Artificial Insemination with low doses of stallion sperm: factors affecting efficiency rates.

LOSINNO, LUIS; TOM STOUT; WILLIAM RICHARD ALLEN; PIETRANI, MELINA

Equine Assisted Reproduction

Independiente

Lugar: Bogotá; Año: 2019; p. 129 - 140

The final goal of artificial insemination (AI) is to deliver an appropriate amount of spermatozoa in the best conditions on the reproductive tract of a fertile mare on the right time. However, what is an appropriate amount? Well, that depends mainly on the type of semen. A standard minimal insemination dose for every type of semen (fresh: 500 million progressively motile sperm, cooled: 25-1000 million progressively motile sperm and frozen: 50-600 million progressively motile sperm) has been used as a reference to inseminate mares for the past 40 years. Nevertheless, several factors have encouraged veterinarians, owners and managers to reduce the number of spermatozoa per dose in prized and ?busy? stallions. Pressure placed on some stallions during reproductive season has led veterinarians to try scientific findings from previous years in order to maximize the efficiency of every semen dose. New reproductive technologies were introduced in order to achieve successful pregnancy rate results. Insemination techniques used for low doses of stallion spermatozoa are: a) through a flexible insemination pipette trans rectally guided deep into uterine horn, and b) hysteroscopic close to the papilla. Over the past 5 years, the ICSI technique has been applied commercially, taking the low dose insemination to the next level, using only one sperm to produce a pregnancy.