A 90-day Feeding Toxicity Study of l-Serine in Male and Female Fischer 344 Rats

A subchronic feeding study of l-serine (l-Ser) was conducted with groups of 10 male and 10 female Fischer 344 rats fed a powder diet containing 0, 0.06, 0.5, 1.5 or 5.0% concentrations of l-Ser for 90 days. There were no toxicologically significant, treatment-related changes with regards to body weight, food intake, water intake or urinalysis data. In several of the hematology, serum biochemistry and organ weight parameters, significant changes were observed between some of the treated groups and the controls. All these changes, however, were subtle and lacked any corresponding pathological findings. In addition, the increased or decreased values remained within the range of the historical control values. In fact, histopathological assessment revealed only sporadic and/or spontaneous lesions. In conclusion, the no-observed-adverse-effect-level (NOAEL) for l-Ser was, therefore, determined to be at least a dietary dose of 5.0% (2765.0 mg/kg body weight/day for males and 2905.1 mg/kg body weight/day for females) under the present experimental conditions.     

Reproductive cycle observation of the Okinawa rail (Gallirallus okinawae) in the wild

The captive breeding program of the Okinawa rail started in 2008. For successful captive breeding, information related to reproduction, such as age at sexual maturity, testicular cycles and ovulatory cycles, is essential to predict when reproduction is possible and when certain reproductive behaviors are most likely to occur. We made gross and histological observations of the reproductive organs of Okinawa rails to gain understanding of sexual maturity, the testicular cycle and the ovulatory cycle. We found that the weight of the testis was smallest in December and largest in March. Changes in the diameter of the seminiferous tubule showed the same pattern. Mature sperm were observed from March to June. The heaviest ovary was observed in April. A single peak of reproduction, from March to April, was observed in males and females. Our observations suggested that the Okinawa rail is a seasonal breeder. Establishing suitable breeding pairs will be critical to ensure success of the Okinawa rail captive breeding program. Our results suggested that pairing must be started before March. If supportive breeding is used, semen should be collected from March to June and artificial insemination conducted in April.     

Amaranthus genetic resources in Indonesia: morphological and protein content assessment in comparison with worldwide amaranths

The morphological variations (growth habit, leaf shape, leaf color, height, stem diameter, number of branches and internodes, leaf area, blade ratio, leaf thickness, number of leaves, and total leaf area) and protein content of 53 Indonesian amaranths (Amaranthus spp.), consisting of weedy-, vegetable-, and ornamental-types, were assessed. The extent of variation in the Indonesian Amaranthus accessions were compared with the worldwide collection (26 accessions from United States Department of Agriculture (USDA) and 5 ornamentals from Nepal) in the experimental field of the University of Tsukuba, Japan. The variation in average values of most morphological traits and protein content in the Indonesian accessions were similar to those of the worldwide germplasm, but the important parameters that influence vegetable yield (e.g., number of leaves and stem diameter) were superior in the Indonesian accessions. Protein content showed a positive correlation with the number of leaves, whereas a negative correlation was observed with leaf thickness. The Indonesian accession of A. viridis and A. dubius showed a great potential to be further selected as parental lines for high protein content and number of leaves. The relatively high protein content of the leaves of Celosia may also potentially serve as an alternative protein source in the tropics.     

Effect of time at pasture and herbage intake on profile of volatile organic compounds of dairy cow milk

Volatile organic compounds (VOCs) in milk were investigated as quantitative markers of herbage intake (HI) at pasture. Eight Holstein cows were fed indoors with concentrate and conserved forages (grass silage, corn silage and hay) (NG), then were divided into three treatments according to the duration of access to pasture: 4 h (G4), 8 h (G8), and 20 h (G20) per day. The HIs were 4.3, 8.6, and 13.0 kg dry matter/day for the G4, G8 and G20 treatments, respectively. Milk from cows was sampled and analyzed VOCs by the steam distillation‐extraction method and gas chromatography‐mass spectrometry (GC‐MS). From the intensity of the GC peak area, the levels of 1‐phytene (3,7,11,15‐tetramethyl‐1‐hexadecene) and 2‐phytene (3,7,11,15‐tetramethyl‐2‐hexadecene) were lowest in NG treatment and markedly increased with grazing time at pasture. With simple regression analysis on the HI to each diterpenoid, a strong correlation was found between the intensity of 1‐phytene in the milk and the HI (r = 0.807, P < 0.001). 1‐phytene content in milk could be useful as a quantitative marker of the HI of grazing cows.     

