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Open Access Publications from the University of California

Scholarly Works (2 results)

  • Thesis
  • Peer Reviewed
UC Davis Electronic Theses and Dissertations (2022)

Intramammary infections, which cause mastitis, can increase treatment and labor costs, decrease milk production, and affect milk quality. Meters that measure quarter somatic cell count (SCC) could be used to make more informed dry cow therapy decisions. The objective of this study was to compare the RT-10 iPhone adapter (RT-10; Dairy Quality Inc., Newmarket, Canada), DeLaval Cell Counter (DSCC; DeLaval, Graiguecullen, Carlow), Porta Check Quick Test (PortaCheck, NJ), California Mastitis Test (ImmuCell, Portland, ME), pH meter (Hanna Instruments, RI), electrical conductivity meter (OHAUS, NJ), and the dual laser infrared temperature thermometer (Klein Tools, IL) for measuring SCC in individual quarters in comparison to a reference standard, the Fourier Transform Spectrometer 600 Combi System (Combi; Bentley Instruments, MN). Meters were evaluated using individual cow quarter samples and bulk-tank samples to measure SCC. To test individual quarter SCC, individual quarter milk samples from 160 cows from 4 commercial dairy herds (40 cows per herd) were collected just before cessation of milking and tested within 4 h of collection. To test bulk-tank SCC, 100 bulk-tank milk samples (25 mL) were collected from UC Davis VMTRC Milk Quality Lab. Meter SCC values were regressed on observed Combi SCC using PROC GLM (SAS Institute, 2021 v. 9.4). Then goodness of fit was evaluated by partitioning of the mean square predicted error (MSPE). For individual quarter SCC, RT-10 had the highest coefficient of determination (R2 = 0.86), lowest mean square predicted error and highest proportion of MSPE due to random variation (96 %). Both the RT-10 and DSCC had the highest sensitivity and specificity for identifying quarter SCC above and below 200,000 cells/mL. For bulk-tank SCC, DSCC had the highest coefficient of determination (R2 = 0.45), lowest mean square predicted error, and highest proportion of MSPE due to random variation (80 %). The RT-10 and DSCC could be used to measure individual quarter SCC to determine which cows to treat at cessation of lactation potentially reducing antibiotic use.KEYWORDS: mastitis, milk meter, somatic cell count

    Cover page: Evaluation of cow-side meters to determine somatic cell count in individual cow quarter and bulk-tank milk samples
    • Article
    • Peer Reviewed
    UC San Francisco Previously Published Works (2014)
    Reading disability is a brain-based difficulty in acquiring fluent reading skills that affects significant numbers of children. Although neuroanatomical and neurofunctional networks involved in typical and atypical reading are increasingly well characterized, the underlying neurochemical bases of individual differences in reading development are virtually unknown. The current study is the first to examine neurochemistry in children during the critical period in which the neurocircuits that support skilled reading are still developing. In a longitudinal pediatric sample of emergent readers whose reading indicators range on a continuum from impaired to superior, we examined the relationship between individual differences in reading and reading-related skills and concentrations of neurometabolites measured using magnetic resonance spectroscopy. Both continuous and group analyses revealed that choline and glutamate concentrations were negatively correlated with reading and related linguistic measures in phonology and vocabulary (such that higher concentrations were associated with poorer performance). Correlations with behavioral scores obtained 24 months later reveal stability for the relationship between glutamate and reading performance. Implications for neurodevelopmental models of reading and reading disability are discussed, including possible links of choline and glutamate to white matter anomalies and hyperexcitability. These findings point to new directions for research on gene-brain-behavior pathways in human studies of reading disability.
      Cover page: Glutamate and Choline Levels Predict Individual Differences in Reading Ability in Emergent Readers
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