Regulation of Fat and Fatty Acid Composition in Beef Cattle

Smith, Stephen B.,Gill, Clare A.,Lunt, David K.,Brooks, Matthew A. Asian Australasian Association of Animal Productio 2009 Animal Bioscience Vol.22 No.9

Fat composition of beef, taken here to mean marbling, can be manipulated by time on feed, finishing diet, and breed type. These three factors also strongly influence the fatty acid composition of beef. Both the amount of marbling and the concentration of monounsaturated fatty acids (MUFA) increase with time on feed in grain-fed and pasture-fed cattle, but much more dramatically in grain-fed cattle. High-concentrate diets stimulate the activity of adipose tissue stearoyl-CoA desaturase (SCD), which is responsible for the conversion of saturated fatty acids (SFA) to their $\Delta{9}$ desaturated counterparts. Also, grain feeding causes a depression in ruminal pH, which decreases those populations of ruminal microorganisms responsible for the isomerization and hydrogenation of polyunsaturated fatty acids (PUFA). The net result of elevated SCD activity in marbling adipose tissue and depressed ruminal isomerization/hydrogenation of dietary PUFA is a large increase in MUFA in beef over time. Conversely, pasture depresses both the accumulation of marbling and SCD activity, so that even though pasture feeding increases the relative concentration of PUFA in beef, it also increases SFA at the expense of MUFA. Wagyu and Hanwoo cattle accumulate large amounts of marbling and MUFA, and Wagyu cattle appear to be less sensitive to the effects of pastures in depressing overall rates of adipogenesis and the synthesis of MUFA in adipose tissues. There are small differences in fatty acid composition of beef from Bos indicus and Bos taurus cattle, but diet and time on feed are much more important determinants of beef fat content and fatty acid composition than breed type.

Marbling and Its Nutritional Impact on Risk Factors for Cardiovascular Disease

Smith, Stephen B. Korean Society for Food Science of Animal Resource 2016 한국축산식품학회지 Vol.36 No.4

This review addresses the role of fat in beef palatability and healthfulness. Particular emphasis is placed on the content of oleic acid in beef, and how this increases with time when cattle are fed a grain-based diet. Oleic acid decreases the melting point of lipids from beef, increasing the perception of juiciness and improving beef flavor. Clinical trials have demonstrated that ground beef containing elevated oleic acid increases, or at the least has no negative effects on the concentration of HDL cholesterol. The amount of fat in published ground beef intervention trials greatly exceeds the amount of fat in equivalent portions of beef from U.S. domestic or Korean Hanwoo cattle. Thus, we conclude 1) Beef cattle should be raised under production conditions that increase the concentration of oleic acid in their edible tissues (i.e., by grain feeding over extended periods of time); and 2) The amount of fat consumed in a typical portion of beef will not increase risk factors for cardiovascular disease.

Marbling and Its Nutritional Impact on Risk Factorsfor Cardiovascular Disease

Stephen B. Smith 한국축산식품학회 2016 한국축산식품학회지 Vol.36 No.4

This review addresses the role of fat in beef palatability and healthfulness. Particular emphasis is placed on the content of oleic acid in beef, and how this increases with time when cattle are fed a grain-based diet. Oleic acid decreases the melting point of lipids from beef, increasing the perception of juiciness and improving beef flavor. Clinical trials have demonstrated that ground beef containing elevated oleic acid increases, or at the least has no negative effects on the concentration of HDL cholesterol. The amount of fat in published ground beef intervention trials greatly exceeds the amount of fat in equivalent portions of beef from U.S. domestic or Korean Hanwoo cattle. Thus, we conclude 1) Beef cattle should be raised under production conditions that increase the concentration of oleic acid in their edible tissues (i.e., by grain feeding over extended periods of time); and 2) The amount of fat consumed in a typical portion of beef will not increase risk factors for cardiovascular disease.

