Identification of Beef Heifers with Superior Uterine Capacity for Pregnancy.

Identification of Beef Heifers with Superior Uterine Capacity for Pregnancy. Biol Reprod. 2016 Jul 14; Authors: Geary TW, Burns GW, Moraes JG, Moss JI, Denicol AC, Dobbs KB, Ortega MS, Hansen PJ, Wehrman ME, Neibergs H, O'Neil E, Behura S, Spencer TE Abstract Infertility and subfertility represent major problems in domestic animals and humans, and the majority of embryonic loss occurs during the first month of gestation that involves pregnancy recognition and conceptus implantation. The critical genes and physiological pathways in the endometrium that mediate pregnancy establishment and success are not well understood. In Study One, predominantly Angus heifers were classified based on fertility using serial embryo transfer (ET) to select animals with intrinsic differences in pregnancy loss. In each of the four rounds, a single in vitro-produced high-quality embryo was transferred into heifers on Day 7 post-estrus and pregnancy was determined on Days 28 and 42 by ultrasound and then terminated. Heifers were classified based on pregnancy success as high fertile (HF), subfertile (SF), or infertile (IF). In Study Two, fertility-classified heifers were resynchronized and bred with semen from a single high fertility bull. Blood samples were collected every other day from Days 0 through 36 post-mating. Pregnancy rate was determined on Day 28 by ultrasound, and was higher in HF (70.4%) than in heifers with low fertility (36.8%; SF and IF). P...
Source: Biology of Reproduction - Category: Reproduction Medicine Authors: Tags: Biol Reprod Source Type: research