Nitrogen flow on an organically managed beef farm in Hokkaido,Japan

Nutrient recycling should be effective at balancing nutrient flows in Japanese animal production. This means replacing imported feed with self-produced feed. The Yakumo Experimental Farm of Kitasato University has produced commercial beef under ‘organic’ management, without the use of agricultural chemicals or imported feed, since 2005. Using a data set obtained from 220 ha of grassland and 250 head of cattle over the 5 years from 2008 to 2012, we estimated nitrogen (N) flow. During 2011 and 2012, we measured grass production, cattle production (selling out), soil parameters and atmospheric deposition (from precipitation and atmospheric ammonia concentrations). To determine N fixation by clover (white clover, Trifolium repens L.), we compared grass + clover plots with grass-only plots. Averaged over the period, N components on the 220 ha of grassland comprised 1952 Mg soil N stock, 3.2 Mg N yr^?1 in living livestock, 14.3 Mg N yr^?1 uptake by grass growth (including 8.6 Mg yr^?1 of N fixed by clover), 15.7 Mg N yr^?1 applied in composted manure, 1.7 Mg N yr^?1 in imported bedding material, 2.8 Mg N yr^?1 in deposition and 1.41 Mg N yr^?1 in meat production. N in composted manure equaled about 0.8% of the huge soil N stock; N in grass production equaled about 0.7%, of which clover fixation supplied 60%; N deposition was not negligible; and N export by meat production was minor. These results show that on this organically managed farm, soil N stock increased gradually (by 8.6 Mg N yr^?1 [220 ha]^?1 = 39 kg N ha^?1 yr^?1 = 0.02% of the soil N stock) and N export was small. Our findings show that it is possible to balance N inputs with N outputs in a beef cattle enterprise without the need for feed or fertilizer imports.     

Amino Acid Composition,Volatile Compounds and Bioavailability of Biocalcium Powders from Salmon Frame as Affected by Pretreatment

Biocalcium powders, Bio-cal-H, and Bio-cal-A, obtained from non-alkaline treated and alkaline treated salmon frame were characterized. Glycine was the dominant amino acid (216.45–321.80 mg/g), followed by glutamic acid (102.52–110.38 mg/g), proline (72.96–96.10 mg/g), and hydroxyproline (72.98–83.75 mg/g) in both biocalcium powders. Bio-cal-H possessed a high abundance of volatile compounds such as 2-propanone, acetonitrile, and 2-butanone than Bio-cal-A. Bio-cal-A had a higher solubility in in vitro simulated gastrointestinal tract than Bio-cal-H and CaCO₃ (P < .05). However, transportation of calcium across Caco-2 cell monolayer of Bio-cal-H was higher than Bio-cal-A and CaCO₃ (P < .05). Overall, biocalcium could serve as a promising source of calcium supplementation.     

High incidence of death due to collision of hatchery-reared Pacific bluefin tuna Thunnus orientalis juveniles in sea cages, as revealed by head and spinal injuries

High mortality of hatchery-reared Pacific bluefin tuna (PBT) juveniles is frequently observed in sea cages after transfer from indoor tanks, and is likely due to collisions of the fish with the net wall of the sea cages. Because collisions frequently cause bone injuries due to physical impact, such injuries can be considered an index of obvious collisions. In the present study, bone injuries of dead juveniles were investigated in order to examine the prevalence of net collision as a cause of death among hatchery-reared PBT juveniles in sea cages. Juvenile PBT were reared in sea cages for 90 days after transfer, and dead fish were collected and examined by the clearing and staining method or by dissection to detect injury to the vertebral column and parasphenoid. The prevalence of injuries to the vertebral column and parasphenoid until day 30 after transfer was low (0.0–12.0 %) when the fish were 5.5–15.2 cm in total length (TL). However, it drastically increased to 17.8–78.0 % for fish 21.0–39.2 cm TL from day 31 onward after transfer. These results suggest that the mortalities of juvenile PBT larger than 20 cm TL in cages were induced by net collisions.     

Simulation study of the vegetation structure and function in eastern Siberian larch forests using the individual-based vegetation model SEIB-DGVM

The global ecosystem model SEIB-DGVM was adapted for an eastern Siberian larch forest through incorporation of empirical rules of allometry, allocation, and phenology developed for a larch stand at the Spasskaya-pad tower site, Yakutsk, Russia. After calibration, the model reconstructed post-fire successional patterns of forest structure and carbon cycling. It also reconstructed seasonal changes in carbon, water, and energy cycling in a mature larch forest. Sensitivity analysis showed that simulated functional properties of forest (LAI, NPP, carbon pools, and water runoff) are mainly determined by climatic environment, and population dynamic parameters (i.e., parameters for establishment and mortality) plays only minor role on them. Sensitivity analysis also showed that plant productivity and biomass were mainly limited by available water at Spasskaya-pad, where mean annual precipitation is only 257 mm. In the model, higher air temperature increases plant productivity via extension of growing season, and decreases plant productivity via causing drought and higher respiration. We found that the net effect is reduction of productivity, suggesting a possibility that global warming induces decrement of plant productivity in eastern Siberian larch forests.     

