Reduction of slaughter age of Hanwoo steers by early genotyping based on meat yield index

Abstract

Objective: This study was conducted to determine early hereditary endowment to establish a short-term feeding program.Methods: Hanwoo steers (n = 140) were equally distributed into four groups (35/group) based on genetic meat yield index (MYI) viz. the greatest, great, low, and the lowest at Jukam Hanwoo farm, Goheung. All animals were fed in group pens (5 animals/pen) with similar feed depending on the growth stage. Rice straw was provided ad libitum, whereas concentrate was fed at 5.71 kg during the growing period (6 to 13 mo) and 9.4 kg during the fattening period (13 to 28 mo). Body weight (BW) was measured at two-month intervals, whereas carcass weight was determined at slaughtering at about 31 months of age. The Affymetrix Bovine Axiom Array 640K single nucleotide polymorphism (SNP) chip was used to determine the meat quantity-related gene in the blood.Results: After 6 months, the highest (p<0.05) BW was observed in the greatest MYI group (190.77 kg) and the lowest (p<0.05) in the lowest MYI group (173.51 kg). The great MYI group also showed significantly (p<0.05) higher BW than the lowest MYI group. After 16 and 24 months, the greatest MYI group had the highest BW gain (p<0.05) and were therefore slaughtered the earliest. Carcass weight was significantly (p<0.05) higher in the greatest and the great MYI groups followed by the low and the lowest MYI groups. Back-fat thickness in the greatest MYI group was highly correlated to carcass weight and marbling score. The SNP array analysis identified the carcass-weight related gene BTB-01280026 with an additive effect. The steers with the allele increasing carcass weight had heavier slaughter weight of about 12 kg.Conclusion: Genetic MYI is a potential tool for calf selection, which will reduce the slaughter age while simultaneously increasing carcass weight, back-fat thickness, and marbling score.

A transcriptomic analysis of skeletal muscle tissues reveals promising candidate genes and pathways accountable for different daily weight gain in Hanwoo Cattle

“…Thus, it is imperative to explore strategies that allow for a shorter age of slaughter while simultaneously ensuring optimal daily weight gain and meat quality. Consequently, numerous endeavors have been undertaken to enhance meat quantity by regulating the in uential factors including dietary treatment, breed type, age, environmental and genetic factors related to carcass weight 11,12 . Therefore, a comprehensive understanding of the genetic architecture of key growth and livestock traits is essential for identifying new genes and genetic pathways that can be leveraged through genomic selection to improve economic traits in livestock breeding programs.…”