Two experiments were conducted to determine the effects of dietary fish oil Ca salts supplementation on the muscle deposition of fatty acids, with the major focus on eicosapentaenoic (EPA) and docosahexaenoic acids (DHA) in beef cattle. For Experiment 1, thirty-eight grazing LowLine Angus steers were divided into three groups and supplemented either control, fish oil (FO)- or palm oil (PO)-based fatty acid Ca salts, supplemented individually in dry form. In Experiment 2, 14 Angus heifers and 14 Angus steers were fed free-choice harvested forage and supplemented either PO or FO Ca salts, delivered as a suspension within dried molasses lick tubs. Growth performances, sensory characteristics and the concentrations of EPA and DHA of the M. Longissimus thoracis (LT) were evaluated. M. Longissimus thoracis fatty acid concentrations of EPA and DHA were greater (P<0.001) for cattle fed FO; whereas C18:2 n-6 and the ratio of n-6 to n-3 were greater (P<0.001) for cattle fed PO in both experiments. Sensory evaluation of LT steaks obtained from the carcasses of the LowLine steers of Experiment 1 did not reveal any adverse effects of the FO supplementation (P≥0.2695). We conclude that supplementing FO Ca-salts to forage-fed beef cattle increases muscle deposition of EPA and DHA, with no adverse effects on flavor. Supplementing fish oil to beef cattle is a way to meet the omega fatty acid requirements of humans.

Fatty acid composition across functional brain regions was determined in bovine brains collected from cattle that were provided supplements of calcium salts containing either palm or fish oil. The Angus cattle were divided into two groups, with one group offered the supplement of calcium salts of palm oil and the other offered the calcium salts of fish oil (n = 5 females and n = 5 males/supplement) for 220 days. These supplements to the basal forage diet were provided ad libitum as a suspension in dried molasses. The fish oil exclusively provided eicosapentaenoic acid (EPA, C20:5 n-3) and docosahexaenoic acid (DHA, C22:6 n-3). The functional regions were dissected from the entire brains following commercial harvest. While the cattle provided diets supplemented with the calcium salts of palm oil had increased (p < 0.01) liver concentrations of C18:1 n-9, C18:2 n-6, and arachidonic acid, the fish-oil-supplemented cattle had greater (p < 0.01) concentrations of liver EPA, DHA, and C18:3 n-3. In the brain, DHA was the most abundant polyunsaturated fatty acid. In the amygdala, pons, frontal lobe, internal capsule, and sensory cortex, DHA concentrations were greater (p < 0.05) in the brains of the cattle fed fish oil. Differences among the supplements were small, indicating that brain DHA content is resistant to dietary change. Arachidonic acid and C22:4 n-6 concentrations were greater across the regions for the palm-oil-supplemented cattle. EPA and C22:5 n-3 concentrations were low, but they were greater across the regions for the cattle fed fish oil. The effects of sex were inconsistent. The fatty acid profiles of the brain regions differed by diet, but they were similar to the contents reported for other species.

The objectives of the current study were to evaluate the effects of dietary Zn fed at approximately 3 times NRC recommendations on milk Zn concentrations and mammary health. Within Rambouillet (WF) and Hampshire (BF) breeds, ewes were ranked by BW and randomly assigned down the rank into 2 treatment groups: Control (n = 45, 37 mg Zn/kg DM) and Zn treatment (n = 44, 113 mg Zn/kg DM). Treatments were delivered via a ZnSO4-fortified alfalfa pellet fed at a rate of 0.45 kg/d DM from a RFID-activated automated feeder from approximately 6 wk before to 4 wk after lambing. Ewe milk was collected twice weekly, and analyzed for mineral content (d 0, 10, and 30 of lactation) and somatic cell count (SCC; d 3–5, 6–9, 10–12, 13–16, 17–19, 20–23, 24–26, 27–29, or 30–32). Single-bearing ewes had greater Ca, Mg, and P (P ≤ 0.04) than multiple-bearing ewes. Day of lactation influenced milk Mg, P, and Zn (P < 0.01), and values generally decreased as lactation progressed. Milk Zn was 1.7-fold greater (P < 0.01) for Zn treatment than Control ewes. Milk Ca, Mg, and P were greater for Control than Zn treatment (P ≤ 0.02) ewes. A breed × litter size effect was detected for LogSCC (P = 0.02). Single-bearing WF ewes had lower LogSCC than multiple-bearing WF ewes (5.36 ± 0.09 vs 5.74 ± 0.07; P < 0.01) but litter size did not affect BF ewe LogSCC (5.80 ± 0.08 vs 5.79 ± 0.09; P = 0.92). Day of lactation impacted ewe SCC (P < 0.01), with peak SCC between d 6 and 9, which began to decline as lactation progressed. In conclusion, dietary Zn above NRC recommendations increased milk Zn.

