Acid Composition Of Longissimus Muscle Research Articles

Effect of Rumen Protected Methionine and α-Tocopherol on Growth Performance, Carcass Characteristics, and Meat Composition of Late Fattening Hanwoo Steer in High-Temperature Seasons

Simple SummaryOver the past 100 years, the average temperature in Korea has risen by 1.8 ℃, more than double the world average (0.75 ℃). High temperatures in summer can cause a decrease in feed intake, body weight gain, rumen mobility, and liver function. This study was conducted to investigate the effects of rumen-protected methionine and α-tocopherol (RPMT) on the growth performance, carcass characteristics, and meat composition of late fattening Hanwoo steers in high-temperature seasons. In this study, supplementations with RPMT are considered to be beneficial to average daily gain, feed conversion ratio, and Commission Internationale de l’Eclairage color stability without adversely affecting the feed intake of the late fattening Hanwoo steers in high-temperature seasons. Thus, supplementations of RPMT has desirable effects on the performance traits in beef cattle and prevents oxidation of longissimus muscle. Henceforward, further studies with more animals and increase the mounts of addition are needed.This study was conducted to investigate the effects of rumen-protected methionine and α-tocopherol (RPMT) on growth performance, carcass characteristics, and meat composition of late fattening Hanwoo steers in high-temperature seasons. Fourteen steers were randomly assigned to one of two diets; control (commercial concentrate) and treatment (commercial concentrate + 20 g of RPMT). Average daily gain was 34% higher in the treatment group than in the control group; however, there was no significant difference due to the small number under investigation. Feed conversion ratio was lower in the treatment group than in the control group (p < 0.05). Supplementation of RPMT had little effect on the fatty acid composition of longissimus muscle. Metmyoglobin in the longissimus muscle was significantly lower in treatment group compared to the control group at the ninth day of storage (p < 0.05). The redness of the longissimus muscle was higher in the treatment group than in the control group on day 9 of storage (p < 0.01). Thus, the results suggest that RPMT have positive effects on growth performance, and Commission Internationale de l’Eclairage color stability in the longissimus muscle of late fattening Hanwoo steers in high-temperature seasons.

Effect of Ferulago angulata (Chavil) essential oil supplementation on lamb growth performance and meat quality characteristics

This study investigated the effects of Ferulago angulata essential oil (FAE) dietary supplementation on growth performance, meat quality characteristics and fatty acid composition of longissimus muscle (LM) in fattening lambs. Forty male lambs with an initial body weight of 23.08 ± 1.8 kg were used in a completely randomized design for a 90-day feeding period. Experimental treatments included: 1- control diet (without essential oil; 0FAE), 2- diet supplemented with 250 mg kg DM FAE (250FAE), 3- diet supplemented with 500 mg kg DM FAE (500FAE) and 4- diet supplemented with 750 mg kg DM FAE (750FAE). Daily weight gains, final body weight and dry matter intake (DMI) decreased linearly. The hot carcass weight, dressing percentage, and feed conversion ratio were not affected. Digestibility of nutrients decreased linearly. The lowest digestibility of nutrients and DMI was observed for 750 FAE. A trend to the lower concentration of ammonia and total VFA occurred with increased content of FAE in the diet. Including FAE did not affect ruminal pH. The physical parameters and chemical composition of meat were not influenced by the treatment. The TBARS value of LM in lambs given the FAE supplementation decreased linearly than control. The supplements increased the concentrations of PUFA and decreased SFA contents in meat linearly. Lambs that used diets containing FAE had the lower n-6: n-3 fatty acid ratio than control treatment. Our findings indicate that FAE (up to 750 ml/kg DM) can be used in diets without adverse effect on physical parameters and chemical composition of meat and it enhanced the anti-oxidative status of lamb’s meat. However, further research is required to determine the effect of higher levels of FAE (more than 500 ml/kg DM) on the ruminal fermentation, diet digestibility and growth performance of lambs.

Inoculation of corn silage with Lactobacillus plantarum and Bacillus subtilis associated with amylolytic enzyme supply at feeding. 2. Growth performance and carcass and meat traits of lambs

