PSXIII-13 Comparison of telomere length in age-matched primiparous and multiparous Brahman cows Academic Article uri icon

abstract

  • Abstract Telomeres are comprised of G-rich nucleotide sequences (5’-TTAGGG-3’) at the chromosome termini that are responsible for protecting chromosomes; however, attrition of these sequences has been observed in conditions of physiological and psychological stress. The purpose of this study was to compare telomere length (TL) in 4-yr-old Brahman cows grouped by first parity (n = 8) and second parity (n = 11). Cows were bled by jugular venipuncture, weighed, and had BCS recorded d+28 prior to calving and d-7 and d-28 post calving. Cows were observed for duration of labor (Tlabor) and calving ease (CE) at the time of parturition. Calf birth weight (CBW) and gender (CG) were recorded. Peripheral leukocytes were isolated, complete blood counts (CBC) were recorded, and genomic DNA was extracted utilizing silicone membrane spin column kits. The relative quantity of telomere products, which is proportional to the average TL, was determined by multiplex quantitative PCR analysis using the ratio of bovine telomere and β-globulin DNA. An absolute standard of bovine telomere (1012–107 dilution series) and β-globulin (109-104 dilution series) genes was utilized to produce relative copy number. All samples were run in triplicate and samples were included if triplicate Cq difference was less than 0.25 cycles. Parity was the fixed effect of interest and random effects included sire and day repeated with cow as the subject. No differences in CBC were seen. Tlabor, CE, CG, and CBW did not impact TL (P < 0.1). A trend was observed for day-parity interaction (P = 0.0918). TL between parity differed most on d-28 (P = 0.1046; parity one 127292 ± 6483; parity two 111045 ± 5376). The stress of parturition and raising the first calf of a cow’s life may be responsible for slight attenuation in TL.

author list (cited authors)

  • O’Daniel, S. E., Riley, D. G., Kochan, K. J., Riggs, P. K., Rouquette, F. M., Randel, R. D., & Welsh, T. H.

citation count

  • 0

publication date

  • December 2019