Effect of breed and corpus luteum on pregnancy rate of bovine embryo recipients

Abstract

-The objective of this study was to evaluate pregnancy rates of recipients of different breed groups (Nellore and crossbreed), as well as the effects of size and type of the corpus luteum (CL) on plasmatic concentrations of progesterone and pregnancy rates of embryo recipients. A total of 152 heifers were synchronized with progesterone implants and on the day of embryo transfer, previously obtained by superovulation and frozen in ethylene glycol, the diameter and type of the corpus luteum (cavitary and compact) was measured and blood was collected for progesterone measurement. The pregnancy rate was 44.1%, with a diameter of corpus luteum higher in recipients that became pregnant (2.03±0.41) compared with nonpregnant ones (1.86±0.34 cm). Plasmatic concentrations of progesterone did not differ between pregnant (1.50±1.05) and non-pregnant (1.31±0.91 ng/mL) animals. The type of corpus luteum did not influence the pregnancy rates. Only Angus and crossbred Marchigiana differ among themselves in pregnancy rates (33.3 and 59.2%, respectively). The pregnancy probability was affected only by CL diameter, but not by P4 plasmatic concentration. Selection of the corpus luteum size at the time of embryo transfer is an important factor to increase pregnancy rates in recipients, and compact and cavitary corpora lutea do not influence the pregnancy rates of bovine embryo recipients. Nellore recipients have pregnancy rates that are satisfactory and comparable to crossbred (Bos taurus × Bos indicus) recipients.

Consequences of eight consecutive applications of equine chorionic gonadotropin on ovarian follicle development and ovulation in bos indicus cows

“…Furthermore, cows in the eCG group had a larger Cl which is associated with better pregnancy rates and lower pregnancy losses (NOGUEIRa et al, 2012;GONElla-DIaZa et al, 2013). It is believed that these results can be extrapolated to the field and in the dose of 300IU eCG can be repeatedly used in subsequent breeding seasons without any deleterious effect on fertility.…”

Berat Lahir dan Mortalitas Anak Sapi Belgian Blue dari Rumpun Resipien dan Ketinggian Tempat Berbeda

“…Tabel Pengaruh maternal (maternal effect) resipien dalam pertumbuhan fetus sampai lahir dipengaruhi oleh genotip dibandingkan paternal genotypenya (Nogueira et al 2012). Sharma et al (2012) menyebutkan lingkungan uterus merupakan regulator pada berat lahir dan dimensi ukuran tubuh anak yang dipengaruh oleh rumpun induk resipien.…”

“…Selanjutnya Nogueira et al (2012) menjelaskan adanya perbedaan performa reproduksi antara Bos taurus dan Bos indicus, dimana dibuktikan dalam penelitiannya Bos indicus (Nellore) lebih efisien dibandingkan Bos taurus (Angus) di Brasil. Peneliti lain mengungkapkan sebaliknya Bos taurus seperti sapi FH lebih direkomendasikan sebagai induk resipien dalam program TE disebabkan tergolong sebagai ternak tipe perah yang memiliki fertilitas, mothering ability superior (Hansen et al 2014).…”

Recipient Selection to Support The Success Rate of Frozen-Thawed Belgian Blue Embryo Transfer

“…This is in line with the statement by Spell [3] who states that the size and character of CL during transfer cannot increase the success rate of TE. Meanwhile, [13] who researched beef cattle states that the success rate of pregnancy is influenced by CL size. Many factors mentioned above became the background of this research which was conducting recipient selection with various estrus detection methods to identify the correlation between estrus expression of standing heat as well as CL characteristic in the success rate of frozenthawed BB embryo transfer.…”