Hormones around estrus
To determine if hormone concentrations differed between lameness scores
around estrus, profiles for progesterone (Days −18 to 0), estradiol (Days −6 to 2)
and cortisol (Days −18 to 2) were aligned to the day estrus was observed (Day 0
defined as N100 points) and analyzed using GLMANOVA for repeated measures.
All steroid concentrations were normalized using logarithmic transformations [log
(progesterone), log (estradiol+1), and log (cortisol)]. Themodel included the fixed
factors of lameness, prior fertility treatment, days from observed estrus, the
interaction between prior fertility treatment and lameness, the random factor cow
ID, the factors lameness and prior fertility treatment were also nested within Cow
ID (as each cow was only present in one lameness category).