Including feed efficiency as a trait for selection has gained interest in the sheep industry because it can result in reduced feed inputs or improve stocking rates, both of which translate into increased profitability for the producer. It is of interest whether the feed efficiency status of a testing population of sheep could be predicted using rumen microbial profiles associated with divergent feed efficiency status in a training population of sheep. Two populations of ewes were fed the same diet, and each group was evaluated for feed efficiency. A total of 20 animals in the testing population were selected for prediction assessment using feed efficiency, including the 6 top-ranked, the 6 bottom-ranked, and 8 middle-ranked ewes stratified over the distribution. Rumen fluid samples were collected and DNA was extracted for sequencing. Using a rumen microbial profile associated with diverging feed efficiency created from the training population, multiple discriminant analyses were performed using the DISCRIM procedure of SAS to determine the probability of correctly identifying lambs in the testing population as low, medium, or high feed efficiency using their microbial profiles. A profile of 6 rumen microbial species were used to correctly (P < 0.001) predict all testing population ewes into their actual feed efficiency status. A regression analysis using the same microbial profile was used to predict feed efficiency values, which were strongly correlated (r = 0.71; P < 0.001) with actual feed efficiency values. These results indicate that specific rumen microbial species may play a role in feed efficiency, and that a microbial profile could be used to rank sheep for feed efficiency.

Thermal tolerance is a key physiological trait that often varies among populations and species, and can be a key determinant of current and future geographic distributions. The cellular basis for organismal differences in thermal tolerance is an active area of research, with chemical constituents of the cytosol and cell membrane likely playing important roles in maintaining cell function at low temperatures. For freeze‐avoiding organisms, the abundance and makeup of sugars and related molecules depress the freezing point, reducing the risk of ice formation. At less extreme temperatures, remodeling of membrane lipids can help maintain fluidity (and function) at cold temperatures. We have found striking differences in critical thermal minima (CTmin) of worker bumble bees reared in common‐garden conditions from queens collected at low and high latitudes. We compared metabolomic and lipidomic signatures of these bees to identify key molecules that likely underlie differences in cold tolerance. PCA analyses of GC‐MS data for aqueous abdominal extracts revealed clear separation of low and high latitude populations and reveal higher levels of several key molecules, including L‐proline, in the high latitude population. Lipid extractions and subsequent GC‐MS reveals variation in fatty acid composition of nutrients (triacylglycerols) and of cellular membranes, for which phospholipid composition is also critical for function at low temperatures. This broad spectrum approach to metabolomics and lipidomics allows us to compare a wide range of metabolites between bees differing in cold tolerance, facilitating ongoing research on the mechanistic basis for this physiological trait linked to the ecology of diverse organisms.Support or Funding InformationThis material is based upon work supported by the National Science Foundation under Grant Nos. DEB‐1457659 and RII Track 2‐1826834. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

The objective of the present work was to investigate how grass feeding in cattle influences the fatty acid (FA) composition in marrow tissue. For a split plot designed experiment, marrow was obtained from the femur, humerus, radius and tibia of four crossbred steers slaughtered at 28 mo of age and fed o n mixture of cool season grasses and legumes. There were no bone type by location within bone interactions (P > 0.42), and the only within bone effect was for trans-vaccenic acid (TVA) where values for medial bone were lowest (P = 0.03) and highest for distal and proximal bone. Total monounsaturated FA and desaturation index were lower (P = 0.01) and total saturated FA were greater (P = 0.01) for proximal vs. distal bone marrow lipids. Marrow conjugated linoleic acid (CLA) was greater (P = 0.02) for distal bones (1.32 %) than for proximal bones (0.86 %). Overall, proportions of 18:3 n-3, CLA, and TVA were 0.60 %, 1.09 % and 2.50 %, respectively. We conclude that the FA profile of marrow in grass-fed cattle represents a healthy, nonatherogenic, animal-based fat source.

