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Humer E.,University of Veterinary Medicine Vienna | Khol-Parisini A.,University of Veterinary Medicine Vienna | Metzler-Zebeli B.U.,University of Veterinary Medicine Vienna | Gruber L.,Institute of Livestock Research | Zebeli Q.,University of Veterinary Medicine Vienna
PLoS ONE | Year: 2016

A decrease in insulin sensitivity enhances adipose tissue lipolysis helping early lactation cows counteracting their energy deficit. However, excessive lipolysis poses serious health risks for cows, and its underlying mechanisms are not clearly understood. The present study used targeted ESI-LC-MS/MS-based metabolomics and indirect insulin sensitivity measurements to evaluate metabolic alterations in the serum of dairy cows of various parities experiencing variable lipolysis early postpartum. Thirty (12 primiparous and 18 multiparous) cows of Holstein Friesian and Simmental breeds, fed the same diet and kept under the same management conditions, were sampled at d 21 postpartum and classified as low (n = 10), medium (n = 8), and high (n = 12) lipolysis groups, based on serum concentration of nonesterified fatty acids. Overall, excessive lipolysis in the high group came along with impaired estimated insulin sensitivity and characteristic shifts in acylcarnitine, sphingomyelin, phosphatidylcholine and lysophospholipid metabolome profiles compared to the low group. From the detected phosphatidylcholines mainly those with diacyl-residues showed differences among lipolysis groups. Furthermore, more than half of the detected sphingomyelins were increased in cows experiencing high lipomobilization. Additionally, strong differences in serum acylcarnitines were noticed among lipolysis groups. The study suggests an altered serum phospholipidome in dairy cows associated with an increase in certain long-chain sphingomyelins and the progression of disturbed insulin function. In conclusion, the present study revealed 37 key metabolites as part of alterations in the synthesis or breakdown of sphingolipids and phospholipids associated with lowered estimated insulin sensitivity and excessive lipolysis in early-lactating cows. © 2016 Humer et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Source

Humer E.,University of Veterinary Medicine Vienna | Khol-Parisini A.,University of Veterinary Medicine Vienna | Gruber L.,Institute of Livestock Research | Wittek T.,University of Veterinary Medicine Vienna | And 2 more authors.
Animal | Year: 2016

Metabolic adaptation includes an array of concerted metabolic and endocrine events that enable dairy cows bridging the period of energy deficit at the onset of lactation. The present study evaluated metabolic, endocrine and reticuloruminal pH changes in 30 (25 Holstein and five Simmental) periparturient dairy cows experiencing variable lipolysis early postpartum. Cows were fed the same close-up and fresh lactation diets and kept in the same management conditions. Blood samples were collected at day 14, and day 4, relative to expected parturition, and at day 2, and day 21 postpartum, and serum metabolites and hormones related to glucose and lipid metabolism, as well as concentrations of several liver enzymes and acute phase proteins were determined. Additionally, reticuloruminal pH was monitored every 10 min over the last 3 days of the observation period. BW and milk yields were recorded and balances of energy and protein were assessed. Based on serum concentration of non-esterified fatty acids (NEFA) postpartum, cows were retrospectively classified into low (n=8), medium (n=11), and high (n=11) lipolysis groups, with NEFA levels of <0.4 mmol/l, between 0.4 and 0.7 mmol/l, and >0.7 mmol/l, respectively. Overall, elevated NEFA concentrations in the High group went along with a higher ratio of NEFA to cholesterol and reduced insulin sensitivity. While serum glucose, energy deficit and BW loss did not differ, cows of the High group exhibited increased lactate concentrations in the serum, compared with the Medium group. No differences in liver enzymes and acute phase proteins were evidenced among fat mobilization groups, whereas concentration of serum billirubin was lowest in the Low group after parturition. Data of milk yield and milk energy output showed no differences among groups, despite divergences in calculated energy balance and BW change postpartum. Cows of the Low group tended to increase dry matter intake but also showed longer time duration of pH below 6.0 in the reticulorumen (on average 299 min/day compared with 99 and 91 min/day for Medium and High groups, respectively). Differences in metabolic, endocrine and reticuloruminal pH responses indicate diverse metabolic adaptation strategies of early-lactation cows to cope with energy deficit postpartum. © The Animal Consortium 2016 Source

Chang M.-L.,Institute of Livestock Research | Chang M.-L.,National Sun Yat - sen University | Liao L.-J.,National Kaohsiung Normal University | Lin J.-H.,National Kaohsiung Normal University | And 5 more authors.
Botanical Studies | Year: 2012