The objective of this research was to investigate the effects of inoculation of corn silage and dietary supplementation of amylolytic enzymes, and their interaction, on lamb growth performance and carcass and meat traits. Whole-crop corn forage was treated either with water (untreated) or with Lactobacillus plantarum MA 18/5U at 1 × 105 cfu/g fresh forage combined with Bacillus subtilis AT553098 at 1 × 105 cfu/g fresh forage (inoculated) and ensiled for 170 d. Forty non-castrated Texel × Dorper male lambs were arranged in a randomized block design (n = 10) and then assigned to one of four diets, as follows: 1) untreated corn silage with no amylolytic enzyme supply (NI-NA); 2) untreated corn silage with amylolytic enzyme supply (NI-WA); 3) inoculated corn silage with no amylolytic enzyme supply (WI-NA); and 4) inoculated corn silage with amylolytic enzyme supply (WI-WA). α-Amylase (602 dextrinizing units/kg of dry matter (DM)) was supplied to the lambs at total mixed ration delivery. Inoculation of corn silage increased (P = 0.003) both digestible energy (DE) and metabolizable energy (ME) intake by 1.4 and 1.2 MJ/kg DM, respectively, and also resulted in higher average daily gain (ADG; P = 0.023) of lambs (233 vs. 212 g/d in lambs fed NI diet). In contrast, dietary supplementation with amylolytic enzymes had no effect on the DM intake (P = 0.90) or ADG (P = 0.15) of lambs. Moreover, inoculation, enzyme supplementation, and their interaction had no significant effects on carcass traits (P ≥ 0.06), commercial cut yield (P ≥ 0.26), chemical composition of meat (P ≥ 0.13), and meat tenderness and color (P ≥ 0.11). In terms of the fatty acid composition of longissimus muscle, inoculation of corn silage increased concentrations of saturated fatty acids (SFA; P = 0.035) from 46.2% to 47.6%, and reduced concentrations of unsaturated fatty acids (UFA; P = 0.035) from 53.8% to 52.5%, compared to the NI diet. Inoculation also reduced the UFA:SFA ratio (P = 0.031) from 1.17 to 1.11, a small but significant difference. Dietary supplementation with amylolytic enzymes did not alter (P ≥ 0.09) SFA, UFA, and polyunsaturated fatty acid concentrations, or their ratios. In conclusion, our results indicated that the silage inoculant examined in the present study is recommended for use in improving lamb production at the farm scale, whereas inclusion of amylolytic enzymes is not required under our experimental conditions.

Effects of an enriched housing environment on sensory aspects and fatty-acid composition of the longissimus muscle of light-weight finished lambs

We analysed the effect of enriched housing on the sensory meat quality and fatty acid composition of longissimus muscle in 60 entire Rasa Aragonesa lambs, housed indoors for 5weeks in six pens (10 lambs/pen, 0.95m2/lamb, initial weight 17.13±0.18kg and carcass mean 12.23±0.23kg); three control pens (barren) and three enriched pens (straw, platform with ramps and a small ramp). The final weight, carcass weight, fatness scores and cooking losses of meat from enriched lambs (EG) were higher and pH24 was lower (P≤0.05). The EG lambs had more C18:0 and total SFA (P≤0.05). Lamb odour and grass odour were more intense in EG (P≤0.05). Overall liking was higher for EG (P≤0.05) and associated with tenderness (P≤0.0001). The results suggest that environmental enrichment can have effects on fatty acid composition and sensory meat quality.

Effect of Inulin and Garlic Supplementation in Pig Diets / Efektywność dodatku inuliny i czosnku w żywieniu tuczników

Abstract The aim of the study was to determine the effect of supplementing inulin and inulin with garlic extract to pig diets on performance, carcass traits, blood metabolic profile and fatty acid composition of longissimus muscle. The experiment was carried out on 48 crossbred [(PL × PLW) × Duroc] fattening pigs with an initial body weight of 30.0 ± 0.5 kg, which were allocated to 3 groups: I (control), II (3% inulin) and III (3% inulin + 500 ml garlic extract added to 1000 l of drinking water). The pigs whose diets were supplemented with inulin or inulin and garlic achieved significantly (P≤0.05) higher daily weight gains compared to control. Supplemental inulin and water extract of garlic significantly (P≤0.05) lowered cholesterol content in blood and longissimus muscle. The highest level of omega-3 and omega-6 fatty acids was established in the longissimus muscle from pigs in group III.

Dietary n‐3 Fatty Acids Significantly Suppress Lipogenesis in Bovine Muscle and Adipose Tissue: A Functional Genomics Approach

Changes in fatty acid composition of longissimus muscle and subcutaneous adipose tissue of German Holstein bulls induced by a grass-silage/n-3 fatty acid based intervention diet versus a maize-silage/n-6 fatty acid based control diet were analyzed and related to shifts in lipogenic gene expression, protein expression, and enzyme activity patterns. Significantly higher amounts of n-3 fatty acids and by mean factors of 2.2-2.5 decreased n-6/n-3 fatty acid ratios in both tissues were obtained upon n-3 fatty acid intervention. In longissimus muscle, these changes of fatty acid profiles were associated with reduced SREBP1c (p=0.02), ACC (p=0.00), FAS (p=0.10) and SCD (p=0.03) gene expression, Δ6D (p=0.03) and SCD (p=0.03) protein expression as well as SCD enzyme activity (p=0.03). In subcutaneous adipose tissue, significantly reduced ACC (p=0.00) and FAS (p=0.01) gene expression, SCD protein expression (p=0.02) and SCD enzyme activity (p=0.03) were detected upon n-3 fatty acid intervention, although lower degrees of correlation between gene and corresponding gene products were obtained in relation to longissimus muscle. The study elucidates tissue-specific functional genomic responses to dietary fatty acid manipulation in regard to fatty acid profile tailoring of animal tissues.

