Trans-11 CLA Research Articles

Replacing soybean meal with house cricket (Acheta domesticus) meal in ruminant diet: effects on ruminal fermentation, degradation, and biohydrogenation

Abstract Insect meals could be a sustainable protein source in ruminant diets to overcome the environmental, market, and feed-food-fuel issues associated with the widespread use of soybean meal (SBM). However, research on this topic is still very scarce. This study was conducted to examine the possibility of replacing SBM with house cricket (Acheta domesticus) meal (HCM) in ruminant feeding. Four cannulated sheep were fed a total mixed ration containing either 10% SBM (Control diet) or 10% of non-defatted HCM (Insect diet) over two consecutive periods. Effects on ruminal fermentation, degradation, and biohydrogenation were evaluated. Despite some differences in rumen dry matter and N degradation kinetics, replacing dietary SBM with HCM did not affect the ruminal disappearance of dry matter, N and, neutral detergent fibre of in situ incubated feedstuffs. Nor were there differences between the meals in the in vitro intestinal digestibility of rumen non-degraded nitrogen. The replacement had no negative effects on rumen pH or ammonia concentrations, but resulted in lower total and individual (i.e. acetate, propionate, butyrate, and minor) volatile fatty acid concentrations. This adverse effect was probably due, at least in part, to the unexpectedly high content of fat in HCM and its relatively high degree of unsaturation. Inclusion of HCM in the diet facilitated modulation of the fatty acid profile of the rumen digesta without negative effects on biohydrogenation pathways (e.g. it increased trans-11 18:1 and cis-9 trans-11 CLA concentrations, with only a small variation in the trans-10:trans-11 18:1 ratio). Replacing SBM with HCM in ruminant diets could be a promising alternative to address the challenges related to SBM and to improve the lipid composition of ruminant-derived products. However, further research is still needed to investigate, for example, the most appropriate level of inclusion of HCM in the diet or the use of defatted meal.

Phenotypic variation in milk fatty acid composition and its association with stearoyl-CoA desaturase 1 (SCD1) gene polymorphisms in Gir cows.

Individual variation in milk fatty acid (FA) composition has been partially attributed to stearoyl-CoA desaturase 1 (SCD1) gene polymorphisms in taurine breeds, but much less is known for Zebu breeds. This study investigated the phenotypic variation in milk FA composition, and the influence of SCD1 variants on this trait and on milk fat desaturase indices (DI) in Gir cows. The functional impact of SCD1 variants was predicted using bioinformatics tools. Milk and blood samples were collected from 312 cows distributed in 10 herds from five states of Brazil. SCD1 variants were identified through target sequencing, and milk FA composition was determined by gas chromatography. Phenotypic variation in milk FA composition fell within the range reported for taurine breeds, with SCD18 index showing the lowest variation among the DI. Fourteen SCD1 variants were identified, six of which not previously described. Regarding the A293V polymorphism, all cows were homozygous for the C allele (coding for alanine), whereas all genotypes were detected for the second SNP affecting the 293 codon (G > A), with compelling evidence for functional effects. Significant associations (based on raw p-values) were found between this SNP and C12:0, cis-9, trans-11 CLA and short-chain FA, and between another SNP (rs523411937) and C15:0 and odd-chain linear FA. A new SNP on Chr26:21277069 was associated with trans-11 C18:1, cis-9, trans-11 CLA, C18:3 n-3 and n-3 FA. These findings indicate that SCD1 polymorphisms also contributes to the phenotypic variation in milk FA composition of Gir cows, with potential use in their breeding programmes.

Effects of feeding graded levels of camelina expeller meal up to 10% of dietary dry matter on production and milk fatty acid profiles in dairy cows

Eight Holstein cows were used in a replicated 4 × 4 Latin square design study to determine the effects of partially replacing canola meal (CM) with 5%, 7.5%, and 10% camelina expeller meal (CEM) on production and milk fatty acid profiles. Replacing CM with CEM did not affect feed intake and milk yield, but milk contents of fat and protein decreased linearly. Feeding increasing amounts of CEM linearly increased milk contents of C18:2n6, C18:3n3, cis-9, trans-11 CLA, trans-10, cis-12 CLA, and total CLA. CEM can be fed up to 10% of dietary DM without negatively affecting production and can increase milk contents of omega-3 fatty acids.

