Correction: Does growth path influence beef lipid deposition and fatty acid composition?

Variation in Acetyl-CoA Carboxylase Beta Gene and Its Effect on Carcass and Meat Traits in Gannan Yaks

Acetyl-CoA carboxylase beta (ACACB) is a functional candidate gene that impacts fat deposition. In the present study, we sequenced exon 37-intron 37, exon 46-intron 46, and intron 47 of yak ACACB using hybrid pool sequencing to search for variants and genotyped the gene in 593 Gannan yaks via Kompetitive allele-specific polymerase chain (KASP) reaction to determine the effect of ACACB variants on carcass and meat quality traits. Seven single nucleotide polymorphisms were detected in three regions. Eight effective haplotypes and ten diplotypes were constructed. Among them, a missense variation g.50421 A > G was identified in exon 37 of ACACB, resulting in an amino acid shift from serine to glycine. Correlation analysis revealed that this variation was associated with the cooking loss rate and yak carcass weight (p = 0.024 and 0.012, respectively). The presence of haplotypes H5 and H6 decreased Warner-Bratzler shear force (p = 0.049 and 0.006, respectively), whereas that of haplotypes H3 and H4 increased cooking loss rate and eye muscle area (p = 0.004 and 0.034, respectively). Moreover, the presence of haplotype H8 decreased the drip loss rate (p = 0.019). The presence of one and two copies of haplotypes H1 and H8 decreased the drip loss rate (p = 0.028 and 0.004, respectively). However, haplotype H1 did not decrease hot carcass weight (p = 0.011), whereas H3 increased the cooking loss rate (p = 0.007). The presence of one and two copies of haplotype H6 decreased Warner-Bratzler shear force (p = 0.014). The findings of the present study suggest that genetic variations in ACACB can be a preferable biomarker for improving yak meat quality.

Supplementation with protected kapok seed oil and choline chloride to improve the performance and lipid status of thin-tailed sheep

Background and Aim

Healthy meat production is an important aspect of increasing sheep productivity. This study aimed to examine the influence of protected kapok seed oil (KSO) in combination with choline chloride (CC) on the feed utilization, lipid status, and performance of thin-tailed sheep.

Materials and Methods

Thirty male thin-tailed sheep (approximately 6 months old, with an average body weight of 12.59 ± 1.48 kg) were divided into six treatment groups (five heads/treatment). Factor 1 consisted of two treatments: K1 (KSO supplementation at 10% supplementation and 75% protection level) and K0 (without KSO supplementation). Factor 2 consisted of three levels of CC: (C0: 0%; C1: 1.5% and C2: 3% feed dry matter (DM) basis supplementation levels). The variables measured were the DM consumption, DM digestibility, organic matter digestibility, nitrogen retention, daily body weight gain (DBWG), and blood and meat lipid status. The data were analyzed using analysis of variance in a completely randomized design in a factorial pattern of 2 × 3 × 5.

Results

Choline chloride supplementation (up to 3%) increased DM consumption in the K0C2 group. The CC and protected KSO (K1C2) supplementation combination resulted in the highest DM consumption level (p < 0.05). The protected KSO supplementation increased DBWG (the DBWG in the K1C0 group was higher than that in the K0C0 group, and the highest DBWG was found in the K1C2 group) (p < 0.05). Protected KSO and CC supplementation decreased cholesterol levels and increased the relative proportion of linoleic acid in meat (p < 0.05).

Conclusion

Combined supplementation with protected KSO and CC improved the feed utilization and performance of male thin-tailed sheep. There were increases in DBWG, decreases in intramuscular fat and cholesterol levels, and increases in meat linoleic acid levels.

Transcriptome profiling reveals stress-responsive gene networks in cattle muscles

In meat-producing animals, preslaughter operations (e.g., transportation, mixing unfamiliar animals, food and water deprivation) may be a source of stress with detrimental effects on meat quality. The objective of this work was to study the effect of emotional and physical stress by comparing the transcriptomes of two muscles (M. longissimus thoracis, LT and M. semitendinosus, ST) in Normand cows exposed to stress (n = 16) vs. cows handled with limited stress (n = 16). Using a microarray, we showed that exposure to stress resulted in differentially expressed genes (DEGs) in both muscles (62 DEGs in LT and 32 DEGs in ST, of which eight were common transcription factors (TFs)). Promoter analysis of the DEGs showed that 25 cis transcriptional modules were overrepresented, of which nine were detected in both muscles. Molecular interaction networks of the DEGs targeted by the most represented cis modules helped identify common regulators and common targets involved in the response to stress. They provided elements showing that the transcriptional response to stress is likely to (i) be controlled by regulators of energy metabolism, factors involved in the response to hypoxia, and inflammatory cytokines; and (ii) initiate metabolic processes, angiogenesis, corticosteroid response, immune system processes, and satellite cell activation/quiescence. The results of this study demonstrate that exposure to stress induced a core response to stress in both muscles, including changes in the expression of TFs. These factors could relay the physiological adaptive response of cattle muscles to cope with emotional and physical stress. The study provides information to further understand the consequences of these molecular processes on meat quality and find strategies to attenuate them.