Estimation of relationships between mineral concentration and fatty acid composition of longissimus muscle and beef palatability traits1

The objective of this study was to determine the influence of beef LM nutrient components on beef palatability traits and evaluate the impact of USDA quality grade on beef palatability. Longissimus muscle samples from related Angus cattle (n = 1,737) were obtained and fabricated into steaks for trained sensory panel, Warner-Bratzler shear force (WBSF), lipid oxidation measured by thiobarbituric acid reactive substances (TBARS), fatty acid, and mineral composition analysis. Pearson phenotypic correlations were obtained by the correlation procedure of SAS. Beef palatability data were analyzed by the GLM procedure of SAS with USDA quality grade as the main effect. Specific mineral concentrations did not demonstrate strong correlations with WBSF or sensory traits (r = -0.14 to 0.16). However, minerals appeared to have a stronger relationship with flavor; all minerals evaluated except Ca and Mn were positively correlated (P < 0.05) with beef flavor. Stearic acid (C18:0), C18:2, C20:4, and PUFA were negatively correlated (P < 0.05) with all 3 panelist tenderness traits (r = -0.09 to -0.22) and were positively correlated (P < 0.05) with WBSF (r = 0.09 to 0.15). The MUFA were positively correlated (P < 0.05) with panelist tenderness ratings (r = 0.07 to 0.10) and negatively associated (P < 0.05) with WBSF (r = -0.11). The strongest correlations with juiciness were negative relationships (P < 0.05) with C18:2, C18:3, C20:4, and PUFA (r = -0.08 to -0.20). Correlations with beef flavor were weak, but the strongest was a positive relationship with MUFA (r = 0.13). Quality grade affected (P < 0.05) WBSF, TBARS, and all trained sensory panel traits, except livery/metallic flavor. As quality grade increased, steaks were more tender (P < 0.05), as evidenced by both WBSF and sensory panel tenderness ratings. Prime steaks were rated juiciest (P < 0.05) by panelists, whereas Select and Low Choice were similarly rated below Top Choice for sustained juiciness. Quality grade influenced (P < 0.05) beef flavor, but not in a linear fashion. Although there were significant correlations, these results indicate tenderness, juiciness, and flavor are not strongly influenced by individual nutrient components in beef LM. Furthermore, the positive linear relationships between USDA quality grade and beef palatability traits suggest quality grade is still one of the most valuable tools available to predict beef tenderness.

Effects of Saururus chinensis extract supplementation on growth performance, meat quality and slurry noxious gas emission in finishing pigs

This study was conducted to evaluate the effects of dietary Saururus chinensis ( S. chinensis) extract supplementation on growth performance, nutrient digestibility, meat quality, longissimus muscle and subcutaneous adipose fatty acid composition and slurry noxious gas emission in finishing pigs. A total of 120 [(Landrace × Yorkshire) × Duroc] pigs (54.10 ± 2.13 kg) were randomly allocated into one of the following dietary treatments: 1) CON, basal diet; 2) S1, basal diet with 1 g/kg S. chinensis extract; 3) S2, basal diet with 2 g/kg S. chinensis extract. There were 10 replications per treatment with 4 pigs (2 gilts and 2 barrows) per pen. Throughout the experiment, no significant difference was observed in growth performance or nutrient digestibility among treatments. However, serum triglyceride and low-density lipoprotein (LDL) cholesterol concentrations as well as total cholesterol to high-density lipoprotein (HDL) cholesterol ratio were significantly decreased in pigs fed S2 diet (P < 0.05) compared with those fed diets without S. chinensis extract. Furthermore, the S. chinensis extract administration improved lightness (L*) value (P < 0.05) while having little effects on the fatty acid composition of longissimus muscle and subcutaneous adipose tissue. Providing S2 diet also decreased slurry concentrations of NH 3 (P < 0.05). Taken together, S. chinensis extract administration had only minor effects on finishing pigs with the exception of improving serum lipid protein profile and decreasing the emission of noxious gases from slurry.

