Hanwoo Steers Research Articles

PSX-32 The rumen microbiome of Hanwoo steers from the growing to fattening stages.

The rumen microbiome contributes significantly to plant material digestion and rumen fermentation. However, little is known about the rumen microbiome composition at different life stages in the Hanwoo cattle breed, native to Korea. Therefore, we aimed to characterize the rumen microbiome in the growing, early fattening, and late fattening stages of Hanwoo steers. Twelve Hanwoo steers were raised from the growing to fattening stage and were fed different diets during the 3 stages. Rumen samples were collected from the steers during the 3 stages (36 samples = 12 animals x 3 stages). The rumen microbiome composition was then analyzed by 16S rRNA gene amplicon sequencing on the MiSeq platform. In total, 2,939,222 16S rRNA gene sequences from 36 rumen samples with at least 60,000 sequences were analyzed. Bacteroidetes was the most dominant phylum in all 3 stages and was greater (P 0.05) among the 3 stage groups. Proteobacteria was the third dominant phylum and was greater (P < 0.05) in the early fattening stage than in the growing stage. At the genus level, relative abundances of Prevotella, Succiniclasticum, Selenomonas, and Anaerovibrio were greater (P < 0.05) in the late fattening stage than in the other 2 stages, whereas those of Treponema, Coprococcus, Anaeroplasma, and Fibrobacter were greater (P < 0.05) in the growing stage than in the other 2 stages. Relative abundances of Ruminococcus and Butyrivibrio were greater (P < 0.05) in the early fattening stage than in the other 2 stages. This study indicates that the rumen microbiome composition in Hanwoo steers is affected by growing stage and diet. Key Words:

PSXII-33 Effects of quality and inclusion rate of roughages on feed intake, growth, rumen fermentation characteristics, and blood parameters of growing Hanwoo steers (Bos taurus coreanae).

PSXII-33 Effects of quality and inclusion rate of roughages on feed intake, growth, rumen fermentation characteristics, and blood parameters of growing Hanwoo steers (Bos taurus coreanae).

Effects of weaning and castration ages on growth performance, blood metabolites, and carcass characteristics in Hanwoo steers

BackgroundRecently, as production costs have been increasing owing to rising feed prices worldwide, shortening the age of slaughter has been recognized as a way to increase farm income. In Korea, the raising period for Hanwoo steers is over 31 months with the delay of weaning and castration stated as one of the reasons for the increase in the raising period. Thus far, studies on age of weaning and castration have been conducted individually, and there have been no studies on the combined effects of weaning and castration ages on the growth performance and carcass characteristics in Hanwoo steers.MethodsWeaning ages were calculated at 80 or 130 days of age, and castration ages were calculated at 90 days and 180 days of age. Calves were allocated to one of the four treatment groups: W80C90 (weaning at 80 days of age and castration at 90 days of age), W80C180, W130C90, and W130C180.ResultsFor the entire experimental period, weaning and castration ages did not significantly affect growth performance of Hanwoo steers. In addition, weaning and castration ages did not affect the overall yield and quality traits of carcass in Hanwoo steers.ConclusionWeaning and castration ages had small effects on growth performance and carcass characteristics in Hanwoo steers. Therefore, the early weaning and castration ages are recommended to reduce the slaughter age without any negative effects on meat quality grade.

Statistical effect analysis on the testosterone concentration, carcass grade and ultrasonic measurement at 30-month-old of Hanwoo steers

This study was conducted to produce a statistical effect analysis on the testosterone concentration, carcass grade and ultrasonic measurement at 30-month-old of Hanwoo steers. A total of 186 Hanwoo steers were used. Testosterone concentration, MAR, u-LMA and u-MAR according to grade were statistically significant differenced (p = 0:021, p :0001, p = 0:003, p :0001). Correlation analysis showed that MAR, u-LMA and u-MAR had a positive correlation (r = 0:921, 0.475, 0.760), and testosterone was a negative correlation (r = 0:278) between the grade. LMA was positive correlation (r = 0:218), and MAR had a negative correlation (r = 0:322) between the testosterone concentration. Carcass grade (LMA, BFT, MAR) and ultrasonic carcass grade (u-LMA, u-BFT, u-MAR) were positive correlation (r = 0:768, r = 0:691, r = 0:854).

