Agreement between ultrasonographic classification of the CL and plasma progesterone concentration in dairy cows

摘要: Abstract We evaluated the agreement between ultrasonographic characteristcs of corpus luteum (CL) and plasma progesterone (P4) concentration in dairy cows. In Phase 1 study, ovaries 8 cows were ultrasonographically examined, P4 was analyzed daily from estrus (Day 0) to Day 4, then at 7 10, again 17 onset next estrus. 2, 157 randomly selected Friesian examined once by ultrasonography, blood samples collected concurrently for P4. On basis values, function CLs classified as follows: 1) non-secretory CL when lower than ng/mL (n=41); 2) evolving 4 (n=55); 3) mid-cycle more (n=61). examination, 3 additional groups established (absence CL, midcycle CL). Ultrasonographic characteristics size their respective concentrations not distinguishable those observed d before susequent The degree two classification 72%. data indicate that functional is difficult determine based on ultrasonography alone.