scholarly journals The Lipid Content of the Subcutaneous Fat Organs of the Chick Embryo

1962 ◽  
Vol 41 (4) ◽  
pp. 1232-1240 ◽  
Author(s):  
G.L. Feldman ◽  
L.M. Churchwell ◽  
T.W. Culp ◽  
F.A. Doyle ◽  
H.T. Jonsson
2020 ◽  
Vol 98 (9) ◽  
Author(s):  
Taylor R Krause ◽  
Jeferson M Lourenco ◽  
Christina B Welch ◽  
Michael J Rothrock ◽  
Todd R Callaway ◽  
...  

Abstract The objective of this study was to explore the relationships between ruminal microbial populations from Angus steers that were divergent in carcass traits related to adipose accumulation. Twenty-four feedlot-finished Angus steers (age: 538 ± 21 d; body weight following lairage: 593.9 ± 43.7 kg) were slaughtered, and ruminal contents and carcass data were collected. Ruminal microbial deoxyribonucleic acid (DNA) extraction and 16S ribosomal ribonucleic acid (rRNA) gene sequencing were performed to determine microbial relative abundances, to estimate microbial diversity, and to predict microbial metabolic pathways. A variety of correlation analyses and one-way ANOVA were performed to investigate the relationships between the rumen microbiome and carcass traits. Marbling score (P = 0.001) and longissimus lipid content (P = 0.009) were positively correlated to Chao1 Richness Index, suggesting that increased intramuscular fat was associated with increased numbers of ruminal microbial species. The phyla Tenericutes and TM7 were negatively correlated (P ≤ 0.05) to marbling score and longissimus lipid content, indicating that lower abundances of these phyla may be associated with improvements in intramuscular fat content. Greater abundance of the bacterial family S24-7 was positively correlated (P = 0.002) to marbling score. Analysis by marbling classification revealed further linkages to microbial richness (P ≤ 0.063), diversity (P = 0.044), and S24-7 (P < 0.001) populations. Computational prediction of the microbial metabolic pathways revealed no differences (P ≥ 0.05) in metabolic pathway expression in rumen microbes between steers in the high- and low-marbling classes. Several phyla, families, and genera were positively correlated (P ≤ 0.05) to both rib fat thickness and yield grade. Collectively, our results suggest that microbial composition is associated to differing performance in carcass adipose traits. Overall, most of the bacterial taxa correlated to the intramuscular and subcutaneous fat depots did not overlap, suggesting the microbial population end products likely impacted adipose accumulation largely via separate adipogenic pathways of the host animal.


1998 ◽  
Vol 49 (6) ◽  
pp. 1009 ◽  
Author(s):  
H. Hearnshaw ◽  
P. F. Arthur ◽  
W. R. Shorthose ◽  
A. J. Sinclair ◽  
D. Johnston ◽  
...  

Carcasses of 435 Angus, Charolais, and Hereford sired progeny out of straightbred Hereford (H × H), and first-cross Brahman × Hereford (B × H), Simmental × Hereford (S × H) and Friesian × Hereford (F × H) dams, were evaluated for meat quality traits. The cattle had been raised and slaughtered for the vealer (both sexes), yearling domestic (both sexes), or the heavy export steer market. Meat samples from the M. longissimus (LD, striploin) and the M. semitendinosis (ST, eyeround) were evaluated for colour, cooking loss, sarcomere length, shear force parameters, instron compression values, lipid content (LD only), cholesterol content (LD, vealers only), and taste panel assessment (LD only). The effects of sire breed and dam breed were small and were significant for only a few traits. The use of either hot carcass weight or pH of meat as a covariate reduced the differences further but did not change sire breed or dam breed rankings. Meat from B × H progeny, which had 25% Bos indicus (Brahman) breeding, was as tender as that from progeny of the other dam breeds, which had no Bos indicus breeding. Striploins from vealer carcasses were more tender and had less fat (mean peak force, 3·8 kg; mean lipid in lean steak, 3·8 g/100 g) than those from yearling domestic carcasses (mean peak force, 4·1 kg; mean lipid in lean steak, 5· 0 g/100 g) which in turn were more tender than those from heavy export steer carcasses (mean peak force, 4·9 kg; mean lipid in lean steak, 6·3 g/100 g). From the total responses of the taste panel, 65% rated vealer striploins of good or excellent overall acceptability, compared with 29% for heavy export steer meat. Trimming subcutaneous fat from striploin steaks of vealers reduced lipid content and cholesterol content by 85% and 32% to 3·8 g/100 g and 55 mg/100 g, respectively.


