PSIII-6 Comparisons of high-density genomic data in Holsteins differing in coat type

Abstract

Abstract Preliminary studies have reported that wild type-haired (WT) Holstein cattle have greater productive potential at a genomic level than their slick-haired (SL) counterpart. The objective of the present study was to evaluate, through a panel of commercial genetic markers (Igenity Elite, Neogen Corp), 49 Holsteins descendants SL [32 SL (n = 11 males and 21 females) and 17 WT (n = 2 males and 15 females)] from the Agricultural Experiment Station of Puerto Rico. These animals received a predictive genomic transmission capacity (PTA) based on DNA tests using more than 100,000 bovine genome markers, which contain information from their parents for a more accurate measure of genetic potential. Traits evaluated included measures of productivity, health, type and other indexes such as: net merit, milk yield, somatic cell score, among others. The data was analyzed using Proc GLIMMIX in SAS and the differences between means were determined by the Tukey test. Various subsets of animals were compared; however, no main differences were found between SL and WT (P >0.05), except for stature (-1.07±0.17 vs -0.39±0.26; P = 0.02, respectively). In a second subset, only lactating cows were evaluated (SL n = 7 and WT n = 7) and differences were found for: hypocalcemia (0.03±0.06 vs -0.21±0.06; P = 0.01), mastitis (-0.11±0.24 vs 0.90±0.24; P = 0.01), PTA type (-0.98±0.26 vs -0.11±0.26; P = 0.03), udder composite (-0.96±0.26 vs -0.07±0.26; P = 0.02), stature (-0.91±0.30 vs 0.04±0.30; P = 0.04), dairy form (-1.64±0.26 vs -0.65±0.26; P = 0.02), fore udder attachment (-0.77±0.30 vs 0.41±0.30; P = 0.02), rear udder height (-1.39±0.34 vs -0.18±0.34; P = 0.03) and width (-1.42±0.29 vs -0.17±0.29; P = 0.01), and udder depth (-0.73±0.27 vs 0.82±0.27; P = 0.002), respectively. These results suggest that SL males and females are genomically similar to WT for the most important economic traits when descending from a SL dam and when compared as a single group. However, differences in type and health traits may occur if the females are compared alone.