Genome-wide association study and prediction of genomic breeding values for fatty-acid composition in Korean Hanwoo cattle using a high-density single-nucleotide polymorphism array.

Genomic selection using high-density single-nucleotide polymorphism (SNP) markers is used in dairy and beef cattle breeds to accurately estimate genomic breeding values and accelerate genetic improvement by enabling selection of animals with high genetic merit. This genome-wide association study (GWAS) aimed to identify genetic variants associated with beef fatty-acid composition (FAC) traits and to evaluate the accuracy of genomic predictions (GPs) for those traits using genomic best linear unbiased prediction (GBLUP), pedigree BLUP (PBLUP), and BayesR models. Samples of the longissimus dorsi muscle of 965 thirty-month-old Hanwoo steers (progeny of 73 proven bulls) were used to investigate 14 FAC traits. Animals were genotyped or imputed using two bovine SNP platforms (50K and 777K), and after quality control, 38,715 (50K) and 633,448 (777K) SNPs were subjected to GWAS and GP study using a cross-validation scheme. SNP-based heritability estimates were moderate to high (0.25 to 0.47) for all studied traits, with some exceptions for polyunsaturated fatty acids. Association analysis revealed that 19 SNPs in BTA19 (98.7 kb) were significantly associated (P < 7.89 × 10-8) with C14:0 and C18:1n-9; these SNPs were in the fatty-acid synthase (FASN) and coiled-coil domain-containing 57 (CCDC57) genes. BayesR analysis revealed that 0.41 to 0.78% of the total SNPs (n = 2,571 to 4,904) explained almost all of the genetic variance; the majority of the SNPs (>99%) had negligible effects, suggesting that the FAC traits were polygenic. Genome partitioning analysis indicated mostly nonlinear and weak correlations between the variance explained by each chromosome and its length, which also reflected the considerable contributions of relatively few genes. The prediction accuracy of breeding values for FAC traits varied from low to high (0.25 to 0.57); the estimates using the GBLUP and BayesR methods were superior to those obtained by the PBLUP method. The BayesR method performed similarly to GBLUP for most of the studied traits but substantially better for those traits that were controlled by SNPs with large effects; this was supported by the GWAS results. In addition, the predictive abilities of the 50K and 777K SNP arrays were almost similar; thus, both are suitable for GP in Hanwoo cattle. In conclusion, this study provides important insight into the genetic architecture and predictive ability of FAC traits in Hanwoo cattle. Our findings could be used in selection and breeding programs to promote production of meat with enhanced nutritional value.

Effects of reductive acetogenic bacteria and lauric acid on in vivo ruminal fermentation, microbial populations, and methane mitigation in Hanwoo steers in South Korea.

Animal science nutrition studies are increasingly focusing on finding solutions to reduce methane (CH4) emissions. In the present study, we evaluated the effect of reductive acetogenic bacteria [acetogen probiotics (AP)] and lauric acid (LA) on in vivo rumen fermentation and microbial populations in Hanwoo steers. Four cannulated Hanwoo steers (392 ± 14 kg) were analyzed in a 4 × 4 Latin square design and were placed in hood-type chambers. They were fed similar amounts of concentrate and rice straw within and experimental design as follows: control (Con; 40 g DM basal feed, nonaddition of AP or LA), T1 = LA (40 g DM basal feed mixed with 40 g LA), T2 = AP (40 g DM basal feed, fermented with AP), and T3 = LA + AP (40 g DM basal feed, fermented with AP and mixed with 40 g LA). The animals were acclimatized to the diet for 15 d, followed by 6 d of the experimental period. Rumen fluid samples for metabolite and molecular analyses were collected 6 h after the morning feeding, with 2-h collection intervals. The enteric CH4 production was monitored on the last 2 d of the experimental period. Concentrations of total volatile fatty acids increased with the increase in time after feeding. Acetate, propionate, and butyrate concentrations were observed to be higher in the treatments than in Con. The addition of LA and AP reduced CH4 emission compared with that of Con (P < 0.01). Nuclear magnetic resonance spectroscopy results revealed no correlation between the LA and Con groups, but AP showed a correlation with LA and Con. Reduction in the number of protozoa which was accompanied by a decrease, because methanogens live symbiotically with protozoa. Supplementation of AP or LA alone and in combination decreased (P < 0.05) the methanogen population, whereas supplementation of LA alone significantly increased (P < 0.05) Ruminococcus flavefaciens and slightly increased total fungi. Thus, dietary supplementation of LA and AP has inhibitory effects on CH4 production in Hanwoo cattle. If the effects of this method can be maintained, reductive acetogens could become an important part of strategies to lower ruminant CH4 emissions.