Fatty Acid Content, Lipid Quality Indices, and Mineral Composition of Cow Milk and Yogurts Produced with Different Starter Cultures Enriched with Bifidobacterium bifidum

This study aimed to analyze the composition of fatty acids, with particular emphasis on the content of cis9trans11 C18:2 (CLA) acid, the content of minerals, and lipid quality indices in raw milk, pasteurized milk, and in yogurts produced with selected starter cultures enriched with Bifidobacterium bifidum. The GC-FID method was used to determine the fatty acid composition of those dairy products. To analyze the contents of microelements (copper, manganese, iron, and zinc) and macroelements (magnesium, calcium) flame atomic absorption spectrometry was used. The content of phosphorus was determined with the usage of the colorimetric method and the contents of sodium and potassium with emission method. Data analysis showed that such technologies as milk pasteurization and milk fermentation had a significant impact on the fatty acid profile and contents of micro- and macroelements. The lipid quality indices: atherogenicity index (AI), index thrombogenicity (TI), hypocholesterolemic/hypercholesterolemic index (H/H), and (n − 6)/(n − 3) ratio, were at similar levels in raw and pasteurized milk and yogurts produced. Starter culture type affected the content of cis-9, trans-11 CLA C18:2 acid in yogurts. Out of the starter cultures applied in the study, only the FD-DVS YC-X16 Yo-Flex starter culture with BB-12 caused a significant (p < 0.05) increase in CLA content. The CLA content of the yogurts produced using this starter culture was 2.67 mg/g fat. In raw milk, pasteurized milk, and the second batch of yogurts, the content of cis-9, trans-11 C18:2 acid was significantly lower and reached 2.26 mg/g fat, 2.17 mg/g fat, and 2.30 mg/g fat, respectively. The study indicated that, when it comes to being a source of minerals, yogurts were better than milk. Yogurts were also characterized by significantly (p < 0.05) higher contents of all micro- and macroelements taken into account in this study than the raw milk used to produce them.

Replacing corn with full-fat corn germ in a basal diet containing cactus (Opuntia stricta) cladodes and sugarcane as forage sources induces milk fat depression associated with the trans-10 shift in dairy cows

Recent evidence indicates that associating cactus Opuntia cladodes with plant oils represents a promising strategy to increase the nutritional value of milk fat. This study aimed to investigate the effects of full-fat corn germ (FFCG), as an alternative to plant oils, on production variables, blood metabolites, and milk fatty acid (FA) composition of dairy cows fed a basal diet containing cactus (Opuntia stricta) cladodes and sugarcane as forages. Ten multiparous Holstein cows with 90 ± 10 d of lactation and yielding 24.2 ± 3.5 kg milk/d were assigned to dietary treatments consisting of 0, 4 (low level; LL), 8 (moderate level; ML), 12 (high level; HL), and 16% (very high level; VHL) of FFCG (DM basis) in a replicated 5 × 5 Latin square design with 21-d periods. DM intake decreased linearly from 18.9 to 16.4 kg/d, whereas a quadratic response was observed for milk yield, which increased 1.7 kg/d from control to ML, and decreased to a similar extent as FFCG further increased in the diet, resulting in a quadratic increase in gross feed efficiency (GFE). Milk protein and lactose contents were unaltered, but milk fat content gradually dropped from 3.49% to 2.23%, which was accompanied by a progressive decrease in milk fat yield and fat-corrected milk yield. Serum cholesterol levels markedly increased from 756 to 1480 mg/L, but other blood metabolites were unaltered. Except for trans-16:1 isomers, proportions of short and medium-chain FA in milk fat decreased in a linear or quadratic fashion as FFCG increased in the diet, whereas the opposite was observed for 18:0 and of 18:1/18:2 isomers, including those with conjugated double bonds. In particular, a trans-11 to trans-10 shift occurred with moderate to higher FFCG levels, resulting in a quadratic change in trans-11 18:1 and cis-9, trans-11 CLA, and a linear increase in trans-10 18:1, trans-10, cis-12 CLA and trans-9, cis-11 CLA. The n-6:n-3 ratio in milk nearly doubled with increasing FFCG, mostly due to a pronounced increase in 18:2 n-6. Proportions of odd-linear and branched-chain FA in milk fat decreased in a quadratic and linear fashion, respectively, with increasing FFCG. These results indicate that FFCG can be an effective source of PUFA for increasing rumen outflow of biohydrogenation intermediates in cows fed cactus Opuntia cladodes as a partial substitute for sugarcane. The marked milk fat depression induced by FFCG suggests that the basal diet was unable to maintain a healthy rumen environment.