We investigated changes in antioxidant content and antioxidant enzyme activity in polyethylene glycol (PEG)-induced water deficit stressed Pluchea indica leaves. We also used diphenylene iodonium (DPI), a plasma membrane NADPH oxidase suicide inhibitor, to examine the role of reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase in the induction of antioxidant defense systems. PEG decreased water content and the reduction ability of 2,3,5-triphenyltetrazolium chloride (TTC), but increased malondialdehyde (MDA), total peroxide, O 2 - and H 2O 2 contents, indicating water deficit-dependent oxidative stress. Total ascorbate (AsA), AsA contents, and AsA/oxidized AsA ratios were increased by moderate water deficit (-0.6 MPa) conditions, while total glutathione (GSH), GSH contents and GSH/GSSG ratios increased as water potential decreased. Superoxide dismutase (SOD) activity was not affected after 24 h of PEG treatment but decreased after 48 h. Catalase (CAT) activity increased as water potential decreased while peroxidase (POX) activity increased only at -1.2 MPa. Ascorbate peroxidase (APX) activity increased under moderate water deficit and glutathione reductase (GR) activity increased as water potential decreased. DPI depressed the induction of antioxidant accumulation and antioxidant enzyme activity by water deficit, indicating that reactive oxygen species (ROS) signals are involved in activating defense systems in P. indica in response to oxidative stress. We conclude that moderate water deficit stress induces both NADPH oxidase-mediated non-enzymatic and enzymatic oxidative defense mechanisms in ROS scavenging in P. indica leaves. Source

Huang P.-L.,National Sun Yat - sen University | Huang P.-L.,Kaohsiung District Agricultural Research and Extension Station | Liu Z.-H.,National Sun Yat - sen University | Chang M.-L.,National Sun Yat - sen University | And 2 more authors.
Scientia Horticulturae | Year: 2011

This study established a highly effective micropropagation system to obtain good plantlet proliferation from floral organs via callus induction and bud differentiation in Guzmania 'Hilda' bromeliad. The best frequencies of organogenic callus formation (20% in petal and 35% in ovary explants) were obtained on media containing a combination of 1.0mgl-1 2,4-dichlorophenoxyacetic acid (2,4-D) with 1.0mgl-1 α-naphthaleneacetic acid (NAA) and 1.5mgl-1 2,4-D with 0.5mgl-1 NAA, respectively. Organogenic calli were cultured on medium with 1.0mgl-1 NAA and 0.5mgl-1 1-phenyl-3-(1,2,3-thiadiazol-5-yl) urea (TDZ) induce the differentiation and regeneration of adventitious buds into plantlets. When the plantlets were cultured in a medium with optimum NAA concentration (0.5-1.0mgl-1) significant improvement in regeneration and elongation was achieved within one month. This overcame the difficulty of delayed elongation in Guzmania plantlets. More than 99% of the regenerated and acclimatized plantlets developed to the flowering stage. © 2011 Elsevier B.V. Source

Metzler-Zebeli B.U.,University of Veterinary Medicine Vienna | Khol-Parisini A.,University of Veterinary Medicine Vienna | Gruber L.,Institute of Livestock Research | Zebeli Q.,University of Veterinary Medicine Vienna
Journal of Applied Microbiology | Year: 2015

Aims: To evaluate the effects of treating barley grain with lactic acid (LA) and heat on postprandial dynamics of 19 microbial taxa and fermentation in the rumen of dairy cows. Methods and Results: This study was designed as a double 3 × 3 Latin square with six rumen-cannulated cows and three diets either containing untreated control barley or barley treated with 1% LA and 1% LA and heat (LAH, 55°C). Microbial populations, pH and volatile fatty acids were assessed in rumen liquid and solids during the postprandial period. Propionate increased and butyrate decreased in rumen solids of cows fed LA and LAH treated barley compared to the control barley. The LA but not LAH treatment depressed Fibrobacter succinogenes in rumen liquid and solids, whereas the opposite effect was observed for Ruminococcus albus in both fractions and Ruminococcus flavefaciens in rumen solids. LA promoted Ruminobacter amylophilus with the effect being more pronounced with LAH. The Lactobacillus group and Megasphaera elsdenii increased in both fractions with LA but not with LAH. Conclusions: LA and LAH treatment of barley differently altered ruminal abundance of certain bacterial taxa and fungi and increased propionate fermentation in rumen solids, whereby LA and LAH effects were consistent and mostly independent of the rumen fraction and time after barley feeding. Significance and Impact of the Study: Results provided evidence that LA and LAH treatment of barley can enhance rumen propionate fermentation without adversely affecting rumen pH. As propionate is the major contributor to gluconeogenesis in ruminants, the present barley treatment may have practical application to enhance energy supply in dairy cows. © 2015 The Society for Applied Microbiology. Source

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