The objective of this study was to analyze equine embryo morphokinetics and whether or not they were indicative of survivability upon successful implantation into the uterus of a recipient female. In equine reproduction, fertility is a lowly heritable trait that has an exceedingly large financial impact on the ability to grow genetic lines. In order to increase pregnancy rates, producers must have access to accurate decision-making tools. Ten (n = 10) fertilized equine embryos collected via flushing by licensed veterinarian, Dr. Gregg Veneklasen, DVM in Canyon, TX. Flushed embryos were filmed for a thirty-five (35) second observation period with an Iolight Microscope and then processed through video motion magnification (VMM) software Lambda Vue, that amplified embryo activity 300x their normal movement. These VMM embryos were then assessed for time specific morphological changes using Image J software. Embryo morphological dimension shifts previously unseen under a simple microscope became humanly perceptible and measurable. For morula stage embryos, measurements of significance were taken on the inner cell mass (ICM), total embryo area, trophoblast to ICM distance, and finally the vertical, diagonal, and horizontal axis of the sub-zonal distance. Protocols were developed for embryos in the blastocyst stages, where measurements were taken on the vertical, diagonal, and horizontal axis of the total embryo, area of the embryo, notation of general ICM location, and trophoblast thickness around the embryo face. All measurements were taken in microns every five seconds for the thirty-five second recording period. Findings presented that embryos with a greater ICM, total embryo area, and sub-zonal vertical, diagonal, and horizontal distance established pregnancies as frequently as embryos with less momentous differences in distance (P < 0.1). This research has shown the relationship between morphokinetics and pregnancy had no significance of determining pregnancy viability. This resulted in enhanced prediction of embryo transfer techniques based on traditional grading, making pregnancy rates more predictable and consistent.

The objective of this study was to evaluate the ability of a specific gravity chamber (SGC) to identify embryos most likely to result in successful implantation following embryo transfer. In this study, 19 in vitro produced (IVP) and 15 in vivo derived (IVD) Grade bovine embryos were allowed to descend through media in an SGC. Descent time through a 1-cm timing region was recorded, and embryos were retrieved from the chamber and transferred into recipient females or cryopreserved and transferred at a later date. To determine if chamber evaluation had an effect on pregnancy status, 27 IVP and 12 IVD embryos that were not evaluated with the SGC were also transferred alongside project embryos. Pregnancy was determined via transrectal ultrasound palpation and recorded. There was no significant difference in conception rates between embryos evaluated with the SGC and those not, indicating that chamber analysis had no negative impact on viability of both IVP (P = 0.54) and IVD (P = 0.93) embryos. Twenty-two of the 34 total project embryos resulted in successful implantation and pregnancy, with 13 pregnancies (68.4%) by IVP and 9 (60%) by IVD. There was no difference in average descent time of pregnant and non-pregnant embryos for IVP (P = 0.54) or IVD embryos (P = 0.24). When divided into groups according to descent time, 32% of all observations for IVP embryos occurred between 30 to 50 seconds with a 66.7% conception rate, and 42% occurred between 70 to 90 seconds with a 75% conception rate (P = 0.85). For IVD, 60% of all observations occurred between 90 to10 seconds, with a conception rate of 66.7% (P = 0.35). Though not significant, the numeric trends highlighted in these data lend support to previous research utilizing specific gravity. Further research is needed to thoroughly evaluate the potential of this technology as a method of noninvasive assessment of embryo viability.

Assessment of embryo quality and viability has traditionally been based on morphological evaluation. However, morphological evaluation, though somewhat reliable, is subjective in nature and varies greatly depending upon the skill and experience of the evaluator. Although research has been conducted with the goal of identifying more accurate and objective methods of evaluation, the issue of repeatability and consistency in predicting the likelihood of a successful pregnancy remains. Previous research has proposed the ability to utilize specific gravity to predict developmental energy reserves based on embryonic weight, theoretically identifying those embryos with an increased chance of success following standard embryonic transfer. The objective of this study was to determine if specific gravity could accurately identify those embryos that were most likely to succeed in generating positive pregnancies. Bovine embryos (n = 20) were dropped through media in a specific gravity chamber. Utilizing an embryo tracking software program, researchers recorded the time elapsed as the embryos descended 1 cm through the media. Embryos were then transferred into recipient cattle, and pregnancy was detected via ultrasound approximately 40 days post transfer. Of the 20 embryos transferred, 12 resulted in positive pregnancies. Descent times of these positive pregnancies ranged from 25.96 to 90.27 seconds, with an average descent time of 59.72 seconds. An analysis of the relationship between descent time and pregnancy outcome showed no significant difference (P > 0.05). Although there was no significance in the findings of this study, additional trials will be performed to thoroughly evaluate the potential of this technology as an objective measurement of embryonic viability.

The objectives of this research were to determine if an F1 USDA Prime, yield grade 1 sire produced from the WTAMU PrimeOne Project (Sire A) was a competitive sire for producing dairy composites when compared to a purebred Angus sire (Sire B), and to evaluate any subsequent reproductive impact of sire on dam. Dairy cows (n = 1,930) were artificially inseminated resulting in 763 pregnancies with 564 births and 536 live calves. Data was collected at a large commercial dairy and analyzed using SAS 9.4 with sire as fixed effect; lactation, breeding technician and services per conception were random effects. Individual animal was experimental unit (n = 536). Conception rates were 40% for Sire A and 31% for Sire B (P ≤ 0.01). Average gestation length (GL) was 284-d and 280-d for Sire A and B, respectively (P ≤ 0.01). Calves by Sire B reported lower average birth weight (BW) than those by Sire A (P ≤ 0.01) with no difference in calving ease score (CE) (P = 0.24). There was no difference in 60-d (P = 0.58) or 120-d calf weights (P = 0.47). However, calves by Sire B reported higher average daily gains at both 60- (0.61 and 0.58 kg; P ≤ 0.01) and 120-d (0.70 and 0.67 kg; P = 0.03). Sire had no effect on morbidity (P = 0.62) or mortality (P = 0.25). Post-partum interval (PPI) and time from first estrus to conception were not different between sires (P = 0.19; P = 0.14). BW and CE did not affect PPI or time from first estrus to conception. Data from this trial indicates the cloned progeny sire increased conception rates, but the purebred Angus sire was more favorable for GL, BW and progeny growth performance. Neither sire negatively impacted subsequent reproductive performance of the dam.