Mechanical texture profile of Hanwoo muscles as a function of heating temperatures

BackgroundCooking temperature and consequently doneness of beef muscles are most important for the palatability and consumer acceptability. Current study assessed the response of mechanical texture of Hanwoo muscles as a function of cooking temperature at different ageing days. Six muscles (Psoas major (PM), Longissimus thoracics (LT), Gluteus medius (GM), Semimembranosus (SM), Biceps femoris (BF) and Triceps brachii (TB)) were collected from each 10 Hanwoo steers. Warner-Bratzler WB-shear force (WBSF) and texture profile analysis (TPA) texture profiles were determined after 3 or 21 days of chiller, and randomly assigned to four groups; non-cooked, cooked at 55, 70 or 85 °C.ResultsToughness of WBSF and TPA hardness of Hanwoo muscles were presence in the order of LT = PM = GM = SM < BF = TB (p < 0.001) for non-cooked raw muscle, and PM < LT = GM = SM < TB=BF (p < 0.001) for cooked meat aged for 3 days. WBSF linearly increased in 3 days aged meats after cooked at a higher temperature (P < 0.05). On the other hand, toughening of the muscles were significantly (P < 0.05) differed at various temperature when muscles were aged for 21 days. WBSF of PM and LT muscles were significantly increased at a higher cooking temperature, while other muscles (i.e., GM, SM, BF, TB) showed the lowest values at 70 °C. In the case of TPA hardness, the effect of cooking temperature was very less in the toughness of the muscle (P > 0.05).ConclusionTaken together, these findings clearly showed that the toughness of the muscle highly depends and varies upon the temperature and ageing of the muscle. Moreover, the effect of cooking temperature was very limited on aged muscles. The results mirror the importance of cooking temperature for objective measurements which ultimately estimate sensory tenderness and other quality traits.

Effects of reductive acetogenic bacteria and lauric acid on in vivo ruminal fermentation, microbial populations, and methane mitigation in Hanwoo steers in South Korea.

Animal science nutrition studies are increasingly focusing on finding solutions to reduce methane (CH4) emissions. In the present study, we evaluated the effect of reductive acetogenic bacteria [acetogen probiotics (AP)] and lauric acid (LA) on in vivo rumen fermentation and microbial populations in Hanwoo steers. Four cannulated Hanwoo steers (392 ± 14 kg) were analyzed in a 4 × 4 Latin square design and were placed in hood-type chambers. They were fed similar amounts of concentrate and rice straw within and experimental design as follows: control (Con; 40 g DM basal feed, nonaddition of AP or LA), T1 = LA (40 g DM basal feed mixed with 40 g LA), T2 = AP (40 g DM basal feed, fermented with AP), and T3 = LA + AP (40 g DM basal feed, fermented with AP and mixed with 40 g LA). The animals were acclimatized to the diet for 15 d, followed by 6 d of the experimental period. Rumen fluid samples for metabolite and molecular analyses were collected 6 h after the morning feeding, with 2-h collection intervals. The enteric CH4 production was monitored on the last 2 d of the experimental period. Concentrations of total volatile fatty acids increased with the increase in time after feeding. Acetate, propionate, and butyrate concentrations were observed to be higher in the treatments than in Con. The addition of LA and AP reduced CH4 emission compared with that of Con (P < 0.01). Nuclear magnetic resonance spectroscopy results revealed no correlation between the LA and Con groups, but AP showed a correlation with LA and Con. Reduction in the number of protozoa which was accompanied by a decrease, because methanogens live symbiotically with protozoa. Supplementation of AP or LA alone and in combination decreased (P < 0.05) the methanogen population, whereas supplementation of LA alone significantly increased (P < 0.05) Ruminococcus flavefaciens and slightly increased total fungi. Thus, dietary supplementation of LA and AP has inhibitory effects on CH4 production in Hanwoo cattle. If the effects of this method can be maintained, reductive acetogens could become an important part of strategies to lower ruminant CH4 emissions.

