Fat Color Research Articles

How Australian consumers value intrinsic and extrinsic attributes of beef products

The purpose of this paper is to determine which information cues on beef labels actually attract consumer interest. We applied a discrete choice experiment to investigate 1002 Australian consumer preferences and willingness-to-pay (WTP) for different beef products. Consumers were presented with a novel experiment in which they indicated “how many” they would purchase for mince, diced, roast, and four cuts of steaks (rump, porterhouse, scotch fillet and eye fillet).The results from an ordered logit model showed that cues related to healthy option purchases play a stronger influential role on Australian consumers decision making compared to other beef attributes. Australian consumers have a stronger preference for less marbled beef. Moreover, white fat colour is more desirable than yellow colour. Furthermore, in relation to labelling information, origin of the beef is a key indicator in consumer’s evaluation process. We observed a highly inflated WTP for origin of the beef. For example a WTP of $5.76 for Scotch fillet steak from “Tasmania” compared a WTP of −$14.22 for the same cut from “China”. This finding may be due to Australian consumers using origin as a cue for food safety or quality.We concluded that preferences for beef products are not similar across consumers from different nations and country-specific research is required to illustrate consumer’s preference. Finally, this study provides managerial and policy implication and recommendations to better understand the relative value to the Australian consumer of beef product appearance and labelling information.

Effects of dietary partly destoned exhausted olive cake supplementation on performance, carcass characteristics and meat quality of growing lambs

In an experiment with 32 male growing Florina (Pelagonia) lambs, effects of replacing barley grain, sunflower meal and wheat bran with partly destoned exhausted olive cake (PDEOC) and soybean meal on productivity, carcass characteristics, meat chemical composition and meat fatty acid (FA) composition was determined. In the 56day experiment, lambs were randomly allocated into four dietary treatments (PDEOC0, PDEOC80, PDEOC160, and PDEOC240) of 8 lambs each and accommodated in individual floor pens. Lambs had an initial body weight (BW) of 16.7±1.81kg, and were fed one of four isonitrogenous (crude protein 162g/kg, dry matter − DM basis) and isoenergetic (net energy for gain 6.11MJ/kg, DM basis) concentrate mixtures ad libitum and alfalfa hay (0.2kg DM/lamb/day). The PDEOC was added to the concentrate mixture at inclusion levels (as mixed basis) of 0, 80, 160, and 240kg/t for treatments PDEOC0, PDEOC80, PDEOC160, and PDEOC240, respectively. No differences (P>0.05) occurred among PDEOC treatments in final BW (29.9kg), BW gain (0.24kg/day), DM intake (0.97kg/day), and feed conversion ratio (4.07kg DM intake/kg BW gain). Moreover, meat chemical composition and carcass characteristics were not affected (P>0.05) with increased PDEOC feeding, except for the fat color, fat firmness, wetness and overall acceptability of carcasses that linearly increased with increasing PDEOC supplementation. Oleic and palmitic acids were the predominant FA in intramuscular fat of all treatments. FA were not affected (P>0.05) with increased PDEOC feeding, except for the lauric acid which decreased (P=0.018), as well as the α-linolenic acid which increased (P=0.020). PDEOC supplementation, at levels up to 240kg/t of concentrate mixtures, in isonitrogenous and iso (net energy) energetic diets for growing lambs did not affect their performance and carcass characteristics, while it improved carcass qualitative traits.

The color of fat: racializing obesity, recuperating whiteness, and reproducing injustice

ABSTRACT I argue here that even sympathetic representations of obesity as a pathology most prevalent among black and Latina/o women and children can help reproduce racial injustice. At a time when fatness is deeply stigmatizing, fat bodies denote civic unfitness, and high white obesity rates jeopardize whiteness, raced and gendered obesity discourses effectively reify white superiority and maintain white dominance. They function as a racial project in two ways. First, they fortify white normativity by associating nonwhiteness with fatness and pathology and by exalting “white” consumption practices. Second, because they unfold in a political context pervaded by welfare-queen imagery, these discourses forge a new public identity of black womanhood, the obese black woman, which revives tropes of black women as insatiable, lazy bad mothers who deplete the state and economy. This imagery invites and justifies discriminatory and exclusionary practices that sustain structural racial inequality. To combat rather than reproduce racial inequality, anti-racist anti-obesity discourses must expose obesity as an embodiment of structural racism and promote structural transformation.

