We evaluated waterlogging tolerance in barley, Italian ryegrass, and oat at three different growth stages. First, we
evaluated crop emergence rate under three conditions: waterlogging at ground level, waterlogging at 5 cm below ground
level, and no waterlogging (control). The emergence rate was the highest in Italian ryegrass, followed by oat and barley.
Next, we evaluated crop responses to waterlogging at the early and late growth stages. In addition, we evaluated recovery
growth after waterlogging. Waterlogging at the early growth stage did not reduce plant dry weight in all crops, whereas
waterlogging at the late growth stage significantly reduced root dry weight at the end of treatment in all crops (P<0.01).
In Italian ryegrass and oat, subsequent growth after waterlogging at the late growth stage showed no significant difference
between plants subjected to waterlogging and those in the control. The shoot dry weight at the harvest stage in barley was
significantly lower under waterlogging at the late growth stage compared with that in the control (P<0.01). Our results
showed that Italian ryegrass exhibited the highest waterlogging tolerance except for waterlogging at the late growth stage,
followed by oat and barley.
In the alpine grazing rangeland of the Tibetan Plateau, where three major rivers originate in China, ten sites (Plot 1 to
10, 20 m × 20 m each) were selected in the habitats of plateau pikas (Ochotona curzoniae) in August 2012 for investigating
the relationship among population density of pleateau pikas, vegetation and soil physical and chemical properties. The
population density was estimated by counting the active (opened) burrows with a filling-burrow method after counting the
number of burrow openings in each plot. A vegetational survey was conducted with quadrat methods in those plots. Soil
samples were collected from 0 to 5 cm depth and physical and chemical properties were determined. The burrow opening
density (BD) ranged from 0 to 133/400 m2 and the available burrow opening density (ABD) ranged from 5 to 63/400 m2
except 0 in Plot 1, 2 and 3. BD was negatively correlated with plant height (r = -0.652, P < 0.05) and tended to be done
with coverage (r = -0.600, P < 0.1) in vegetation and positively with bulk density (r = 0.607, P < 0.1) and negatively with
2- content (r = -0.572, P < 0.1) in soil. ABD tended to be correlated with plant height (r = -0.562, P < 0.1) and bulk
density (r = 0.593, P < 0.1). Generalized liner model analyses showed that BD and ABD were affected positively by soil
hardness and TN and negatively by plant height (P < 0.001). BD only was negatively affected by TC in soil (P < 0.001).
With cation and anion contents in soil, BD and ABD were negatively affected by Ca2+, NH4
+ and SO4
2- (P < 0.001), and also
only BD was affected by Mg2+ (P < 0.001). It was suggested that the increase of population density of plateau pikas might
be related with the lowered plant height, increases of soil hardness and the TN content and decrease of the TC content
where domestic herbivores have grazed intensively.
The Silky fowl is a famous black-boned chicken breed; adult Silky fowl are characterized
by low body weight and produces less number of eggs. Current research efforts have mainly focused on the
improvement in egg production. Previous studies have indicated a relationship between egg production and
DNA markers and a high genetic variation in Silky fowls in the Oita’s selection population. We have embarked
on the improvement in the rate of egg production in this specific population. Some valuable markers
related with egg production include the prolactin receptor and the growth hormone receptor, which were
localized to the Z chromosome. In this study, five DNA markers on the Z chromosome were analyzed in
the 5th generation of the Oita’s Silky fowl population. Genotyping of five DNA markers was performed using
polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) to study the relationship
between DNA marker and production trait. The relationship was analyzed by linear mixed model using SAS
Mixed procedure. Hatching group and genotype effects of five DNA markers were included as fixed effect in
the model. Sire and dam effect was included as random effect. Genotypes and trait values were obtained for
202 female and 58 male individuals of the 5th generation. In the females, rs16773406 showed significance for
egg production rate (p< 0.05), and for body weight at 150 days of age (p< 0.001). Markers rs15991083 showed
significance for average egg weight (p< 0.05). In the males, embigin and rs15991083 showed significance for
body weight at 150 days of age (p< 0.05), whereas rs16763148 and rs16773406 showed significance for body
weight at 300 days of age (p< 0.05).
The objective of this study was to evaluate the feasibility of using the ultrasound technique
in the genetic improvement of young Japanese Black bulls. Ultrasonic scanning was undertaken at
approximately 11 months of age, between the 6th -7th and 12th-13th rib cross section on the left side in performance
test stock to obtain ultrasonic carcass traits of rib eye area (REA7/13), trapezius muscle thickness
(TMT), latissimus muscle thickness (LMT), rib thickness (RT), subcutaneous fat thickness (SFT), intermuscular
fat thickness (IMFT) and beef marbling score (BMS). Data were collected from 525 young Japanese Black
bulls at the Livestock Improvement Association of Miyazaki. Single trait analysis was conducted by applying
a mixed model that included a random effect for sire and fixed effects for testing year and season. Age at the
start of the performance test was included as a covariate. The variance components were estimated by the
residual maximum likelihood procedure and heritability was computed. Except BMS all ultrasonic carcass
traits had moderate heritabilities, ranging from 0.15 to 0.40. Selection based on the phenotypic values of these
ultrasonic traits should be effective for the genetic improvement of young Japanese Black bulls.
This research was conducted to clarify the effectiveness of an increased supply of original
formula feed in reducing decreases in milk performance in lactating goats in a hot environment. Ten animals
were divided into two groups (dry forage freely feeding (DFG), original formula feed freely feeding (CFG)). All
the animals were kept in the first thermoneutral environment (FTE: 20.0˚C, relative humidity 80.0%) for 12
days, then transitioned to a hot environment (HE: 32.0˚C, 80.0%) for 13 days before being returned to the second
thermoneutral environment (STE) for 12 days. In the HE, the TDN and DCP intake of CFG were higher
than DFG. While the milk yield of DFG in the HE significantly decreased compared to the TE, the milk yield
of CFG remained unaffected by heat stress. The concentration and yields of milk components of both groups
in the HE was significantly lower than those in the TE. However, in the HE, milk component yields of CFG
were significantly larger than DFG. These results indicate that the increased original formula feed feeding
was not only effective in reducing decreases in milk yield in lactating goats in a HE, but was also effective in
reducing decreases in milk component yields.
In Kushima, Miyazaki Prefecture, Japan, we previously discovered three triploid hybrid
seedlings of Miscanthus sacchariflorus. Therefore, at this location, we expected to discover some mature
triploid Miscanthus plants. We collected rhizomes of 65 mature plants (31 M. sinensis; 34 M. sacchariflorus)
from Kushima, and determined the 2C DNA contents of these plants by using propidium iodide flow cytometry.
We compared these data with the 2C DNA contents of 170 plants from 4 other sites in Japan. We determined
the average 2C DNA content of the 31 mature M. sinensis (5.22 pg) was markedly lower than that
of the 34 mature M. sacchariflorus (8.72 pg). We found no mature plant showing intermediate DNA content
between the 2 species. The 2C DNA content of M. sacchariflorus tended to be higher in Kushima than in
any of the other 4 sites. Contrary to our prediction, we did not obtain triploid hybrids in mature Miscanthus
plants at any of our study sites, including Kushima. In addition, we found a higher number of putative tetraploid
hybrids occur in Kushima that in any of the other 4 sites. The large variations of relative DNA contents
among M. sacchariflorus populations may be caused by natural hybridization.