Fatty acid (FA) composition of lipids plays a crucial role in the functioning of lipid-containing structures in organisms and may be affected by the temperature an organism experiences, as well as its diet. We compared FA composition among four bee genera: Andrena, Bombus, Megachile, and Osmia which differ in their thermal ecology and diet. Fatty acid methyl esters (FAME) were prepared by direct transesterification with KOH and analyzed using gas-liquid chromatography with a flame ionization detector. Sixteen total FAs ranging in chain length from eight to 22 carbon atoms were identified. Linear discriminant analysis separated the bees based on their FA composition. Andrena was characterized by relatively high concentrations of polyunsaturated FAs, Bombus by high monounsaturated FAs and Megachilids (Megachile and Osmia) by relatively high amounts of saturated FAs. These differences in FA composition may in part be explained by variation in the diets of these bees. Because tongue (proboscis) length may be used as a proxy for the types of flowers bees may visit for nectar and pollen, we compared FA composition among Bombus that differed in proboscis length (but have similar thermal ecology). A clear separation in FA composition within Bombus with varying proboscis lengths was found using linear discriminant analysis. Further, comparing the relationship between each genus by cluster analysis revealed aggregations by genus that were not completely separated, suggesting potential overlap in dietary acquisition of FAs.

Maternal obesity in women is increasing worldwide. The objective of this study was to evaluate differences in adipose tissue metabolism and function in adult male offspring from obese and control fed mothers subjected to an ad libitum feeding challenge. We developed a model in which obese ewes were fed 150% of feed provided for controls from 60 days before mating to term. All ewes were fed to requirements during lactation. After weaning, F1 male offspring were fed only to maintenance requirements until adulthood (control = 7, obese = 6), when they were fed ad libitum for 12 weeks with intake monitored. At the end of the feeding challenge offspring were given an intravenous glucose tolerance test (IVGTT), necropsied, and adipose tissue collected. During the feeding trial F1obese males consumed more (P < 0.01), gained more weight (P < 0.01) and became heavier (P < 0.05) than F1control males. During IVGTT, Obese F1 offspring were hyperglycemic and hypoinsulinemic (P < 0.01) compared to F1 control F1. At necropsy perirenal and omental adipose depots weights were 47% and 58% greater respectively and subcutaneous fat thickness 41% greater in F1obese vs F1control males (P < 0.05). Adipocyte diameters were greater (P ≤ 0.04) in perirenal, omental and subcutaneous adipose depots in F1obese males (11, 8 and 7% increase vs. control, respectively). When adipose tissue was incubated for 2 hrs with C-14 labeled acetate, subcutaneous, perirenal, and omental adipose tissue of F1 obese males exhibited greater incorporation (290, 83, and 90% increase vs. control, respectively P < 0.05) of acetate into lipids. Expression of fatty acid transporting, binding, and syntheses mRNA and protein was increased (P < 0.05) compared to F1 control offspring. Maternal obesity increased appetite and adiposity associated with increased adipocyte diameters and increased fatty acid synthesis in over-nourished adult male offspring.

Many view bison as a healthful alternative to other red meat sources, and as a way to decrease health risks, they associate it with meat consumption. Using mice as a model for immune function, we hypothesized that consumption of meat from range-fed bison would decrease prostaglandin (PG) E₂ and alter prostacyclin (PGI₂) release upon immune challenge when compared with mice fed meat from grain-finished bison, range-fed beef, feedlot steers, free-ranging elk, or chicken breast. After 2 weeks on an experimental diet and inflammatory stimulation, mouse peritoneal macrophage was isolated and analyzed in 12 animals per diet. Peritoneal cell arachidonic acid increased in response to a chicken-based diet (P < .05), which was likely attributable to higher arachidonic acid intake. Release of PGE₂ was lowest in mice consuming meat of range-fed beef, range-fed bison, and elk but was highest with meat of grain-finished beef and intermediate in mice fed chicken (P < .05). Mice fed elk meat had the greatest PGI₂, whereas PGI₂ was decreased in mice fed meat of either range bison, range beef, or chicken (P < .05) and intermediate in mice fed meat of steers or bison finished in a feedlot. We conclude that consumption of meats characteristic of range-fed ruminants or wild ungulates supports reduced PGE₂ and greater PGI₂ synthesis, indicating potentially greater immune health and lower blood clotting potential than meat from grain-finished cattle or bison in this model system.

