Composition of Bovine Muscle Lipids at Various Carcass Locations

Evaluation of genomic prediction considering non-additive genetic effects on fatty acid traits of Japanese Black cattle

Genomic prediction was conducted using 2494 Japanese Black cattle from Hiroshima Prefecture and both single-nucleotide polymorphism information and phenotype data on monounsaturated fatty acid (MUFA) and oleic acid (C18:1) analyzed with gas chromatography. We compared the prediction accuracy for four models (A, additive genetic effects; AD, as for A with dominance genetic effects; ADR, as for AD with the runs of homozygosity (ROH) effects calculated by ROH-based relationship matrix; and ADF, as for AD with the ROH-based inbreeding coefficient of the linear regression). Bayesian methods were used to estimate variance components. The narrow-sense heritability estimates for MUFA and C18:1 were 0.52-0.53 and 0.57, respectively; the corresponding proportions of dominance genetic variance were 0.04-0.07 and 0.04-0.05, and the proportion of ROH variance was 0.02. The deviance information criterion values showed slight differences among the models, and the models provided similar prediction accuracy.

Effects of parent-of-origin models with different pedigree information on beef carcass traits and fatty acid composition in Japanese Black cattle

Genomic imprinting should be considered in animal breeding systems to avoid lead in bias in genetic parameter estimation. The objective of this study was to clarify the effects of pedigree information on imprinting variances for carcass traits and fatty acid composition in Japanese Black cattle. Carcass records [carcass weight, rib eye area, rib thickness (RT), subcutaneous fat thickness and beef marbling score (BMS)] and fatty acid composition were obtained for 11,855 Japanese Black feedlot cattle. To estimate and compare the imprinting variances for the traits, two imprinting models with different pedigree information [the sire-dam gametic relationship matrix (Model 1) and the sire-maternal grandsire (MGS) numerator relationship matrix (Model 2)] were fitted. The ratio of the imprinting variance to the total additive genetic variance for RT (6.33%) and BMS (19.00%) was significant in Model 1, but only that for BMS (21.09%) was significant in Model 2. This study revealed that fitting the sire-MGS model could be useful in estimating imprinting variance under certain conditions, such as when restricted pedigree information is available. Furthermore, the present result suggested that the maternal gametic effects on BMS should be included in breeding programmes for Japanese Black cattle to avoid selection bias caused by imprinting effects.

Superior single nucleotide polymorphisms that contribute to two main routes of the fatty acid synthesis pathway in Korean cattle

The fatty acid composition of adipose tissue in livestock has been recognized as an important carcass trait that affects meat quality. To determine the overall positive effect on fatty acid synthesis, we investigated PPARγ, SREBPs, FABP4, SCD, and FASN genes because SNP and/or SNP combinations were strongly affecting each fatty acid synthesis pathway. We screened their SNPs, SNP combinations, and genotype. Furthermore, we studied the economic traits C18:1, monounsaturated fatty acid (MUFA), and marbling score (MS). To enhance the accuracy of the predictive genetic effect, we applied a statistical adjustment model excluding environmental factors. We also selected superior genes, gene combinations, and genotypes for each economic trait by using multifactor dimensionality reduction. Based on the results, g.3977-325 T>C (CC) was selected as the best genotype of the SNP and the combination (g.10153 A>G, g.3977-325 T>C) (AACC, AGCC, GGCC), (g.3690 G>A, g.3977-325 T>C) (GGCC, GACC), (g.3977-325 T>C, g.25670 C>T) (CCCC, CCCT, CCTT) (genotypes of the best SNP combination) was selected as the best gene combination for C18:1 and MUFA. In addition, g.3977-325 T>C (CC) was selected as the best genotype of the SNP and the combination (g.3977-325 T>C, g.6974 G>A) (TTAA, CTAA, CCAA, CCGA, CCGG) as the best SNP combination for MS. We integrated genes that were selected as excellent SNP and SNP combinations affecting two main routes of the fatty acid synthesis pathway and identified the best and final SNP, SNP combination, and superior genotype.