Effect of optimal sodium stearoyl-2-lactylate supplementation on growth performance and blood and carcass characteristics in Hanwoo steers during the early fattening period

ObjectiveThis study was conducted to evaluate the effect of different levels of total digestible nutrients (TDN) and sodium stearoyl-2-lactylate (SSL) supplementation on growth performance and blood and carcass characteristics in Hanwoo steers during the early fattening period.MethodsSixty Hanwoo steers (average body weight, 333±36.4 kg) were randomly allotted to 3 treatments, with twenty steers per treatment, and ten steers per pen with a size of 80 m2. Dietary treatments were as follows: CON, basal diet; treatment (TRT) 0.5, 0.5% down-spec of TDN with 0.1% SSL; TRT 1.0, 1.0% down-spec of TDN with 0.1% SSL.ResultsThe results demonstrated that average daily gain and feed efficiency increased with TRT 0.5 (0.85 kg and 11.68) vs CON (0.82 kg and 11.27) or TRT 1.0 (0.78 kg and 10.74), indicating that 0.1% SSL supplementation in the feed of early fattening steers may result in a saving of 0.5% TDN. No significant differences were observed amongst all treatments (p> 0.05) for blood metabolite concentration and blood corpuscle values, which were all within the normally accepted range for healthy steers.ConclusionOur study suggests that a TDN 0.5% down spec with 0.1% SSL supplemented feed may be effective and profitable for the early fattening period of Hanwoo steers without causing adverse effects.

Comparison of Marbling Fleck Characteristics and Objective Tenderness Parameters with Different Marbling Coarseness within Longissimus thoracis Muscle of High-marbled Hanwoo Steer.

It is important to understand how marbling traits and tenderness differ among beef steaks from the carcass grading site and other regions within the longissimus thoracis (LT) muscle, as these characteristics are closely associated with consumer acceptability and willingness to purchase. Thus, the aim of this study was to compare the marbling fleck traits and objective tenderness parameters in the groups classified by the coarseness index (CI) of marbling fleck (high and low groups) at the carcass grading site (13th thoracic vertebra; 13T) and three different locations (13T, 9T, and 6T) within the LT muscle from well-marbled (marbling score 7 to 9) Hanwoo steer. Image analysis showed that the longitudinal locations had a significant effect on marbling fleck traits. The total area of large marbling fleck divided by the total marbling area (coarseness) was higher at the central region (13T to 12T) compared to the front thoracic region (6T to 5T) in the high CI group (0.23 vs. 0.17, p<0.05), whereas no significant differences were observed in the total number of marbling fleck within the LT muscle in the high or low CI groups (p>0.05). Location effect on objective tenderness parameters within the LT muscle was somewhat limited, although the high CI group had a lower Warner-Bratzler shear force (WBS) value than did the low group (p<0.05). Taken together, the degree of coarseness of marbling fleck decreased from the carcass grading site to the front thoracic site, whereas the objective tenderness parameters, including WBS and hardness, of the grading site did not differ from the other regions within the LT muscle.

Effect of Supplementation Levels of Copra and Palm Meal on Growth Performance and Carcass Characteristics of Hanwoo Steers

Effect of Supplementation Levels of Copra and Palm Meal on Growth Performance and Carcass Characteristics of Hanwoo Steers

Functional Partitioning of Genomic Variance and Genome-Wide Association Study for Carcass Traits in Korean Hanwoo Cattle Using Imputed Sequence Level SNP Data