Comprehensive Transcriptome Analysis Reveals the Role of lncRNA in Fatty Acid Metabolism in the Longissimus Thoracis Muscle of Tibetan Sheep at Different Ages

Long noncoding RNA (lncRNA) plays an important regulatory role in mammalian adipogenesis and lipid metabolism. However, their function in the longissimus thoracis (LT) muscle of fatty acid metabolism of Tibetan sheep remains undefined. In this study, fatty acid and fat content in LT muscle of Tibetan sheep were determined, and RNA sequencing was performed to reveal the temporal regularity of lncRNA expression and the effect of lncRNA-miRNA-mRNA ceRNA regulatory network on lipid metabolism of LT muscle in Tibetan sheep at four growth stages (4-month-old, 4 m; 1.5-year-old, 1.5 y; 3.5-year-old, 3.5 y; 6-year-old, 6 y). The results indicated that the intramuscular fat (IMF) content was highest at 1.5 y. Moreover, the monounsaturated fatty acid (MUFA) content in 1.5 y of Tibetan sheep is significantly higher than those of the other groups (P < 0.05), and it was also rich in a variety of polyunsaturated fatty acids (PUFA). A total of 360 differentially expressed lncRNAs (DE lncRNAs) were identified from contiguous period transcriptome comparative groups of 4 m vs. 1.5 y, 1.5 y vs. 3.5 y, 3.5 y vs. 6 y, and 4 m vs. 6 y, respectively. Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis found that the target genes in lncRNA trans-mRNA were significantly related to the protein digestion, absorption, and fatty acid biosynthesis pathways (P < 0.05), which demonstrated that DE lncRNA trans-regulated the target genes, and further regulated the growth and development of the LT muscle and intramuscular fatty acid metabolism in Tibetan sheep. We further analyzed the role of the lncRNA-miRNA-mRNA regulatory network in the lipid metabolism of Tibetan sheep. Additionally, GPD2, LIPE (lipase E hormone-sensitive enzyme), TFDP2, CPT1A, ACACB, ADIPOQ, and other mRNA related to fatty acid and lipid metabolism and the corresponding lncRNA-miRNA regulatory pairs were identified. The enrichment analysis of mRNA in the regulatory network found that the AMPK signaling pathway was the most significantly enriched (P = 0.0000112361). Comprehensive transcriptome analysis found that the LIPE, ADIPOQ, ACACB, and CPT1A that were regulated by lncRNA might change the formation of energy metabolism in Tibetan sheep muscle through the AMPK signaling pathway, and oxidized muscle fibers are transformed into glycolytic muscle fibers, reduced IMF content, and the fatty acid profile also changed.

The effect of feed restriction on the fat profile of Santa Inês lamb meat

Consumers today are increasingly more demanding regarding their food, seeking healthier and better quality products, and in this context animal nutrition plays a key role. The meat composition can be altered by animal feed itself, being that lipid profile may directly contribute to consumer health, reducing the predisposition of developing cardiovascular diseases, main cause of mortality in the world. Thus, the aim of this study was to assess the effect of dietary feed restriction in Santa Inês lambs on their intramuscular, intermuscular, and subcutaneous fat profile, fat profile of the longissimus thoracis et lumborum (LTL) muscle, and the total meat lipids and cholesterol. Three groups of lambs were subjected to diets: without restriction (WR), and 30 and 60% feed restriction. Overall, stearic, palmitic, and oleic acids were the predominant and the lowest lipid and cholesterol levels were observed at the highest restriction level, presenting higher polyunsaturated:saturated (PUFA:SFA) and desirable (DFA) fatty acid ratios (p < 0.05). Lambs subjected to 60% dietary feed restriction had a better quality meat with lower lipid and cholesterol contents, and profile favorable for human health due the presence of unsaturated fatty acids, that is important parameter the market demands to meet the consumers’ expectations.