Relationships between mineral concentrations and physicochemical characteristics in the Longissimus thoracis muscle of Japanese Black cattle

The relationship between mineral concentrations, and the relationship of mineral concentrations with physicochemical characteristics in muscles were investigated using the Longissimus thoracis (LT) muscle of 44 Japanese Black steers. We determined moisture content, fat content, meat color, fatty acid composition and mineral concentrations in the LT muscle. Magnesium (Mg), potassium (K) and zinc (Zn) concentrations had negative correlations with fat content, but sodium (Na), manganese (Mn), copper (Cu) and molybdenum (Mo) concentrations were not correlated with fat content. The concentrations of Mg, Mn, Fe, Cu and Zn largely and positively contributed to the first principal component of mineral concentrations. Because the red muscle was rich in these minerals compared to the white muscle, the variation of these minerals probably results from the abundance of red fibers in the LT muscle. The concentration of K was positively correlated with moisture content but Na concentration was not related to moisture content, suggesting that the intracellular fluid volume can largely affect moisture content. The results of the present experiment suggest that mineral concentrations reflect some traits such as not only fat content but also the composition of myofiber type and the intracellular fluid volume in the LT muscle of Japanese Black cattle.

Detection of superior genotype of fatty acid synthase in Korean native cattle by an environment-adjusted statistical model

OBJECTIVE

This study examines the genetic factors influencing the phenotypes (four economic traits:oleic acid [C18:1], monounsaturated fatty acids, carcass weight, and marbling score) of Hanwoo.

METHODS

To enhance the accuracy of the genetic analysis, the study proposes a new statistical model that excludes environmental factors. A statistically adjusted, analysis of covariance model of environmental and genetic factors was developed, and estimated environmental effects (covariate effects of age and effects of calving farms) were excluded from the model.

RESULTS

The accuracy was compared before and after adjustment. The accuracy of the best single nucleotide polymorphism (SNP) in C18:1 increased from 60.16% to 74.26%, and that of the two-factor interaction increased from 58.69% to 87.19%. Also, superior SNPs and SNP interactions were identified using the multifactor dimensionality reduction method in Table 1 to 4. Finally, high- and low-risk genotypes were compared based on their mean scores for each trait.

CONCLUSION

The proposed method significantly improved the analysis accuracy and identified superior gene-gene interactions and genotypes for each of the four economic traits of Hanwoo.

Identification of leptin gene polymorphisms associated with carcass traits and fatty acid composition in Japanese Black cattle

Previous studies have indicated that some leptin gene polymorphisms were associated with economically important traits in cattle breeds. However, polymorphisms in the leptin gene have not been reported thus far in Japanese Black cattle. Here, we aimed to identify the leptin gene polymorphisms which are associated with carcass traits and fatty acid composition in Japanese Black cattle. We sequenced the full-length coding sequence of leptin gene for eight Japanese Black cattle. Sequence comparison revealed eight single nucleotide polymorphisms (SNPs). Three of these were predicted to cause amino acid substitutions: Y7F, R25C and A80V. Then, we genotyped these SNPs in two populations (JB1 with 560 animals and JB2 with 450 animals) and investigated the effects on the traits. Y7F in JB1 and A80V in JB2 were excluded from statistical analysis because the minor allele frequencies were low (< 0.1). Association analysis revealed that Y7F had a significant effect on the dressed carcass weight in JB2; R25C had a significant effect on C18:0 and C14:1 in JB1 and JB2, respectively; and A80V had a significant effect on C16:0, C16:1, C18:1, monounsaturated fatty acid and saturated fatty acid in JB1. The results suggested that these SNPs could be used as an effective marker for the improvement of Japanese Black cattle.

Relationship between Single Nucleotide Polymorphisms in the Peroxisome Proliferator-Activated Receptor Gamma Gene and Fatty Acid Composition in Korean Native Cattle

The peroxisome proliferator-activated receptor gamma (PPARγ) gene plays an important role in the biosynthesis process controlled by a number of fatty acid transcription factors. This study investigates the relationships between 130 single-nucleotide polymorphisms (SNPs) in the PPARγ gene and the fatty acid composition of muscle fat in the commercial population of Korean native cattle. We identified 38 SNPs and verified relationships between 3 SNPs (g.1159-71208 A>G, g.42555-29812 G>A, and g.72362 G>T) and the fatty acid composition of commercial Korean native cattle (n = 513). Cattle with the AA genotype of g.1159-71208 A>G and the GG genotype of g.42555-29812 G>A and g.72362 G>T had higher levels of monounsaturated fatty acids and carcass traits (p<0.05). The results revealed that the 3 identified SNPs in the PPARγ gene affected fatty acid composition and carcass traits, suggesting that these 3 SNPs may improve the flavor and quality of beef in commercial Korean native cattle.

