Acid Composition In Cattle Research Articles

Gene co-expression and alternative splicing analysis of key metabolic tissues to unravel the regulatory signatures of fatty acid composition in cattle

ABSTRACT Increasing the healthy/unhealthy fatty acid (FA) ratio in meat is one of the urgent tasks required to address consumer concerns. However, the regulatory mechanisms ultimately resulting in FA profiles vary among animals and remain largely unknown. In this study, using ~1.2 Tb high-quality RNA-Seq-based transcriptomic data of 188 samples from four key metabolic tissues (rumen, liver, muscle, and backfat) together with the contents of 49 FAs in backfat, the molecular regulatory mechanisms of these tissues contributing to FA formation in cattle were explored. Using this large dataset, the alternative splicing (AS) events, one of the transcriptional regulatory mechanisms in four tissues were identified. The highly conserved and absent AS events were detected in rumen tissue, which may contribute to its functional differences compared with the other three tissues. In addition, the healthy/unhealthy FA ratio related AS events, differential expressed (DE) genes, co-expressed genes, and their functions in four tissues were analysed. Eight key genes were identified from the integrated analysis of DE, co-expressed, and AS genes between animals with high and low healthy/unhealthy FA ratios. This study provides an applicable pipeline for AS events based on comprehensive RNA-Seq analysis and improves our understanding of the regulatory mechanism of FAs in beef cattle.

Alpine and lowland grazing differentially alter the reproductive tract redox milieu and amino acid composition in cattle

An alpine environment is unique due to pasture biodiversity, with an abundant content of natural antioxidant polyphenols. The present study investigated the effects of lowland and alpine grazing on the oviduct and uterine tissue redox status and amino acid concentrations in plasma and reproductive fluids. In the first experiment, heifers grazed on lowland (H-LOW: n = 13) and on alpine (H-ALP: n = 15) pastures. In the second experiment, heifers grazed on the same lowland (HS-LOW: n = 6) and on a different alpine (HS-ALP: n = 6) pasture. The abundance of mRNA transcripts for antioxidant enzymes in the oviduct (glutathione S-transferase alpha 2, glutathione synthetase (GSS)) and the endometrium (catalase, glutathione-disulfide reductase, GSS) was less (P < 0.05), and for glutathione peroxidase 4 in the endometrium greater (P = 0.006) in the H-LOW than in the H-ALP group. The abundance of mRNA transcript for catalase was less in the endometrium in the H-LOW than in the H-ALP (P = 0.001) group. Catalase and NAD(P)H quinone dehydrogenase 1 concentrations in the oviduct were greater in the HS-LOW than in the HS-ALP group (P < 0.05). Of 32 amino acids analysed, there were differences in concentrations in the H-LOW and H-ALP group of 13, seven and 15 in plasma, oviduct and uterine fluids, respectively (P < 0.05). Comparing the HS-LOW to the HS-ALP groups, there were 13, one and three amino acids in the plasma, oviduct and uterine fluids, respectively, that were differentially abundant (P < 0.05). The grazing systems had some effect on the redox status and amino acid patterns in reproductive tissues.

PSXIV-7 Red blood cells are a better indicator than plasma for predicting subcutaneous trans fatty acid composition in cattle

Abstract The trans (t)-18:1 in beef has become of interest as partially-hydrogenated-vegetable-oils are removed from the food supply. Predicting t-18:1 in beef early in the feeding period would be useful if limitations are put on t18:1 in beef. The objective of the present study was to determine which blood component is a better predictor of t18:1 in beef. Accordingly, proportions of t10-18:1 and t11-18:1 (i.e. major t-18:1 isomers) were measured in heifer red blood cells (RBC) and plasma (2 pens of 7 animals) after 0, 28, 56 and 76d on a barley-grain-based diet, and also correlated with post-slaughter subcutaneous fat. Blood components were subjected to direct base then acid methylation, and subcutaneous fat to base methylation after freeze drying. c10-17:1 methyl ester was included as an internal standard. Fatty acid methyl esters were purified using Superclean LC-SI-SPETM and then analyzed by GC using a 100m CP-Sil88 column. Fatty acids were analyzed using the Mixed Models procedure of SAS (v 9.3; SAS Institute, Cary, IN) with time as a repeated measure, and pen as a random factor. Pearson correlation coefficients were generated using the PROC CORR procedure of SAS. Proportions of total t-18:1 declined in both RBC and plasma during later stages of finishing (P &amp;lt; 0.05). At 28d, t11-18:1 decreased and t10-18:1 increased in RBC and plasma (P &amp;lt; 0.05). By 76 d, proportions of t10-18:1 declined in both RBC and plasma to 0 d levels. RBC and plasma t-18:1 compositions were highly correlated for all time points and overall (R≥0.7, P ≤ 0.02). Correlations with post slaughter backfat were, however, consistently greater for RBC compared to plasma. The use of RBC t-18:1 composition may, therefore, be superior for predicting t-18:1 composition in other tissues, and the length of finishing on barley could be useful for manipulating the composition and content of t18:1 in beef.

