Fat Content Of Longissimus Muscle Research Articles

Dietary copper supplementation modulates performance and lipid metabolism in meat goat kids

Forty-eight male Lezhi black goat kids with similar body weight ((12.09±1.70) kg) and age ((60±5) d) were used to determine the effect of dietary copper (Cu), in the form of reagent grade Cu sulfate (CuSO4·5H2O), on performance, serum lipid profile, and the relative mRNA abundance of genes involved in lipid metabolism. Goat kids were stratified by body weight and randomly assigned to one of 4 treatment groups. Each treatment consisted of 12 replicate pens with each pen containing one goat kid. Treatment groups received the basal diet with no supplemental Cu (control), basal diet plus 10 mg of Cu kg−1 of dry matter (DM), basal diet plus 20 mg of Cu kg−1 of DM, or basal diet plus 30 mg of Cu kg−1 of DM. Goats were housed individually in pens and fed a high-concentrate pelleted diet for 60 d. Average daily gain, average daily feed intake and feed:gain of goats were not affected by dietary Cu supplementation (P>0.10). No differences were detected in serum total cholesterol, triglyceride, and high density lipoprotein cholesterol concentrations of goat kids fed with different Cu concentrations (P>0.05). However, serum low density lipoprotein cholesterol concentrations decreased linearly (P=0.01) as the concentration of dietary Cu increased. Intramuscular fat content of longissimus muscle increased (P=0.002) quadratically and liver Cu concentrations increased (P<0.001) linearly as dietary Cu concentration increased. Compared with the control, dietary supplementation of 20 mg Cu kg−1 DM decreased the relative mRNA abundance of fatty acid-binding protein 4 (P=0.01) and lipoprotein lipase (P=0.05), and tended to decrease the relative mRNA abundance of carnitine palmitoyltransferase I (P=0.06) in longissimus muscle of goats. The relative mRNA abundance of peroxisome proliferator-activated receptor alpha (P<0.001), carnitine acetyltransferase (P=0.001), and carnitine palmitoyltransferase I (P=0.001) were also decreased in liver by Cu supplementation. These results indicate that dietary supplementation of Cu modified lipid metabolism by increasing muscular fat and decreasing serum low density lipoprotein cholesterol, and the modification might be associated with the reduction of relative mRNA abundance of genes for oxidation of long-chain fatty acid in muscle and liver of Lezhi black goat kids.

Accurate prediction and genome-wide association analysis of digital intramuscular fat content in longissimus muscle of pigs.

Intramuscular fat (IMF) content is a critical indicator of pork quality that affects directly the purchasing desire of consumers. However, to measure IMF content is both laborious and costly, preventing our understanding of its genetic determinants and improvement. In the present study, we constructed an accurate and fast image acquisition and analysis system, to extract and calculate the digital IMF content, the proportion of fat areas in the image (PFAI) of the longissimus muscle of 1709 animals from multiple pig populations. PFAI was highly significantly correlated with marbling scores (MS; 0.95, r2 =0.90), and also with IMF contents chemically defined for 80 samples (0.79, r2 =0.63; more accurate than direct analysis between IMF contents and MS). The processing time for one image is only 2.31s. Genome-wide association analysis on PFAI for all 1709 animals identified 14 suggestive significant SNPs and 1 genome-wide significant SNP. On MS, we identified nine suggestive significant SNPs, and seven of them were also identified in PFAI. Furthermore, the significance (-log P) values of the seven common SNPs are higher in PFAI than in MS. Novel candidate genes of biological importance for IMF content were also discovered. Our imaging systems developed for prediction of digital IMF content is closer to IMF measured by Soxhlet extraction and slightly more accurate than MS. It can achieve fast and high-throughput IMF phenotype, which can be used in improvement of pork quality.

Fat depot-specific effects of body fat distribution and adipocyte size on intramuscular fat accumulation in Wagyu cattle.

