Possible effects of the MC4R Asp298Asn polymorphism on pig production traits under ad libitum versus restricted feeding.

The missense mutation Asp298Asn in the melanocortin 4 receptor (MC4R) is associated with daily gain or fatness in pigs (Sus scrofa domesticus). However, to the best of our knowledge, no study has directly compared the effects of the polymorphism between different feeding levels, even though diet plays a vital role in the swine industry. To explore possible differences, data from 439 mostly commercial hybrids fattened ad libitum and 119 commercial hybrids fattened with restricted feed ration were collected. The recorded traits were average daily gain (ADG), feed conversion ratio (FCR), carcass weight (CW), dressing percentage (DP), lean meat content (LM), backfat thickness (BFT), lean cuts weight, and meat quality parameters such as pH, temperature, drip loss, and CIELAB colour space. The general linear model revealed that the overall effect of MC4R was not statistically significant, but significant differences (p < 0.05) were found in ADG, FCR, CW, DP, LM, and BFT. In the ad libitum category, the AA genotype (298Asn/298Asn) tended to be the most favourable for growth-related traits, with the lowest LM, which is consistent with previous findings. In the restricted category, on the other hand, GA heterozygotes (298Asp/298Asn) achieved the best performance in terms of growth, whereas AA homozygotes showed the worst performance. Therefore, these results raise the possibility of an interaction between MC4R and the feeding level.

Comparative Characterization of Immune Response in Sheep with Caseous Lymphadenitis through Analysis of the Whole Blood Transcriptome.

Caseous lymphadenitis (CL) is a chronic contagious disease that affects small ruminants and is characterized by the formation of pyogranulomas in lymph nodes and other organs. However, the pathogenesis of this disease and the response of the host genome to infection are not yet fully understood. This study aimed to investigate the whole blood transcriptome and evaluate differential gene expression during the later stages of CL in naturally infected ewes. The study included diseased, serologically positive (EP), exposed, serologically negative (EN) ewes from the same infected flock and healthy ewes (CN) from a different flock. RNA sequencing was performed using the Illumina NextSeq system, and differential gene expression was estimated using DESeq2 and Edge R approaches. The analysis identified 191 annotated differentially expressed genes (DEGs) in the EP group (102 upregulated and 89 downregulated) and 256 DEGs in the EN group (106 upregulated and 150 downregulated) compared to the CN group. Numerous immunoregulatory interactions between lymphoid and nonlymphoid cells were influenced in both EP and EN ewes. Immune DEGs were preferentially assigned to antigen presentation through the MHC complex, T lymphocyte-mediated immunity, and extracellular matrix interactions. Furthermore, the EP group showed altered regulation of cytokine and chemokine signaling and activation and recombination of B-cell receptors. Conversely, NF-kappa B signaling, apoptosis, and stress response were the main processes influenced in the EN group. In addition, statistically significant enrichment of the essential immune pathways of binding and uptake of ligands by scavenger receptors in EP and p53 signaling in the EN group was found. In conclusion, this study provides new insights into the disease course and host-pathogen interaction in naturally CL-infected sheep by investigating the blood transcriptome.

Genealogical analysis of European bison population revealed a growing up population despite very low genetic diversity.

In 1919, the European bison population became extinct in the wild. The rescue of the lowland subspecies and the whole species was achieved mainly thanks to individuals from the Bialowieza Forest (Polish-Belarusian border). There are currently two breeding lines-the lowland (purebred B. b. Bonasus) founded by 7 individuals and the lowland-Caucasian (hybrids of B. b. Bonasus and B. b. caucasicus) founded by 12 individuals. This genealogical study was conducted on 15,071 individuals recorded in the pedigree book between 1881 and 2020. Its objective was to determine the level of genetic variability and inbreeding almost 100 years after the rescue measures were initiated. The completeness of the pedigree of the reference population was 77% in the fifth generation backwards. A maximum of 23 generations can be traced back in the pedigree. The average inbreeding coefficient and the mean average relatedness of the reference population were very high, about 17% and 16% respectively. No significant amount of new inbreeding was discovered. The reference population has lost 9.11% of the total genetic diversity compared to the population of founders. A male of the Caucasian subspecies Kaukasus was discovered among the ancestors of the lowland lineage reference population. The effective population size calculated based on the increase in inbreeding was 23.93 individuals, based on complete generations equivalent it was 16.1 individuals. Wright's F-statistics showed very small differences in genotypic frequencies between individuals within the two lineages in the reference population (FIS = 0.10), between individuals and the total population (FIT = 0.04) and low differentiation between lineages (FST = 0.06). The population of the European bison from the Bialowieza Forest is generally very uniform but still shows good fitness.

Genome-Wide Association Study for Body Conformation Traits and Fitness in Czech Holsteins.

The aim of this study was a genome-wide association study (GWAS) on conformation traits using 25,486 genotyped Czech Holsteins, with 35,227 common SNPs for each genotype. Linear trait records were collected between 1995 and 2020. The Interbull information from Multiple Across Country Evaluation (MACE) was included for bulls that mostly had daughter records in a foreign country. When using the Bonferroni correction, the number of SNPs that were either significant or approached the significance threshold was low-dairy capacity composite on BTA4, feet and legs composite BTA21, total score BTA10, stature BTA24, body depth BTA6, angularity BTA20, fore udder attachment BTA10. Without the Bonferroni correction, the total number of significant or near of significance SNPs was 32. The SNPs were localized on BTA1,2,4,5,6,7,8,18,22,25,26,28 for dairy capacity composite, BTA15,21 for feet and legs composite, BTA10 for total score, BTA24 stature, BTA6,23 body depth, BTA20 angularity, BTA2 rump angle, BTA9,10 rear legs rear view, BTA2,19 rear legs side view, BTA10 fore udder attachment, BTA2 udder depth, BTA10 rear udder height, BTA12 central alignment, BTA24 rear teat placement, BTA8,29 rear udder width. The results provide biological information for the improvement of body conformation and fitness in the Holstein population.