Carcass characteristics, chemical and fatty acid composition of Longissimus muscle of Purunã bulls slaughtered at 18 or 24 months of age

This study was carried out to evaluate carcass characteristics, chemical and fatty acid composition of the Longissimus muscle of 78 Puruna bulls (39 bulls/treatment) slaughtered at 18 or 24 months old. The experimental design was completely randomized. The bulls were distributed into two systems: 1) Finished in feedlot 13 to 18 months old (T18), or 2) Finished in feedlot from 21 to 24 months old (T24). The diet, roughage:concentrate ratio of 52:48 (dry matter basis), contained 12% crude protein and 72% total digestible nutrients. The T18 system showed lower (p < 0.05) conformation (12.46 vs. 13.41 points), higher (p < 0.05) subcutaneous fat thickness (3.82 vs. 3.11 mm), lower (p < 0.05) Longissimus area (66.17 vs. 70.87 cm 2 ), lower (p < 0.05) muscle percentage (60.64 vs. 64.26%) and higher (p < 0.05) fat percentage (23.56 vs. 20.00%). Moisture (73.27%), ash (1.05%), crude protein percentages (22.56%) and total cholesterol content (36.47 mg/100 g of muscle) were similar (p < 0.05) between both slaughter ages. The total lipid percentage was higher (p < 0.05) for the T18 system (1.61 vs. 1.33%). Longissimus muscle fatty acid composition was not influenced (p < 0.05), with exception of C18:1 n-9 and C18:3 n-3, which were lower (p < 0.05) for the T18 system. Saturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, n-6, n-3 percentage and PUFA/SFA and n-6/n-3 ratio did not change (p < 0.05) according to slaughter age.

Intramuscular fat and fatty acid composition of longissimus muscle from divergent pure breeds of cattle

The objective of this study was to compare the fatty acid (FA) composition of intramuscular fat from the LM of 3 divergent breeds of cattle: Angus (AN, n = 9), Brahman (BR, n = 7), and Romosinuano (RM, n = 11). Cattle were blocked by breed and finished 129 d before slaughter in one year and 157 d in the next year. Longissimus muscle samples were collected from each carcass between the 10th and 13th ribs, trimmed of external fat, frozen in liquid nitrogen, homogenized, and used for fat extraction, using a modified Folch procedure. Extracted fat was analyzed for FA by using a GLC system with an HP-88 capillary column. Fatty acid composition was expressed using both a normalized percentage (%) and gravimetric calculation (mg/g of fresh muscle tissue) in relation to degree of saturation, which was determined using a saturation index (ratio of total SFA to total unsaturated FA). Crude fat determination revealed that LM from AN purebred cattle had the greatest amount of intramuscular fat (7.08%; P = 0.001). Although intramuscular fat of LM from RM contained a reduced percentage of total SFA (P = 0.002) compared with AN, it had the greatest percentage of total PUFA (P < 0.001 and P = 0.020). The percentages of total MUFA were similar among the 3 breeds (P = 0.675). The gravimetric calculation, a measure of actual FA concentration, showed significantly greater concentrations of SFA (26.67 mg/g), MUFA (26.50 mg/g), and PUFA (2.37 mg/g) in LM from AN cattle, as compared with LM from BR and RM cattle (P < 0.001). Interestingly, BR purebreds had the least PUFA concentration (1.49 mg/g; P <or= 0.001) in the LM, although their intramuscular fat content was similar to that of RM (P = 0.924). Regardless of breed, the MUFA proportion was always the greatest (47.58%; P <or= 0.005), whereas PUFA was the least contributor to FA composition (1.49 to 2.37 mg/g and 4.36 to 8.78%; P < 0.001). Beef LM fatty acid composition was characterized by palmitic and oleic acids being the most abundant FA (P < 0.001). These results suggested a genetic variation in FA synthesis and deposition among breeds that influenced both marbling and its composition.

Chemical and Fatty Acid Composition of Longissimus Muscle of Crossbred Bulls Finished in Feedlot

This work was carried out to study the chemical and fatty acid composition of Longissimus muscle (LM) of crossbred young bulls finished in a feedlot. After weaning (at 8 months old), the bulls were kept in a feedlot for 180 days. The bulls were kept in individual pens and fed (twice daily) with corn silage, soybean hulls, cracked corn, limestone, urea and mineral salt. The bulls were slaughtered with a final weight of 464 kg. Forty bulls were used: 10 Caracu (CAR), 10 Canchim (CAN), 10 Caracu vs. Charolais (CCH) and 10 Canchim vs. Aberdeen Angus (CAA). The percentages of moisture, ash, crude protein, total lipids, as well as the fatty acid composition, were measured in the LM. The moisture percentage was lower (p 0.05) among bulls from CAR, CAN and CCH genetic groups. Ash percentage was lower (p 0.05) among CAN, CCH and CAA genetic groups. Similarly, there was no difference (p>0.05) in crude protein among the different genetic groups. Total lipids percentage was higher (p 0.05) among genetic groups. PUFA/SFA ratio ranged from 0.10 to 0.15, with no difference (p>0.05) among genetic groups. Similarly, n-6/n-3 ratio ranged from 12.6 to 16.3, without difference (p>0.05) among genetic groups.