The color of fat and its central role in the development and progression of metabolic diseases.

Excess caloric intake does not always translate to an expansion of the subcutaneous adipose tissue (SAT) and increase in fat mass. It is now recognized that adipocyte type (white, WAT, or brown, BAT), size (large vs. small) and metabolism are important factors for the development of cardiometabolic diseases. When the subcutaneous adipose tissue is not able to expand in response to increased energy intake the excess substrate is stored as visceral adipose tissue or as ectopic fat in tissues as muscle, liver and pancreas. Moreover, adipocytes become dysfunctional (adiposopathy, or sick fat), adipokines secretion is increased, fat accumulates in ectopic sites like muscle and liver and alters insulin signaling, increasing the demand for insulin secretion. Thus, there are some subjects that despite having normal weight have the metabolic characteristics of the obese (NWMO), while some obese expand their SAT and remain metabolically healthy (MHO). In this paper we have reviewed the recent findings that relate the metabolism of adipose tissue and its composition to metabolic diseases. In particular, we have discussed the possible role of dysfunctional adipocytes and adipose tissue resistance to the antilipolytic effect of insulin on the development of impaired glucose metabolism. Finally we have reviewed the possible role of BAT vs. WAT in the alteration of lipid and glucose metabolism and the recent studies that have tried to stimulate browning in human adipose tissue.

Mexican consumers at the point of meat purchase. Beef choice

Within-consumer preference replication achieved through systematic image manipulation was used in consumer surveys in four cities across Mexico (Mexico City, n=195; Guadalajara, n=100; Hermosillo, n=132; Veracruz, n=61) to study beef preferences. Images of beef steaks controlled for lean and fat colour, fat cover and marbling were presented to consumers to determine the characteristics used in beef choice and the levels of preference of these characteristics. The most important choice criteria were fat cover (62% preferring little fat cover) and marbling (59% preferring non-marbled). Lean colour was also important with 24% and 29% choosing light and dark red beef, respectively. Fat colour was the least important of the four attributes studied (18% and 19% choosing white and yellow, respectively), but was nevertheless important given that 43% of consumers used three or four characteristics to make their choice. Imported and domestic beef in the Mexican marketplace appear to respond to the range of consumers' beef preferences at the point of purchase.

Effects of ractopamine hydrochloride and immunological castration in pigs. Part 2: belly quality characteristics and fatty acid composition

The effects of immunocastration and ractopamine in the diet on the belly quality were investigated from two crossbred pigs under different conditions of production, diet, management, and slaughter arranged in factorial design using two levels of addition of ractopamine in the diet, 0 and 7.5 ppm, and three genders (gilts, immunocastrated and barrows). The quality of bellies were analyzed for chemical composition, pH, meat and fat color, backfat thickness and fatty acid profile of the fat. The addition of ractopamine showed no significant influence on pH, color and chemical composition in two crossbred pigs. The immunocastrated had thicker belly backfat compared to the bellies of the gilts. The contents of fatty acids polyunsaturated, linoleic, linoleic, arachidonic, total omega 3 and omega 6 were higher for immunocastrated pigs, as well as presenting values greater than 0.4 for the PUFA:SFA ratio, thus, providing bellies with better nutritional quality. The bellies of the gilts and immunocastrated pigs had higher concentrations of iodine value, indicative of higher unsaturated fat content. The results indicated that the addition of ractopamine and immunocastration had little influence on the quality of bellies as well as in their fatty acid profiles, suggesting the continuity of implementation of these techniques.

