• Differences in leukocyte profile, gene expression, and metabolite status of dairy cows with or without sole ulcers

      O'Driscoll, Keelin; McCabe, Matthew; Earley, Bernadette; Marie Curie Intra-European Fellowship; 252611 (Elsevier, 2014-12-31)
      Sole ulcers are one of the most severe pathologies causing lameness in dairy cows and are associated with abnormal behavior and impaired production performance. However, little is known about how or whether lameness caused by sole ulcers affects the cow systemically. This study compared hematology profile, leukocyte gene expression, and physiological responses [metabolite, cortisol, the endogenous steroid hormone dehydroepiandrosterone (DHEA), and haptoglobin concentrations] of cows with sole ulcers and healthy cows. Twelve clinically lame cows (lame) were identified as having at least one sole ulcer and no other disorder, and matched with a cow that had good locomotion and no disorders (sound), using days in milk, liveweight, body condition score, and diet. Blood samples were taken from all 24 cows within 24 h of sole ulcer diagnosis. Leukocyte counts were obtained using an automated cell counter, cortisol and DHEA concentration by ELISA, and plasma haptoglobin, urea, total protein, creatine kinase, and glucose were analyzed on an Olympus analyzer. Expression of 16 genes associated with lameness or stress were estimated using reverse transcription-PCR. Data were analyzed using the MIXED procedure in SAS software (version 9.3; SAS Institute Inc., Cary, NC). Lame cows had a higher neutrophil percentage, a numerically lower lymphocyte percentage, and tended to have a higher neutrophil:lymphocyte ratio than sound cows. Serum cortisol and DHEA concentrations were higher in lame than in sound cows. Lame cows also tended to have higher haptoglobin and glucose levels than sound, as well as higher protein yet lower urea levels. Sound cows tended to have higher relative expression of the gene coding for colony-stimulating factor 2 than lame, but in all other cases where differences were detected in cytokine gene expression (IL-1α, IL-1β, CXCL8, and IL-10), relative gene expression in sound cows tended to be, or was, lower than in lame. Relative expression of MMP-13, GR-α, Fas, haptoglobin, and CD62L were, or tended to be, higher in lame than sound cows. A high neutrophil:lymphocyte ratio in combination with higher cortisol levels in cows with ulcers is indicative of physiological stress. Moreover, increased DHEA and a higher cortisol:DHEA ratio, as well as a tendency for higher haptoglobin levels and increased haptoglobin mRNA expression, are indicative of systemic inflammation. Increased cytokine mRNA expression indicates activation of the immune system compared with healthy cows. Increased expression of MMP-13 mRNA has been found in cows with impaired locomotion and thus could be implicated in development of claw horn disorders.
    • Leukocyte profile, gene expression, acute phase response, and metabolite status of cows with sole hemorrhages

      O'Driscoll, Keelin; McCabe, Matthew; Earley, Bernadette; Marie Curie Intra-European Fellowship; 252611 (Elsevier, 2017-08-23)
      Sole hemorrhages result from disruption to normal claw horn formation and are caused by a variety of internal and external factors. Evidence suggests that they are painful, although they do not usually cause clinical lameness and are difficult to detect by observing cow gait. Little is known about how or whether sole hemorrhages affect the cow systemically. This study compared hematology profile, leukocyte gene expression, and physiological responses of cows with no/mild hemorrhages (category 1; n = 17), moderate hemorrhages (category 2; n = 18), and severe hemorrhages (category 3; n = 12). At approximately 100 d in milk, all cows in the study herd (n = 374) were locomotion scored before hoof examination. The cows included in the study were not clinically lame and had no other hoof disorder. Blood samples were taken from all cows within 24 h of selection. Leukocyte counts were obtained using an automated cell counter, cortisol and dehydroepiandrosterone (DHEA) concentration by ELISA, and plasma haptoglobin, urea, total protein, creatine kinase and glucose were analyzed on a clinical chemistry analyzer. Expression of 16 genes associated with lameness or stress were estimated using real-time quantitative PCR. Data from cows within each category were compared using the Mixed procedure in SAS (version 9.3; SAS Institute Inc., Cary, NC). Fixed effects included hemorrhage severity category and lactation number, with days in milk and body condition score included as covariates. Locomotion score worsened as sole hemorrhage category worsened. Locomotion score of category 1 cows tended to be lower than that of category 2 cows and was lower than that of category 3 cows. The locomotion score of category 3 cows was also greater than that of categories 1 and 2 combined. Category had no effect on leukocyte number, on any of the individual leukocyte cell numbers or percentages, cortisol or DHEA concentration, cortisol:DHEA ratio, or relative expression of any of the genes investigated, and we detected no differences in plasma glucose, protein, or creatine kinase concentrations between categories. However, category 3 cows had greater plasma concentrations of haptoglobin and tended to have lesser concentrations of plasma urea than category 1 and 2 cows. The differences in gait between cows with no or minor sole hemorrhages and cows with severe hemorrhages indicate that hemorrhages may be associated with discomfort or pain. Nevertheless, the only physiological measure that changed with increasing locomotion score was plasma haptoglobin concentration. Haptoglobin has previously been found to be elevated in lame cows, and thus shows promise as a marker for limb pain.