Browsing by Subject "Artificial insemination"
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Item A comparison of semen thawing for artificial insemination in cattle.(2011-05-26T18:13:05Z) Kaczyk, Brittni L.; Kaczyk, Brittni Lanay; Serrano, Gabriela I.; May, Brain J.; Scott, Cody B.; Salisbury, Michael W.; Angelo State University. Department of Agriculture.Beef cows (n=23) were used to compared conception rates of two different thawing methods used for artificial insemination (AI). Cows were divided into the treatment or control group based on time of estrus. In the treatment, frozen semen was placed directly into the AI gun and inserted into the female for deposition after a minimum of 30 seconds. The control females experienced the typical thawing process of semen straws placed in a water bath for a minimum of 30 seconds, then loaded into the AI gun and deposited into the uterus of the female. Conception rates were similar between semen thawing methods (P > 0.51). Additionally, the study analyzed semen motility using the two different thaw methods and found no difference (P = 1.0). In conclusion, thawing semen directly in the reproductive tract of the female provides the same conception rates as traditional thaw methods.Item Conception rate differences in sexed vs. non-sexed semen(2011-06-21T22:18:13Z) Brooks, Kayla L.; Brooks, Kayla Lynn; Salisbury, Michael; Ammerman, Loren; Engdahl, Gil; May, Brian; Angelo State University. Department of Agriculture.The objective of this study was to determine if sexed semen has similar conception rates as non-sexed semen. Eighty-four Angus females from the Angelo State University’s Management, Instruction and Research Center were synchronized at the beginning of this study; however, only 54 showed signs of estrus and were artificially inseminated (10 Heifers and 44 multiparous cows). The 54 females were split randomly into three different treatment groups. Heifers and cows in treatment one were inseminated with Y-bearing sexed semen. Females in treatment two were inseminated with X-bearing sexed semen; while the last treatment was our control which received non-sexed semen. Results in heifers and cows were similar, and no differences were noted among the three treatment groups (P>0.5). Differences might be noted with a larger number of females. Date of parturition was estimated using ultrasound, and is a viable management tool because it is possible to predict, on average, within 9 days of parturition with a 36 day maximum and an exact prediction for the minimum.Item Improving Semen Parameters Through Modification of Semen collection/extension(Texas Tech University, 2000-12) Johnson, Dustie LeeTo date, the common thread in the use of semen extenders/collection techniques, whether used for fresh extended semen, chilled semen, or cryopreserved semen, is that the extenders have all traditionally added post-collection. The objective of this study was to determine if modifying the method of collection/extension of semen would improve semen parameters by lessening cold and pH shock. Ten canine semen samples were collected with a modified artificial vagina to allow for a true split collection. The treatment half of the sample was collected into warmed extension media. The control half was collected into a dry container and no attempts to maintain temperature were used. Standard semen parameters along with the available sperm pool and number of inseminations were evaluated at specific time intervals and evaluations continued until the samples reached zero percent motility. Data analysis was performed with SPSS using the general linear model, Chi square and appropriate t-tests. There was a difference between the treatment and control groups for Motility (P<.001), Motility by Time (P<.001), Time to Zero Motility (P<.001), Time to Last Full Insemination (P<.03), Forward Progression (P<.001), Acrosome Reaction (P<.001), Acrosome Reaction by Time (P<.017), and Viability (P<.001). There was no difference in morphology between the treatment and control groups (P>.062). Modification of the semen collection/extension procedure resulted in improved semen parameters for extended periods of time post collection. The data suggest the improvement in semen parameters would result in improved quality and longevity of semen used for artificial insemination procedures and infertility treatment, possibly due to decreased effects of cold and pH shock. Further studies resulting in viable offspring will be needed to confirm these observations.Item Ovarian and hormonal events during synchronization of ovulation and timed appointment breeding of Bos indicus-influenced cattle using intravaginal progesterone, GnRH and prostaglandin F2(alpha)(Texas A&M University, 2007-04-25) Saldarriaga Lopez, Juan PabloObjectives were to 1) evaluate the use of the CO-Synch + CIDR (COS-C) protocol for synchronization of ovulation and timed AI (TAI) in Bos indicus-influenced cattle, 2) compare cumulative pregnancy rates after COS-C synchronization and TAI to those in a traditional management (TM) scheme, and 3) evaluate specific ovarian, hormonal, and estrual events associated with COS-C. The COS-C regimen included insertion of a controlled internal drug release device (CIDR) containing progesterone and injection of GnRH (GnRH-1) on day 0, removal of the CIDR and injection of prostaglandin F2a (PGF on d 7, and injection of GnRH (GnRH-2) and TAI 48 h later. In experiment 1 (Exp. 1), 335 females were stratified by BCS, parity and d postpartum before random assignment to COS-C or TM. An additional 96 females in which TM controls were not available for comparison also received COS-C. Conception rates to TAI averaged 39% (n = 266). Cumulative pregnancy rates were greater (P < 0.05) after 30 and 60 d of the breeding season in COS-C than in TM (n = 170 and 165 females respectively). In experiment 2 (Exp. 2), 100 postpartum (F1) females were stratified as in Exp. 1 within four replicates (25 each) and assigned randomly to receive either COSC or COS (no CIDR) treatment. No differences were observed between treatments and all data were pooled. Percentages of cows ovulating after GnRH-1, developing a synchronized follicular wave, exhibiting luteal regression to PGF, and ovulating to GnRH-2 were 40, 60, 93, and 72%, respectively. In experiment 3 (Exp. 3), primiparous (F1) heifers (n = 32) and pluriparous cows (n = 18) received the Select Synch + CIDR synchronization regimen (no GnRH-2 or TAI). Mean intervals from CIDR removal to estrus and ovulation, and from estrus to ovulation were 70 ???? 2.9, 99 ???? 2.8, and 29 ???? 2.2 h, respectively. Relatively low TAI conception rates (< 50%) were attributed to failure of 40% of cattle to develop a synchronized follicular wave after GnRH-1 and to inappropriate timing of TAI/GnRH-2. It may be possible to improve TAI conception rates by delaying TAI/GnRH-2 to between 66 and 72 h, and by developing methods to increase the number of ovulations after GnRH-1.Item Use of unique collection device improves conception rates of bovine and equine(Texas Tech University, 2008-12) Graves-Evenson, Kory K.; Prien, Samuel D.; Albin, Robert C.; Jackson, Samuel P.; Thompson, Leslie D.While the practice of artificial insemination may date back eight centuries, there is still a need for improved techniques for semen handling. Previous research from this laboratory using a canine or equine model, demonstrated that semen collected in a modified collection device, the Device for Improved Semen Collection (DISC), remained fertile for longer periods as compared to samples collected using standard techniques. The object of the present study was to perform controlled breeding trials involving cattle and horses comparing semen collected in the DISC to a traditional control (TC). All sires were collected in both the DISC and the TC. Following collection, all semen samples were processed using standard techniques designed to produce breeding doses consistent with industry standards. Cells were then held a minimum of 24 hrs prior to breeding. In two separate trials, cattle were synchronized with a standard 2-shot prostaglandin protocol. Horses were bred using cells that had been held for periods of 24, 48 or 72hrs post extension. Data collected from the present study supports earlier work, demonstrating extended motility (and in theory fertility) from semen collected in the DISC. Pregnancy data from all three fertility trials demonstrate higher conception rates in animals bred with sperm collected in the DISC unit. Further, to date, no birth defects have been recorded. These data indicate that the DISC to be a superior system for semen collection, resulting in higher conception rates without increased risk of birth defects.