Ectopic fats have been recognized as a new risk factor for metabolic syndrome. In obese humans, ectopic fat accumulations are affected by body fat distribution. Intramuscular adipose tissue is categorized as one of the ectopic fats. Japanese black cattle (Wagyu) are characterized by the ability to accumulate high amounts of intramuscular adipose tissue. In Japan, the marbling level is indicated by the beef marbling standard number (BMS No.), which reflects the intramuscular fat content of longissimus muscle. We hypothesized that the intramuscular fat accumulation is affected by the body fat distribution in Wagyu cattle. In this study, we showed that the BMS No. was not correlated with the subcutaneous and visceral adipocyte diameter. In contrast, the BMS No. was positively correlated with intramuscular adipocyte diameter. These results indicate that the intramuscular adipocyte diameter of Wagyu is hypertrophied with an increase in the intramuscular fat accumulation. In addition, we showed that the BMS No. was positively correlated with the subcutaneous fat percentage. In contrast, the BMS No. was negatively correlated with the visceral fat percentage. These results indicate that highly marbled Wagyu cattle have a higher percentage of subcutaneous fat and a lower percentage of visceral fat.

The inclusion of de-oiled wet distillers grains in feedlot diets reduces the expression of lipogenic genes and fat content in Longissimus muscle from F1 Angus-Nellore cattle.

The inclusion of agro-industry by-products originated from corn ethanol production has increased in animal nutrition in Brazil, reducing formulation costs. In the literature, there is no consensus on how the high inclusion of de-oiled wet distillers grains can affect beef quality and the expression of lipogenic genes in Longissimus muscle. The aim of this study was to evaluate the effects of WDG in the diet of F1 Angus-Nellore cattle on meat quality characteristics, chemical composition and expression of genes involved in lipid metabolism. A hundred F1 Angus-Nellore bulls, with average initial body weight (BW) of 369.5 ± 49 kg were used. The experiment was carried out in a randomized block design, and the animals were divided into two blocks (light and heavy) according to the initial body weight. The animals were fed diets containing levels of 0 (control), 15, 30 and 45% of WDG replacing dry corn and soybean meal. After 129 days of feedlot, the animals were slaughtered and samples of the longissimus thoracis (LT) muscle were collected for quality analyzes such as shear force (3, 10 and 17 aging days), color (luminosity, red, Chroma and Hue), cooking losses, pH and chemical composition (moisture, protein, lipids and ash contents). In addition, the expression of the PPARα, PPARγ, SREBP-1c, SCD1, LPL, FABP4, FASN, ACOX, CPT2, GPX1 and ACACA genes was investigated in the LT muscle by real-time reverse transcription polymerase chain reaction (RT-PCR). Data were analyzed using polynomial contrasts (linear, quadratic and control vs. WDG). There was no interaction (P > 0.05) between aging times and the inclusion of WDG in the diets on the meat quality (pH, cooking losses, coloration and tenderness). However, diets with increasing levels of WDG caused a linear reduction (P = 0.01) in the intramuscular fat of LT. The lipogenic genes SCD1, PPARγ, FASN and CPT2 were less expressed (P < 0.05) in response to the inclusion of WDG. These results suggest that the inclusion of WDG reduced the expression of lipogenic genes and consequently the marbling of LT muscle without affecting tenderness (shear force) and meat color traits.

Characterisation of carcass composition and meat quality of male suckling buffalo calves kept on natural grassland

Abstract. The aim of this observational study (field experiment) was to evaluate carcass composition and meat quality of male suckling buffalo calves. The animals were born between June and September 2011 and were kept on natural pasture in a cow/calf herd. From the end of November 2011, the suckling calves were fed only roughage as feed supplement in a feedlot until slaughter. For a generalised characterisation, the basic statistics of 18 male calves were calculated. The animals were slaughtered at an average live weight of 196.0 kg. Growth, live weight development and most carcass traits varied substantially between individual calves. The 12th rib muscle composition measured by computer tomography indicated comparable meat contents as evaluated by manual dissection of the carcass. Meat quality parameters (pH and colour) and the nutrient composition (protein, fat, ash) of longissimus muscle samples of calves were relatively similar. The intramuscular fat content of longissimus muscle was low, but shows a high variation between 0.3–1.1 %.

