Long-term alteration of follicular steroid concentrations in relation to subclinical endometritis in postpartum dairy cows
MP Green, AM Ledgard, SE Beaumont, MC Berg, KP McNatty, AJ Peterson, PJ Back
JOURNAL OF ANIMAL SCIENCE | OXFORD UNIV PRESS INC | Published : 2011
The focus of this study was to investigate the effect of subclinical endometritis (scEndo) on ovarian follicular steroid concentrations in early postpartum pasture-fed dairy cows. Mixed-age lactating dairy cows (n = 169) were examined to ascertain uterine health status on d 21 postpartum (±3 d). From this herd, a cohort of scEndo and uninfected cows (n = 47) were selected using uterine cytology to determine scEndo. To ensure cows with scEndo were selected for the study, a conservative threshold [>18% polymorphonuclear (PMN) cells among uterine nucleated cells] was chosen as a selection threshold. Ovarian follicular dynamics were assessed by ultrasonography on d 21, 42, and 63 postpartum. On ..View full abstract
Awarded by DairyNZ Inc., Hamilton, New Zealand
Awarded by Foundation for Research, Science and Technology (FRST), Wellington, New Zealand
The authors thank the AgResearch farm staff for assistance with data collection, N. Lopez Villalobos (Massey University, Palmerston North, New Zealand) for statistical advice, E. Thorstensen (University of Auckland, Auckland, New Zealand) for undertaking the steroid hormone analysis, and R. Lee (AgResearch Ltd., Hamilton, New Zealand) for help preparing the manuscript. Partial funding was received from DairyNZ Inc., Hamilton, New Zealand (contract number AN808), and Foundation for Research, Science and Technology (FRST), Wellington, New Zealand (contract number UOAX0814).