The effect of cooking on the fatty acid composition of longissimus muscle from beef heifers fed rations designed to increase the concentration of conjugated linoleic acid in tissue

Longissimus dorsi (LD) muscle from 60 Charolais crossbred heifers, aged for 14 days was used to investigate the effect of cooking on the content of PUFA and CLA fatty acids. Animals were offered a control diet of grass silage and concentrates (CO) or rations designed to enhance the concentration of CLA in tissue, i.e. unsupplemented grazed pasture (G), sunflower-oil supplemented grazing (SFG) or linseed-oil oil supplemented grazing (LSG). The SFG diet was the most effective for increasing the concentration of CLA but also caused the highest n−6/ n−3 fatty acid ratio. There were no changes in the relative distribution of fatty acids upon cooking (140 °C for 30 min) and this procedure can be recommended because it preserves the nutritional value of the meat. It is concluded that irrespective of the change in the fatty acid composition of LD due to alteration in the diet of the cattle, cooking did not cause thermal degradation of PUFA, or thermal degradation or oxidative synthesis of CLA.

Flavour differences of cooked longissimus muscle from Chinese indigenous pig breeds and hybrid pig breed (Duroc × Landrace × Large White)

The objectives of this study were to investigate the flavour quality and volatile aroma compounds of cooked longissimus muscle from five typical Chinese indigenous pig breeds: Lantang (LT), Dahuabai (HB), Laiwu (LW), Rongchang (RC), Tongcheng (TC) and typical hybrid pig breed Duroc × Landrace × Large White (DLW). The chemical compositions of the main meat flavour precursors of the longissimus muscle from all six breeds were also examined. Distinct differences in amino acid composition and fatty acid composition of longissimus muscle, between the breeds, were observed. Among all six breeds, LW and RC had the highest intramuscular fat content and the lowest crude protein content; DLW had the lowest longissimus muscle fat content and the highest crude protein content. One-way analysis of variance showed that 23 volatile compounds were significantly affected by breed. Sensory analysis indicated that cooked longissimus muscle from DLW had the lowest pork flavour intensity and flavour-liking, compared with the Chinese indigenous breeds. LW and HB showed the highest pork flavour intensity and flavour-liking in cooked longissimus muscle.

숙성온도와 기간이 한우 거세우 배최장근의 육질 특성에 미치는 영향

본 연구는 숙성온도와 숙성기간이 한우 거세우 배최장근의 육질 특성에 미치는 영향을 구명하고자 숙성온도를 0, <TEX>$4^{\circ}C$</TEX>로 하여 2, 7, 14, 21, 28, 49일 동안 숙성하면서 한우 거세우 배최장근의 pH, 전단력, MFI, 가열 및 육즙감량, 전자현미경 관찰, 관능검사 및 아미노산 조성을 분석하였다. pH는 숙성온도가 <TEX>$0^{\circ}C$</TEX>일 때 숙성 21일까지, 숙성온도가 <TEX>$4^{\circ}C$</TEX>일 때 숙성 14일까지 증가하다가 감소하였다(p<0.05). 전단력 값은 숙성 14일부터 28일까지 <TEX>$4^{\circ}C$</TEX>에서 숙성한 배최장근이 <TEX>$4^{\circ}C$</TEX>보다 유의적으로 낮았고, 숙성기간이 경과함에 따라 유의적으로 연도가 향상되었다(p<0.05). MFI의 경우 <TEX>$4^{\circ}C$</TEX>에서 숙성한 배최장근 보다 <TEX>$0^{\circ}C$</TEX>에서 높은 경향을 보였고, 숙성기간이 경과함에 따라 유의적으로 증가하였다(p<0.05). <TEX>$0^{\circ}C$</TEX>에서 숙성한 배최장근의 가열 및 육즙감량이 <TEX>$4^{\circ}C$</TEX>보다 적은 경향이었고, 숙성기간이 경과함에 따라 유의적으로 증가하였다(p<0.05). 관능검사에서 연도와 다즙성은 <TEX>$0^{\circ}C$</TEX>에서 숙성한 배최장근이 <TEX>$4^{\circ}C$</TEX> 보다 좋은 평가를 보였고, 숙성기간이 경과하면서 유의적으로 높은 평가를 얻었다(p<0.05). 전자현미경에 의한 미세구조 변화는 <TEX>$4^{\circ}C$</TEX>에서 숙성한 배최장근이 <TEX>$0^{\circ}C$</TEX>보다 1주일 빠르게 Z-disk의 붕괴가 확실하게 관찰되었고, 숙성기간이 경과하면서 Z-disk의 붕괴정도가 많아졌다. 아미노산 함량 변화는 <TEX>$4^{\circ}C$</TEX>에서 숙성한 배최장근이 <TEX>$0^{\circ}C$</TEX>보다 높은 경향이었고, 숙성기간이 경과하면서 각 아미노산 조성의 함량이 유의적으로 증가하였다(p<0.05). 이상의 결과를 종합하면, 한우 거세우 등심의 최적 숙성 조건은 <TEX>$0^{\circ}C$</TEX>에서는 14일간, <TEX>$4^{\circ}C$</TEX>에서는 7일간 숙성하는 것이 바람직한 것으로 사료되며, 향후 숙성기술의 산업적 적용을 위하여 한우의 부위 및 근육별 적정 숙성기간 설정 연구가 필요할 것으로 생각된다. This study was conducted to investigate the effect of ageing temperature(0 and <TEX>$4^{\circ}C$</TEX>) and time(2, 7, 14, 21, 28, and 49 days) on the meat quality of longissimus muscle from Hanwoo steer. The pH, Warner-Bratzler shear force(WBSF), myofibrillar fragmentation index(MFI), cooking and purge loss, sensory, morphological changes, and amino acid composition were assessed. The pH of longissimus muscle increased significantly(p<0.05) for 21 days at <TEX>$0^{\circ}C$</TEX> and 14 days at <TEX>$4^{\circ}C$</TEX>, but decreased thereafter. Longissimus muscle aged from 14 days to 28 days at <TEX>$4^{\circ}C$</TEX> had a lower WBSF than longissimus muscle aged at <TEX>$0^{\circ}C$</TEX>(p<0.05). The WBSF of longissimus muscle decreased significantly(p<0.05) with ageing time. The MFI, cooking and purge loss, tenderness, and juiciness scores were higher for longissimus muscle aged at <TEX>$4^{\circ}C$</TEX> than at <TEX>$0^{\circ}C$</TEX>. As ageing time increased, the MFI, cooking and purge loss, tenderness, juiciness, and amino acid composition of longissimus muscle increased significantly(p<0.05) with ageing at 0 or <TEX>$4^{\circ}C$</TEX>. Transmission electron microscopy showed Z-disk degradation and morphological changes of the myofibrils correlating with increased tenderness during the ageing time. Based on these results, the proper ageing conditions of longissimus muscle of Hanwoo steer were 14 days of ageing at <TEX>$0^{\circ}C$</TEX> or 7 days of ageing at <TEX>$4^{\circ}C$</TEX>. However, further study on the application of ageing technology to this industry is necessary for the optimization of ageing conditions for the sub-primals or muscles from Hanwoo beef.

