Systemic Mycobacteriosis in an Aborted Thoroughbred Fetus in Japan

A male Thoroughbred fetus was aborted on day 251 of pregnancy. Gross and histological examinations detected systemic granulomatous lesions in many superficial and visceral lymph nodes and organs including the liver, tonsils, lungs, thymus, spleen, right thyroid gland and gastrointestinal tract, and suppurative placentitis, pyogranulomatous amnionitis and intralesional acid-fast bacilli were also detected. An examination of the DNA base sequence of the β subunit of RNA polymerase demonstrated that Mycobacterium avium strain 104 had infected several organs. To the best of our knowledge, this is the first report of equine fetal mycobacterial infection in Japan.     

Do cattle (Bos taurus) retain an association of a visual cue with a food reward for a year?

Use of visual cues to locate specific food resources from a distance is a critical ability of animals foraging in a spatially heterogeneous environment. However, relatively little is known about how long animals can retain the learned cue–reward association without reinforcement. We compared feeding behavior of experienced and naive Japanese Black cows (Bos taurus) in discovering food locations in a pasture. Experienced animals had been trained to respond to a visual cue (plastic washtub) for a preferred food (grain‐based concentrate) 1 year prior to the experiment, while naive animals had no exposure to the cue. Cows were tested individually in a test arena including tubs filled with the concentrate on three successive days (Days 1–3). Experienced cows located the first tub more quickly and visited more tubs than naive cows on Day 1 (usually P < 0.05), but these differences disappeared on Days 2 and 3. The performance of experienced cows tended to increase from Day 1 to Day 2 and level off thereafter. Our results suggest that Japanese Black cows can associate a visual cue with a food reward within a day and retain the association for 1 year despite a slight decay.     

Estimation of aboveground biomass in mangrove forests using high-resolution satellite data

Mangroves play important roles in providing a range of ecosystem services, mitigation of strong waves, protection of coastlines against erosion, maintenance of water quality, and carbon sink in the context of global warming. For trees in mangrove forests in southern Ranong Province, Thailand, we investigated the allometric relationship between crown area derived from high-resolution satellite data and stem diameter and used the resulting model to estimate aboveground biomass. We used QuickBird panchromatic and multispectral data acquired for the study area on 15 October 2006 as the high-resolution satellite data. Individual tree crowns were extracted from the satellite image of panchromatic data by using the watershed method, and the species were identified by using the maximum-likelihood method for the multispectral data. Overall classification accuracy for species identification was 88.5 %. The biomass derived from our field survey was plotted against aboveground biomass in the sample plots, estimated from the QuickBird data. The regression line through the origin between the satellite-estimated biomass and biomass based on the field data had a slope of 1.26 (R ² = 0.65). Stand aboveground biomass estimated from the high-resolution satellite data was underestimated because of a lack of data on the biomass of suppressed trees and inappropriate segmentation of crowns of large trees into two or more trees.     

Productivity of Bahiagrass Pastures in South-western Japan: Synthesis of Data from Grazing Trials

This study examined the rate of herbage production and herbage quality of bahiagrass (Paspalum notatum Flügge) using data from five grazing trials in the low‐altitude region of Kyushu, south‐western Japan, in an effort to (a) evaluate productivity of bahiagrass pastures, (b) analyse its relationship to meteorological, vegetational and managerial variables, and (c) obtain implications for better management of bahiagrass pastures. The rate of herbage production, ranging from ?56 to 213 kg DM ha^?1 day^?1, tended to increase from spring (April–May) to mid‐summer (July) and decrease thereafter. The rate was expressed by a multiple regression equation where nitrogen fertilizer rate, air temperature, rainfall and herbage mass had positive effects. Dry matter digestibility (DMD) and crude protein (CP) concentration of herbage were in the range of 471–727 and 84–161 g kg^?1 DM respectively. DMD was expressed by a regression equation where the day number from 1 April and herbage mass had negative effects, and the sampling height and nitrogen rate had positive effects. CP concentration was expressed by an equation showing a positive effect of nitrogen rate and a negative effect of herbage mass. The results indicate that management of bahiagrass pastures should aim at maintaining herbage mass closely above the critical level below which intake by grazing animals is restricted, in order to increase quality and ensure quantity. This is particularly important when nitrogen fertilizer is applied.     