Quantitative traits are usually controlled by numerous genomic variants with small individual effects, and variances associated with those traits are explained in a continuous manner. However, the relative contributions of genomic regions to observed genetic variations have not been well explored using sequence level single nucleotide polymorphism (SNP) information. Here, imputed sequence level SNP data (11,278,153 SNPs) of 2109 Hanwoo steers (Korean native cattle) were partitioned according to functional annotation, chromosome, and minor allele frequency (MAF). Genomic relationship matrices (GRMs) were constructed for each classified region and fitted in the model both separately and together for carcass weight (CWT), eye muscle area (EMA), backfat thickness (BFT), and marbling score (MS) traits. A genome-wide association study (GWAS) was performed to identify significantly associated variants in genic and exon regions using a linear mixed model, and the genetic contribution of each exonic SNP was determined using a Bayesian mixture model. Considering all SNPs together, the heritability estimates for CWT, EMA, BFT, and MS were 0.57 ± 0.05, 0.46 ± 0.05, 0.45 ± 0.05, and 0.49 ± 0.05, respectively, which reflected substantial genomic contributions. Joint analysis revealed that the variance explained by each chromosome was proportional to its physical length with weak linear relationships for all traits. Moreover, genomic variances explained by functional category and MAF class differed greatly among the traits studied in joint analysis. For example, exon regions had larger contributions for BFT (0.13 ± 0.08) and MS (0.22 ± 0.08), whereas intron and intergenic regions explained most of the total genomic variances for CWT and EMA (0.22 ± 0.09–0.32 ± 0.11). Considering different functional classes of exon regions and the per SNP contribution revealed the largest proportion of genetic variance was attributable to synonymous variants. GWAS detected 206 and 27 SNPs in genic and exon regions, respectively, on BTA4, BTA6, and BTA14 that were significantly associated with CWT and EMA. These SNPs were harbored by 31 candidate genes, among which TOX, FAM184B, PPARGC1A, PRKDC, LCORL, and COL1A2 were noteworthy. BayesR analysis found that most SNPs (>93%) had very small effects and the 4.02–6.92% that had larger effects (10-4 × , 10-3 × , and 10-2 × ) explained most of the total genetic variance, confirming polygenic components of the traits studied.

Comparison and estimation of the growth curve models of Hanwoo steer (Bos taurus coreanae)

The present study was conducted to estimate and compare the three types of growth models in Hanwoo steer (Bos aurus coreanae). The Gompertz, Von Bertalanffy, and Logistic nonlinear models were used. A total of 2,239 Hanwoo steers (Bos taurus coreanae) from 6 months to 24 months old (2003 to 2014) and 8,916 growth data from the Hanwoo improvement Center were used to estimate the growth model which included three parameters. These parameters were A, mature body weight; b, growth ratio; and k, intrinsic growth rate. Regression equations using the Gompertz, Von Bertalanffy, and Logistic models were calculated as respectively. The mean square errors (MSEs) for each model were 1945.9, 1958.7, and 1935.0, respectively. The equation using the Logistic model showed the lowest value among three models. The estimated birth weights from the Gompertz, Von Bertalanffy, and Logistic models were 50.35 kg, 36.94 kg, and 74.13 kg, respectively. Furthermore, the estimated mature weights from the Gompertz, Von Bertalanffy, and Logistic models were 919.0 kg, 1043.3 kg, and 770.0 kg, respectively. In addition, the estimated age and body weight at inflection from the Gompertz, Von Bertalanffy, and Logistic models were 349.0 days and 338.1 kg, 317.9 days and 308.2 kg, and 397.8 days and 385.0 kg, respectively. Based on the results, we concluded that the regression equation using the Logistic model was the most appropriate among the growth models for measuring data. However, further studies would be needed in order to obtain more accurate parameters using a much wider period of data from birth to shipping age.

Investigation of blood biomarkers related to meat quality and quantity in Hanwoo steers.

ObjectiveThis study was conducted to investigate the correlation between blood components and carcass traits, and to find the biomarkers related to meat quality and quantity in Hanwoo steers.MethodsOne hundred twenty-six Hanwoo steers (8 to 9 months of age, body weight of 185.6±24.38 kg) were used to find the correlation between blood compositions and carcass traits. The steers were fed concentrate and rice straw (30 steers) or total mixed rations (96 steers) during the whole experimental period. Blood samples were collected from the jugular vein at the growing (8 to 12 months), fattening (13 to 23 months) and finishing phases (24 to 30 months). Steers were slaughtered at 30 to 31 months of age (body weight of 701.6±60.45 kg) and the carcass traits were evaluated. Blood metabolites and hormones were analyzed and the correlation coefficients and regression equations with carcass traits were determined.ResultsAverage concentrations of retinol, leptin and insulin were 1.10 IU, 30.34 ng, and 35.35 ng per mL of blood plasma, respectively. Retinol has negative correlations (p<0.01) with insulin and leptin. Blood insulin and total protein decreased with the age of steers, but retinol, aspartic acid transaminase (AST), glucose, cholesterol and triglyceride increased. In the finishing phase, significant (p<0.01) negative correlations occurred between blood retinol content and marbling score, and between blood AST content and longissimus muscle area of 13th rib, and the following regression equations were obtained: Marbling score (1–9) = −0.009×retinol (IU/100 mL)+ 9.125 (R2 = 0.643), Longissimus muscle area (cm2) = −0.250× AST(U/L)+112.498 (R2 = 0.450).ConclusionIt is possible to make highly marbled beef by controlling the blood retinol content during the fattening and finishing phases of Hanwoo steers. Accordingly, blood retinol and AST could be biomarkers for determining beef quality and quantity, respectively, prior to slaughter.