Association between FASN gene polymorphisms ultrasound carcass traits and intramuscular fat in Qinchuan cattle

Fatty acid synthase (FASN) is an enzyme involved with fat deposition and fatty acid composition in cattle. This study was conducted to detect single nucleotide polymorphisms (SNPs) of the FASN gene and explore their relationships with ultrasound carcass traits in order to assess the potential use of the FASN gene for the breeding selection of Qinchuan cattle for desirable carcass traits. The frequencies of SNP g.12740C>T, g.13192T>C and g.13232C>T were identified in 525 individual Qinchuan cattle which were also assessed for backfat depth, eye muscle area and intramuscular fat by ultrasound. According to the PIC values, g.13192T>C possessed an intermediate polymorphism (0.25<PIC<0.5). The SNPs of g.13232C>T, g.12740C>T possessed low polymorphism (PIC<0.25). Chi-square tests showed that g.13192T>C were in Hardy-Weinberg disequilibrium (c2<c0.052). Two SNPs were found to be associated with variation in ultrasound carcass traits. The H2H2 diplotypes had a greater back fat depth than H1H1, H1H4 and H1H2 (P<0.01). The TT genotype at g.13192T>C was associated with a greater eye muscle area and the TT genotype at g.13232C>T was associated with greater intramuscular fat. When these genotypes were combined there was no difference in eye muscle area and intramuscular fat between the diplotypes. The H2H2 diplotype was associated with carcass traits that are likely to provide economic advantage in Qinchuan cattle. Variations in the FASN genes and their corresponding genotypes may be considered as molecular markers for economic traits in cattle breeding.

0342 Expression levels of the bovine SCD gene are significantly associated with fatty acid composition of cattle

0342 Expression levels of the bovine SCD gene are significantly associated with fatty acid composition of cattle

Quantitative Trait Loci and Candidate Genes Affecting Fatty Acid Composition in Cattle and Pig

Investigations into fatty acid composition in meats are becoming more important due to consumer demand for high quality healthy food. Marker-assisted selection has been applied to livestock to improve meat quality by directly selecting animals for favorable alleles that affect economic traits. Quantitative trait loci affecting fatty acid composition in cattle and pigs were investigated, and five candidate genes (ACACA, FASN, SCD, FABPs, and SREBP-1) were significantly associated with fatty acid composition. The information presented here should provide valuable guidelines to detect causative mutations affecting fatty acid composition in cattle and pigs.

Identification and utilization of genes associated with beef qualities

The fatty acid composition of adipose tissue in beef has been recognized as an important trait because of its relationship with beef quality, including favorable beef flavor and tenderness. Over the last decade, we have tried to identify the genes responsible for the fatty acid composition in cattle, and have found the following. (i) Genetic polymorphism of stearoyl-CoA desaturase (SCD) is one of the responsible genes associated with fatty acid composition. The average effects of gene substitution of the SCD type A gene on the monounsaturated fatty acid (MUFA) percentage and the melting point of intramuscular fat were approximately +1.0% and -1.0°C, respectively. (ii) Intron polymorphism of sterol regulatory element binding protein-1 (SREBP-1) also affected MUFA. (iii) No effect of SCD or SREBP-1 genotypes on any representative carcass traits of Japanese Black in the field population was observed. (iv) Additional genetic markers adipocytes fatty acid binding protein 4 (FABP4) and liver X receptor α also affected the fatty acid composition. (v) SCD and FABP4 significantly affected fatty acid composition in Holstein steers. These findings will bring new insight into the fat-related carcass traits of beef cattle and will thus contribute to the beef industry.