Change of fatty acid composition of the lumbar longissimus during the final stage of fattening in the Japanese Black cattle

Consideration of the shortened fattening period seems to be worthwhile for the realization of profitable beef production. In this study, change of fatty acid composition of the lumbar longissimus during the final stage of fattening was investigated in Japanese Black cattle. Each of 110 fattening animals was sampled three times: the initial two samples were taken by biopsy (25.7 months and 27.5 months on average) and the final one was from carcasses (29.9 months on average). Preliminary analysis indicated that removing muscle tissues from the constant body position of the living animals should be essential for sampling. Average monounsaturated fatty acids (MUFA) at three sampling points were 58.1%, 58.5% and 60.5%, and the differences of the third sampling with the first and second samplings were significant. Both in steers and heifers, MUFA also increased as the fattening stage proceeded, and MUFA of the heifers at all the sampling points were significantly higher than those of the steers. The increasing rate of MUFA rose from 0.21 percentage points (pp)/month at period 1 (from the first sampling to the second sampling) to 0.84 pp/month at period 2 (from the second sampling to the slaughter).

Identification of exonic nucleotide variants of the thyroid hormone responsive protein gene associated with carcass traits and Fatty Acid composition in korean cattle

The thyroid hormone responsive protein (THRSP) gene is a functional gene that can be used to indicate the fatty acid compositions. This study investigates the relationships of exonic single nucleotide polymorphisms (SNPs) in the THRSP gene and fatty acid composition of muscle fat and marbling score in the 612 Korean cattle. The relationships between fatty acid composition and eight SNPs in the THRSP gene (g.78 G>A, g.173 C>T, g.184 C>T, g.190 C>A, g.194 C>T, g.277 C>G, g.283 T>G and g.290 T>G) were investigated, and according to the results, two SNPs (g.78 G>A and g.184 C>T) in exon 1 were associated with fatty acid composition. The GG and CC genotypes of g.78 G>A and g.184 C>T had higher unsaturated fatty acid (UFA) and monounsaturated fatty acid (MUFA) content (p<0.05). In addition, the ht1*ht1 group (Val/Ala haplotype) in a linkage disequilibrium increased MUFAs and marbling scores for carcass traits (p<0.05). As a result, g.78 G>A and g.184 C>T had significantly relationships with UFAs and MUFAs. Two SNPs in the THRSP gene affected fatty acid composition, suggesting that GG and CC genotypes and the ht1*ht1 group (Val/Ala haplotype) can be markers to genetically improve the quality and flavor of beef.

Identification of Stearoyl-CoA Desaturase (SCD) Gene Interactions in Korean Native Cattle Based on the Multifactor-dimensionality Reduction Method

Fat quality is determined by the composition of fatty acids. Genetic relationships between this composition and single nucleotide polymorphisms (SNPs) in the stearoyl-CoA desaturase1 (SCD1) gene were examined using 513 Korean native cattle. Single and epistatic effects of 7 SNP genetic variations were investigated, and the multifactor dimensionality reduction (MDR) method was used to investigate gene interactions in terms of oleic acid (C18:1), mono-unsaturated fatty acids (MUFAs) and marbling score (MS). The g.6850+77 A>G and g.14047 C>T SNP interactions were identified as the statistically optimal combination (C18:1, MUFAs and MS permutation p-values were 0.000, 0.000 and 0.001 respectively) of two-way gene interactions. The interaction effects of g.6850+77 A>G, g.10213 T>C and g.14047 C>T reflected the highest training-balanced accuracy (63.76%, 64.70% and 61.85% respectively) and was better than the individual effects for C18:1, MUFAs and MS. In addition, the superior genotype groups were AATTCC, AGTTCC, GGTCCC, AGTCCT, GGCCCT and AGCCTT. These results suggest that the selected SNP combination of the SCD1 gene and superior genotype groups can provide useful inferences for the improvement of the fatty acid composition in Korean native cattle.