Beef Consumption and HDL Metabolism in Men and Women

Stephen B. Smith 한국식품영양과학회 2020 한국식품영양과학회 학술대회발표집 Vol.2020 No.10

Current situation and future prospects for global beef production: overview of special issue

Smith, Stephen B.,Gotoh, Takafumi,Greenwood, Paul L. Asian Australasian Association of Animal Productio 2018 Animal Bioscience Vol.31 No.7

The demand for beef as a protein source is increasing worldwide, although in most countries beef accounts for considerably less than half of total meat consumption. Beef also provides a highly desirable eating experience in developed countries and, increasingly, in developing countries. The sustainability of beef production has different meanings in the various geographical and socio-economic regions of the world. Natural resources including land mass and uses, rainfall and access to livestock feed, and the robustness of the economy are major determinants of the perception of beef sustainability. In this overview of the 2016 International Symposium on "Future Beef in Asia" and this subsequent Special Edition of the Asian-Australasian Journal of Animal Sciences on "Current Situation and Future Prospects for Global Beef Production", the contributions have been grouped into the following categories: Countries in Southeast Asia; Europe; and Countries producing highly marbled beef for export and/or domestic consumption. They also include reference to Special Topics including marbled beef production, and use of "omics" technologies to enhance beef quality assurance. Among these broad categories, notable differences exist across countries in the production and marketing of beef. These reflect differences in factors including natural resource availability and climate, population size, traditional culture and degree of economic development including industrial and technological developments. We trust that the International Symposium and this Special Edition on Current Situation and Future Prospects for Global Beef Production, the contents of which that are briefly summarized in this paper, will serve as a valuable resource for the livestock industries, researchers and students with an interest in enhancing the prospects for sustainable, efficient beef production that satisfies the growing size and complexity of consumer demands and markets for beef.

Supplementary prenatal copper increases plasma triiodothyronine and brown adipose tissue uncoupling protein-1 gene expression but depresses thermogenesis in newborn lambs

Smith, Stephen B.,Sweatt, Craig R.,Carstens, Gordon E. Asian Australasian Association of Animal Productio 2020 Animal Bioscience Vol.33 No.3

Objective: We tested the hypothesis that increasing dietary copper (Cu) to gravid ewes would enhance brown adipose tissue (BAT) thermogenesis in their offspring. Methods: Twin-bearing ewes were assigned on d 70 of gestation to diets containing 3, 10, or 20 ppm dietary Cu (n = 8 per group). Twin lambs were assigned at birth to a cold (6℃) or warm (28℃) environmental chamber for 48 h. Blood was collected from ewes and from lambs and perirenal BAT was collected after 48 h in the environmental chambers. Results: Prenatal Cu exposure increased ewe plasma triiodothyronine (T₃) and thyroxine concentration (T₄) (p<0.01) but prenatal Cu exposure had no effect on lamb plasma concentrations of T₃, T₄, glucose, or nonesterified fatty acid concentration (p≥0.08). The high level of prenatal Cu exposure depressed 48-h rectal temperature (p = 0.03). Cold exposure decreased BAT norepinephrine (NE) and increased BAT dopamine (p≤0.01), but prenatal Cu exposure had no effect on BAT cytochrome C oxidase activity or BAT NE or dopamine (p≥0.07). However, BAT of lambs from high-Cu ewes maintained higher uncoupling protein-1 (UCP1) gene expression than BAT of lambs from low- and medium-Cu ewes following warm or cold exposure in environmental chambers (p = 0.02). Cold exposure caused near depletion of BAT lipid by 48 h (p<0.001), increased BAT cytochrome c oxidase activity (p<0.01), and depressed plasma fatty acid concentrations (p<0.001). Conclusion: Although prenatal Cu exposure increased BAT UCP1 expression during warm and cold exposure, prenatal cold Cu exposure depressed 48-h rectal temperature. Cold exposure decreased BAT lipid content by over 80% and decreased lamb plasma fatty acid concentration by over 40%, indicating that fuel reserves for thermogenesis were nearly depleted by 48 h of cold exposure.

Feasibility of Using Bacteriophage Therapy to Reduce Morbidity and Mortality Associated with Spinal Epidural Abscesses

Doub James B.,Tran Jeremy,Smith Ryan,Pease Tyler,Koh Eugene,Ludwig Stephen,Lee Alina,Chan Ben 대한감염학회 2023 Infection and Chemotherapy Vol.55 No.2