Quantifying the relative contribution of ante- and post-mortem factors to the variability in beef texture

This study aims to investigate the relative contribution of ante- and post-mortem factors to the final quality of beef. In all, 112 steers (four breed-crosses) were arranged in a 2 × 2 × 2 factorial experimental including production system, growth implant and β-adrenergic agonist strategies. Carcasses were suspended by the Achilles tendon or the aitch bone and meat was aged for 2/6/13/21/27 days (longissimus muscle) or 2/27 days (semimembranosus muscle). Meat quality traits related to beef texture were measured. Statistical analyses were developed including ante- and post-mortem factors and their relative contribution to the variability observed for each measured trait was calculated. The main factor responsible for the variability in sarcomere length was the suspension method (91.1%), which also influenced drip-loss (44.3%). Increasing the percentage of British breeds increased (P < 0.05) the intramuscular fat content in longissimus muscle, but only when implants were not used. Thus, the breed-cross, implant strategy and their interaction were responsible for >58% of the variability in this trait. The variability in instrumental and sensory tenderness was mainly affected by post-mortem factors (carcass suspension, ageing time and their interaction), explaining generally ∼70% of the variability in these traits. Breed-cross was the second most important effect (∼15%) when carcass suspension was not considered in the model, but still ageing time was responsible for a much larger proportion of the variability in tenderness (>45%). In conclusion, post-mortem handling of the carcasses may be much more effective in controlling beef tenderness than pre-mortem strategies.

Perfil de ácidos graxos e composição química do músculo longissimus dorsi de cordeiros alimentados com dietas contendo polpa cítrica

Objetivou-se com este trabalho avaliar os efeitos da substituição do milho por polpa cítrica na composição química e no perfil de ácidos graxos do músculo longissimus dorsi de cordeiros. Utilizaram-se 32 cordeiros Santa Inês não-castrados abatidos aos 141 dias de idade com peso médio de 33 kg. Os cordeiros foram alimentados com ração contendo 90% de concentrado (milho moído e/ou polpa cítrica, farelo de soja e minerais) e 10% de feno de "coastcross" (Cynodon spp). A polpa cítrica foi adicionada nos níveis de 23,7; 46,1; e 68,4% da matéria seca em substituição a 33, 67 e 100% do milho, respectivamente. A substituição total do milho pela polpa cítrica promoveu aumento de 177% na concentração de ácido linolênico (C18:3), enquanto a substituição parcial resultou em aumento de 72% no ácido linoleico conjugado (C18:2 cis-9 trans-11). Não houve alteração na concentração total de ácidos graxos saturados, monoinsaturados e poliinsaturados. Entretanto, a quantidade de gordura intramuscular do longissimus dorsi diminuiu com o aumento de polpa cítrica na ração, sem alterar os teores de umidade, proteína e cinzas. A substituição do milho por polpa cítrica na ração modifica a quantidade e o perfil de lipídios do músculo longissimus dorsi de cordeiros.

Effects of growth rate during the early fattening period on growth, carcass characteristics and circulating hormones in the different growth hormone genotypes of Japanese black steers

ABSTRACTOne of the bovine growth hormone (GH) genetic variants is a substitution of leucine (Leu) to valine (Val) at amino acid position 127 of the protein. The GH genotypes of 14 Japanese black steers used in the present study were Leu/Leu (A, n = 7) and Val/Val (B, n = 7). The steers in each genotype group were divided into two groups based on intended growth rate (high, 1.0 kg/day; low, 0.6 kg/day) during 10–17 months of age. The overall mean concentration of plasma GH was higher (P &lt; 0.05) in the A group than in the B group. The serum concentration of insulin‐like growth factor‐I was higher (P &lt; 0.05) in the B group than in the A group. The carcass weight of the A group was greater (P &lt; 0.01) than that of the B group. However, there was no significant difference in carcass weights between the 1.0 kg/day and 0.6 kg/day groups (P &gt; 0.05). The rib thickness of the 1.0 kg/day group was greater (P &lt; 0.05) than that of the 0.6 kg/day group. The crude fat content of longissimus muscle was greater (P &lt; 0.05) for the 0.6 kg/day group compared with the 1.0 kg/day group.