Carcass Characteristics and Primal Cuts Yields by Live Weight of Hanwoo Steers in Gyeongbuk Province

Carcass Characteristics and Primal Cuts Yields by Live Weight of Hanwoo Steers in Gyeongbuk Province

Comparison of meat quality, fatty acid composition and aroma volatiles of Chikso and Hanwoo beef.

ObjectiveAlthough Hanwoo has been selected as the superior commercial beef cattle breed in Korea, Chikso (Korean brindle cattle) is still recognized as a valuable breed for beef production. The aim of this study was to compare the meat quality, fatty acid composition and aroma volatiles of beef from Chikso and Hanwoo steers maintained under identical feed management, as information regarding these characteristics is still limited.MethodsA total of 19 carcasses with a quality grade of 1 were selected, and strip loin (longissimus lumborum) cuts were collected from 11 Hanwoo carcasses and 8 Chikso carcasses. Meat quality and aroma analyses were performed at day four postmortem.ResultsThough Hanwoo strip loin tended to have higher fat content (15.37%) than Chikso (12.01%), no significant differences were observed. Meat pH, water-holding capacity, cooking loss, shear force value, instrumental surface color (Commission International De L’eclairage L*, a*, b*, chroma, and hue angle) and fatty acid composition were not significantly different. Roasted Chikso beef released more intense aroma than roasted Hanwoo beef based on the total area units of identified volatiles. Among identified volatiles, the amounts of toluene, heptanal, octanal, and nonanal were higher in roasted Chikso beef than in roasted Hanwoo beef. In addition, the aroma pattern of the roasted beef from these breeds was well-discriminated by electronic nose.ConclusionNo distinct differences were found in terms of meat quality between Hanwoo and Chikso beef in this study. However, the aroma pattern and volatiles of roasted Hanwoo and Chikso beef were different according to instrumental analysis.

In vitro and in vivo evaluation of kenaf (Hibiscus cannabinus L.) as a roughage source for beef cattle.

ObjectiveThe goal of this study was to evaluate kenaf as a roughage source in vitro and its effects on meat quality of Hanwoo (Korean native) cattle.MethodsThree roughage materials, rice straw silage, ryegrass silage, and kenaf silage, were tested in a batch culture and feeding trial. Rumen fermentation parameters, including gas, pH, volatile fatty acid (VFA), and ammonia were analyzed. In the feeding trial, Hanwoo steers (373.5±5.1 kg, n = 36, 11 month of age) were divided into three feeding groups (n = 12 each). Animals were fed with each silage and concentrate until the fattening stage.ResultsCrude protein, ether extract, and non-structural carbohydrates were greater in kenaf silage. Total gas production was higher in ryegrass silage, followed by kenaf silage and rice straw silage (p<0.05). Total VFA and individual VFA (acetate, propionate, and n-butyrate) were greater in kenaf silage than rice straw silage (p<0.05). In vitro dry matter digestibility showed a similar trend to that of total gas and VFA production; it was higher in ryegrass silage and lower in rice straw (p<0.05). Throughout the feeding trial, the rice straw silage group showed significantly greater average daily gain than did the others (p<0.05). The feed conversion ratio in the group fed kenaf silage was significantly greater than that of others (p<0.05). No significant differences were observed in yield or quality traits, including carcass weight, ribeye area, backfat thickness, and scores for marbling, meat color, and fat color (p>0.05).ConclusionThe results indicated that no negative effects on growth performance and carcass characteristics occurred across treatments. Therefore, kenaf could be substituted for rice straw, which is most widely used as a roughage source in Korea.