Fish Oil의 첨가가 한우 거세우의 육성성적, 배최장근의 지방산 조성 및 도체특성에 미치는 영향

본 연구는 fish oil의 첨가가 한우거세우의 증체, 배최장근의 지방산 조성 및 도체등급에 미치는 영향을 구명하고자 평균체중 440.8±32.4kg의 한우거세우 20두를 공시하여 실시하였다. 시험구 배치는 fish oil을 첨가하지 않는 FO-0구와 fish oil을 3% 첨가하는 FO-3구의 2처리로 하였다. 총 증체량과 일당증체량은 fish oil의 첨가에 관계없이 비슷한 결과를 보였다. Fish oil의 첨가는 배최장근의 단백질, 지방 및 회분 함량에 영향을 미치지 않았다. 배최장근의 isoleucine 및 glycine 함량은 fish oil의 첨가로 감소되었으나(p<0.05), cystein 함량은 증가되었다(p<0.05). Fish oil의 첨가는 배최장근의 myristic acid 및 eicosenoic acid 함량은 감소시켰으나(p<0.05), oleic acid 및 arachidonic acid 함량은 증가시켰다(p<0.05). 또한 배최장근의 EPA 및 DHA 함량은 fish oil의 첨가로 증가되었다(p<0.05). 도체중, 등지방두께, 배최장근단면적, 육량지수 및 육량등급은 fish oil의 첨가에 관계없이 두 처리구간에 유사한 경향을 보였다. 육색은 fish oil의 첨가로 개선되었으며 (p<0.05), 육질 1등급 이상 출현두수는 fish oil의 첨가로 증가하는 결과를 보였다. 따라서 본 연구의 결과에서 한우거세우에 대한 fish oil의 첨가는 쇠고기의 지방산 중에서 풍미 및 기호성에 관여하는 oleic acid 함량, 인간의 건강과 관련이 있는 EPA 및 DHA 함량 및 육질 1등급 이상 출현두수를 증가시키는데 효과적인 것으로 나타났다. Twenty Hanwoo steers (average body weight=440.8±32.4kg) were used to investigate the effects of fish oil supplementation on growth performance, fatty acid composition of longissimus muscle and carcass characteristics. The experiment was done with two treatment groups; FO-0, without fish oil and FO-3, supplemented with 3% fish oil. Total gain and average daily gain (ADG) of steers were similar between two groups. Fish oil supplementation had no effects on contents of protein, ether extract and ash in longissimus muscle. Contents of isoleucine and glycine in longissimus muscle were decreased by fish oil supplementation (p<0.05), but content of cystein was increased by fish oil supplementation (p<0.05). Fish oil supplementation decreased contents of myristic acid and eicosenoic acid in longissimus muscle (p<0.05), but increased contents of oleic acid and arachidonic acid in longissimus muscle (p<0.05). Contents of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in longissimus muscle were increased by fish oil supplementation p<0.05). Carcass weight, back fat thickness, rib-eye area, yield index and yield grade were similar between two groups. Meat color was improved by fish oil supplementation (p<0.05), Ratio of quality grade ‘1 or over’ increased by fish oil supplementation. Therefore, the present study indicating that fish oil supplementation had positive effects on content of oleic acids in relation to flavor of beef, contents of EPA and DHA in relation to human health and ratio of quality grade ‘1 or over’.