Comparison of symptomatic and neurophysiological activities of enantiomers of the insecticide 3-phenoxybenzyl 1-(4-ethoxyphenyl)-2,2-dichlorocyclopropane-1-carboxylate

The insecticidal activities of optical isomers of 3-phenoxybenzyl 1-(4-ethoxyphenyl)-2,2-dichlorocyclopropanecarboxylate and related compounds were measured with American cockroaches and their knockdown activities were evaluated with house flies. The activities of the S(?)-isomer of the dichlorocyclopropanecarboxylate were higher than those of the R(+)-isomer. The effects of the compounds on the inward membrane currents induced by a stepdepolarizing pulse in crayfish axonal membranes were examined under voltage clamp conditions by the sucrose gap method. The compounds induced a tail current upon step repolarization of the membrane. The tail current decayed to zero in each record, but developed with time after the start of application of the compound until a steady level was reached. The rate of decay of the tail current observed in axonal membranes treated with the S(?)-isomer was slower than with the R(+)-isomer. The rates of development of the tail current induced by the two isomers were not very different.     

Effects of amino acids infused into the vein on ghrelin‐induced GH,insulin and glucagon secretion in lactating cows

To investigate the effects of amino acids on ghrelin‐induced growth hormone (GH), insulin and glucagon secretion in lactating dairy cattle, six Holstein cows were randomly assigned to two infusion treatments in a cross‐over design. Mixture solution of amino acids (AMI) or saline (CON) was continuously infused into the left side jugular vein via catheter for 4 h. At 2 h after the start of infusion, synthetic bovine ghrelin was single injected into the right side jugular vein through the catheter. Ghrelin injection immediately increased plasma GH, glucose and non‐esterified fatty acids (P < 0.05) with no difference between both treatments. Additionally, plasma insulin and glucagon concentrations were increased by ghrelin injection in both treatments. The peak value of plasma insulin concentration was greater in AMI compared with CON (P < 0.05). Plasma glucagon concentration showed no difference in the peak value reached at 5 min between both treatments, and then the plasma levels in AMI compared with CON showed sustained higher values (P < 0.05). After plasma glucose concentration reached the peak, the decline was greater in AMI compared with CON (P < 0.05). These results showed that the increased plasma amino acids may enhance ghrelin action which in turn enhances insulin and glucagon secretions in lactating cows.     

<Emphasis Type="Italic">Pythium</Emphasis> and <Emphasis Type="Italic">Phytophthora</Emphasis> species associated with root and stem rots of kalanchoe

Pythium and Phytophthora species were isolated from kalanchoe plants with root and stem rots. Phytophthora isolates were identified as Phytophthora nicotianae on the basis of morphological characteristics and restriction fragment length polymorphism (RFLP) analysis of the rDNA-internal transcribed spacer regions. Similarly, the Pythium isolates were identified as Pythium myriotylum and Pythium helicoides. In pathogenicity tests, isolates of the three species caused root and stem rots. Disease severity caused by the Pythium spp. and Ph. nicotianae was the greatest at 35°–40°C and 30°–40°C, respectively. Ph. nicotianae induced stem rot at two different relative humidities (60% and >95%) at 30°C. P. myriotylum and P. helicoides caused root and stem rots at high humidity (>95%), but only root rot at low humidity (60%).     

Contagious equine metritis eradicated from Japan

Contagious equine metritis (CEM), a contagious venereal disease of horses, invaded Japan in 1980 and spread in the Thoroughbred population of the Hidaka-Iburi district of Hokkaido. To eradicate CEM, we ran a program aimed at detecting Taylorella equigenitalis, the causal agent, in carrier horses by using the PCR test, followed by culling or treatment. In 2001, the first year of the program, 12,356 Thoroughbred racing stallions and mares were tested and 11 carriers were found. Four, two, one, and one carrier mares were detected in 2002, 2003, 2004, and 2005, respectively, by application of the program at the same scale as in 2001. No PCR-positive horses were found from 2006 to 2010. These results strongly suggest that CEM was eradicated from Japan by 2010.     

Mapping the quantitative trait loci (QTL) for body shape and conformation measurements on BTA1 in Japanese Black cattle

The detection and mapping of segregating quantitative trait loci (QTL) that influence withers height, hip height, hip width, body length, chest width, chest depth, shoulder width, lumbar width, thurl width, pin bone width, rump length, cannon circumference, chest girth, abdominal width and abdominal girth at weaning was conducted on chromosomal regions of bovine chromosome one. The QTL analysis was performed by genotyping half‐sib progeny of five Japanese Black sires using microsatellite DNA markers. Probability coefficients of inheriting allele 1 or 2 from the sire at specific chromosomal locations were computed. The phenotypic data of progeny were regressed on these probability coefficients in a within‐common‐parent regression analysis using a linear model that included fixed effects of sex, parity and season of birth, as well as age as a covariate. F‐statistics were calculated every 1 cM on a linkage map. Permutation tests of 10 000 iterations were conducted to obtain chromosome‐wide significance thresholds. A significant QTL for chest width was detected at 91 cM in family 3. The detection of this QTL boosts the prospects of implementing marker‐assisted selection for body conformation traits in Japanese Black beef cattle.