Ractopamine hydrochloride and immunological castration in pigs. Part 1: fresh belly characteristics for bacon processing and quality

Abstract The effects of ractopamine and immunological castration on belly characteristics, processing yield, physicochemical and sensory quality of bacon were investigated from two crossbred pigs under different conditions of animal production, diet, management and slaughter arranged in factorial design using 2 ractopamine levels (0 and 7.5 ppm) and 3 genders (barrows, immunocastrated and gilts). Before processing, belly firmness, weight, length, width and thickness were measured, and then, bacon processing yield evaluated. After processing, bacon slices were digitally imaged and analyzed for lean meat and fat areas, pH, instrumental color of meat and fat, cooking loss and sensory quality. The ractopamine did not alter belly characteristics, but significantly increased the process yield and decreased cooking loss. Barrows and immunocastrated pigs showed firmer bellies, which could be advantageous for bacon processing and slicing. Barrows presented the highest total area of bacon slices. The results of this study indicate that both techniques ractopamine in the finishing diets and immunocastration of pigs can be combined with no further consequences for belly processing and to bacon quality and with some advantages.

The response of growing native turkeys to different feed colours and forms.

A total number of 180 1-day old native turkey chicks were chosen in this study, for evaluating the impacts of using different attracting colours and forms of the offered feed on growth performance, carcass traits and some of health aspects, in a 3×2 factorial experimental design. The birds were allocated into three main groups according to feed colour (non-coloured, orange and green feeds), then each main group was divided to three subgroups corresponded to feed form (mash and crumbles feed) respectively. The obtained results indicated that feed colours and forms changed significantly the final body weight, body weight gain, feed conversion, gizzard percentage, meat juiciness, plumage conditions and mortality rate. However, there were no significant differences among the treatments in carcass traits, meat quality (percentages of heart, liver, abdominal fat colour, flavour and tenderness) and body temperature. Significant interactions of feed colours×forms groups were existed in most studied traits except in feed consumption, giblets, meat quality traits, plumage conditions and body temperature. Finally, considering the obtained results, it was observed that the native turkeys prefer green feed as crumbles over non-coloured or mash feed. Consequently, feeds for turkey chicks should be in green mash or crumbles during the growing period to maximize the profit.

Dietary whole and cracked linseed increases the proportion of oleic and α-linolenic acids in adipose tissues and decreases stearoyl-coenzyme A desaturase, acetyl-coenzyme A carboxylase, and fatty acid synthase gene expression in the longissimus thoracis muscle of Yanbian Yellow cattle

We hypothesized that supplementation of linseed in a beef cattle fattening diet would increase PUFA concentrations in intramuscular adipose tissue and depress (), (), and () gene expression by decreasing () expression. Conversely, supplemental linseed would upregulate expression of () and () in muscle of Yanbian Yellow steers. Thirty steers were assigned at random to 3 groups of 10 steers fed either the basal diet (corn grain and corn silage-based commercial concentrate [CON]), the CON diet plus 8% whole linseed (WLS; DM basis), or the CON diet plus 8% cracked linseed (CLS; DM basis) for 6 mo. The WLS and CLS supplements did not affect carcass weight, backfat thickness, or marbling scores ( > 0.10) but increased rib eye area and fat color (more yellow; < 0.05). The WLS and CLS diets decreased the proportions of 16:0 and 18:0 and increased the proportions of 18:1-9, 18:3-3, -9, -11 conjugated linoleic acid, total MUFA, and total PUFA in intramuscular, intermuscular, and subcutaneous adipose tissues. The WLS and CLS diets increased and gene expression whereas the supplements depressed , , , and gene expression in longissimus thoracis muscle, relative to CON muscle, consistent with our hypothesis. Because the WLS and CLS treatments did not affect any measure of carcass adiposity, these results indicated that linseed supplements promoted uptake of dietary lipids while concurrently depressing de novo fatty acid biosynthesis in adipose tissue.

