Genetic Basis of Blood-Based Traits and Their Relationship With Performance and Environment in Beef Cattle at Weaning.

The objectives of this study were to explore the usefulness of blood-based traits as indicators of health and performance in beef cattle at weaning and identify the genetic basis underlying the different blood parameters obtained from complete blood counts (CBCs). Disease costs represent one of the main factors determining profitability in animal production. Previous research has observed associations between blood cell counts and an animal's health status in some species. CBC were recorded from approximately 570 Angus based, crossbred beef calves at weaning born between 2015 and 2016 and raised on toxic or novel tall fescue. The calves (N = ∼600) were genotyped at a density of 50k SNPs and the genotypes (N = 1160) were imputed to a density of 270k SNPs. Genetic parameters were estimated for 15 blood and 4 production. Finally, with the objective of identifying the genetic basis underlying the different blood-based traits, genome-wide association studies (GWAS) were performed for all traits. Heritability estimates ranged from 0.11 to 0.60, and generally weak phenotypic correlations and strong genetic correlations were observed among blood-based traits only. Genome-wide association study identified ninety-one 1-Mb windows that accounted for 0.5% or more of the estimated genetic variance for at least 1 trait with 21 windows overlapping across two or more traits (explaining more than 0.5% of estimated genetic variance for two or more traits). Five candidate genes have been identified in the most interesting overlapping regions related to blood-based traits. Overall, this study represents one of the first efforts represented in scientific literature to identify the genetic basis of blood cell traits in beef cattle. The results presented in this study allow us to conclude that: (1) blood-based traits have weak phenotypic correlations but strong genetic correlations among themselves. (2) Blood-based traits have moderate to high heritability. (3) There is evidence of an important overlap of genetic control among similar blood-based traits which will allow for their use in improvement programs in beef cattle.

Application of tension to prerigor goat carcasses to improve cooked meat tenderness.

In two separate experiments, carcasses of intact Kiko × Boer male kids were assigned randomly to tension treatments applied 30 min postmortem: 1) suspended by the Achilles tendon (AT); 2) suspended from the pelvic bone with front and hind legs tied together (TS); or 3) suspended by the Achilles tendon, and the fore- and hindsaddle were separated at the 12th/13th thoracic intervertebral disk, external fat, accessory muscles and epimysium surrounding the longissimus muscle (LM) were cut (TC), and a 2.3-kg weight attached to the neck (TC + W). Warner-Bratzler shear force values for the LM were reduced (P < 0.05) 24.4 to 35.9 N in TS carcasses compared to AT carcasses, and WBSF values of SM from TS carcasses were 25.0 and 20.3 N less (P < 0.05) than those for AT and TC + W carcasses, respectively. Results indicated that cooked goat meat tenderness, particularly the LM and SM, may be improved greatly by suspending goat carcasses by the pelvic bone.