Foods ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1982
Author(s):  
Yifei Wang ◽  
Rubén Domínguez ◽  
José M. Lorenzo ◽  
Benjamin M. Bohrer

The relationships between the lipid content, lipid oxidation, and discoloration rate of ground beef during a simulated retail display were characterized in this study. A total of 276 batches of ground beef were manufactured with inside rounds and subcutaneous fat from 138 beef carcasses at different targeted levels of lean:fat. There was a total of four different targeted grind levels during the manufacture of the ground beef, and the lipid content for the samples used in this study ranged from 2% to 32% total lipid. Fatty acid composition was determined based on subcutaneous fat, whereas the proximate composition of moisture and total lipids, instrumental color, visual discoloration, and lipid oxidation measured as thiobarbituric acid reactive substances were evaluated on ground beef patties during 7 days of simulated retail at 4 °C display under LED lights. Analysis for the correlation and the creation of linear regression models indicated that lipid content played a more critical role in the discoloration rate compared to lipid oxidation and fatty acid composition. Lipid oxidation could be more reliably predicted by lipid content and instrumental color compared to visual discoloration. Overall, ground beef formulated with greater lipid content is expected to experience greater rates of lipid oxidation and discoloration during retail display.


1994 ◽  
Vol 58 (2) ◽  
pp. 237-242 ◽  
Author(s):  
N. D. Cameron ◽  
S. C. Bishop ◽  
B. K. Speake ◽  
J. Bracken ◽  
R. C. Noble

AbstractFatty acid synthetase and lipoprotein lipase activities, lipid content of adipose tissue and the fatty acid composition of subcutaneous fat, sampled by biopsy at the 13th rib, were measured in 20-week-old rams from lines of Texel-Oxford (TO) and Scottish Blackface (SB) sheep, both divergently selected for carcass lean content. A total of 150 animals were measured, with close to equal numbers of animals per selection line-breed combination.In both breeds, the high (lean) selection lines had significantly lower backfat depths (TO : 0·5 mm and SB : 0·6 mm, s.e.d. 0·2) than the low (fat) lines. The lipid content of subcutaneous fat was 65 mg lipid per g fat tissue wet weight (s.e.d. 24) greater in TO rams than in SB rams. The TO low line had a higher lipid content than the high selection line (426 v. 448 (s.e.d. 36)) and although the SB selection lines did not differ, the selection line with breed interaction was not significant. SB rams had higher fatty acid synthetase activity (3·1 v. 2·6 (s.e.d. 0·3) on a log scale) but there were no differences between selection lines. Lipoprotein lipase activities were similar between breeds and selection lines. The lower concentration of myristic acid (C14:0) of TO rams compared with SB rams (0·9 (s.e.d. 0·3)) was the only breed or selection line difference which was statistically significant for fatty acid composition of subcutaneous fat.Lipid content of subcutaneous fat and lipoprotein lipase activity were highly correlated and both were positively correlated with performance test traits, especially with backfat depth. The correlation between backfat depth and fatty acid synthetase activity was not different from zero. Performance test traits, lipid content of subcutaneous fat and lipoprotein lipase activity were positively correlated with the unsaturated fatty acids, with the exception of C18 :1 when correlations were negative.


2019 ◽  
Vol 3 (2) ◽  
Author(s):  
L. M. Wang ◽  
S. Huang ◽  
S. Chalupa-Krebzdak ◽  
S. M. Vasquez Mejia ◽  
B. M. Bohrer