The effect of dietary rumen-protected trans-10,cis-12 conjugated linoleic acid or a milk fat-depressing diet on energy metabolism, inflammation, and oxidative stress of dairy cows in early lactation

The objective of this study was to determine the effects of milk fat depression induced by supplementing conjugated linoleic acid (CLA; trans-10,cis-12 and cis-9,trans-11 CLA) or feeding a higher starch and oil-containing diet (HSO) on metabolic changes in dairy cows after calving. The main hypothesis was that the 2 strategies to decrease milk fat yield could have different effects on performance, energy balance (EB), and inflammatory status in early lactation. Thirty-three Nordic Red dairy cows were used in a randomized block design from 1 to 112 d of lactation and fed one of the following treatments: control (CON), CLA-supplemented diet, or HSO diet. Dry matter intake and milk yield were measured daily whereas milk composition was measured weekly throughout the experiment. Nutrient digestibility, EB, and plasma hormones and metabolites were measured at 3, 7, 11, and 15 wk of lactation in respiration chambers. The HSO diet led to lower intakes of dry matter, neutral detergent fiber, and gross energy compared with CON and CLA diets. The CLA diet and especially the HSO diet resulted in lower energy-corrected milk yield during the first 7 wk of lactation than those fed CON. The EB was numerically higher for HSO and CLA diets compared with CON at wk 3 and 7. Plasma glucose concentration was higher by the CLA diet at wk 3 and by the HSO diet from wk 3 to 15 compared with CON. Plasma nonesterified fatty acids were higher at wk 3 in the CON group (indicating more lipid mobilization) but decreased thereafter to similar levels with the other groups. The HSO-fed cows had higher plasma ceruloplasmin, paraoxonase, and total bilirubin concentrations in the entire experiment and showed the highest levels of reactive oxygen metabolites. These results suggest an increased inflammatory and oxidative stress state in the HSO cows and probably different regulation of the innate immune system. This study provides evidence that milk fat depression induced by feeding HSO (as well as CLA) decreased milk fat secretion and improved EB compared with CON in early lactation. The increase in plasma glucose and paraoxonase levels with the HSO diet may imply a better ability of the liver to cope with the metabolic demand after parturition. However, the negative effect of HSO on feed intake, and the indication of increased inflammatory and oxidative stress warrant further studies before the HSO feeding strategy could be supported as an alternative to improve EB in early lactation.

