Inbreeding effects on in vitro embryo production traits in Guzerá cattle

Abstract

Inbreeding has been associated with the impairment of reproductive performance in many cattle breeds. Although the usage of reproductive biotechnologies has been increasing in bovine populations, not much attention has been given to the impact of inbreeding over cow's performance on artificial reproduction. The objective of this study was to estimate the impact of inbreeding on in vitro embryo production in a Guzerá breed population. The inbreeding coefficient (F), calculated as half of the co-ancestry of the individual's parents, was used as an estimate of inbreeding. The inbreeding coefficients of the donor, sire (used on in vitro fertilization) and of the embryos were included, separately, in the proposed models either as classificatory or continuous variables (linear and quadratic effects). The percentage of non-inbred individuals (or embryos) and mean F of donors, embryos and sires were 29.38%; 35.76%; 42.86% and 1.98±2.68; 1.32±3.13; 2.08±2.79, respectively. Two different models were considered, one for oocyte production traits and other for embryo production traits. The increase of F of the donor significantly (P<0.05) impaired the number of viable oocytes (N OV), number of grade I oocytes (N GI) and number of cleaved embryos (N CLV). Moreover, the donor's F influenced the percentage of grade I oocytes (P GI), percentage of viable embryos (P EMB) and percentage of cleaved embryos that turned into embryos (P CXE). No significant (P>0.05) effects were observed for the sire (father of the embryos) inbreeding coefficient over the traits analysed. Embryo's F influenced (P<0.05) the number of viable embryos (N EMB), percentage of viable embryos (P EMB) and percentage of cleaved embryos that turn into embryos (P CXE). Results suggested that an increase in the inbreeding coefficient might impair the embryos ability to survive through challenges imposed by the in vitro environment. Submitting highly inbred Guzerá female donors to in vitro embryo production may, in the long-term, have negative implications on the number of embryos obtained per cow and increase the relative costs of the improvement programmes based on this technology. High levels of inbreeding should be avoided when selecting Guzerá female donors and planning in vitro fertilization mating.

Symposium review: The genomic architecture of inbreeding: How homozygosity affects health and performance

“…Bjelland et al (2015) compared empirical genomic inbreeding values with expected inbreeding values using simulated data and a pedigree of 11,484 Holsteins and found only negligible effects of inbreeding on embryo viability. In contrast, Perez et al (2017) found that increased F PED i of the donor significantly reduced the number and the percentage of both viable and high-grade oocytes, as well as the number and percentage of cleaved embryos. Furthermore, increased F PED i of the embryo also had significant effects on viability.…”

Respuesta a la suplementación con propilenglicol en vacas multiovuladas, para la producción de embriones

“…La flexibilidad en los resultados de este experimento, hace suponer que la respuesta ante la multiovulación en vacas, se vio afectada por múltiples factores (Mikkola y Taponen, 2017;Perez et al, 2017), incluyendo el efecto paterno que fue significativo en este estudio. Esta multifactoriedad, dificulta la evaluación de la respuesta animal ante un suplemento.…”

Inbreeding depression causes reduced fecundity in Golden Retrievers

“…While inbreeding depression has been extensively explored in plants (Lande and Schemske 1985), geographically isolated wild animal populations (Furlan et al 2012; Hagenblad et al 2009), and endangered and zoo populations (Roelke et al 1993), much research of late has addressed the same phenomenon in domestic species, many of which have been selectively bred for performance, production, and companionship. The correlation between inbreeding and impaired production in the dairy, wool, and meat industry has been well described (Ercanbrack and Knight 1991; Norén et al 2016; Mokhtari et al 2014; Pereira et al 2016; Perez et al 2017). More recently, inbreeding has been correlated with reduced performance in Australian Thoroughbred horses (Todd et al 2018).…”