Obtaining an Ogura-type CMS line from asymmetrical protoplast fusion between cabbage (fertile) and radish (fertile)

Cytoplasmic male sterile (CMS) plants were obtained by asymmetrical protoplast fusion between red cabbage (fertile) and normal radish (fertile). The CMS plants showed restriction fragment length polymorphism (RFLP) patterns of mitochondrial (mt) DNA that were different from those of both parental lines. PCR analysis of mtDNA of the CMS plants and though Southern blot analysis showed that the mtDNA of the CMS line had the characteristics of the ogura CMS type. The results suggested that the orf138 gene and the ogura type atp6 gene are present in normal fertile cabbage and radish at a low copy level. This revised version was published online in July 2006 with corrections to the Cover Date.     

Measurement of above-ground plant biomass, forage availability and grazing impact by combining satellite image processing and field survey in a dry area of north-eastern Syria

Field survey and satellite image processing methods were used to estimate the total available forage over an area of 95 034 ha in north‐eastern Syria, and to assess grazing impact on the area. The above‐ground plant biomass was measured by a quadrat method at three sites in each of eight vegetation classes. Available forage was measured by excluding woody parts of shrubs from the whole aerial plant parts. The total above‐ground plant biomass and available forage were estimated by extrapolating the measured point data to the whole target area using classified vegetation data by satellite image processing. Grazing impact was assessed by calculating the differences between the total available forage at the end of growing season and the end of dry season. The values for the estimated total available forage (s.e. of mean) in the area were 55 628 000 (12 920 000) kg DM and 30 007 000 (2 437 000) kg DM at the end of growing season and dry season respectively. Although the area of the cereal fields covered only 0·315 of the area, about 0·69 and 0·82 of the available forage existed in the harvested cereal fields at the ends of growing season and dry season respectively. The integration of cereal fields and rangeland is a normal land use system for livestock management in the area. The higher cover of herbaceous vegetation types showed higher grazing impacts which reduced the total available forage at the end of the growing season by 0·817 (0·199) at the end of the dry season. Although these dense herbaceous vegetation types could possibly produce more available forage, they would incur more intensive grazing impact. On the contrary, lighter grazing impact would occur with a higher cover of shrub vegetation types. The importance of maintaining plant cover over the rangeland area to protect the land against soil erosion is stressed.     

Effect of dietary glucosylceramide from sea cucumber on plasma and liver lipids in cholesterol-fed mice

Various physiological functions of dietary glucosylceramides (GlcCer) have been reported, such as preventing colon cancer and improving skin barrier function. One potential GlcCer source used as a foodstuff is sea cucumber. In this study, our objective was to determine the effect of dietary GlcCer prepared from sea cucumber on plasma and liver lipids in cholesterol-fed mice. ICR mice were fed four different diets (control diet, sea cucumber GlcCer supplemented diet, high cholesterol supplemented diet, and high cholesterol + sea cucumber GlcCer supplemented diet). Dietary GlcCer decreased total cholesterol significantly in ICR mice. The mRNA expression of LDL receptor was increased significantly, while the expression of the gene CYP7A1, which is involved in bile acid formation, was decreased significantly compared with the control (diet without cholesterol). These results suggest that the expression of the cholesterol homeostasis gene in liver is modulated due to the cholesterol lowering effect of dietary GlcCer.     

Behaviour of nutrients released from crystalline minerals of artificial potassium silicate fertilizer and their supply to the Japanese mustard spinach (Brassica rapa var. perviridis)

Artificial potassium silicate fertilizer (PSF) is a typical slow-release potassium fertilizer. However, the exact minerals that are released by PSF and the nutrients that are made available to plants remain unclear. This study quantitatively investigated the behaviour of nutrients released from PSF by the batch-release test and their supply to plants by the plant growth tests, respectively, to determine the quantitative relationship between nutrients released from PSF and taken up by the plant. X-ray diffraction (XRD) analysis showed that kalsilite, åkermanite, and potassium–magnesium silicate were the most abundant crystalline minerals in PSF. The XRD peaks of åkermanite and potassium–magnesium silicate were absent after citric acid extraction at a liquid/solid ratio of 20 to 100 (CA20 and CA100). Magnesium-use efficiencies in PSF (11%) and residue treatments after ammonium acetate extraction (AC, 10%) were higher than those in residue treatments after CA20 (1.8%) and CA100 (6.0%). Potassium (%) released by AC in the batch-release test (4.5%) was compatible with the difference of potassium-use efficiencies between the treatments of PSF (21%) and the AC-residue (16%). Likewise, potassium (%) released by CA20 (8.8%) was lower than the difference of potassium-use efficiencies between the treatments of PSF (21%) and CA20-residue (7.9%). This study suggests that potassium is rapidly released from potassium–magnesium silicate in PSF and is readily available to plants.