Proposal of a Value-Based Grading System for the Commercial Beef Industry in the Dominican Republic

ObjectivesManagement conditions of beef cattle is very different in the Central American/Caribbean region when compared with other regions in the world. Consequently, a beef grading scheme different than the one used in other regions of the world and unique to the cattle in that region is justified. Objectives of the current study were 1) to determine marketing systems used for beef cattle in the Dominican Republic, 2) to propose a value-based beef marketing system offering incentive to beef producers for providing packers with a high quality, consumer preferred product, and 3) to provide the industry with more information pertaining to possible measureable components related to beef quality.Materials and MethodsQuality was evaluated in 96 cattle sourced from 3 commercial producers. Cattle were slaughtered under federal inspection at a commercial processing facility in the Dominican Republic. Quality characteristics measured included subcutaneous fat color (1 indicated white color; 2 indicated cream color; and 3 indicated yellow color), subcutaneous fat uniformity (1 indicated fat not evident or uniform; 2 indicated fat evident, but not uniform; and 3 indicated fat evident and uniform), muscling (1 indicated heavy muscle; 2 indicated moderate muscling; 3 indicated light muscling; and 4 indicated very light muscling), and number of permanent incisor teeth (ranging from 0 to 8) as an indicator of maturity. A proposed value-based grading grid was used with the combined score of subcutaneous fat color, subcutaneous fat uniformity, and muscling on the y axis (3 to 10) and the number of permanent incisor teeth (0 to 8) on the x axis. The grid was then used to assign quality scores (listed in ascending order of highest quality to lowest quality: AAA, AA, A, B, and C). Statistical analysis included determining descriptive statistics with the MEANS procedure of SAS (SAS Inst. Inc., Cary, NC), determining the fixed effect of producer using a multi-variance model with the MIXED procedure of SAS, and summarization with frequency distributions based on calculations with the proposed value-based grading grid.ResultsThe average for each characteristic was the following: fat color was 1.81 ± 0.05, fat uniformity was 1.01 ± 0.01, muscling was 1.60 ± 0.05, and the number of permanent incisor teeth was 3.27 ± 0.14. Based on the proposed value-based grading grid, 31% of carcasses graded AAA, 16% of carcasses graded AA, 44% of carcasses graded A, 7% of carcasses graded B, and 2% of carcasses graded C. Beef carcasses from producer 1, producer 2, and producer 3 had fat color scores of 1.90 ± 0.10, 1.73 ± 0.07, and 1.86 ± 0.07; fat uniformity scores of 1.00 ± 0.02, 1.00 ± 0.02, and 1.02 ± 0.02; muscling scores of 1.85 ± 0.08, 1.17 ± 0.06, and 1.88 ± 0.06; average permanent incisor teeth of 3.50 ± 0.31, 3.28 ± 0.23, and 3.15 ± 0.22; and an average value-based grade of A30, A83, and A70, respectively.ConclusionThe proposed value-based grading grid was successful in differentiating beef carcasses in the Dominican Republic based on fat color, fat uniformity, muscling, and the number of permanent incisor teeth. If adopted, this grading system provides a unique system that could work for the Dominican Republic; as well as, an incentive for beef producers to produce a higher quality and more consistent product. More research is warranted in developing relationships between carcass characteristics measured in this study and consumer acceptance.

Evaluation of Warm-Season Annual Grasses for Southern Forage-Finished Beef Systems