ObjectivesGround beef is more susceptible to lipid oxidation compared to whole muscle beef cuts. This is due to its smaller particle size and greater surface area, which makes the meat products more prone to be exposed to various environmental factors during production. The objective of this study was to determine the relationships among ground beef lipid content, instrumental color, visual discoloration, and lipid oxidation over a 7d simulated retail display period.Materials and MethodsBeef inside rounds (IMPS #168) from the right sides of steer carcasses (n = 63) were collected from a commercial processing facility and delivered to the U of Guelph Meat Science Laboratory for further analyses. Each inside round was trimmed of all subcutaneous fat and connective tissue, and then fabricated into ground beef patties (113 g/patty) at two targeted fat addition levels (no added fat and 25%). Lean ground beef (no added fat) was made by grinding cubes of inside round muscle through a Sirman Master 90 Y12 meat grinder (Sirman USA, Franklin Park, IL). Regular ground beef (25% added fat) was made by grinding cubed round muscle with an additional 25% subcutaneous fat that originated from the rib primal of the same carcass. For the simulated retail shelf life study, 2 crust frozen patties (crust frozen for 1 h to improve packaging ability) were placed on a Styrofoam meat tray with a soaker pad and overwrapped with PVC film. In total, there were 4 trays of patties per ID (2 trays/targeted fat level). Trays were placed under two LED lights (52 W, 1850 lumens, color temperature of 4000K, 1612.5 to 2152 lux) at 4°C and the locations on shelves were changed every 24 h. Minolta L*, a*, b* color and subjective surface discoloration were evaluated every 24 h for 7 d. Lipid peroxidation of patties before and after the retail display was estimated using thiobarbituric reactive substances (TBARS; mg MDA/g fat). Lipid content of patties was quantified using Soxhlet extraction with petroleum ether. Summary statistics and Pearson correlation coefficients were determined using the PROC CORR procedure of SAS. Correlations were regarded as weak at r < |0.35|, moderate at |0.36| ≤ r ≤ |0.67|, and strong at r ≥ |0.68|.ResultsLipid content in the 126 ground beef samples evaluated in this study ranged from 3.47% to 30.43% (16.30% ± 6.18%). A moderate and significant correlation was observed between lipid content and change in TBARS values (r = –0.59, P < 0.0001). Similarly, an increase in lipid content is moderately correlated with a decrease in a* values (r = –0.58, P < 0.0001) and an increase in surface discoloration after a 7d display period (r = 0.53, P < 0.0001). Δ TBARS values was weakly correlated with Δ L* (r = 0.24, P < 0.01), Δ a* (r = 0.11, P = 0.25), and visual discoloration (r = –0.16, P = 0.09). Finally, Δ a* was strongly correlated with surface discoloration values at d7 (r = –0.76, P < 0.0001).ConclusionAn increase of lipid content in ground beef had a moderate association with decreased redness, greater surface discoloration, and less change in lipid oxidation over a 7d simulated retail display period. Color values were not great predictors of lipid oxidation values and trained technicians often equated visual discoloration in beef to a deviation from the desired cherry red color.


Author(s):  
C.D. Fermin ◽  
M. Igarashi

Otoconia are microscopic geometric structures that cover the sensory epithelia of the utricle and saccule (gravitational receptors) of mammals, and the lagena macula of birds. The importance of otoconia for maintanance of the body balance is evidenced by the abnormal behavior of species with genetic defects of otolith. Although a few reports have dealt with otoconia formation, some basic questions remain unanswered. The chick embryo is desirable for studying otoconial formation because its inner ear structures are easily accessible, and its gestational period is short (21 days of incubation).The results described here are part of an intensive study intended to examine the morphogenesis of the otoconia in the chick embryo (Gallus- domesticus) inner ear. We used chick embryos from the 4th day of incubation until hatching, and examined the specimens with light (LM) and transmission electron microscopy (TEM). The embryos were decapitated, and fixed by immersion with 3% cold glutaraldehyde. The ears and their parts were dissected out under the microscope; no decalcification was used. For LM, the ears were embedded in JB-4 plastic, cut serially at 5 micra and stained with 0.2% toluidine blue and 0.1% basic fuchsin in 25% alcohol.


Author(s):  
J. P. Brunschwig ◽  
R. M. McCombs ◽  
R. Mirkovic ◽  
M. Benyesh-Melnick

A new virus, established as a member of the herpesvirus group by electron microscopy, was isolated from spontaneously degenerating cell cultures derived from the kidneys and lungs of two normal tree shrews. The virus was found to replicate best in cells derived from the homologous species. The cells used were a tree shrew cell line, T-23, which was derived from a spontaneous soft tissue sarcoma. The virus did not multiply or did so poorly for a limited number of passages in human, monkey, rodent, rabbit or chick embryo cells. In the T-23 cells, the virus behaved as members of the subgroup B of herpesvirus, in that the virus remained primarily cell associated.


Author(s):  
Grace C.H. Yang

The size and organization of collagen fibrils in the extracellular matrix is an important determinant of tissue structure and function. The synthesis and deposition of collagen involves multiple steps which begin within the cell and continue in the extracellular space. High-voltage electron microscopic studies of the chick embryo cornea and tendon suggested that the extracellular space is compartmentalized by the fibroblasts for the regulation of collagen fibril, bundle, and tissue specific macroaggregate formation. The purpose of this study is to gather direct evidence regarding the association of the fibroblast cell surface with newly formed collagen fibrils, and to define the role of the fibroblast in the control and the precise positioning of collagen fibrils, bundles, and macroaggregates during chick tendon development.


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