Ovulation is a prostaglandin (PG)-dependent process. Although n-3 polyunsaturated fatty acids (PUFA) and conjugated linoleic acid (CLA) have differing effects in the body, both reduce PG synthesis. We hypothesized that dietary n-3 fatty acids and CLA would differentially alter ovarian PG profiles through reductions in expression of enzymes involved in PG biosynthesis resulting in enhanced ovulation. Our objectives were to determine how dietary stearidonic acid and eicosapentaenoic acid (EPA) at 0.3 g/100 g diet and mixed isomers of CLA at 0.7 g/100 g diet, human achievable levels with daily consumption of fish or beef and dairy products, respectively, would influence ovulation and ovarian cyclooxygenase-1 (COX-1) and COX-2 expression in ovulation-induced rats. After 27 days on diet and ovulation induction, ovaries were isolated and analyzed from 22 pups per diet. Eicosapentaenoic acid ingestion reduced ova release by 16% while increasing PGE2 and PGF2α release without altering COX-1 or COX-2 expression. Conversely, ovarian COX-1 expression was increased 135% with stearidonic acid ingestion associated with increased PGF2α without altering PGE2 or ova release. Conjugated linoleic acid ingestion reduced COX-2 expression to 65% of that in rats consuming control and EPA diets; however, without affecting ovulation or PGs. Although it is generally believed that the COX-2 is the primary COX involved in ovulation, these results demonstrated that the n-3 PUFA differently affect ovarian COX-1 expression and that this effect differs from CLA, which reduced COX-2 expression. Further, although ovarian PGF2α is the primary PG altered by dietary n-3 PUFA, n-3 PUFA differentially influence ovarian PG biosynthesis and can decrease ova release, possibly induced through constitutive COX-1 enzyme expression.

ABSTRACT Beef steers representing four biological types were evaluated for fatty acid profiles and meat characteristics in muscle tissue developed on grazed forages. Biological types included six large‐framed, late maturing, nine medium‐framed, late maturing, nine medium‐framed, intermediate maturing, and nine medium‐framed, early maturing steers. Longissimus dorsi muscles were removed and frozen after 7 days of dry aging. Tenderness and cook loss were similar between biological types. Significant differences ( P < 0.05) in fatty acid profiles were found between biological types. The medium‐framed, early maturing animals scored highest ( P < 0.05) in marbling, had the highest ( P < 0.05) concentration of total n‐3 fatty acids, and had the lowest n–6/n–3 ratio at 1.03:1. All biological types had a mean n–6/n–3 ratio well below the recommended < 4:1 for human cardiovascular health. Under this dietary management system, medium‐framed, early maturing beef steers should be considered for producing grass‐fed beef based on both carcass merit and fatty acid composition. PRACTICAL APPLICATIONS Beef cattle that reach physiological maturity (i.e. puberty) earlier than their contemporaries should be selected for the production of grassfed beef if fully developed on forages. Those animals have the ability to deposit fat earlier than their later‐maturing contemporaries. Additionally, medium‐framed beef animals should be selected over larger‐framed animals as skeletal frame does not contribute to meat quality but requires more nutritional input for growth and maintenance. This ability to deposit fat exclusively on forage nutrients, without energy or protein supplementation, should be exploited when developing grassfed beef. Fat deposition, particularly intramuscularly (IM), contributes positively to meat quality. Fatty acids, especially the ratio of n‐6/n‐3, are optimized when beef animals have been fully developed on nutrient‐dense forages. Forages must be managed in such a way to capture those nutrients for animal intake and protect the plants for regrowth in a pasture setting.

