lengths ( X , mm) was significantly ( P < 0.001, n = 56) described by a linear regression: Y = 0.49 X + 3.42 (19.0 ≤ X ≤ 70.2). Among burrows of different lengths [crayfish total length (TL) × 1, × 2, × 3, and × 4], crayfishes significantly preferred burrows that were greater than TL × 3 ( P < 0.001, n = 588).     

Effects of dietary phosphorus level on non-faecal phosphorus excretion from yellowtail (Seriola quinqueradiata Temminck & Schlegel) fed purified and practical diets

Non-faecal phosphorus (P) was determined for large yellowtail to estimate a minimum available P requirement (Experiment  1) and to justify inorganic P supplementation in a fish meal-based diet (Experiment 2). In Experiment 1, purified diets with incremental P concentrations were fed to yellowtail (mean weight 917 g) at a feeding rate of 1.5% of body weight. The peaks of non-faecal P excretion appeared 5–6 h after feeding in fish fed more than 4.5 g available P kg⁻¹ dry diet. Broken-line analysis indicated that the minimum available P requirement was 4.4 g kg⁻¹ dry diet. In Experiment 2, a purified diet (PR) containing 6.5 g available P kg⁻¹ and a fish meal-based diet with (F1) and without (F0) additional phosphorus were fed to yellowtail (mean weight 1.1 kg) at 1.5% (PR) and 2% (F0 and F1) feeding rates respectively. There was no significant difference in P excretion between fish fed the F0 (5.5 g soluble P kg⁻¹ dry diet) and the PR diet. However, significantly higher (34.5%) amounts of non-faecal P excretions (7.4 g soluble P kg⁻¹ dry diet) were found in fish fed F1 compared with the F0 diet. This suggested that there was an excess of dietary P in the F1 diet and that supplementation is not needed in fish meal-based diets for large yellowtail.     

Colonic mast cell infiltration in rats with TNBS-induced visceral hypersensitivity

Colonic mucosal mast cells are implicated in the pathogenesis of visceral hypersensitivity associated with irritable bowel syndromes. This study was designed to investigate the roles of mucosal mast cells in development of an experimental visceral hypersensitivity induced by 2,4,6-trinitrobenzene sulfonic acid (TNBS) in rats. TNBS, when injected into the proximal colon through laparotomy, produced a significant decrease in pain threshold of the distal colon to mechanical distention, indicating a visceral hypersensitivity. In the proximal colon that was directly insulted by TNBS, mucosal necrosis and extensive inflammatory cell infiltration were observed with concomitant increase in tissue myeloperoxide (MPO) activity. In the distal colon where distention stimuli were applied, the number of mucosal mast cells significantly increased following TNBS treatment, although neither mucosal injury nor increase in tissue MPO activity was observed. In an organ culture, spontaneous release of a mucosal mast cell-specific protease (RMCP-2) from the distal colon tissue of TNBS-treated rats was significantly larger than that of sham animals. Furthermore, TNBS-induced visceral hypersensitivity was significantly suppressed by subcutaneous pretreatment with a mast cell stabilizer doxantrazole in a dose-dependent manner. These findings suggest that prominent colonic mast cell infiltration associated with an enhanced spontaneous mediator release is responsible, at least partly, for development of visceral hypersensitivity induced by TNBS in rats.     

Supplementation effect(s) of organic acids and/or lipid to plant protein‐based diets on juvenile yellowtail,Seriola quinqueradiata Temminck et Schlegel 1845, growth and,nitrogen and phosphorus excretion

A feeding experiment was conducted to investigate the effect of organic acids and/or lipid supplementation on growth, utilization and environmental loading of nitrogen (N) and phosphorus (P) in juvenile yellowtail fed fishmeal (FM) and plant protein (PP) diets. Six diets as FM (FM‐based), FM+P (FM with inorganic P), FM+L (FM with lipid), PP+CA (PP with citric acid), PP+L+CA (PP with lipid and citric acid) and PP+L+FA (PP with formic acid) were formulated. Yellowtails were fed each of the diets in duplicate groups; once a day, 6 days a week to near satiation at water temperature 19.0–25.0 °C for 16 weeks. Fishmeal with inorganic P gave the best growth while PP+L+FA the lowest. However, growth increased in PP+CA and PP+L+CA. Addition of lipid significantly increased N and P retention resulting in significant reduction in N and P excretion. Citric acid and FA supplementation to PP diets also increased retention of P; hence, its excretion was lowered. Thus, CA, FA and lipid in juvenile yellowtail diets can help to partially replace FM with PP sources and reduce inorganic P use to minimize environmental loading from aquafeeds.     

Effect of total mixed ration silage containing agricultural by-products with the fermented juice of epiphytic lactic acid bacteria on rumen fermentation and nitrogen balance in ewes

The goal of this study was to determine the effects of the fermented juice of epiphytic lactic acid bacteria (FJLB) on the quality of total mixed ration (TMR) silage containing agricultural by-products, its digestibility, rumen fermentation, and nitrogen balance in ewes. TMR was prepared from rice straw, corn stover silage, brewer grain, tofu waste, steam-flaked corn, and a mineral mixture. The treatments consisted of silage additives added to TMR: CON (no silage additive), FJLB, COM (commercial additive), and MIX (FJLB + COM). Four cannulated ewes were assigned to the 4 × 4 Latin square design. The MIX treatment produced a lower (P < 0.01) pH than did the CON and FJLB treatments and a higher (P < 0.01) lactic acid concentration than did the other treatments. The fiber content in the COM treatment was lower (P < 0.05) than that in the other treatments. The FJLB treatment had similar fermentation quality and chemical composition to those of the CON and COM treatments in all parameters observed. Although the silage quality index (Fleig point) was higher in the MIX and COM treatments than in the CON treatment, all silages had good quality. No silage additives affected intake, digestibility, rumen fermentation, or nitrogen balance. In conclusion, the TMR silage prepared from agricultural by-products mixed with wet-type food by-products with or without FJLB added resulted in well-preserved fermentation, and this product might be used as a ruminant feed.