Effects of Copper and Zinc Source on Performance, Carcass Characteristics, and Lipid Metabolism in Finishing Steers

An experiment was conducted to determine the effects of Cu and Zn source on performance, trace mineral status, lipid metabolism, and carcass quality of finishing steers. In the study, 195 steers were blocked by origin, stratified by BW, and sorted into 24 pens. Pens within blocks were then randomly assigned to treatments in a 2 × 2 factorial arrangement. Factors were 10 mg of Cu/kg of dietary DM from CuSO4 or 10 mg of Cu/kg of dietary DM from organic Cu and 90 mg of Zn/kg of dietary DM from ZnSO4 or 36 mg of Zn/kg of dietary DM from organic Zn with 54 mg of Zn/kg of DM from ZnSO4. Steers were fed a high concentrate finishing diet until they reached an approximate BW of 580 kg. Diets were fed once daily in the morning to allow ad libitum access to feed throughout the day. Daily feed offerings were recorded and feed refusal was measured every 28 d. Body weights were recorded for each steer and blood samples were collected from 3 steers per pen every 28 d. Three weeks prior to slaughter, subcutaneous adipose tissue biopsies were taken from 1 steer per pen. Postharvest longissimus dorsi muscle samples were collected and evaluated for fatty acid composition. There were no Cu or Zn main effects or Cu × Zn interactions for ADG, DMI, or feed efficiency. The effect of Cu or Zn source was similar across treatments for hot carcass weight, dressing percent, rib eye area, subcutaneous fat thickness, kidney, pelvic, and heart fat, and marbling score. There was a Zn effect for calculated yield grade. Steers receiving organic Zn had a lesser (P = 0.03) calculated yield grade than steers receiving inorganic Zn. Serum cholesterol, plasma Cu and Zn concentrations, fatty acid composition of longissimus muscle and subcutaneous fatty acid synthase activity were similar across treatments. Results from this study indicate that trace mineral source had little influence on performance, carcass characteristics, and lipid metabolism.

Effect of a grass-based and a concentrate feeding system on meat quality characteristics and fatty acid composition of longissimus muscle in different cattle breeds

The objective of this study was to examine the effects of feeding system and breed on the content of the beneficial n-3 polyunsaturated fatty acids and conjugated linoleic acids (CLA) in beef muscle. German Simmental (GS) ( n=31) and German Holstein (GH) ( n=33) bulls were produced on either an indoor concentrate system or a grass-based system consisting of a period of summer pasture feeding followed by a winter indoor period on grass silage and a concentrate containing linseed. All animals were slaughtered at 620 kg. The grass-based system increased ( P<0.05) the percentage of n-3 fatty acids in the longissimus muscle lipids of bulls (GS 2.22 vs. 0.46%, GH 1.61 vs. 0.34%). The n-6 fatty acid proportions were not affected by the feeding system in GS and GH loin muscle. Therefore, the n-6 /n-3 ratio of grass-based GS bulls was 2.0 and of GH was 1.9 in contrast to 8.3 and 6.5 for bulls fed concentrates indoors. The grass-based system increased the percentage of C18:1 trans fatty acid isomers in both breeds. The percentage of CLA cis-9, trans-11 (0.87% vs. 0.72% in GS, 0.84% vs. 0.75% in GH) in muscle was significantly higher in animals on the grass-based system.

Effect of diet on the deposition of n-3 fatty acids, conjugated linoleic and C18:1trans fatty acid isomers in muscle lipids of German Holstein bulls.

