Growth performance of Black Bengal,Saanen, and their crossbred F1 as affected by sex,litter size,and season of kidding

The objective of the present study was to determine the factors that influenced growth performance of the goat kids of Black Bengal (BB), Saanen (SA), and their crossbred F1 (male Bengal × female Saanen [BBSA] and male Saanen × female Black Bengal [SABB]). Data for 674 kids were analyzed from 316 litters and 134 does. All kids were weekly measured on their characteristics (body weight, length, height at the withers, and chest girth) from birth to 11 weeks old. The kid’s breed and sex, litter size, and season of kidding influenced birth weight and other characteristics through the experiment. The SA and BBSA kids showed similar performance, which were higher than BB and SABB kids. Male kids had higher performance than female kids, and kids from a single litter showed the highest performance. Kids born during rainy season showed lower performance than those born in hot and cool seasons. In conclusion, the crossbred BBSA is superior to SABB or BB to raise in tropical climate Moreover, sex, litter size, and kidding season also affected growth performance during the preweaning period up to 11 weeks old.     

Competitive enzyme-linked immunosorbent assay for the detection of the antibodies specific to akabane virus.

A competitive enzyme-linked immunosorbent assay (C-ELISA) using neutralizing monoclonal antibodies (MAbs) against Akabane virus (AKAV) was developed to detect antibodies to AKAV in cattle sera. The performance of the test using 7 different competitor MAbs was evaluated in sequential serum samples and sera from cattle infected with various bovine arboviruses. The dynamics of the antibody response expressed by percentage of inhibition (PI) in C-ELISA coincided with those of neutralizing antibody titers in sequential serum samples from 2 cattle experimentally infected with AKAV. The value of PI in C-ELISA for convalescent sera from cattle infected with arboviruses correlated with the neutralizing antibody titer to AKAV but was unaffected by the antibodies to other arboviruses. In the validation experiment of C-ELISA using 286 bovine sera previously examined for the AKAV antibody by serum neutralization (SN) test, the relative specificity of C-ELISA was more than 98%, whereas the relative sensitivities of individual MAbs ranged from 49% to 82.2%. Overall agreement between C-ELISA and the SN test varied from 72% to 90% depending on the MAb. These results suggest that the C-ELISA is acceptable as a rapid and specific method for detecting antibodies to AKAV and is a potential alternative to the SN test.     

Genetic analysis for sow stayability at different parities in purebred Landrace and Large White pigs

Genetic parameters for sow stayability were estimated from farrowing records of 10,295 Landrace sows and 8192 Large White sows. The record for sow stayability from parity k to parity k + 1 (k = 1, …, 6) was 0 when a sow had a farrowing record at parity k but not at parity k + 1, and 1 when a sow had both records. Heritability was estimated by using single-trait linear and threshold animal models. Genetic correlations among parities were estimated by using two-trait linear–linear and single-trait random regression linear animal models. Genetic correlations with litter traits at birth were estimated by using a two-trait linear–linear animal model. Heritability estimates by linear model analysis were low (0.065–0.119 in Landrace & 0.061–0.157 in Large White); those by threshold model analysis were higher (0.136–0.200 & 0.110–0.283). Genetic correlations among parities differed between breeds and models. Genetic correlation between sow stayability and number born alive was positive in many cases, implying that selection for number born alive does not reduce sow stayability. The results seem to be affected by decisions on culling made by farmers.     

Immunogenic properties and mycoplasmal pneumonia of swine (MPS) lung lesions in Large White pigs selected for higher peripheral blood immune capacity

Immunogenic properties and mycoplasmal pneumonia of swine (MPS) lung lesions were compared between the immunity‐selected Large White line and the non‐selected Large White line. The selected Large White line showed a higher level of pulmonary MPS lesions compared with the non‐selected Large White line. Subsequent to vaccination, the percentage of natural killer cells and T cells (CD3⁺CD4⁺CD8^‐ and CD3⁺CD4^?CD8⁺ T cells) were significantly increased in the non‐selected line but remained unchanged in the immunity‐selected Large White line. Secretion of Mycoplasma hyopneumoniae vaccine‐specific immunoblogulin G and phagocyte activity in peripheral blood were significantly higher in the immunity‐selected Large White line than in the non‐selected line. Expression of interleukin (IL)‐4 and IL‐6 messenger RNA in hilar lymph nodes was significantly lower in the immunity‐selected Large White line than in the non‐selected line. However, expression of IL‐10 in all immune tissues was significantly higher in the immunity‐selected Large White line. These results suggest that the selection for high immunity was not effective in increasing resistance to MPS lung lesions.     

Strong antiviral activity of heated and hydrated dolomite--preliminary investigation

Heated and hydrated naturally occurring dolomite showed very strong antiviral activity. Infectivity of avian and human influenza, avian infectious bronchitis (coronavirus), Newcastle disease (paramyxovirus) and avian laryngotracheitis (herpesvirus) viruses dropped at least 1,000 fold following contact with the dolomite for five minutes at 4 degrees C. Dolomite is expected to be useful to inhibit the incidence of emerging and re-emerging infectious diseases.     

