( ( ( The ( final ( Graafian follicle ) ) ) ( at ( day 20 ) ) ) ( ( leads ( to ( ovulation ( on ( ( day 1 ) ( of ( the ( subsequent ( estrous cycle ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NP (DT The) (JJ final) (NNP Graafian) (NN follicle)) (PP (IN at) (NP (NN day) (CD 20)))) (VP (VBZ leads) (S (VP (TO to) (VP (VB ovulation) (PP (IN on) (NP (NP (NN day) (CD 1)) (PP (IN of) (NP (DT the) (JJ subsequent) (NNS estrous) (NN cycle))))))))) (. .)))
The final Graafian follicle at day 20 leads to ovulation on day 1 of the subsequent estrous cycle.
(ROOT (S (NP (NNP Ovulation)) (VP (VBZ occurs) (SBAR (IN before) (S (NP (DT the) (NN endometrium)) (VP (VBZ thickens) (PP (IN in) (NP (JJ estrous) (NNS cycles))))))) (. .)))