Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.4.1.2 (glutamate dehydrogenase)
 4,380 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The transition of pregnancy to lactation, with the concomitant negative energy balance during early lactation, requires substantial adaptive performance of the cow. Apart from clinical disease problems, the identification of cows with suboptimal adaptation is relevant to be able to adequately treat these animals or modify the ration. Effective approaches are necessary to provide maximal information at the earliest time possible. We therefore aimed to identify a measurement that, when applied at a defined point in time relative to calving, was relevant as much as possible to other information on metabolic and health status during early lactation. Blood samples were collected weekly from 4 wk antepartum to 12 wk postpartum from 38 high-yielding Holstein-Friesian cows. Nonesterified fatty acids, beta-hydroxybutyrate, IGF-I, and leptin were measured in serum, and BCS was recorded. Health status was characterized using the concentrations of haptoglobin, the number of leukocytes and neutrophils, as well as the activity of glutamate dehydrogenase (GLDH) in blood to evaluate liver status. Using the factors related to fat mobilization, the animals were classified according to their values recorded at one defined point in time or time interval as being above or below certain thresholds. For each criterion, the groups classified were compared with regard to the time-course yielded from all recordings. From 7 criteria of classification, the most closely related to the variables of fat mobilization was obtained when using NEFA and IGF-I (thresholds of 0.5 mM and 39 ng/mL in wk 1 postpartum, respectively). Both items were then combined into to the criterion NEFA + IGF-I. Applying these criteria, the relations to indices of health and liver status were detectable on the basis of NEFA- and NEFA + IGF-I-classes, which yielded differences in both GLDH and leukocyte numbers. Animals with NEFA > 0.5 mM showed increased GLDH activity but decreased leukocyte numbers. The time and effort required for measuring the IGF-I-concentration in addition to NEFA is not justified for evaluating the metabolic status. Nonesterified fatty acid values > or = 0.5 mM during the first week of lactation were considered as the most suitable criterion for identifying limited adaptive performance.
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PMID:Evaluation of classification modes potentially suitable to identify metabolic stress in healthy dairy cows during the peripartal period. 1746 19

Dry period (DP) length affects energy metabolism around calving in dairy cows as well as milk production in the subsequent lactation. The aim of the study was to investigate milk production, body condition, metabolic adaptation, and hepatic gene expression of gluconeogenic enzymes in Holstein cows (>10,000 kg milk/305 d) with 28- (n=18), 56- (n=18), and 90-d DP (n=22) length (treatment groups) in a commercial farm. Cows were fed total mixed rations ad libitum adjusted for far-off (not for 28-d DP) and close-up DP and lactation. Milk yield was recorded daily and body condition score (BCS), back fat thickness (BFT), and body weight (BW) were determined at dry off, 1 wk before expected and after calving, and on wk 2, 4, and 8 postpartum (pp). Blood samples were taken on d -56, -28, -7, 1, 7, 14, 28, and 56 relative to calving to measure plasma concentrations of metabolites and hormones. Liver biopsies (n=11 per treatment) were taken on d -10 and 10 relative to calving to determine glycogen and total liver fat concentration (LFC) and to quantify mRNA levels of pyruvate carboxylase (PC), cytosolic phosphoenolpyruvate carboxykinase, and glucose-6-phosphatase. Time course of milk yield during first 8 wk in lactation differed among treatment. Milk protein content was higher in 28-d than in 90-d DP cows. Milk fat to protein ratio was highest and milk urea was lowest in 90-d DP cows. Differences in BW, BFT, and BCS were predominantly seen before calving with greatest BW, BFT, and BCS in 90-d DP cows. Plasma concentrations of NEFA and BHBA were elevated during the transition period in all cows, and the greatest increase pp was seen in 90-d DP cows. Plasma glucose concentration decreased around calving and was greater in 28-d than in 90-d DP cows. Dry period length also affected plasma concentrations of urea, cholesterol, aspartate transaminase, and glutamate dehydrogenase. Plasma insulin concentration decreased around calving in all cows, but insulin concentration pp was greater in 28-d than in 56-d DP cows. Hepatic glycogen concentration decreased and LFC increased after calving in all cows, and LFC was greater pp in 90-d DP than in 28-d DP cows. Hepatic PC mRNA abundance pp tended to increase most in 90-d DP cows. Changes on glucose metabolism were more balanced in cows with a reduced DP, whereas cows with extended DP and elevated body condition indicated greatest metabolic changes according to lipid and glucose metabolism during the transition period.
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PMID:Effects of dry period length on milk production, body condition, metabolites, and hepatic glucose metabolism in dairy cows. 2554 7