Gene expression studies in humans and animals have shown that elevated stearoyl-CoA desaturase (SCD1) activity is associated with increased fat accumulation and monounsaturation of saturated fatty acids in skeletal muscle.However, results of the two reported association studies in humans are inconsistent.In the present study, we annotated the bovine SCD1 gene and identified 3 single nucleotide polymorphisms (SNPs) in its 3'untranslated region (UTR).Genotyping these SNPs on a Wagyu x Limousin reference population revealed that the SCD1 gene was significantly associated with six fat deposition and fatty acid composition traits in skeletal muscle, but not with subcutaneous fat depth and percent kidney-pelvic-heart fat.In particular, we confirmed that the high stearoyl-CoA desaturase activities/alleles were positively correlated with beef marbling score, amount of monounsaturated fatty acids and conjugated linoleic acid content, but negatively with amount of saturated fatty acids.The inconsistent associations between human studies might be caused by using different sets of markers because we observed that most associated markers are located near the end of 3'UTR.We found that the proximity of the polyadenylation signal site is highly conserved among human, cattle and pig, indicating that the region might contain functional elements involved in posttranscriptional control of SCD1 activity.In conclusion, our cross species study provided solid evidence to support SCD1 gene as a critical player in skeletal muscle fat metabolism.

ABSTRACT 1,2-Propanediol (1,2-PD) added exogenously to cultures or produced endogenously from l -rhamnose is metabolized to n -propanol and propionate in Listeria innocua Lin11. The pduD gene, which encodes a diol dehydratase ß subunit homolog, is required for 1,2-PD catabolism. pduD and 16 other genes within the pduA -to- pduF region of a large gene cluster are induced in medium containing 1,2-PD.

Human breast milk is a complex mixture of organic and inorganic compounds. Some compounds, such as conjugated linoleic acid (CLA), come partly from the mother's diet and are produced by the mother's body and secreted into the milk. Although several studies have examined the effect of chronic CLA supplementation on breast milk CLA appearance, little is known about the transfer of food CLA to breast milk over the short term. The objective of this study was to conduct a preliminary analysis of the kinetics of CLA appearance in breast milk over the short term. Seven women expressed breast milk at 4- to 6-hour intervals for 2 days after eating either CLA-enriched (1912 mg CLA) or control (231 mg CLA) cookies. Milk samples were freeze-dried, fatty acid methyl esters were prepared using methanolic-potassium hydroxide (KOH), and CLA isomers were quantified by gas chromatography. Analysis revealed the following: (1) CLA enrichment of total fatty acids in the breast milk for 48 hours post ingestion of the CLA-enriched cookies was 2.9-fold above control; (2) total breast milk CLA content for 48 hours post CLA-enriched cookies ingestion was 46% greater than post CLA-moderate cookies ingestion; (3) after ingestion of the CLA-enriched cookies, breast milk CLA enrichment plateaued between 8 to 28 hours. This preliminary study suggests that breast milk fatty acids are enriched in CLA compared to control within 28 hours after the ingestion of a CLA-rich food product and invites further research on the extent and timing with which breast milk composition reflects dietary CLA content.

