Location: Livestock and Range Research LaboratoryTitle: Increased conception rates in beef cattle inseminated with nanopurified bull semen
|ODHIAMBO, JOHN - University Of Missouri|
|DEJARNETTE, J - Select Sires, Inc|
|KENNEDY, CHELSEY - University Of Missouri|
|SUAREZ, SUSAN - Cornell University - New York|
|SUTOVSKY, MIRIAM - University Of Missouri|
|SUTOVSKY, PETER - University Of Missouri|
Submitted to: Biology of Reproduction
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/26/2014
Publication Date: 9/17/2014
Citation: Odhiambo, J.F., Dejarnette, J.M., Geary, T.W., Kennedy, C.E., Suarez, S.S., Sutovsky, M., Sutovsky, P. 2014. Increased conception rates in beef cattle inseminated with nanopurified bull semen. Biology of Reproduction. 91(4):1-10.
Interpretive Summary: In order for beef and dairy producers to make money, they need to have high pregnancy rates in their cows each year. They also want to improve the genetics of their herds, so many producers use artificial insemination (AI). This project was conducted to improve the fertility level of semen used for AI. This study evaluated a magnetic bead to remove damaged sperm from bulls to improve fertility. Sperm were collected from bulls and mixed with the magnetic beads before freezing for AI. A total of 798 cows were bred to sperm that had received different cleaning treatments. When cows were bred with sperm using one of the cleaning treatments (PNA), pregnancy rates were increased about 10%. The second cleaning treatment tested (UBI) did not improve pregnancy rates. A total of 466 healthy calves were born with no negative side effects. Since the method is cheap and can be done easily while freezing semen, it can be used to improve fertility with AI.
Technical Abstract: Reproductive performance is of paramount importance to the cattle industry. Since recent progress has been achieved by optimizing estrus and ovulation synchronization protocols in cows, improvements are desired to increase the fertility of bulls enrolled in artificial insemination (AI) programs. This study evaluated a nanoparticle based magnetic purification method that removes defective spermatozoa (~30% of sample) from bull semen and improves sperm viability and fertilizing ability in vitro. In a two year AI field trial with 798 cows, a conception rate (CR) of 64.5 ± 3.7 % was achieved with a 10 million sperm dose of PNA nanopurified spermatozoa, comparable to control non-purified full dose of 20 million spermatozoa per dose (CR=63.3 ± 3.2 %), and significantly higher than a 10 million sperm dose of non-purified control semen (CR=53.7 ± 3.2 %; P < 0.05). A total of 466 healthy calves were delivered and no negative side effects were observed on the inseminated animals or offspring. Since the method is inexpensive and can be fully integrated in current protocols for semen cryopreservation, it is feasible for use in the AI industry to improve fertility with reduced sperm dosage inseminations. Spermatology will benefit by gaining new tools for the identification of candidate biomarkers of sperm quality such as binder of sperm protein 5 (BSP5), described in the present study.