Currently, reproductive failure is the first reason for involuntary culling, which stresses the economic importance of improving fertility. Estrous synchronization programs have been researched extensively since the mid 1990’s (Pursley et al. 1995; Moreira et al., 2001; Dewey at al., 2010) with the main objective of improving artificial insemination (AI) submission rate, decrease intervals betw...

Physiological principals underlying synchronization of estrus identified 1) hormones naturally controlling the estrous cycle of cattle, 2) hormones commercially available, 3) mode of action of the hormones commercially available, and 4) when/how they might be used to manage estrus and breeding of beef cattle. The products available are progestogens (melengestrol acetate (MGA) and progesterone d...

The objectives of this study were to evaluate estrus response and pregnancy rates resulting from timed artificial insemination (AI) following estrus synchronization using CIDR in postpartum beef cattle. A total of 100 cows were randomly divided into three groups. Groups 1, 2 and 3 were artificially inseminated at 48-50 h (n=30), 53-55 h (n=30) and 58-60 h (n=40) after CIDR removal, respectively...

Synchronizing estrus is an effective way to maximize the use of time and labor required to detect standing estrus in cattle. However, estrous synchronization can also benefit overall herd management. Cows that are synchronized 1) exhibit standing estrus at a predicted time, 2) conceive earlier in the breeding season, 3) calve earlier in the calving season, and 4) wean calves that are older and ...

Embryos from Bos indicus are more resistant to elevated culture temperature (i.e. heat shock) than embryos from some Bos taurus breeds. The present experiment was designed to determine if Brahman embryos have greater resistance to heat shock than Holstein embryos at a stage in development before the embryonic genome was fully activated. A second objective was to test breed effects on estrus syn...

Estrous synchronization and artificial insemination (AI) are reproductive management tools available to beef producers for over 30 years. Synchronization of the estrous cycle has the potential to shorten the calving season, increase calf uniformity, and enhance the possibilities for utilizing AI. Artificial insemination allows producers the opportunity to infuse superior genetics into their ope...