Fertilization and embryo survival rates in control and progesterone or hcg treated heifers

Abstract

A total of 98 heifers were used in a study of fertilization and embryonic mortality rates. Fertilization rate recorded at day 4 was 90 p. 100. Embryo survival at day 42 was 52 p. 100. Progesterone supplementation did not affect circulating progesterone level and slightly increased embryo survival rate. HCG administration induced accessory corpus luteum formation, increased circulating progesterone level and slightly increased embryo survival. The increases in embryo survival following progesterone or HCG were not