McKenzie’s laboratory (U. MO; 1930s) described the estrous cycle of domestic animals. Brownell (Cornell; 1936) reported AI and bull bred pregnancy rates were similar. Between 1938 (first, EJ Perry, NJ) and 1940, 54 AI organizations in 21 states were formed. Ulberg, Christian and Casida (1951) controlled time of ovulation in cows with progesterone (P) injected daily. Trimberger and Hansel (1955)...

Sustainability - the new hype of 21st century has brought discomfort for government and society. Sustainable agriculture is essential to face our most concerning challenges: climate change, food security, environmental footprint, all which add consumers' opinions choices. Improvements in reproductive indexes can enhance animal production efficiency, guaranteeing profit sustainability. Estrus de...

The objective of this study was to evaluate two protocols of estrous synchronization in non-lactating Toggenburg goats. Nineteen goats were allocated, according to body condition score and weight, into two groups (A and B) and evaluated utilizing two treatments (T1 and T2). Animals in the T1 and T2 groups received an intravaginal sponge (day 0) containing 60 mg medroxyprogesterone acetate for 6...

The objective of the present study was to evaluate estrus synchronization and conception rate after progesterone releasing intravaginal device (PRID) treatment from the early luteal phase in the presence or absence of estradiol benzoate (EB) in heifers. Heifers (n=11) were assigned randomly to two treatments; insertion of a PRID containing 1.55 g progesterone with a capsule attached including 1...

Synchronization of estrus and ovulation are of paramount importance in modern livestock improvement programs. These methods are critical for assisted reproduction technologies, including artificial insemination and embryo transfer, that can increase productivity. In the current study, subcutaneous implants containing norgestomet were placed for long (14 days), medium (9 days), and short (5 days...

Commercial cow-calf producers have an increasing number of options available for the synchronization of estrus and ovulation to facilitate the incorporation of an artificial insemination (AI) program. At the same time, low-cost production and/or the ability to produce a higher valued product are essential for economic success in the cow-calf industry. Previous research has examined the costs of...

Reproductive efficiency is the most important factor impacting the economics of a cow calf operation. The economic value of reproduction for commercial beef producers was reported to be five times greater than calf growth (Trenkle and Willham, 1977). Maximizing reproductive efficiency depends upon the successful completion of the following events: a heifer must reach puberty before the start of...

Abstract One of the biotechnology reproductive used is estrus synchronization. This study determined body’s physiological, estradiol level, and ovarian follicle diameter in Peranakan Ongole (PO) cow synchronization using modified progesterone-PGF2α double injection PGF2α. 10 PO cows which were divided into two groups. Group 1, given a intravaginal sponge containing 250 mg progesterone/sponge fo...