Uterine Disease; Understanding The Underlying Causes And Envisioning Solutions
This thesis was carried out to improve our understanding regarding uterine disease in dairy cattle. Several independent research projects were conducted to address the following aims: i) Evaluate the association between the pattern of proinflammatory and anti-inflammatory cytokine gene expression by blood monocytes and uterine tissue, and incidence of uterine disease, ii) Evaluate the association between cellular and systemic energy status, and incidence of uterine disease, iii) Evaluate the association between a single nucleotide polymorphism in the neutrophil IL-8 receptor and incidence of uterine disease, iv) Evaluate the efficacy of prostaglandin F2-alpha(PGF2-alpha) in treating uterine disease, v) Evaluate the effect of early ovulation on the prevalence of uterine disease and fertility. Chapter 2 describes the association between uterine disease and cytokine expression in blood monocytes from lactating Holstein cows. Cows that developed metritis had decreased gene expression and secretion of pro-inflammatory cytokines compared to cows that had subclinical endometritis (SCE) or healthy cows. The lower level of expression of pro-inflammatory cytokines around calving may impair activation of inflammation and predispose cows to the development of metritis. Chapter 3 describes the association between SCE and cytokine expression by uterine tissue from Holstein cows. Gene expression of the main pro-inflammatory cytokines was decreased in the first week after calving but was increased at the time of diagnosis of SCE in cows that had SCE. Chapter 4 describes the association between uterine disease and indicators of neutrophil and systemic energy status in lactating Holstein cows. Cows that developed uterine disease experienced a greater degree of negative energy balance and had decreased ability to maintain PMN glycogen levels which could be the predisposing factor for disease because of decreased availability of oxidative fuels. Chapter 5 describes the association between a single nucleotide polymorphism in the neutrophil IL-8 receptor (SNP +735) and incidence of uterine disease. Cows with the SNP +735 were not more likely to develop uterine disease. Chapter 6 describes Effect of PGF2-alpha on SCE and Fertility in Dairy Cows. Administration of PGF2-alpha did not affect prevalence of SCE but increased hazard of pregnancy in cows without SCE and cows with low body condition score. Chapter 7 describes the effect of Early Postpartum Ovulation on SCE and Fertility in Dairy Cows. Early postpartum ovulation was associated with decreased prevalence of SCE and improved fertility.
Dissertation or Thesis