The use of cryopreserved spermatozoa has many advantages compared with fresh or extended semen for artificial insemination (AI). These models indicate that the fertility of cryopreserved boar spermatozoa can be predicted effectively by including traditional and novel laboratory assays that consider functions of spermatozoa. A second model to predict the number of piglets sired by boar was also effective ( p < 0.05, r 2 = 0.57). The regression model to predict the percent of litter sired by each boar was highly effective ( p < 0.001, r 2 = 0.87) and included five traits acrosome-compromised spermatozoa, percent live spermatozoa (0 and 60 min post-thaw), percent total motility, and the number of zona-bound spermatozoa. Means of each laboratory evaluation were calculated for each boar and those values were applied to multiple linear regression analyses to determine which sperm traits could collectively estimate fertility in the simplest model. Fertility of the same ejaculates subjected to laboratory assays was determined for each boar by multi-sire AI and defined as (i) the mean percentage of the litter sired and (ii) the mean number of piglets sired in each litter. Finally, spermatozoa–oviduct binding and competitive zona-binding assays were applied to assess sperm adhesion to these two matrices.
In vitro fertilization, cleavage, and blastocyst development were also determined. Traditional post-thaw analyses of motility, viability, and acrosome integrity were performed on each ejaculate. Our objective was to test novel and traditional laboratory analyses to identify characteristics of cryopreserved spermatozoa that are related to boar fertility. Predicting the fertility of individual frozen ejaculates for selection of higher quality semen prior to AI would increase overall success. All rights reserved.Due to reduced fertility, cryopreserved semen is seldom used for commercial porcine artificial insemination (AI). In summary, acceptable fertility is possible with frozen semen and has merit for application as a reproductive management tool.Ĭopyright © 2013 Elsevier B.V. A progressive improvement of fertility over time was observed mainly due to adaptive procedures associated with an introduced technology. The mean (±SD) total number piglets born were 12.5 (☓.9). Of 2696 recorded services, 2122 (78.7%) of the females farrowed. Sows and gilts were inseminated three times PM/AM/PM and AM/PM/AM, respectively. Within 2-5min of thawing, the sows or gilts were inseminated via intra-cervical deposition using a standard AI pipette. For AI, eight straws were thawed (to achieve at least 2.0×10(9)motile sperm) and diluted with 60mL of extender pre-warmed to 26☌. Ninety eight percent of the ejaculates that were frozen showed at least a 50% post-thaw motility and were approved for shipment. For each frozen ejaculate, a post-thaw quality check was performed.
Semen was prepared for cryopreservation using Androhep(®) CryoGuard™, packaged in 0.5mL French straws (average 500 million total sperm per straw) and frozen using a programmable freezer (IceCube™). The sperm-rich fraction was collected and only those collections having ≥80% motility and ≤15% abnormalities were further processed.
All artificial insemination (AI) occurred on a single 1800 sow farm in Indiana, USA. The frozen semen sourced from a boar stud in Manitoba, Canada. The objective in the present study was to assess application of frozen semen throughout a 4 year period comprising more than 2600 AI services.
Little information exists on the long term use of frozen boar semen in commercial pork production operations. Albeit, frozen semen is an effective technology for the transfer of genes between breeding pyramids and also to reliably provide semen for planned matings. Less than 1% is inseminated using frozen semen. Worldwide, greater than 90% of sows are inseminated with fresh semen.
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