Researchers assess effectiveness of fixed-time AI

A fixed-time insemination protocol described yesteryear researchers from Brazil could encourage greater role of frozen semen inwards equine reproduction.

One of the reasons frozen semen is non to a greater extent than widely used for breeding mares is the demand for insemination to direct house about the fourth dimension of ovulation. This necessitates repeated ultrasound examinations when the mare is inwards season, making the technique time-consuming in addition to labour intensive.

For artificial insemination alongside frozen semen to popular off to a greater extent than widespread, a simplified routine is needed that is less labour intensive, simply does non sacrifice fertility.

Bruno Ribeiro Avanzi in addition to his colleagues at the Department of Animal Reproduction in addition to Veterinary Radiology, at Universidade Estadual Paulista inwards Botucatu, used a fixed-time insemination protocol to make excogitation rates comparable alongside those using a to a greater extent than traditional approach.

The function was presented at the sixth International Symposium on Stallion Reproduction held at the University of Veterinary Medicine, Vienna, inwards September 2012, in addition to has been published inwards the Journal of Equine Veterinary Science.

Semen from 2 stallions was used inwards the study. One stallion, a Westphalen, was of expert fertility, the other, a Mangalarga Marchador (Iberian breed), was of piteous fertility.

The semen was collected, processed in addition to frozen using a touchstone method.

Twenty nine mares were enrolled inwards the study. The oestrus bicycle was monitored yesteryear rectal palpation in addition to ultrasound scanning. Once a pre-ovulatory follicle of at to the lowest degree 35mm diameter was present, each mare received an injection of the gonadotrophin-releasing hormone deslorelin acetate.

Growth of the follicle was monitored every 6 hours, starting eighteen hours afterwards the deslorelin.

Half of the mares were inseminated when ovulation had been detected, the others were inseminated forty hours afterwards the direction of deslorelin regardless of whether ovulation had occurred or not.

All mares were inseminated into the tip of the uterine horn side yesteryear side to the follicle.

For frozen semen from the fertile stallion, the researchers reported pregnancy rates of 46.7% (7 of fifteen horses) when bred 6 hours afterwards ovulation, in addition to 66.6% (10 from 15) for inseminations performed forty hours afterwards ovulation induction.

The less fertile stallion achieved pregnancy rates of 35.7% (5 from fourteen horses) when bred 6 hours afterwards ovulation in addition to 21.4% (3 of fourteen horses) for inseminations performed forty hours afterwards induction of ovulation.

The researchers conclude that insemination at a fixed fourth dimension afterwards ovulation induction is efficient. “The introduce information supports the feasibility of equine frozen semen equally a applied scientific discipline to live on widely used in addition to spread since it reduces mare direction in addition to costs.”

The inquiry was funded yesteryear the Foundation for Research Support of the State of São Paulo.

 

Influence of insemination fourth dimension on pregnancy rates of mares inseminated alongside frozen semen

B.R. Avanzi, R.S. Ramos, G.H.M. Araujo, E.G. Fioratti, G.M. Greco, L.A. Trinca, J.A. Dell’Aqua, C.M. Melo, F.O. Papa
Journal of Equine Veterinary Science (2012) 32,

Equine Science Update

 

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