Effect of ovary lipid of skipjack tuna on rat serum components after stress application

Lipid extracted from the ovary of skipjack tuna by the method that we developed is rich in phospholipid-type docosahexaenoic acid. The ovary lipid of skipjack tuna (OLS) was studied for its anti-stress activity in male Wistar rats, focusing on stress-related blood components: recovery from stress was examined after application of water immersion restraint stress. As a result, serum corticosterone (CORT) secretion was inhibited and decreased rapidly after stress application in rats given OLS compared with control rats. As CORT acts as a glucocorticoid, non-esterified fatty acid (NEFA) is expected to increase by stress application. However, the concentration tended to be lower in rats given OLS than in control rats. With respect to OLS concentration, OLS increased serum dehydroepiandrosterone, secretion concentration-dependently. In addition, as with the recovery study, it tended to inhibit the increase in NEFA. These results indicate that OLS may have an anti-stress activity against acute stress.     

Nutrient leaching from the plow layer by water percolation and accumulation in the subsoil in an irrigated paddy field

To estimate the impact of water percolation on the nutrient status in paddy fields, the seasonal variations of the concentrations of cations, anions, inorganic carbon (IC), and of dissolved organic carbon (DOC) in percolating water that was collected from just below the plow layer (PW-13) and from drainage pipes at the 40 em depth (PW-40), as well as in irrigation water were measured in an irrigated paddy field. Total amounts of Ca, Mg, K, Fe, and Mn leached from PW-13 during the period of rice cultivation were estimated to range from about 390 to 770, 65 to 130, 33 to 66, 340 to 680, and 44 to 87 kg ha^-1, respectively. Amounts of losses that were estimated from the differences between the input by irrigation water and the output by percolation water from the plow layer corresponded to 11 to 26, 22 to 47,5.9 to 12, and 13 to 26% of exchangeable Ca and Mg, amorphous Fe, and easily reducible Mn in the plow layer, respectively. The concentrations of Ca, Mg, K, Fe, and Mn in PW13 were higher than those in PW-40. The amounts of these nutrients that were retained in the subsoil between the 13 em and 40 em soil depth corresponded to 83, 86, 61, 99, and 89% of the amounts that percolated from the plow layer, respectively. Total amounts of IC and DOC that percolated from the plow layer ranged from 750 to 1,500 and 85 to 170 kg-C ha^-1, which corresponded to 5.0 to 10.0% and 0.6 to 1.1% of the total carbon content in the plow layer, respectively. Eighty eight % of IC in the percolating water from the plow layer was also retained in the subsoil.     

Improvement of preservation method for ammonia-oxidizing bacteria by freeze-drying

Long-term preservation of ammonia-oxidizing bacteria had been achieved until now by using the silica gel-freezing method. Recently, the freeze-drying method for the preservation of microorganisms has been widely used, and has been applied to the preservation of ammonia-oxidizing bacteria. The 10% skim milk-l% pyruvate or glutamate ratio was optimum as a dispersion-medium, and the preservation temperature of the freeze-dried cells was effective at -80°C. This method of preservation was found to be considerably more effective than the silica gel-freezing method.     

Habitat modification by invasive crayfish can facilitate its growth through enhanced food accessibility

Background

Invasive ecosystem engineers can facilitate their invasions by modifying the physical environment to improve their own performance, but this positive feedback process has rarely been tested empirically except in sessile organisms. The invasive crayfish Procambarus clarkii is an ecosystem engineer that destroys aquatic macrophytes, which provide a physical refuge for animal prey, and this destruction is likely to enhance vulnerability to predators. Using two series of mesocosm experiments, we tested the hypothesis that the invasive crayfish increases its feeding efficiency on animal prey by reducing submerged macrophytes, thus increasing its individual growth rate in a positive density-dependent manner.

Results

In the first experiment, increasing crayfish density reduced both macrophytes and animal prey (dragonfly and chironomid larvae) and, importantly, increased the growth rate of individual crayfish, in accordance with our expectation. In the second experiment, we used artificial macrophytes to clarify whether the physical architecture of macrophytes itself protects animal prey and limits crayfish growth rate. Increasing the artificial macrophyte quantity not only increased the survival of animal prey, but also retarded the crayfish growth rate.

Conclusions

We conclude that macrophytes strengthen bottom-up control of crayfish, but this effect can be relaxed by increasing the density of crayfish via reduction in macrophytes. This positive feedback process may explain the crayfish outbreaks and regime shifts occasionally observed in invaded freshwater ecosystems.

     

Identification of Trichoderma SKT-1, a biological control agent against seedborne pathogens of rice

Trichoderma SKT-1 was previously reported as a powerful biological control agent against seedborne pathogens of rice, but the taxonomic disposition of the fungal isolate was not clear. Trichoderma SKT-1 produced irregular pyramidal warts on conidia and had an optimum growth temperature of 30°C. Morphological characteristics and colony growth were identical to those of known species of Trichoderma, including the newly recognized species T. asperellum. The 5.8S rDNA with the internal transcribed spacer (ITS) region (ca. 514 bp) of the fungus was compared with those of known species to determine the phylogenetic placement of the fungus. The length and sequence of the regions from Trichoderma SKT-1 were completely identical to those of an isolate of T. asperellum NRRL 5242 (AJ230669). On the basis of these results, we concluded that Trichoderma SKT-1 was T. asperellum.