Background: The aim of this study was to determine the feasibility of using bacteriophage therapeutics in spinal epidural abscess (SEA) by reviewing the causes and outcomes of SEA at a single institution and testing a bacteriophage for activity against preserved SEA clinical isolates. Materials and Methods: Medical records were reviewed of patients that received incision and drainage for SEA at a single medical center. Causative organisms, incidence of coinciding bacteremia and outcomes were recorded. A subset of SEA patients (N = 11), that had preserved clinical isolates, were assessed to evaluate if a bacteriophage therapeutic had ample activity to those isolates as seen with spot tests and growth inhibition assays. Results: Staphylococcus aureus was the predominate bacterial cause (71%) and bacteremia was associated with 96% of S. aureus SEA. Over 50% of the patients either died within three months, had recurrence of their infection, required repeat debridement, or had long term sequalae. A single bacteriophage had positive spot tests for all the S. aureus clinical isolates and inhibited bacterial growth for more than 24 hours for 9 of the 11 (82%) clinical isolates. Conclusion: SEA is associated with significant mortality and morbidity making this a potential indication for adjuvant bacteriophage therapeutics. Since S. aureus is the predominate cause of SEA and most cases are associated bacteremia this creates a potential screening and treatment platform for Staphylococcal bacteriophages therapeutics, allowing for potential pilot studies to be devised.

Historical Overview of the Effect of β-Adrenergic Agonists on Beef Cattle Production

Johnson, Bradley J.,Smith, Stephen B.,Chung, Ki Yong Asian Australasian Association of Animal Productio 2014 Animal Bioscience Vol.27 No.5

Postnatal muscle hypertrophy of beef cattle is the result of enhanced myofibrillar protein synthesis and reduced protein turnover. Skeletal muscle hypertrophy has been studied in cattle fed ${\beta}$-adrenergic agonists (${\beta}$-AA), which are receptor-mediated enhancers of protein synthesis and inhibitors of protein degradation. Feeding ${\beta}$-AA to beef cattle increases longissimus muscle cross-sectional area 6% to 40% compared to non-treated cattle. The ${\beta}$-AA have been reported to improve live animal performance, including average daily gain, feed efficiency, hot carcass weight, and dressing percentage. Treatment with ${\beta}$-AA increased mRNA concentration of the ${\beta}_2$ or ${\beta}_1$-adrenergic receptor and myosin heavy chain IIX in bovine skeletal muscle tissue. This review will examine the effects of skeletal muscle and adipose development with ${\beta}$-AA, and will interpret how the use of ${\beta}$-AA affects performance, body composition, and growth in beef cattle.

Ground Beef High in Total Fat and Saturated Fatty Acids Decreases X Receptor Signaling Targets in Peripheral Blood Mononuclear Cells of Men and Women

Choi, Seong H.,Gharahmany, Ghazal,Walzem, Rosemary L.,Meade, Thomas H.,Smith, Stephen B. Wiley (John WileySons) 2018 Lipids Vol.53 No.3

Oleic acid in Angus and Hanwoo (Korean native cattle) fat reduced the fatty acid synthase activity in rat adipose tissues

( Kim Margarette C. Nogoy ),( Hyoun Ju Kim ),( Dong Hoon Lee ),( Stephen B. Smith ),( Hyun A Seong ),( Seong Ho Choi ) 한국축산학회(구 한국동물자원과학회) 2021 한국축산학회지 Vol.63 No.2

This study aimed to determine the blood lipid profiles, fatty acid composition, and lipogenic enzyme activities in rat adipose tissues as affected by the Angus beef fat (ABF) and Hanwoo beef fat (HBF) containing high oleic acid (OA) content. We assigned 60 Sprague Dawley rats with a mean bodyweight of 249 ± 3.04 g to three groups (n = 20 each) to receive diets containing 7% coconut oil (CON), 7% ABF, or 7% HBF. The OA content was highest in the HBF (45.23%) followed by ABF (39.51%) and CON (6.10%). The final body weight of the HBF-fed group was significantly increased, probably due to increased feed intake, indicating the palatability of the diet. The HBF and ABF significantly increased high-density lipoprotein cholesterol (HDL-C), decreased triglyceride (TG) and total cholesterol (TC) levels, and also tended to attenuate glutamic oxaloacetic transaminase (GOT) and glutamic pyruvic transaminase (GPT) levels in the bloodstream of the rats compared to CON. As compared to CON, lauric, myristic, and palmitic acids were significantly lower, and those of OA and α-linolenic acid (ALA) were significantly higher in the adipose tissues of HBF and ABF-fed groups. The HBF and ABF also reduced lipogenesis as induced by depleted fatty acid synthase (FAS) activity in rat adipose tissues. Nevertheless, between the two fats, HBF showed high feed intake due to its high palatability but reduced lipogenic enzyme activity, specifically that of FAS, and increased HDL-C, decreased TC and TG levels in the bloodstream, reduced saturated fatty acids (SFA), and increased oleic and ALA contents in rat adipose tissues indicating that HBF consumption does not pose significant risks of cardiovascular disease.