Publications by authors named "Yoshihisa Ohtani"

The Illumina MiSeq platform has been widely used as a standard method for studying the rumen microbiota. However, the low resolution of taxonomic identification is the only disadvantage of MiSeq amplicon sequencing, as it targets a part of the 16S rRNA gene. In the present study, we performed three experiments to establish a high-resolution and high-throughput rumen microbial profiling approach using a combination of MinION platform and buccal swab sample, which is a proxy for rumen contents.

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This study was to examine the effects of dietary vitamin K (VK) 3 supplementation on immune-related substances in milk, oxidative stress indices in plasma and VK1, and menaquinone 4 (MK-4) in plasma and milk in periparturient dairy cows. Forty healthy perinatal Holstein-Friesian dairy cows were used in this study. Twenty-one animals were randomly selected and categorized into the VK3 supplemented (50 mg/day/head as VK3) group; the remaining 19 were categorized into the control group.

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The effect of dietary vitamin K (VK3) on ruminant animals is not fully investigated. The aim of this study was to examine the effects of dietary VK3 on lactation performance, rumen characteristics, and VK1 and menaquinone (MK, or VK2) dynamics in the rumen, plasma, and milk of dairy cows. Eight Holstein dairy cows in late lactation periods were used in two crossover trials including a control (nontreatment) and a 50 or 200 mg/day (d) VK3 supplementation group.

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This study evaluated the effects of increasing the proportion of concentrate in the diet on the rumen pH and bacterial community in Japanese Black beef cattle at different fattening stages. Six rumen-cannulated beef cattle were studied in the middle (Mid group, n=3, age 21-22 months) and late (Late group, n=3, age 31 months) fattening stages. The cattle were fed rice straw with control (CON period) or high-concentrate (HC period) diets for 14 consecutive days in each period.

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A Gram-stain-variable, strictly anaerobic, rod-shaped, catalase-negative and endospore-forming bacterial strain, designated MJC39, was isolated from grass silage preserved in Hokkaido, Japan. Growth occurred at 20-42 °C, pH 5.0-7.

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This study was conducted to investigate the arginine-vasopressin (AVP)- and oxytocin-induced changes in plasma adrenocorticotropic hormone (ACTH), growth hormone (GH), insulin and glucagon levels and their metabolite concentrations in goats. In this study, five goats were intravenously injected with either AVP (0.3 nmol/kg body weight (BW)) or oxytocin (0.

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Although our previous report demonstrated that adiponectin and AdipoR1 gene expressions changed among different lactation stages in the bovine mammary gland, its in vivo kinetics remain unclear in ruminant animals. In this study, we investigated the changes in circulating concentrations of adiponectin, as well as other metabolic hormones and metabolites, (i) during the periparturient period and (ii) among different lactation stages, in Holstein dairy cows. In experiment 1, serum adiponectin concentrations increased after parturition.

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Two SNPs, i.e. L127V and T172M, of bovine growth hormone (GH) causing the presence of GH gene haplotypes A, B, and C was previously shown to alter intramuscular fatty acid (FA) composition in Japanese Black (JB) heifers.

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Although the functions of adiponectin, a differentiated adipocyte-derived hormone, in regulating glucose and fatty acid metabolism are regulated by two subtypes of adiponectin receptors (AdipoRs; AdipoR1 and AdipoR2), those in ruminants remain unclear. Therefore we examined the messenger RNA (mRNA) expression levels of adiponectin and its receptors in various bovine tissues and mammary glands among different lactation stages, and the effects of lactogenic hormones (insulin, dexamethasone and prolactin) and growth hormone (GH) on mRNA expression of the AdipoRs in cultured bovine mammary epithelial cells (BMEC). AdipoRs mRNAs were widely expressed in various bovine tissues, but adiponectin mRNA expression was significantly higher in adipose tissue than in other tissues.

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5'-Uridylic acid (UMP), which is present at high concentrations in cow's colostrum, has been shown to cause a reduction in increased plasma levels of insulin and glucose after ingestion of milk replacer in pre-weaning calves. However, the precise mechanisms of UMP action have not been investigated, and its action has not been investigated in other pre-weaning ruminants. In order to demonstrate whether UMP causes changes in postprandial metabolic and hormonal parameters in pre-weaning goats, 11 Saanen kids were given milk replacer (twice a day) without (n = 5) or with (n = 6) UMP (1 g for each meal, 2 g/day for each head) for 14 days.

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Synopsis of recent research by authors named "Yoshihisa Ohtani"

  • - Yoshihisa Ohtani's recent research primarily focuses on the nutritional and microbial dynamics within ruminant livestock, exploring effects of dietary supplements such as vitamin K on health and productivity in dairy cows and the gut microbiota of cattle.
  • - His studies employ advanced sequencing techniques, like MinION Amplicon Sequencing, to enhance the resolution of microbial profiling in the rumen, providing insights into the complex interactions between diet and microbial communities.
  • - Ohtani has also investigated hormonal and metabolic responses in various animal species, contributing to a better understanding of growth dynamics, metabolic hormone regulation, and immune responses during critical life stages such as periparturition and lactation.

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