Dietary Fatty Acid Composition Impacts the Fatty Acid Profiles of Different Regions of the Bovine Brain.

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.

Predicting residual feed intake status using rumen microbial profiles in ewe lambs1.

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.

Fatty acid composition in native bees: Associations with thermal and feeding ecology.

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 sheep increases fatty acid synthesis, upregulates nutrient transporters, and increases adiposity in adult male offspring after a feeding challenge.

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.

Prostaglandin E2 production in mice is reduced by consumption of range-fed sources of red meat.

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.

Dietary omega-3 fatty acids differentially influence ova release and ovarian cyclooxygenase-1 and cyclooxygenase-2 expression in rats.

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 PGE(2) and PGF(2alpha) release without altering COX-1 or COX-2 expression. Conversely, ovarian COX-1 expression was increased 135% with stearidonic acid ingestion associated with increased PGF(2alpha) without altering PGE(2) 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 PGF(2alpha) 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.

Human breast milk enrichment in conjugated linoleic acid after consumption of a conjugated linoleic acid-rich food product: a pilot study.

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.

Significant associations of stearoyl-CoA desaturase (SCD1) gene with fat deposition and composition in skeletal muscle.

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.

Exogenous or L-rhamnose-derived 1,2-propanediol is metabolized via a pduD-dependent pathway in Listeria innocua.

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.

Maternal undernutrition from early- to mid-gestation leads to growth retardation, cardiac ventricular hypertrophy, and increased liver weight in the fetal sheep.

Early gestation is critical for placentomal growth, differentiation, and vascularization, as well as fetal organogenesis. The fetal origins of adult disease hypothesis proposes that alterations in fetal nutrition and endocrine status result in developmental adaptations that permanently change structure, physiology, and metabolism, thereby predisposing individuals to cardiovascular, metabolic, and endocrine disease in adult life. Multiparous ewes were fed to 50% (nutrient restricted) or 100% (control fed) of total digestible nutrients from Days 28 to 78 of gestation. All ewes were weighed weekly and diets adjusted for individual weight loss or gain. Ewes were killed on Day 78 of gestation and gravid uteri recovered. Fetal body and organ weights were determined, and numbers, morphologies, diameters, and weights of all placentomes were obtained. From Day 28 to Day 78, restricted ewes lost 7.4% of body weight, while control ewes gained 7.5%. Maternal and fetal blood glucose concentrations were reduced in restricted versus control pregnancies. Fetuses were markedly smaller in the restricted group than in the control group. Further, restricted fetuses exhibited greater right- and left-ventricular and liver weights per unit fetal weight than control fetuses. No treatment differences were observed in any gross placentomal measurement. However, caruncular vascularity was enhanced in conceptuses from nutrient-restricted ewes but only in twin pregnancies. While these alterations in fetal/placental development may be beneficial to early fetal survival in the face of a nutrient restriction, their effects later in gestation as well as in postnatal life need further investigation.