Identification of the SNP (Single Nucleotide Polymorphism) for Fatty Acid Composition Associated with Beef Flavor-related FABP4 (Fatty Acid Binding Protein 4) in Korean Cattle

In this study, we investigated the relationship between unsaturated fatty acids influencing beef flavor and four types of SNPs (c.280A>G, c.388G>A, c.408G>C and c.456A>G) located at exon 2, 3 and 4 of the FABP4 gene, which is a fatty acid binding protein 4 in Korean cattle (n = 513). When analyzing the relationship between single genotype, fatty acids and carcass trait, individuals of GG, GG, CC and GG genotypes that are homozygotes, had a higher content of unsaturated fatty acids and marbling scores than other genotypes (p<0.05). Then, haplotype block showed strong significant relationships not only with unsaturated fatty acids (54.73%), but also with marbling scores (5.82) in ht1×ht1 group (p<0.05). This ht1×ht1 group showed significant differences with unsaturated fatty acids and marbling scores that affected beef flavor in Korean cattle. Therefore, it can be inferred that the ht1×ht1 types might be valuable new markers for use in the improvement of Korean cattle.

Identification of novel single nucleotide polymorphisms (SNPs) of the lipoprotein lipase (LPL) gene associated with fatty acid composition in Korean cattle

The lipoprotein lipase (LPL) gene can be considered a functional candidate gene that regulates fatty acid composition. In this study, genetic associations between fatty acid composition and exonic single nucleotide polymorphisms (SNPs) in the LPL gene were examined using 612 Korean cattle. We investigated the relationship between unsaturated fatty acids and five novel SNPs (c.322G>A, c.329A>T, c.527T>G, c.988C>T and c.1591G>A), and confirmed that three polymorphic SNPs (c.322G>A, c.329A>T and c.1591G>A) were associated with fatty acid composition. Korean cattle with an AA genotype of c.322G>A, c.329A>T, and GA genotype of c.1591G>A had higher levels of monounsaturated fatty acids and carcass traits (P < 0.05). Our findings confirmed that three novel SNPs we identified in the LPL gene can affect fatty acid composition and carcass traits. Therefore, selection for AA and GA genotypes should be recommended to genetically improve beef quality and flavor.

Genetic parameters for fatty acid composition and feed efficiency traits in Japanese Black cattle

We estimated the genetic parameters related to feed intake (FI), feed efficiency traits (including feed conversion ratio (FCR) and residual feed intake (RFI) of digestible crude protein (DCP) and total digestible nutrients (TDN)), beef marbling score (BMS), melting point of fat (MP) and fatty acid composition. Fat and meat (Musculus trapezius) samples were taken from the carcasses of 863 Japanese Black steers derived from 65 sires, for determination of the MP and fatty acid composition of the total lipid in intramuscular adipose tissue. Genetic parameters were estimated using uni- and bivariate animal models. In addition, pedigree information for 4841 animals was used. Heritability estimates for BMS, MP, individual fatty acids, monounsaturated fatty acids (MUFA), the ratio of saturated fatty acids to MUFA (MUS) and the ratio of elongation (ELONG) were generally high. The FI values of TDN and DCP were also high, but FCRs and RFIs of those were low (0.09 to 0.22). Genetic correlation of BMS with MP was -0.34 (favorable) and with C18:1, MUFA, MUS and ELONG values were 0.40, 0.28, 0.29 and 0.37, respectively (favorable). Genetic correlations of MP with C18:1, MUFA, MUS and ELONG were negative (also favorable) and high (-0.85, -0.98, -1.00 (-0.996) and -0.66, respectively). The correlation estimates for feed efficiency traits of DCP were quite similar to those of TDN. Genetic correlations of BMS with FCRs and RFIs of TDN and DCP were all positive (unfavorable; 0.21 to 0.51), and in particular, the correlations with RFIs of those were high. The correlations of C18:1, MUFA, MUS and ELONG with RFIs of TDN and DCP were positive (unfavorable) but low (0.06 to 0.17), whereas the corresponding correlations with FCRs of those were all negative (favorable; -0.38 to -0.10). These results suggest that the quantity and quality of beef fat can be simultaneously improved and that the quality of beef fat (fatty acid composition) can be improved directly or indirectly with MP. Furthermore, selecting MP or fatty acid traits does not significantly affect feed efficiency.