Effect of lipid supplementation on the endogenous synthesis of milk cis-9,trans-11 conjugated linoleic acid in dairy sheep and goats: A tracer assay with 13C-vaccenic acid

A major proportion of milk rumenic acid (RA; cis-9,trans-11 CLA) is synthesized through mammary Δ9-desaturation of vaccenic acid (VA; trans-11 18:1). Diet composition may determine the relative contribution of this endogenous synthesis to milk RA content, with effects that might differ between ruminant species. However, this hypothesis is mostly based on estimated values, proxies of stearoyl-CoA desaturase (SCD) activity, and indirect comparisons between publications in the literature. With the aim of providing new insights into this issue, in vivo Δ9-desaturation of 13C-labeled VA (measured via milk 13C-VA and -RA secretion) was directly compared in sheep and goats fed a diet without lipid supplementation or including 2% of linseed oil. Four Assaf sheep and 4 Murciano-Granadina goats were used in a replicated 2 × 2 crossover design to test the effects of the 2 dietary treatments during 2 consecutive 25-d periods. On d 22 of each period, 500 mg of 13C-VA were i.v. injected to each animal. Dairy performance, milk fatty acid profile, including isotope analysis, and mammary mRNA abundance of genes coding for SCD were examined on d 21 to 25 of each period. Supplementation with linseed oil improved milk fat concentration and increased the content of milk VA and RA. However, the isotopic tracer assay suggested no variation in the relative proportion of VA desaturated to milk RA, and the percentage of this CLA isomer deriving from SCD activity would remain constant regardless of dietary treatment. These results put into question a major effect of lipid supplementation on the endogenous synthesis of milk RA and support that mammary Δ9-desaturation capacity would not represent a limiting factor when designing feeding strategies to increase milk RA content. The lack of diet-induced effects was common to caprines and ovines, but inherent interspecies differences in mammary lipogenesis were found. Thus, the higher proportions of VA desaturation and endogenous synthesis of milk RA in sheep supported a greater SCD activity compared with goats, a finding that was not associated with the similar mRNA abundance of SCD1 in the 2 species. On the other hand, transfer efficiency of the isotopic tracer to milk was 37% higher in caprine than in ovine, suggesting a greater efficiency in mammary fatty acid uptake from plasma in caprine.

Physicochemical, nutritional, and sensory attributes of Minas frescal cheese from grazing cows fed a supplement containing different levels of babassu coconut (Orbignyaspeciosa)

Alternative feeds can reduce milk production costs, but quality attributes of dairy products may also be affected. The physicochemical, sensory, and fatty acid (FA) profiles of Minas frescal cheese produced from grazing cows fed different levels of cracked babassu coconut (CBC) were investigated in the present study. Actual and adjusted cheese yields in kg cow−1 d−1 decreased as CBC levels increased in the supplement. Physicochemical composition was unaltered, whereas proportions of trans-11 18:1 and cis-9, trans-11 CLA linearly increased in cheese from cows fed increasing CBC levels. Conversely, the n-6:n-3 FA ratio showed a linear decreasing pattern. Yellow intensity decreased linearly, whereas a quadratic response was observed for aroma and appearance scores. In conclusion, feeding CBC to grazing cows induces beneficial changes in FA composition and other quality attributes of Minas frescal cheese, but cheese yield in kg cow−1 d−1 is strongly reduced, limiting the use of CBC in dairy cow diets.

Suppression of amyloid-β secretion from neurons by cis-9, trans-11-octadecadienoic acid, an isomer of conjugated linoleic acid.

Two common conjugated linoleic acids (LAs), cis-9, trans-11 CLA (c9,t11 CLA) and trans-10, cis-12 CLA (t10,c12 CLA), exert various biological activities. However, the effect of CLA on the generation of neurotoxic amyloid-β (Aβ) protein remains unclear. We found that c9,t11 CLA significantly suppressed the generation of Aβ in mouse neurons. CLA treatment did not affect the level of β-site APP-cleaving enzyme 1 (BACE1), a component of active γ-secretase complex presenilin 1 amino-terminal fragment, or Aβ protein precursor (APP) in cultured neurons. BACE1 and γ-secretase activities were not directly affected by c9,t11 CLA. Localization of BACE1 and APP in early endosomes increased in neurons treated with c9,t11 CLA; concomitantly, the localization of both proteins was reduced in late endosomes, the predominant site of APP cleavage by BACE1. The level of CLA-containing phosphatidylcholine (CLA-PC) increased dramatically in neurons incubated with CLA. Incorporation of phospholipids containing c9,t11 CLA, but not t10,c12 CLA, into the membrane may affect the localization of some membrane-associated proteins in intracellular membrane compartments. Thus, in neurons treated with c9,t11 CLA, reduced colocalization of APP with BACE1 in late endosomes may decrease APP cleavage by BACE1 and subsequent Aβ generation. Our findings suggest that the accumulation of c9,t11 CLA-PC/LPC in neuronal membranes suppresses the production of neurotoxic Aβ in neurons.