     

Bone morphological analyses in Spontaneously Diabetic Torii (SDT) fatty rats

The Spontaneously Diabetic Torii (SDT) fatty rat, a model for obese type 2 diabetes, shows bone quantitative abnormalities, namely low bone mineral density (BMD). The objective of this study was to evaluate bone morphological changes, in particular identifying the bone qualitative abnormalities, in the SDT fatty rat. Male SDT fatty rats showed increases in total trabecular area and trabecular number and decreases in trabecular thickness in cancellous bones of the proximal tibia, indicating trabecular miniaturization. The SDT fatty rat is useful for investigation of pathophysiological changes in bone quality in diabetic osteoporosis.     

Molecular detection of Mycoplasma haemofelis and 'Candidatus Mycoplasma haemominutum' Infection in cats by direct PCR using whole blood without DNA extraction

Detection of hemotropic Mycoplasma spp. infection was attempted in cats by PCR using whole blood without DNA extraction. A total 46 of 54 (85%) cats with suspected Mycoplasma spp. infection showed a positive reaction, corresponding completely with the results of standard PCR testing. The direct PCR assay was sensitive enough to detect more than 0.0061% parasitemia for ;C. M. haemominutum' and 0.0075% parasitemia for M. haemofelis. These data indicate that the direct PCR assay might be sufficient for use as a tool in clinical examinations.     

Evaluation of intestinal intramucosal pH,arterial and portal venous blood gas values,and intestinal blood flow during small intestinal ischemia and reperfusion in dogs

OBJECTIVES: To determine whether small intestinal ischemia and reperfusion affects intestinal intramucosal pH (pHi), arterial and portal venous blood gas values, and intestinal blood flow (IBF) and to investigate relationships between regional intestinal tissue oxygenation and systemic variables in dogs. ANIMALS: 15 healthy adult Beagles. PROCEDURE: Occlusion of superior mesenteric artery (SMA) for 0, 30, or 60 minutes, followed by reperfusion for 180 minutes, was performed; IBF, pHi, arterial and portal venous blood gas values, arterial pressure, and heart rate were measured at various time points; and intestinal mucosal injury was histologically graded. RESULTS: Occlusion of the SMA induced significant decreases in pHi and IBF. After the release of the occlusion, IBF returned rapidly to baseline values, but improvement in pHi was slow. Arterial and portal venous blood gas analyses were less sensitive than tonometric measurements of pHi, and there was no correlation between results of blood gas analyses and tonometric measurements. Histologic score for intestinal mucosal injury increased significantly, depending on duration of ischemia, and there was a correlation between tonometric results and the histologic score. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that it is difficult to accurately evaluate local oxygenation disorders by monitoring at the systemic level, whereas clinically pHi is the only reliable indicator of inadequate regional intestinal tissue oxygenation in dogs.     

Flow cytometric analysis of chicken NK activity and its use on the effect of restraint stress

Immune system is organized by the influence of both neural and endocrine systems. NK activity plays an important role in the innate immunity. In this study, we observed the effects of restraint stress on chicken peripheral blood NK activity. Viability of FITC-labeled RP9 was measured with PI after treatment with the effector cells. Chicken peripheral blood CD8alpha+ cells expressed strong cytotoxic activity, in contrast to thrombocytes, while peripheral blood CD3+ CD8alpha+ cells and CD4+ cells had little cytotoxic activity. Con A supernatant enhanced the cytotoxic activity of CD8alpha+ cells. Therefore, it is considered that these cytotoxic activities measured by flow cytometry (FCM) analysis are NK activity. When chickens were exposed to restraint stress, the levels of serum corticosterone increased transiently over a short period of time while the NK activity decreased. The decreased NK activity, however, did not recover to the intact levels for a long time, even once the serum corticosterone levels had recovered. These data indicate that chicken NK activity is able to be measured by flow cytometric analysis and that restraint stress causes severe damage to the chicken NK activity.     

Milking performance evaluation and factors affecting milking claw vacuum levels with flow simulator

Milking performance of milking machines that matches the production capability of dairy cows is important in reducing the risk of mastitis, particularly in high‐producing cows. This study used a simulated milking device to examine the milking performance of the milking system of 73 dairy farms and to analyze the factors affecting claw vacuum. Mean claw vacuum and range of fluctuation of claw vacuum (claw vacuum range) were measured at three different flow rates: 5.7, 7.6 and 8.7 kg/min. At the highest flow rate, only 16 farms (21.9%) met both standards of mean claw vacuum ≥35 kPa and claw vacuum range ≤ 7 kPa, showing that milking systems currently have poor milking performance. The factors affecting mean claw vacuum were claw type, milk‐meter and vacuum shut‐off device; the factor affecting claw vacuum range was claw type. Examination of the milking performance of the milking system using a simulated milking device allows an examination of the performance that can cope with high producing cows, indicating the possibility of reducing the risk of mastitis caused by inappropriate claw vacuum.