Fatty acid composition of muscle and fat tissues of Omani Jebel Akhdar goats of different sexes and weights

This paper describes the fatty acid (FA) composition of muscle and fat tissue in Omani Jebel Akhdar buck, wether and does slaughtered at 11, 18 or 28 kg body weight (BW). The fat percentage in dry matter (DM) of the subcutaneous and kidney fats ranged between 85 and 98% and that of muscle ranged between 17 and 21%. Subcutaneous fat tended to have lower DM than kidney fat. Palmitic (C16:0), stearic (C18:0) and oleic (C18:1) acids comprised the largest proportions of FA in the muscle tissue (approximately 80%) with oleic acid being the most abundant. Ninety-one percent of the total FA were contributed by the C16 and C18 fatty acids being 31.6 and 58.5%, respectively. C19 and C20 were not detected in the muscle tissue. The essential FA, C20:2, C20:3 and C20:4 contributing about 1%. Muscle tissue of the Jebel Akhdar goat contained an average 51.3% and 48.7% of saturated (SFA) and unsaturated fatty acids (UFA), respectively. Polyunsaturated FA (PUFA) constituted about 5% and monounsaturated (MFA) 43.5% of the total FA. Subcutaneous fat contained more total FA (68.08%) than kidney fat (48.14%) in the whole tissue. Kidney fat contained higher percentages of C16 and C18 but less C:18:1 than subcutaneous fat. The proportions of SFA to UFA was high in both fat depots with the SFA being much higher in the kidney than subcutaneous fats. C16, C18 and C:18:1c acids comprised 64.2 and 78% and C16s and C18s made up 81 and 85% of total FA in subcutaneous and kidney fats, respectively. In both subcutaneous and kidney fats, there was a trend of increasing values of DM and fat percentage with intact males having the lowest and females the highest values. Males had higher levels of C15, C18:2 and C18:3 but lower levels of C17, C18 and total C16, C18 and C18:1 in muscle tissue. Intact males had higher levels of C10, 12, 15 FA but lower C16:1 and C16+18+18:1 than others in subcutaneous fat. Intact males had a similar trend for C12 and 14 but lower SFA and higher UFA in kidney fat. There was a trend of increasing DM and fat% in dry matter with increasing body weight. C10, 12 and 14 of the kidney fat decreased with increasing slaughter weight. There was a trend of the two C16 FA decreasing and the four C18 increasing with BW in the kidney fat. This resulted in proportions of the total C16 and C18 FA increasing from 81.8 to 86.8%. These findings confirm those of other studies on goat meat quality that, as judged by fatty acid composition it is not inferior to that of meats from other farm animals.

The SNPs in the ACACA gene are effective on fatty acid composition in Holstein milk

Fatty acid composition is an important economic trait for both dairy and beef cattle and controlled by genetic factors. Candidate genes controlling fatty acid composition may be found in fat synthesis and metabolism pathways. Acetyl-CoA carboxylase is the flux-determining enzyme in the regulation of fatty acid synthesis in animal tissues. One of two isozymes of this enzyme, acetyl-CoA carboxylase-α (ACACA), catalyses the first committed step of fatty acid synthesis in mammalian cytosol, leading to the biosynthesis of long-chain fatty acids. In the current study, the sequence comparison of the coding sequence (CDS) and two promoter regions (PIA and PIII) in bovine ACACA gene was performed between Japanese Black and Holstein cattle to detect nucleotide polymorphisms influencing fatty acid composition in milk and beef. Five single nucleotide polymorphisms (SNPs) were identified in the CDS region, 28 SNPs in the PIA region and three SNPs in the PIII region. Association study revealed that CCT/CCT type of PIII_#1, #2/PIA_#26 indicated a higher percentage of C14:0 in the milk of the Holstein cattle than CCT/GTC type (p = 0.050) and that a difference of the percentage of C16:0 was observed between CCT/CCT and GTC/GTC type (p = 0.023). CDS_#2 T/T type indicated a higher percentage of C18:0 than T/C type (p = 0.008). In addition, the Japanese Black cattle with CC/GT type of PIII_#1, #2 showed a higher percentage of C18:2 in the meat than those with GT/GT type (p = 0.025). Since PIII is the promoter specific to mammary gland during lactation, the altered expression of the ACACA gene owing to the SNPs in the PIII region may influence the fatty acid composition in the milk.