Association of the amino acid motifs of BoLA-DRB3 alleles with mastitis pathogens in Japanese Holstein cows

The association of the polymorphism of bovine leukocyte antigen ( BoLA-DRB3 ) genes, identified by the polymerase chain reaction sequence-based typing (PCR-SBT) method, with resistance and susceptibility to mastitis caused by Streptococci , coagulase-negative Staphylococci, Escherichia coli and Staphylococcus aureus was investigated. Blood samples for DNA extraction were collected from 170 Holstein cows (129 mastitis and 41 healthy cows) from 5 districts in Chiba prefecture, Japan. Susceptibility or resistance to the mastitis-causing pathogens was thought to vary by the presence of amino acid substitutions at the 9, 11, 13, and 30 positions. DRB3*0101 and DRB3*1501 had amino acid motifs of Glu⁹, Ser¹¹, Ser¹³, and Tyr³⁰, and they were considered to have susceptibility to all 4 mastitis pathogens. In contrast, DRB3*1101 and DRB3*1401 had amino acid motifs of Gln⁹, His¹¹, Gly¹³, and His³⁰ in these positions, and they also had Val⁸⁶, so these alleles were considered to have resistance to Streptococcal and coagulase-negative Staphylococcal mastitis. However, in the case of Escherichia coli mastitis, amino acid substitutions at the 9, 11, 13, and 30 positions had little effect, but rather substitutions at the 47, 67 positions of pocket 7, and at the 71, 74 positions of pocket 4, Tyr⁴⁷, Ile⁶⁷, Ala⁷¹, and Ala⁷⁴, were associated with resistance. This motif was present in DRB3*1201 .     

Phytotoxic activity of middle-chain fatty acids II: peroxidation and membrane effects

Pelargonic acid (PA), an aliphatic 9-carbon monocarboxylic acid, is a phytotoxic burn-down compound. In the light peroxidizing activity can be measured as ethane and propane formation with cress or tobacco seedlings. This effect is strong at low pH (4–5), and saturated acids with 9–10 carbon atoms represent the optimum chain length. Methyl or ethyl esters are inactive, and safeners have no influence. In contrast to the peroxidative herbicides like acifluorfen methyl neither photosynthesis nor protoporphyrin IX is involved, although peroxidation requires light. Chlorophyll is necessary since etiolated seedlings show little peroxidation. Singlet oxygen quenchers like eugenol markedly reduce peroxidation. Membrane leakage of a similar rate is observed in light as well as in darkness. PA was described as a penetration enhancer intercalating with membranes. Our data corroborate that conclusion. Accordingly, the herbicidal mode of action of pelargonic acid is due first to membrane leakage in dark or light and second to peroxidation driven by radicals originating in the light by sensitized chlorophyll displaced from the thylakoids.     

Risk factors for equine monocytic ehrlichiosis seropositivity in horses in Colorado

A study was conducted in April through August 1989 whereby 318 horses were tested for immunofluorescent antibody (IFA) titers to Ehrlichia risticii. The state of Colorado was divided into four regions and an approximately equal number of horses was tested in each region. Questionnaires were completed for each horse; a multiple logistic regression model was used to identify risk factors for horses being exposed to E. risticii.

Of the 318 horses tested, 48 (16%) had IFA titers of 1:40 or greater (range 1:40–1:1280). There was no association between the region of Colorado and seropositivity. Other variables which were not identified as risk factors included gender, transportation to other parts of Colorado, transportation to other states and exposure to other horses. When the variables were examined individually, older horses, Quarter horses, horses housed at a boarding stable, and horses having access to pasture or direct access to a stream, pond or lake were more likely to have positive titers. Horses confined to a stall with a run were less likely to be exposed to E. risticii. All apparent associations disappeared when the factors were tested in the multiple logistic regression model.     

Dental incremental lines in Sika deer (Cervus nippon); polarized light and fluorescence microscopy of ground sections

Periodic growth incremental lines are found universally in dental hard tissues. This periodicity theoretically allows for estimation of age, even in days, which would be useful in studies of wild animals. In the present study, enamel and dentin increments of the sika deer (Cervus nippon) were observed in ground sections with a polarized light microscope, and their periodicity was examined by the use of a chronological labeling method with fluorochromes. Enamel increments occurred at a mean interval of 10.6 (SD=1.5) microm, and mean spacing of dentin increments was 17.3 (SD=1.8) microm. Fluorochromic marking revealed that incremental lines form each day in enamel and almost every second day in dentin. The fluorescence-labeled lines suggest that enamel formation of the first molar is complete by the age of 5 months. Due to its longer interval of incremental lines and longer term of formation, we conclude that dentin is more suitable than enamel for day-age estimation in sika deer. Experimental confirmation of incremental growth periodicity in various species can improve the reliability of use of tooth increments for age estimation and life history reconstruction.