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Follicle Dynamics and its Relation with Plasma Concentrations of Progesterone, Luteinizing Hormone and Estradiol during the Egg‐Laying Cycle in Ostriches
Author(s) -
Bronneberg RGG,
Vernooij JCM,
Stegeman JA,
Taverne MAM
Publication year - 2009
Publication title -
reproduction in domestic animals
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.546
H-Index - 66
eISSN - 1439-0531
pISSN - 0936-6768
DOI - 10.1111/j.1439-0531.2007.01057.x
Subject(s) - follicle , luteinizing hormone , ovulation , biology , ovarian follicle , medicine , endocrinology , follicle stimulating hormone , hormone , ovary , zoology , blood sampling , andrology
Contents The aims of this study were (i) to describe the changes in the volume of large ovarian follicles (diameter >3 cm) during the 48 h egg laying cycle in farmed ostriches, and (ii) to quantify factors affecting the volume of the largest measured follicle and the plasma concentrations of progesterone (P 4 ) and estradiol‐17β (E 2 β). In eight egg‐producing birds, which all ovulated during the study period, transcutaneous ultrasound scanning and blood sampling was performed at 3 h intervals. The average volume of the total number of visualized large follicles ( V total ), the largest measured follicle ( V F1 ), the second largest follicle ( V F2 ) and of all follicles smaller than F2 ( V F3–Fn ) were each higher before than after oviposition. V total , V F2 and V F3–Fn nearly doubled in the 24‐h period before oviposition, while V F1 remained at an equal, rather high level until oviposition. Immediately after oviposition V total , as well as the volume of the other follicle categories, decreased within 6 h, i.e. around the moment of ovulation. By performing statistical analysis on the basis of linear mixed‐effects modelling, we quantified that: (i) V F1 was 13.2% higher before than after oviposition and increased with 6.5% when LH increased with 1 ng/ml; (ii) P 4 levels were 93.2% higher before than after oviposition and increased with 43.1% for every 3 h closer to oviposition; when LH and E 2 β levels and V F1 increased with 1 ng/ml, 10 pg/ml and 10 ml, respectively, P 4 increased with 116.6%, 50% and 6.1%; and (iii) E 2 β levels were 35.6% higher before than after oviposition, increased with 2.7% for every 3 h closer to oviposition and increased with 14.6% when LH increased with 1 ng/ml. It is concluded that during the egg‐laying cycle in ostriches: (i) follicular mass, as estimated by the volume of visualized follicles larger than 3 cm, increases before and decreases after ovulation, and (ii) follicular dynamics and its accompanying endocrine plasma hormone profiles during the egg‐laying cycle in ostriches follow a pattern similar to that in chickens.