Effects of species and sex on plasma hormone and metabolite concentrations in crossbred Brahman cattle and crossbred water buffalo

Buffalo meat is tasty and indistinguishable from beef, and has been described as being lean and low in cholesterol in comparison with beef. However, little is known about the plasma hormone and metabolic profiles related to fat metabolism in buffalo, and how their levels are affected by species and sex. In this study levels of plasma hormones and metabolites were compared between species and sexes. Ten growing crossbred Brahman cattle and ten growing crossbred buffaloes (five males and five females in each), with an average age of 22 months were used. The animals were fed on an experimental diet composed of corn silage, brewer's spent grain and a concentrate mixture at a 50:30:20 ratio on a dry matter basis during a fattening period of 6 months. Blood samples were collected every month during the experiment, and were analysed for plasma leptin, insulin, glucose, triglyceride (TG) and total cholesterol (TC) concentrations. Plasma leptin, insulin and TC concentrations increased during fattening and were significantly (Pb0.05) higher in cattle than in buffaloes. These concentrations in cattle showed a big difference between sexes in comparison with buffaloes, and were higher in females than in males. The plasma glucose and TG concentrations did not differ (PN0.05) between cattle and buffaloes. The crude fat content of longissimus muscle was significantly higher in cattle than in buffalo. Differences in body fat deposition seem to have an influence on plasma leptin, insulin and TC concentrations differently between cattle and buffaloes.

Carcass- and meat quality of pasture &amp;lt;i&amp;gt;vs&amp;lt;/i&amp;gt; concentrate fed German Simmental and German Holstein bulls

Abstract. Many factors affect ruminant carcass and meat quality, and among the genetic and environmental factors, feeding plays an important role in the determination of quality. In a large study, sixty-four German Holstein and German Simmental bulls were randomly allocated to either an indoor concentrate feeding system or periods of pasture feeding following by a finishing period. During this period the animals got a concentrate containing linseed to improve the meat quality for the consumer and enhance the contents of beneficial fatty acids in beef. German Simmental bulls grew faster in both feeding groups (concentrate and grass-based) compared to German Holstein bulls. Because of that significantly more days of fattening were necessary to reach the slaughter weight of 620 kg. The feeding system did not affect the carcass weights of both breeds. The results of cutting according to the regulations of the Deutsche Landwirtschaftsgesellschaft (DLG-Schnittführung für die Zerlegung der Schlachtkörper von Rind, Kalb, Schwein und Schaf) showed diet effects for different cuts. Pasture feeding significantly decreased the weights of flank, flat ribs and brisket of both breeds. The intramuscular fat content of longissimus muscle was affected by the diet in the case of German Simmental bulls, only. The intramuscular fat content of longissimus muscle of pasture-fed German Simmental bulls was decreased to 1.5 % compared with concentrate-fed bulls (2.6 %). No diet effect was found in the intramuscular fat content of longissimus muscle of German Holstein bulls. The colour investigations of both muscles (longissimus and semitendinosus) showed that the beef produced by pasture feeding is darker. The Warner- Bratzler shear force values (WBSF) of pasture fed bulls were significantly higher compared to the concentrate fed bulls. Pasture feeding resulted in a significant increase in the concentration of n-3 fatty acids up to a factor of 2.8 in longissimus muscle of bulls compared with the concentrate feeding system.