Fatty acid composition of beef is associated with exonic nucleotide variants of the gene encoding FASN

Genetic associations of fatty acid composition with exonic single nucleotide polymorphisms (SNPs) in the gene encoding fatty acid synthase (FASN) were examined using 513 Korean cattle. All five individual SNPs of g.12870 T>C, g.13126 T>C, g.15532 C>A, g.16907 T>C and g.17924 G>A were associated with a variety of fatty acid compositions and further with marbling score (P < 0.05). Their genotypes of CC, TT, AA, TT, and GG were associated with increased monounsaturated fatty acids and with decreased saturated fatty acids (P < 0.05). The genotypes at all the SNPs also increased marbling score (P < 0.05). Further genetic associations with fatty acid composition suggested that homozygous genotype with the haplotype of ATG at g.15532, g.16907, and g.17924 in a linkage disequilibrium block increased monounsaturated fatty acids and marbling score (P < 0.05). We concluded that the five exonic SNPs of g.12870, g.13126, g.15532, g.16907, and g.17924 in the FASN gene could change fatty acid contents. Their genotypes of CC, TT, AA, TT, and GG and haplotype of ATG at g.15532, g.16907, and g.17924 were recommended for genetic improvement of beef quality.

Effect of SCD and SREBP genotypes on fatty acid composition in adipose tissue of Japanese Black cattle herds

Fatty acid composition of beef adipose tissue is one of important traits because high proportions of monounsaturated fatty acid are related to favorable beef flavor and tenderness. In this study, we investigated effects of genetic factors such as stearoyl-CoA desaturase (SCD) and sterol regulatory element binding protein (SREBP) on beef carcass traits including fatty acid composition using two cattle populations. Sire effect was significantly related to almost all traits except BMS, suggesting that the trait examined in this study is highly controlled by genetic factors. The effect of SCD genotype on fatty acid composition was detected remarkably in both cattle groups, especially on stearic and oleic acids. This result was consistent with our previous studies and suggests that SCD is associated with fatty acid composition. Unlike SCD genotyping, the effect of SREBP genotype was not identified in this study. Our results suggested that SCD genotype would contribute to improving beef quality in field populations. Further studies about the relationship among these factors will bring an insight into the molecular mechanism of fatty acid metabolism in cattle.

Effects of the fattening period on the fatty acid composition of fat deposits and free amino acid and inosinic acid contents of the longissimus muscle in carcasses of Japanese Black steers

The effects of the fattening period on carcass characteristics, fatty acid composition of fat deposits, and muscle free amino acid (FAA) and inosinic acid (IMP) contents were evaluated in Japanese Black steers. Ten castrated, 10-month-old calves derived from the same sire were divided into five to be slaughtered at the age of 30 months after a 20-month fattening period (20-month group) and five to be slaughtered at the age of 34 months after a 24-month fattening period (24-month group). Concerning the fatty acid composition of subcutaneous fat, the percentage of palmitoleic acid was higher (P < 0.05) in the 24- than in the 20-month group, but no difference was noted in any other fatty acids. For intermuscular fat, no difference was observed in any fatty acids. The percentages of oleic acid and total monounsaturated fatty acid of intramuscular and perinephric fat were higher (P < 0.05) in the 24- than in the 20-month group. Of the FAAs in the longissimus thoracis muscle, the threonine and tyrosine contents were lower (P < 0.05) in the 24- than in the 20-month group. The IMP content was higher (P < 0.05) in the 24- than in the 20-month group, suggesting an effect of prolongation of the fattening period.