ObjectivesIn the southeastern United States, long growing seasons allow for near year-round forage production but high summer temperatures and drought can negatively impact forage production, nutritive value, and, consequently, performance of grazing animals. Warm-season annual grasses are typically higher in nutritive value than common warm-season perennial forages in the Southeast. Drought tolerant warm-season annuals may provide forage-finished beef producers with alternative options during the summer months. The objective of this research was to evaluate and compare drought tolerant warm-season annual grasses for beef forage-finishing systems in the Southeast across a 3-yr grazing trial in central Georgia (2014 to 2016).Materials and MethodsSixteen 0.81-ha paddocks were blocked by previous land management and randomly assigned to 1 of 4 forage treatments with 4 replications. Treatments included: ‘Tifleaf 3’ pearl millet (PM), ‘Tifleaf 3’ pearl millet plus ‘Red River’ crabgrass (PMCG), ‘Sugar Grazer II’ sorghum sudangrass (SS), and ‘Surpass’ brown mid-rib sorghum sudangrass (BMR) which were planted in mid to late spring of each year. Each year 32 previously stockered Angus crossbred steers (434 ± 19 kg) were stratified by weight, paired, and randomly assigned to treatment paddocks. Paddocks were split into 2 sub-paddocks for rotational grazing. Additional steers and heifers were used as “put-and-take” animals to maintain forages in a vegetative stage. All treatment steers were weighed after an 8-h fast at the beginning, mid-point, and end of the grazing period and average daily gain (ADG) and total body weight gain (BWG) were calculated. Steers were slaughtered under USDA inspection in September of 2014, 2015, and 2016 after 70, 63, and 56 d on treatment, respectively. Carcass quality and yield data were collected 24-h post-mortem and boneless strip loin (longissimus lumborum) sub-primals were removed from the right side of each carcass, vacuum packaged, boxed, and allowed to age (0 ± 2°C) for 21 d. After aging, steaks (2.54-cm) were fabricated from each strip loin starting at the anterior end and allocated to proximate analysis, Warner-Bratzler shear force (WBSF), and trained sensory analysis. Data were analyzed using PROC GLIMMIX (SAS v9.4; SAS Inst. Inc., Cary, NC). Pasture served as the experimental unit with steer as the observational unit. Year was included as a fixed effect, while block and pasture were included as random effects. Means were separated using the PDIFF option of LSMEANS at ɑ ≤ 0.05.ResultsNo differences (P > 0.05) were observed among treatments for ADG, BWG, dressing percent, subjective lean and fat color, fat L*, a*, and b*, lean L*, marbling, lean and skeletal maturity, fat thickness, adjusted fat thickness, kidney pelvic and heart (KPH) fat, yield grade, percent lipid, protein, and moisture, WBSF, beef flavor intensity, or off-flavor intensity. Treatment effects (P < 0.05) were observed for lean a*, lean b*, ribeye area (REA), percent ash, and juiciness, however, these differences were small in magnitude. Differences (P < 0.05) in initial and sustained tenderness were observed among treatments in 2014 only. Differences were observed across years for most variables, which were attributed to variability in weather conditions for the given year.ConclusionThis data shows that PM, PMCG, SS, and BMR are viable warm-season annual options for beef forage-finishing systems in the southeastern United States.

RESEARCHING OF MEAT AND FAT COLOUR AND MARBLING IN BEEF

The studies of meat and fat colour and marbling in Longissimus dorsi of different cattle — beef-producing (Aberdeen-Angus,Herefordbreeds) and dual-purpose (Simmental, Black-and-white breeds) — allowed to define groups by the colour values according to Lab international colour model. Measurements were performed 24 hours post-mortem between 12th and 13th ribs. It was found that different ranges of meat colour differed primarily in L* (lightness) and a* (redness) values, while b* (yellowness) values did not significantly differ. The highest differentiation between ranges of fat colour was noted in b* values, whereas L* and a* slightly differed. Moreover, visual assessment of beef marbling by four grades (small, moderate, good, and rich) and instrumental (microstructural) analysis using a computer image analysis system were carried out. The morphometric study of marbling was conducted in accordance with the principles of system quantitative analysis. To perform quantitative measurements, object analysis parameters (area) were specified. Both automatic and manual measurements of specified parameters were used. The study of Longissimus dorsi marbling established high agreement between visual and instrumental evaluations of marbling.

Compensatory growth in crossbred Aberdeen Angus and Belgian Blue steers: Effects on the colour, shear force and sensory characteristics of longissimus muscle

The effect of feed restriction (99days) followed by compensatory growth during a 200day re-alimentation period on the colour and sensory characteristics of meat from Aberdeen Angus×Holstein-Friesian (AN) and Belgian Blue×Holstein-Friesian (BB) steers was examined. Compensatory growth had no effect on muscle pH and temperature decline, chemical composition, drip loss, fat colour, or juiciness, but increased (P=0.009) Warner-Bratzler shear force and decreased tenderness (P=0.08) and overall liking (P=0.09). Compared to meat from BB steers, meat from AN steers had a higher intramuscular fat concentration and was rated similarly for tenderness, but higher for many of the flavour characteristics examined. While adjustment for intramuscular fat concentration removed some of these differences, genotype-specific flavour differences remained. It is concluded that genotype had greater effects on meat quality than the compensatory growth feeding regime imposed in this study.