Estimates of genetic parameters for fatty acid compositions in the longissimus dorsi muscle of Hanwoo cattle

We estimated the heritabilities (h2) and genetic and phenotypic correlations among individual and groups of fatty acids, as well as their correlations with six important carcass and meat-quality traits in Korean Hanwoo cattle. Meat samples were collected from the longissimus dorsi muscles of 1000 Hanwoo steers that were 30-month-old (progeny of 85 proven Hanwoo bulls) to determine intramuscular fatty acid profiles. Phenotypic data on carcass weight (CWT), eye muscle area (EMA), back fat thickness (BFT), marbling score (MS), Warner–Bratzler shear force (WBSF) and intramuscular fat content (IMF) were also investigated using this half-sib population. Variance and covari.ance components were estimated using restricted maximum likelihood procedures under univariate and pairwise bivariate animal models. Oleic acid (C18:1n-9) was the most abundant fatty acid, accounting for 50.69% of all investigated fatty acids, followed by palmitic (C16:0; 27.33%) and stearic acid (C18:0; 10.96%). The contents of saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) were 41.64%, 56.24% and 2.10%, respectively, and the MUFA/SFA ratio, PUFA/SFA ratio, desaturation index (DI) and elongation index (EI) were 1.36, 0.05, 0.59 and 0.66, respectively. The h2 estimates for individual fatty acids ranged from very low to high (0.03±0.14 to 0.63±0.14). The h2 estimates for SFAs, MUFAs, PUFAs, DI and EI were 0.53±0.14, 0.49±0.14, 0.23±0.10, 0.51±0.13 and 0.53±0.13, respectively. The genetic and phenotypic correlations among individual fatty acids and fatty acid classes varied widely (−0.99 to 0.99). Notably, C18:1n-9 had favourable (negative) genetic correlations with two detrimental fatty acids, C14:0 (−0.76) and C16:0 (−0.92). Genetic correlations of individual and group fatty acids with CWT, EMA, BFT, MS, WBSF and IMF ranged from low to moderate (both positive and negative) with the exception of low-concentration PUFAs. Low or near-zero phenotypic correlations reflected potential non-genetic contributions. This study provides insights on genetic variability and correlations among intramuscular fatty acids as well as correlations between fatty acids and carcass and meat-quality traits, which could be used in Hanwoo breeding programmes to improve fatty acid compositions in meat.

Nutrient requirement for maintenance and nutritional changes of the Hanwoo steers in early-fattening stage under heat stress

Nutrient requirement for maintenance and nutritional changes of the Hanwoo steers in early-fattening stage under heat stress

Effect of fermented total mixed rations on the growth performance, carcass and meat quality characteristics of Hanwoo steers.

This study was conducted to assess the effects of fermented total mixed ration (FTMR) on the growth performance, carcass and meat quality traits of Hanwoo steers. The present study evidenced that the FTMR had a strong effect on dry matter intake, body weight, daily gain, slaughter weight and carcass characteristics compared with control animals. The results showed that the dry matter intake (7.17±0.13kg), average body weight (615.20±112.82kg), and daily gain (0.56±0.16kg) were greater in animals receiving FTMR than in control animals (P<0.05). The meat quality characteristics indicated that cooking loss and the pH values did not vary between control and FTMR treated animals; however, animals in the treated groups (FTMR) had higher meat quality grades, carcass weight (396.13±18.35), fat thickness (13.25±1.75), marbling score (5.63±0.56), meat color (40.06±1.23), crude fat (18.39±1.32) and sensory characteristics (flavor 5.03±0.17; tenderness 4.42±0.33; juiciness 5.10±0.16). Nevertheless, the shear force values decreased significantly in FTMR-treated animals compared with control group steers. Overall, FTMR may not only improve the growth performance, biochemical metabolites, and fatty and acetic acid profiles of steers, but may also enhance the carcass and meat quality characteristics of Hanwoo steers. Regarding economics, our research findings suggest that FTMR-based feeds may enhance Hanwoo steer meat quality at a low cost.