This study examined the effects of feeding diets rich in either n-3 or n-6 polyunsaturated fatty acids (PUFA) on the fatty acid composition of longissimus muscle in beef bulls. Thirty-three German Holstein bulls were randomly allocated to either an indoor concentrate system or periods of pasture feeding (160 days) followed by a finishing period on a concentrate containing linseed to enhance the contents of n-3 PUFA and conjugated linoleic acids (CLA) in beef muscle. The relative proportion and concentration (mg/100 g fresh muscle) of n-3 fatty acids in the phospholipid and triglyceride fractions were significantly increased (p < or = 0.05) in muscle lipids of pasture-fed bulls. The pasture feeding affected the distribution of individual CLA isomers in the muscle lipids. The proportion of the most prominent isomer, CLA cis-9,trans-11, was decreased from 73.5 to 65.0% of total CLA in bulls fed on concentrate as compared to pasture. The second most abundant CLA isomers were CLA trans-7,cis-9 and CLA trans-11,cis-13 in bulls fed on concentrate and pasture, respectively. Diet had no effect on the concentration of C18:1 trans-11. In contrast, the concentration of the C18:1 trans-13/14, trans-15, and trans-16 isomers in the muscle lipids was up to two times higher in pasture-fed as compared to concentrate-fed bulls. Pasture feeding enhanced the concentration of n-3 fatty acids, but the diet had no effect on the concentration of CLA cis-9,trans-11.

Effect of finishing system (feedlot or pasture), high-oil maize, and copper on conjugated linoleic acid and other fatty acids in muscle of finishing steers

AbstractSixty Angus steers (413 ± 8.0 kg) were used to determine the effects of copper (Cu), maize type, and finishing system (confinement v. pasture) on performance, carcass characteristics, and fatty acid composition of longissimus muscle in steers. Steers in confinement were given individually high concentrate diets containing either typical or high-oil maize, using Calan gate feeders. Steers grazing pasture (tall fescue) were maintained in four pastures with each pasture containing five steers. Salt was used to limit concentrate intake in pasture steers to approximately 0.6 of that observed in confinement steers. One half of the steers in each treatment received a CuO needle bolus at the initiation of the study while the remaining steers received no supplemental Cu. Equal numbers of steers per treatment were harvested after 91, 112 or 133 days on food. Rate of gain was lower (P &lt; 0.01; 1.2 v. 1.6 kg/day) for pasture-fed steers compared with steers receiving typical maize. Cu supplementation increased (P &lt; 0.05) ADG in steers given typical maize (1.8 v. 1.5 kg/day) and those on pasture (1.3 v. 1.1 kg/day) but not in steers given high-oil maize diets (1.5 v. 1.5 kg/day). Gain, dry-matter intake and gain/food did not differ between steers given typical or high-oil maize. Plasma cholesterol concentrations were lower (P &lt; 0.01) in steers given typical maize relative to steers given high-oil maize. Steers receiving a Cu bolus had higher plasma (P &lt; 0.05) and liver (P &lt; 0.01) Cu concentrations than steers not receiving a Cu bolus. Steers receiving typical maize had lower (P &lt; 0.05) liver Cu concentrations than steers receiving high-oil maize. Steers finished on pasture with limited concentrate had conjugated linoleic acid (CLA) concentrations in longissimus muscle that were approximately three times higher (P &lt; 0.01) than steers given typical maize. Cu supplementation tended (P &lt; 0.10) to increase muscle CLA. Longissimus muscle from pasture-fed steers was lower (P &lt; 0.01) in C16: 0 and higher (P &lt; 0.05) in C10: 0, C17: 0, C18: 3, C20: 3 and total polyunsaturated fatty acids than steers given typical maize. Muscle C18: 1 trans and C17: 0 tended to be reduced (P &lt; 0.10) by Cu supplementation. These results indicate that finishing cattle on pasture with limited grain increases CLA in longissimus muscle and that Cu supplementation also alters the fatty acid composition of muscle.

Effect of Fish Oil Supplement on Growth Performance, Ruminal Metabolism and Fatty Acid Composition of Longissimus Muscle in Korean Cattle

We investigated the effect of fish oil (FOS) on growth performance, ruminal metabolism and fatty acid composition and physical characteristics of longissimus muscle in 10 steers and 10 bulls of Korean cattle. Concentrates diet was supplemented with FOS at 5% of the diet. FOS contained 3.34% eicosapentaenoic acid (EPA) and 24.87% docosahexaenoic acid (DHA) of total fatty acids by weight. Average daily weight gain and feed efficiency were not affected (p>0.871) by FOS, but feed intake was decreased. FOS had lower (p<0.003) pH and higher (p<0.001) NH3-N than that of control. There was a treatment effect (p<0.001) for serum cholesterol concentrations. FOS increased (p<0.009) concentrations of n-3 fatty acids, including linolenic, EPA and DHA in longissimus muscle. Physical traits were significantly (p<0.015) changed by feeding FOS except for pH and lightness (L). We concluded that the fatty acid composition and physical properties of the muscle in fattening Korean cattle can be altered by feeding 5% FOS. (Asian-Aust. J. Anim. Sci. 2002. Vol 15, No. 1 : 66-71)