Effects on performance and meat quality of Holstein bulls fed high concentrate diets without implants following immunological castration

The objective of this study was to evaluate the effect of the GnRH vaccine on the performance and meat quality of Holstein bulls fed high concentrate diets. A total of 493 approximately 7month old bulls (initial BW 298±1.2kg) were allocated into 3 treatment groups, intact bulls (n=164), animals surgically castrated at 15 to 17d of the study (n=164), and animals vaccinated on 0 and 28d of the study with the GnRH vaccine (n=165). Animals were slaughtered between 131 and 133d and carcass quality was evaluated. Hot carcass weight, dressing percentage, fat classification and meat quality parameters did not differ significantly between surgically castrated and vaccinated animals but differed (P<0.05) from intact bulls. Carcass classification, pH at 26h, and fat color were not affected by treatment.

Biallelic β-carotene oxygenase 2 knockout results in yellow fat in sheep via CRISPR/Cas9.

The recently emerged CRISPR/Cas9 approach represents an efficient and versatile genome editing tool for producing genetically modified animals. Β-carotene oxygenase 2 (BCO2) is a key enzyme in the progress of β-carotene metabolism and is associated with yellow adipose tissue color in sheep. We have recently demonstrated targeted multiplex mutagenesis in sheep and have generated a group of BCO2-disrupted sheep by zygote injection of the CRISPR/Cas9 components. Here, we show that biallelic modification of BCO2 resulted in yellow fat, compared with the fat color in monoallelic individuals and wild types (snow-flower white). We subsequently characterized the effects of gene modifications at genetic levels employing sequencing and Western blotting, highlighting the importance of the BCO2 gene for the determination of fat color in sheep. These results indicate that genetic modification via CRISPR/Cas9 holds great potential for validating gene functions as well as for generating desirable phenotypes for economically important traits in livestock.

Physical characteristics and proximate and mineral composition of Saanen goat male kids meat from Vojvodina (Northern Serbia) as influenced by muscle

The aim of this study was to investigate the influence of the anatomical location of muscles on their physical characteristics and proximate and mineral composition. Physical (pH value, water-holding capacity − WHC, and instrumental colour − CIEL*a*b* values) characteristics and proximate (moisture, protein, total fat and total ash) and mineral (K, P, Na, Mg, Ca, Zn, Fe, Cu, Ni and Mn) composition were determined in four (M. psoas major − PM, M. longissimus dorsi − LD, M. semimembranosus − SM, and M. triceps brachii − TB) muscles of Saanen goat male kids. Many significant or numerical differences were found in the mean values of quality characteristics among the particular muscle types. Muscles had no significant influence (P>0.05) on Mg, Ca, Ni and Mn content. The PM muscles were the highest in pH24h (5.83), CIEa* (22.47, reddest muscle), CIEb* (5.90) values, moisture (77.61g/100g), Na (78.2mg/100g), Fe (1.57mg/100g), Cu (0.131mg/100g) and Mn (0.013mg/100g) content and had the highest WHC, darkest colour (CIEL*=38.03), and lowest content of total fat (1.40g/100g),K (330mg/100g) and Ni (0,019mg/100g). The LD muscles were the highest in K (392mg/100g), Mg (26.1mg/100g), Ca (11.8mg/100g) and Ni (0.030mg/100g) content, and the lowest in CIEa* (14.71) and CIEb* (3.84) values, total ash (1.15g/100g), Zn (2.24mg/100g), Cu (0.092mg/100g) and Mn (0.011mg/100g) content. The highest content of protein (20.69g/100g), total ash (1.20g/100g) and P (255mg/100g), and the lowest pH24h (5.68) value, WHC and moisture (76.42g/100g), Na (64.2mg/100g), Fe (1.07mg/100g) and Mn (0.011mg/100g) content were found in SM muscles. The lightest colour (CIEL*=44.02), the highest content of total fat (2.15g/100g), Zn (3.21mg/100g) and Mn (0.013mg/100g), and the lowest content of protein (19.29g/100g), total ash (1.15g/100g), P (223mg/100g), Mg (24.3mg/100g) and Ca (10.6mg/100g) were found in TB muscles. Significant relationships between quality characteristics of meat in number of cases were determined. This study was undertaken to increase the available information on the physicochemical traits of goat meat. This is important to provide, update and improve regularly nutrient composition data of goat meat.

