Evaluation of genetic components in traits related to superovulation, in vitro fertilization, and embryo transfer in Holstein cattle

• Published in: Journal of Dairy Science
• Main Authors: Gaddis, Kristen L. Parker, Null, Daniel J., Cole, John Bruce, Hansen, Peter James
• Other Authors: Uludağ Üniversitesi/Veteriner Fakültesi/Hayvan Bilimleri Anabilim Dalı., orcid:0000-0002-5611-4993, Dikmen, Serdal, A-5731-2018, 8280302600
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 2016
• Subjects: Agriculture; Food science & technology; Embryo transfer; Genetic parameter; In vitro fertilization; Superovulation; Signaling pathway; Ovulation rate; Parameters; Genome; Growth; Fertility; Estradiol; Schemes; Program; Success; Animals; Cattle; Female; Fertilization in vitro; Oocytes; Reproduction; dairy & animal science; Embryo; Bison Bison Athabascae; Blastocyst; Animal; Bovine; Oocyte; Veterinary; Bison bison athabascae
• Online Access: http://hdl.handle.net/11452/30134; https://doi.org/10.3168/jds.2016-11907; https://www.sciencedirect.com/science/article/pii/S0022030217300735

The objectives of this study were to estimate variance components and identify regions of the genome associated with traits related to embryo transfer in Holsteins. Reproductive technologies are used in the dairy industry to increase the reproductive rate of superior females. A drawback of these methods remains the variability of animal responses to the procedures. If some variability can be explained genetically, selection can be used to improve animal response. Data collected from a Holstein dairy farm in Florida from 2008 to 2015 included 926 superovulation records (number of structures recovered and number of good embryos), 628 in vitro fertilization records (number of oocytes collected, number of cleaved embryos, number of high-and low-quality embryos, and number of transferrable embryos), and 12,089 embryo transfer records (pregnancy success). Two methods of transformation (logarithmic and Anscombe) were applied to count variables and results were compared. Univariate animal models were fitted for each trait with the exception of pregnancy success after embryo transfer. Due to the binary nature of the latter trait, a threshold liability model was fitted that accounted for the genetic effect of both the recipient and the embryo. Both transformation methods produced similar results. Single-step genomic BLUP analyses were performed and SNP effects estimated for traits with a significant genetic component. Heritability of number of structures recovered and number of good embryos when log-transformed were 0.27 +/- 0.08 and 0.15 +/- 0.07, respectively. Heritability estimates from the in vitro fertilization data ranged from 0.01 +/- 0.08 to 0.21 +/- 0.15, but were not significantly different from zero. Recipient and embryo heritability (standard deviation) of pregnancy success after embryo transfer was 0.03 (0.01) and 0.02 (0.01), respectively. The 10-SNP window explaining the largest proportion of variance (0.37%) for total structures collected was located on chromosome 8 beginning at 55,663,248 bp. Similar ...