Number of intramuscular adipocytes and fatty acid binding protein-4 content are significant indicators of intramuscular fat level in crossbred Large White × Duroc pigs1

Intramuscular fat content is generally associated with improved sensory quality and better acceptability of fresh pork. However, conclusive evidence is still lacking for the biological mechanisms underlying i.m. fat content variability in pigs. The current study aimed to determine whether variations in i.m. fat content of longissimus muscle are related to i.m. adipocyte cellularity, lipid metabolism, or contractile properties of the whole muscle. To this end, crossbred (Large White x Duroc) pigs exhibiting either a high (2.82 +/- 0.38%, HF) or a low (1.15 +/- 0.14%, LF) lipid content in LM biopsies at 70 kg of BW were further studied at 107 +/- 7 kg of BW. Animals grew at the same rate, but HF pigs at slaughter presented fatter carcasses than LF pigs (P = 0.04). The differences in i.m. fat content between the 2 groups were mostly explained by variation in i.m. adipocyte number (+127% in HF compared with LF groups, P = 0.005). Less difference (+13% in HF compared with LF groups, P = 0.057) was noted in adipocyte diameter, and no significant variation was detected in whole-muscle lipogenic enzyme activities (acetyl-CoA carboxylase, P = 0.9; malic enzyme, P = 0.35; glucose-6-phosphate dehydrogenase, P = 0.75), mRNA levels of sterol-regulatory element binding protein-1 (P = 0.6), or diacylglycerol acyltransferase 1 (P = 0.6). Adipocyte fatty acid binding protein (FABP)-4 protein content in whole LM was 2-fold greater in HF pigs than in LF pigs (P = 0.05), and positive correlation coefficients were found between the FABP-4 protein level and adipocyte number (R2 = 0.47, P = 0.02) and lipid content (R2 = 0.58, P = 0.004). Conversely, there was no difference between groups relative to FABP-3 mRNA (P = 0.46) or protein (P = 0.56) levels, oxidative enzymatic activities (citrate synthase, P = 0.9; beta-hydroxyacyl-CoA dehydrogenase, P = 0.7), mitochondrial (P = 0.5) and peroxisomal (P = 0.12) oxidation rates of oleate, mRNA levels of genes involved in fatty acid oxidation (carnitine-palmitoyl-transferase 1, P = 0.98; peroxisome proliferator-activated receptor delta, P = 0.73) or energy expenditure (uncoupling protein 2, P = 0.92; uncoupling protein 3, P = 0.84), or myosin heavy-chain mRNA proportions (P > 0.49). The current study suggests that FABP-4 protein content may be a valuable marker of lipid accretion in LM and that i.m. fat content and myofiber type composition can be manipulated independently.

Non-destructive estimation of the intramuscular fat content of the longissimus muscle of pigs by means of spectral analysis of ultrasound echo signals

The eating quality of porcine meat is supposed to increase with increasing intramuscular fat content (IMF). The aim of this study was to investigate the use of acoustic parameters obtained by spectral analysis of ultrasound echo signals to non-destructively predict intramuscular fat content of porcine longissimus muscle. Ultrasound is regarded as a promising non-destructive technique to characterize tissue. Ultrasound data acquisition was performed at slaughter with a clinical B-mode device equipped with a 3.5 MHz center-frequency transducer on 115 warm carcasses about 45 min postmortem. Acoustic parameters quantifying attenuation, backscattering and cepstral structure were calculated off-line from the recorded primary raw ultrasound echo signals. Their relationship to IMF content was investigated. IMF level significantly influenced powerspectrum amplitudes and backscatter parameters. With partial least-squares regression (PLS), the IMF content could be predicted with root mean standard error of prediction RMSEP of 0.36% IMF. The ultrasound parameters were able to correctly classify nearly 80% of the carcasses into HIGH and LOW level class, respectively. Results indicate the potential use of ultrasound spectral analysis for non-destructive evaluation (NDE) of pig carcasses in order to estimate the IMF content.