Inferring phenotypic causal structures among meat quality traits and the application of a structural equation model in Japanese Black cattle.

Meat quality is one of the most important traits determining carcass price in the Japanese beef market. Optimized breeding goals and management practices for the improvement of meat quality traits requires knowledge regarding any potential functional relationships between them. In this context, the objective of this research was to infer phenotypic causal networks involving beef marbling score (BMS), beef color score (BCL), firmness of beef (FIR), texture of beef (TEX), beef fat color score (BFS), and the ratio of MUFA to SFA (MUS) from 11,855 Japanese Black cattle. The inductive causation (IC) algorithm was implemented to search for causal links among these traits and was conditionally applied to their joint distribution on genetic effects. This information was obtained from the posterior distribution of the residual (co)variance matrix of a standard Bayesian multiple trait model (MTM). Apart from BFS, the IC algorithm implemented with 95% highest posterior density (HPD) intervals detected only undirected links among the traits. However, as a result of the application of 80% HPD intervals, more links were recovered and the undirected links were changed into directed ones, except between FIR and TEX. Therefore, 2 competing causal networks resulting from the IC algorithm, with either the arrow FIR → TEX or the arrow FIR ← TEX, were fitted using a structural equation model () to infer causal structure coefficients between the selected traits. Results indicated similar genetic and residual variances as well as genetic correlation estimates from both structural equation models. The genetic variances in BMS, FIR, and TEX from the structural equation models were smaller than those obtained from the MTM. In contrast, the variances in BCL, BFS, and MUS, which were not conditioned on any of the other traits in the causal structures, had no significant differences between the structural equation model and MTM. The structural coefficient for the path from MUS (BCL) to BMS showed that a 1-unit improvement in MUS (BCL) resulted in an increase of 0.85 or 1.45 (an decrease of 0.52 or 0.54) in BMS in the causal structures. The analysis revealed some interesting functional relationships, direct genetic effects, and the magnitude of the causal effects between these traits, for example, indicating that BMS would be affected by interventions on MUS and BCL. In addition, if interventions existed in this scenario, a breeding strategy based only on the MTM would lead to a mistaken selection for BMS.

Differences between sexes, muscles and aging times on the quality of meat from Wagyu × Angus cattle finished in feedlot

Our objectives were to assess quality parameters and chemical composition, and to evaluate the effects of sex, muscle and aging time on the quality of meats from Wagyu × Angus cross cattle reared under tropical conditions. Analyses were performed on the longissimus thoracis, semitendinosus and triceps brachii muscles obtained from chilled carcasses of a total of 30, 24-month-old, male (immunocastrated) and female animals (15 each sex). An effect of sex (P ≤ 0.05) was observed for subcutaneous fat thickness, marbling score, and ribeye area. The longissimus thoracis muscle from males was less (P &lt; 0.0001) marbled than that from females, but males had greater subcutaneous fat thickness (P = 0.0001) and greater ribeye area (P = 0.0411) compared with females. No effect of sex (P ≥ 0.05) was observed for fat colour measures. An interaction effect of sex and muscle (P &lt; 0.03) was detected for cooking loss, yellow intensity (b*), ash, and fat. Main effect of sex was not observed (P &gt; 0.07) only for the ultimate pH and water-holding capacity. Greater shear force and moisture values were observed (P &lt; 0.01) in meat from males than that from females, but a greater value of luminance (L*), red intensity (a*), chroma (C), hue (Ho), dry matter and protein was observed (P &lt; 0.001) in meat from females than that from males. Main effect of muscle was not observed only for water-holding capacity (P = 0.13). Ultimate pH and shear force values were lesser (P &lt; 0.001) in the longissimus thoracis muscle compared with other muscles. The triceps brachii muscle had the least (P ≤ 0.001) L* and Ho values among muscles, whereas the semitendinosus muscle had the greatest values of a* and C (P &lt; 0.001). The semitendinosus muscle presented the greatest (P &lt; 0.01) protein content compared with other muscles, although not differing in moisture and dry matter content from the triceps brachii muscle. An interaction effect of sex × aging time was observed for ultimate pH (P = 0.0110), meat colour parameters (except for Ho; P ≤ 0.01), and fat L* (P = 0.0025). Greater cooking loss, shear force, and fat a* values were observed (P &lt; 0.01) in meat from males than that from females, but greater values of meat Ho, fat a* and Ho, dry matter, and protein were observed (P ≤ 0.03) in meat from females than that from males. Meat aging of longissimus thoracis reduced shear force. Based on these findings, we recommend that meat from Wagyu × Angus cross cattle should be aged during 7 days because, although differences between 7 and 14 days were observed in either aging times, meat subjected to this process is considered as very tender, based on shear force values. In addition, aging in a shorter period of time can reflect on costs by reducing particularly those related with energy, due to less refrigeration time.

