Embryo Survival in First-Service and Repeat-Breeder Cattle after Ovariectomy and Hormone Therapy

Repeat-breeder Females in Beef Cattle: Influences and Causes 1'2

Straightbred and crossbred heifers (165) and cows (241) that were nonpregnant after exposure to fertile bulls for two consecutive breeding periods of 45 to 60 d (repeat breeders) and contemporary cows (102) that had produced a calf in the previous calving season (controls) were placed with bulls and were observed for mating. Repeat-breeder and control females were slaughtered at 2 to 51 d postm...

EFFBCT OF OIL ON EMBRYONIC DEVELOPMENT IN V%TRO AND ON EMBRYO SURVIVAL AFTER ONE-STEP VITRIFICATION IN CAttLE

Changes in Implantation and Survival Rates and Embryo Quality After Progesteron

Purpose: Determining the effect of progesterone on the embryo quality (total cell number and diameter of blastocyst), survival and implantation rates of mouse blastocyst with or without ovarian stimulation. Materials and Methods: Female 6-10 weeks old NMRI mice were divided into four groups as follows: (a) Non-stimulated pregnant mice as control (b) Non-stimulated pregnant mice with daily inje...

Amylase activity in cerical mucus and serum during estrus in normal and repeat breeder cattle

Aim: To compare the amylase activity in the cervical mucus and serum during estrus in normal and repeat breeder cattle and find out importance in fertility. Materials and methods: Twenty cyclic crossbred cattle were divided into two groups: normal (n =10) and repeat breeder (n =10). Animals exhibiting spontaneous estrus, were artificially inseminated (AI) twice, as per AM-PM schedule along with...

Platelet concentrate in bovine reproduction: effects on in vitro embryo production and after intrauterine administration in repeat breeder cows

BACKGROUND A repeat breeder cow (RBC) can be defined as an animal that after 3 or more inseminations cannot get pregnant because of fertilization failure or early embryonic death. If no cause is identified precisely, inadequate uterine receptivity is responsible for implantation failures. Since a large number of identified molecular mediators, such as cytokines, growth factors and lipids have b...