Effects of protozoa on the antioxidant activity in the ruminal fluid and blood plasma of cattle

The objective of this study was to investigate the antioxidant status in ruminal fluid and blood plasma among three faunated and two defaunated (protozoa‐free) cattle (average bodyweight of 225 kg), fed hay plus concentrate. The extra cellular antioxidant activity of the mixed protozoa and bacteria suspensions were also studied in vitro. The antioxidant activity was detected by means of the free radical scavenging ability. The activity (units/microbial nitrogen) of the protozoal suspension increased from 59 (0 h) to 318 (18 h), and decreased to 40 (24 h) during incubation. The activity of the bacterial suspension also increased from 111 (0 h) to 644 (18 h), and decreased to 533 (24 h). The antioxidant activity (units/mL, U/mL) in the ruminal fluid of faunated (ranging from 116 to 254) and defaunated (ranging from 66 to 110) cattle was increased after 2 h and decreased after 5 h of feeding, being significantly higher in the faunated cattle. The antioxidant activity of blood plasma (U/mL) ranged from 248 to 316 in the faunated and 121–170 in the defaunated cattle during 0–5 h after feeding, being significantly higher in the faunated cattle. Therefore, defaunation possibly causes a decrease in the antioxidant level in the ruminal fluid, and may impair the health and performance of ruminants through an oxidant–antioxidant imbalance.     

Development of a high-throughput field phenotyping rover optimized for size-limited breeding fields as open-source hardware

Phenotyping is a critical process in plant breeding, especially when there is an increasing demand for streamlining a selection process in a breeding program. Since manual phenotyping has limited efficiency, high-throughput phenotyping methods are recently popularized owing to progress in sensor and image processing technologies. However, in a size-limited breeding field, which is common in Japan and other Asian countries, it is challenging to introduce large machinery in the field or fly unmanned aerial vehicles over the field. In this study, we developed a ground-based high-throughput field phenotyping rover that could be easily introduced to a field regardless of the scale and location of the field even without special facilities. We also made the field rover open-source hardware, making its system available to public for easy modification, so that anyone can build one for their own use at a low cost. The trial run of the field rover revealed that it allowed the collection of detailed remote-sensing images of plants and quantitative analyses based on the images. The results suggest that the field rover developed in this study could allow efficient phenotyping of plants especially in a small breeding field.     

Winter longitudinal variation in the body size of larval fishes in the Seto Inland Sea,Japan

This study revealed the spatial variation in abundance and body size of larval fishes in the Seto Inland Sea, Japan, in January 2014 and 2015. Fish larvae were collected by a 1.3-m-diameter ring net towed at the surface and at 10-m depth at 21 stations. The most dominant species was the sandlance Ammodytes japonicus, constituting 82% of total larval fish caught. The body size of A. japonicus was greater [ca. 9 mm total length (TL) in 2014] in eastern areas than in western areas (ca. 5 mm TL in 2014). This trend was also observed in rockfishes (Sebastiscus marmoratus and Sebastes inermis species complex), suggesting a common phenomenon in this region. Because the water temperature was lower in eastern areas, it is likely that the longitudinal differences in larval body size are attributable to earlier spawning in eastern areas caused by different temperature conditions.     

Trisomic analysis of new gene for late heading in rice, Oryza sativa L

A near isogenic line, T65-LH7 bred from a rice variety, Ketan Nangka by five times of successive backcrossing with Taichung 65 (T65) as recurrent parent was found to carry a recessive lateness gene tentatively designated as ef6(t). The present study was performed to investigate the allelic relationships between ef6(t) and other heading time genes, Ef1, Efx, ef2(t), ef3(t), ef4(t) and ef5 by allelism test and to locate the chromosomal location of ef6(t) by trisomic analysis. In allelism test, six testers carrying each of heading time genes, Ef1, Efx, ef2(t), ef3(t), ef4(t) and ef5 were used. Those testers were the near isogenic lines of T65. T65-LH7 was crossed with respective testers. Heading times in F₂ and/or B₁F₁ plants were examined. All F₂ and/or B₁F₁ populations derived from those crosses exhibited digenic segregations, respectively. These results suggested that ef6(t) was independent of Ef1, Efx, ef2(t), ef3(t), ef4(t) and ef5. Sub sequently, trisomic analysis of ef6(t) was performed using seven Triplo lines having extra chromosomes, 2, 4, 5, 7, 9, 10 and 12. These Triplo lines were the near isogenic lines of T65. They were used as maternal parent to cross with T65-LH7. Heading times in F₂ plants obtained from self-pollination of F₁ plants were observed. Among F₂ plants examined only those derived from a cross between Triplo-7 and T65-LH7 showed a typical trisomic segregation manner, suggesting that ef6(t) was located on chromosome 7. Consequently, the nomenclature of the present gene should be designated as ef6.     

Effects of Susceptibility of Test Plants on Modes of Cucumovirus Transmission by Myzus persicae

In sequential transmission tests of Peanut stunt virus S (PSV-S) and Cucumber mosaic virus V (CMV-V) using Myzus persicae, these viruses behave as a semipersistent virus in Phaseolus vulgaris, but as a nonpersistent virus in Nicotiana tabacum, regardless of the species of plant used as the virus source. In addition, viruliferous aphids retained virus infectivity and transmitted it to P. vulgaris, even after they lost infectivity to N. tabacum. Apparently, the mode of transmission by the aphids differs depending on the plant species used for the assay. After mechanical inoculation with purified PSV-S or CMV-V, P. vulgaris appeared more susceptible to PSV-S than N. tabacum. However, the susceptibility to CMV-V appeared similar in both assay plants. Received 22 May 2000/ Accepted in revised form 14 September 2000     

Rumen fermentation,milk production and conjugated linoleic acid in the milk of cows fed high fiber diets added with dried distillers grains with solubles

The effects of corn dried distillers grains with solubles (DDGS) feeding on rumen fermentation and milk production in cows were evaluated using diets high in neutral detergent fiber (NDF, 45.9–46.6%). The control diet (Control) consisted mainly of hay, corn silage and concentrates. In the experimental diets, the concentrates were replaced with DDGS as 10% dry matter (DM) (10%DDGS) and 20% DM (20%DDGS). Eight cows were used for each 14‐day treatment period. Effect of DDGS feeding on DM intake was not significant. Ruminal volatile fatty acids and ammonia‐N at 5 h after feeding of 20%DDGS were decreased compared to Control, whereas protozoal count at 2 h after feeding of 20%DDGS was higher than that of 10%DDGS. Milk yield of cows fed DDGS diets was greater than that of Control, although percentages of milk protein and solids‐not‐fat were decreased by DDGS diets. The proportions of C10:0, C12:0, C14:0 and C16:0 in the milk fat decreased, and those of C18:0, C18:1, C18:2 and cis‐9, trans‐11 conjugated linoleic acid (CLA) increased markedly with elevated DDGS. Increase in trans‐11 C18:1 was observed in the rumen fluid at 5 h after feeding. These findings suggest that DDGS feeding enhanced milk yield, as well as CLA synthesis under a high dietary NDF condition.