Effect of feeding management from grass to concentrate feed on growth, carcass characteristics, meat quality and fatty acid profile of Timahdite lamb breed

Thirty male Timahdite lambs were divided into 3 groups (n=10) and raised during 3 months under pasture (PP), pasture and concentrate (PC), and closed feeding systems with concentrate and hay (CC).Lambs were slaughtered at an average age of 276±6days and a mean live weight of 41±1kg. Carcass's conformation was studied by the measurements method.Instrumental meat quality and fatty acid profile in the semimembranous muscle were analyzed. Results showed that the feeding systems did not affect (P>0.05) the lambs' average daily gain and the carcass quality, except the hind limb compactness index (P<0.05), while they affected significantly the subcutaneous fat color and meat characteristics (P<0.05). Lambs from PP and PC groups showed higher lightness and yellowness indexes (L* and b*) of subcutaneous fat, normal meat ultimate-pH, higher water holding capacity and greater meat lightness color compared to CC group (P < 0.05).The study of fatty acid profile showed that, compared to CC lambs, PP lambs had better percentage of polyunsaturated fatty acids (PUFA), especially n-3 fatty acids, with lower n-6/n-3 ratio apart from greater percentage of conjugated linoleic acid (P<0.01).Based on these results, it is concluded that better quality meat was produced on open pastoral system of feeding with optimum PUFA.

The genotoxic and antigenotoxic properties of citrus phenolic limonene on mammalian cell lines

This study aimed to investigate the effects of a natural saline pasture on digestibility, intake, growth, carcass traits and meat quality of lambs. Forty weaned female Queue Fine de l′Ouest lambs (25.4 ± 4.33 kg) were allotted into two groups. The first group raised indoor (I) with oat straw ad libitum and the second grazed natural saline pasture (SP). Both groups were supplemented the same concentrate with 300 and 500 g for SP and I respectively, to have the same average daily gain (ADG). On the 49th day, digestibility and intake were determined on 8 lambs randomly selected from each group, using total fecal collection and Acid Insoluble Ash (AIA) marker method. After 83 days, the 16 lambs were slaughtered at 34 kg. Dry matter (DM), organic matter (OM), crude protein (CP) digestibility and metabolizable energy (ME) were higher (P < 0.001) for SP. Digestible crude protein (DCP)/ME ratio was higher (P < 0.05) for SP group. DM intake (P < 0.05) was lower for SP, while digestible crude protein intake (DCPI) and ME intake (MEI) were similar between the two groups. Water intake was higher for SP (P < 0.001). Final weight and ADG were similar between groups. Carcass dressing and high-priced joints percentages were higher for SP group. Lambs from the SP group had a higher percentage of muscle (P < 0.001) and a lower fat proportion (P < 0.01). No effect of feeding system on carcass linear measurements and on compactness indexes (P > 0.05) was noted. Kidney fat decreased in favor of SP group (P < 0.01). There were no differences for fat color, whereas meat of I group had a higher lightness and yellowness than that of SP one. Meat of SP group had a higher DM, protein level (P < 0.05) and lower intramuscular fat (P < 0.01). It has higher content of Fe and Zn (P < 0.01). It could be concluded rearing lambs on saline pasture, with a moderate concentrate supplementation, allowed acceptable growth performances, leaner carcass, and higher nutritional meat quality lambs.