Comparison of follicular and oocyte development and reproductive hormone secretion during the ovulatory period in Hungarian native breed, Mangalica, and Landrace gilts.
Only a very small amount of physiological data is available about the low fertility (mean litter size is 5.7+/-0.8) of Hungarian native breed, Mangalica (M), sows. The aim of the present paper is to reveal the differences in preovulatory follicle development and intrafollicular oocyte maturation between M and Landrace (L) gilts, with special reference to the peri- and postovulatory secretion and peripheral concentrations of estradiol-17beta (E2), progesterone (P4), and luteinizing hormone (LH). The number of preovulatory follicles was 6.8+/-1.4 and 19.6+/-6.6 in M and L gilts, respectively. A lower degree of cumulus expansion and a lower percentage of mature oocytes (TI/M II) was noted in M. Higher LH and E2 peak levels, a longer E2 to LH peak interval, and lower embryo survival was confirmed. Interestingly, despite the lower number of corpora lutea, a higher peripheral blood level of P4 was shown in M than in L gilts. Both diminished follicular development and protracted oocyte maturation may be involved in low fecundity in M, and the present findings may explain these reproductive phenomena.
Rátky
Jozsef
J
Research Institute for Animal Breeding and Nutrition, Herceghalom, Hungary.
Brüssow
Klaus-Peter
KP
Egerszegi
Istvan
I
Torner
Helmut
H
Schneider
Falk
F
Solti
Laszlo
L
Manabe
Noboru
N
D000818:Animals; D001835:Body Weight; D002843:Chromatin / Q000378:metabolism; D004958:Estradiol / Q000378:metabolism; D005260:Female; D006728:Hormones / Q000378:metabolism; D007986:Luteinizing Hormone / Q000378:metabolism; D008540:Meiosis; D009865:Oocytes / Q000378:metabolism*; D006080:Ovarian Follicle / Q000378:metabolism*; D010053:Ovary / Q000378:metabolism; D010060:Ovulation; D011374:Progesterone / Q000378:metabolism; D011863:Radioimmunoassay; D012098:Reproduction; D013045:Species Specificity; D013552:Swine
D002843:Chromatin; D006728:Hormones; D011374:Progesterone; D004958:Estradiol; D007986:Luteinizing Hormone