The effect of flame-broiling on fatty acid composition of beef cattle longissimus muscle was determined. Samples of longissimus muscle were taken adjacent to the following vertebrae: thoracic 4, thoracic 12, and lumbar 6. For each sample, the entire longissimus muscle (2.54 cm) was trimmed of external fat and separated from the bone. Each steak was cut in half sagitally with one half used for cooking. Steaks were flame-broiled to achieve an internal temperature of 65°C. Raw and cooked steaks were placed into whirl-pack bags and frozen prior to being freeze-dried. Freeze-dried raw and cooked samples were ground and 125 mg of material was subjected to direct fatty acid methyl ester preparation using methanolic KOH, and analyzed by GLC. Fatty acid data were analyzed as a 3 × 2 factorial with longissimus muscle location as the first treatment factor and raw vs. cooked as the second treatment factor. Flame-broiling resulted in 63.1% moisture loss (P<0.0001); therefore, because of the variability in moisture loss, fatty acid data were expressed on a DM basis. No location × cooking interactions were detected (P≥0.14). Total fatty acid concentration was not affected by location (P=0.79) or flame-broiling (P=0.57). Weight percentages of 18:1cis-9 and 18:2cis-9, trans-11 decreased (P≤0.05) from 39.5 to 38.0% and 0.5 to 0.4% for raw vs. flame-broiled steaks, respectively. Weight percentages of 18:1trans-11 (2.2 vs. 1.6%), 17:0 (0.9 vs. 0.7%), and 15:0 (0.5 vs. 0.4%) were greater (P≤0.03) in flame-broiled than in raw steaks. Weight percentage of 18:1trans-9 tended to be greater (P=0.06) in raw (0.2%) compared to flame-broiled (0.1%) steaks. Weight percentages of other fatty acids were not affected (P=0.21 to 0.94) by flame-broiling. Neither location within the longissimus muscle nor flame-broiling, once corrected for moisture loss, affected total fatty acid concentrations, and only slight alterations occurred in fatty acid composition by flame-broiling beef longissimus muscle steaks.

The purpose of this study was to determine blood and liver lipid responses in rats to stepwise replacement of palm oil with high-stearate and high-oleate lipids with and without dietary cholesterol. Two 28-day experiments were conducted in which 12% fat (wtwt) was fed to rats in diets containing 0 (EXP1) or 0.4% cholesterol (EXP2). Nine diets were compared in each experiment: 12% palm oil was replaced in 3% increments by a high-stearate lipid (five treatments); 6% palm oil combined with 6% high-oleate safflower oil, 12% high-oleate safflower oil, 12% tallow, and 12% corn oil. Gain: consumption ratios were lower when rats were fed high-stearate fats. Plasma and liver cholesterol were greater when rats were fed 0.4% cholesterol (EXP2 compared with EXP1). The tallow diet produced the lowest plasma cholesterol in EXP1, but the highest level in EXP2. Similar plasma cholesterol levels, occurred for groups fed 12% palm oil, corn oil, and saffower oil, with or without dietary cholesterol. In EXP1, dietary treatments had little effect on liver cholesterol. In EXP2, liver cholesterol decreased as consumption of the high-stearate fat increased, and was highest with 12% saffower oil. Proportions of hepatic fatty acids generally reflected intake; however, greater (16:1 and 18:1) and lower (18:0 and 20:4) occurred in cholesterol-supplemented rats (EXP2 compared to EXP1). In conclusion, rat plasma and liver lipid responses to different dietary fats are affected by dietary cholesterol, the presence of which greatly increases liver cholesterol, liver total fat, and tallow-induced hypercholesterolemia.

The objectives of this study were to identify and quantify volatile compounds in beef that was dry aged or vacuum packaged and then oven roasted or microwave cooked. Supercritical CO2 was used to extract the volatile compounds, and gas chromatography coupled with mass spectrometry or flame ionization detection was used for analyses. Classes of compounds isolated and identified included hydrocarbons (alkanes, alkenes, aromatic), alcohols, aldehydes, acids, ketones, esters, lactones, thiazoles, pyrazines, phenols, and furans. Differences in relative proportions of certain hydrocarbons, terpenoids, aldehydes, and ketones were observed for individual combinations of cooking x packaging interactions, some of which were directly attributed to autoxidation. Results indicate that quantifying single compounds was not sufficiently accurate. Instead, using total weight percentages of chemical classes was preferable.

ABSTRACT Washed mechanically separated (MS) beef and washed hand boned (HB) beef samples were prepared with an emulsifier or silent cutter. Higher yields of washed beef were obtained with the silent cutter, but differences in composition were small. Bone particle size in MS beef was reduced with the emulsifier and the silent cutter. Washed MS beef contained more iron, fat and cholesterol than washed HB beef. Collagen content of washed MS beef was about twice as high (P < 0.05) as that of washed HB beef. The major proteins in all washed beef lots were myosin and actin. Minor differences in amino acids and fatty acids between MS beef and HP beef existed. Binding properties of washed beef and fish surimi in restructured beef steaks were similar. Overall, washed MS and HB beef are low in fat and high in protein quality and have the potential to replace much of the salt in restructured beef products.