Effect of Dietary Supplementation with Lipids of Different Unsaturation Degree on Feed Efficiency and Milk Fatty Acid Profile in Dairy Sheep.

Simple SummaryThe use of fats derived from palm is becoming very common in dairy sheep farms to increase the energy concentration of the diet and therefore the milk production. However, these fats may negatively affect the nutritional quality of milk, whereas feeding unsaturated oils may improve milk fatty acid profile. In this regard, our results in dairy sheep suggested that using palm fat had no evident disadvantage in terms of milk fatty acid composition compared with a diet without supplementation. Nevertheless, it had no positive effects on production or indicators of feed efficiency (for example, milk yield per unit of feed consumed). By contrast, supplementation with oils rich in unsaturated fatty acids (specifically olive oil and soybean oil) improved milk fatty acid profile, with stronger effects with the use of the most unsaturated fat: soybean oil. For example, the latter oil induced the greatest increases in fatty acids with potentially positive effects on human health (e.g., conjugated linoleic acid). In addition, from a practical point of view, the use of soybean oil might also be recommendable to improve the amount of milk produced per unit of feed consumed, compared with the use of palm fat.Lipids of different unsaturation degree were added to dairy ewe diet to test the hypothesis that unsaturated oils would modulate milk fatty acid (FA) profile without impairing or even improving feed efficiency. To this aim, we examined milk FA profile and efficiency metrics (feed conversion ratio (FCR), energy conversion ratio (ECR), residual feed intake (RFI), and residual energy intake (REI)) in 40 lactating ewes fed a diet with no lipid supplementation (Control) or supplemented with 3 fats rich in saturated, monounsaturated and polyunsaturated FA (i.e., purified palmitic acid (PA), olive oil (OO), and soybean oil (SBO)). Compared with PA, addition of OO decreased milk medium-chain saturated FA and improved the concentration of potentially health-promoting FA, such as cis-9 18:1, trans-11 18:1, cis-9 trans-11 CLA, and 4:0, with no impact on feed efficiency metrics. Nevertheless, FA analysis and decreases in FCR and ECR suggested that SBO supplementation would be a better nutritional strategy to further improve milk FA profile and feed efficiency in dairy ewes. The paradox of differences observed depending on the metric used to estimate feed efficiency (i.e., the lack of variation in RFI and REI vs. changes in FCR and ECR) does not allow solid conclusions to be drawn in this regard.

The inhibitory effect of trans-10,cis-12 conjugated linoleic acid on sterol regulatory element binding protein-1 activation in bovine mammary epithelial cells involved reduced proteasomal degradation of insulin-induced gene-1

Trans-10,cis-12 conjugated linoleic acid (t10,c12 CLA) is well recognized as a key CLA isomer responsible for the reduction in milk fat synthesis that leads to milk fat depression in dairy cows. Sterol regulatory element binding protein-1 (SREBP1) is a key transcription factor in bovine mammary gland coordinating transcription of the genes for fatty acid synthesis. SREBP1 activation requires the removal of insulin-induced gene-1 (Insig1) that serves as a repressor of SREBP1 in the endoplasmic reticulum (ER). We hypothesized that t10,c12 CLA reduced SREBP1 activation by delaying Insig1 degradation. In the present study, we used undifferentiated bovine mammary epithelial cells (MAC-T cells) and treated them with t10,c12 CLA for 6 h. We found that SREBP1 protein expression declined over 56% when cells were treated with 60 µM or greater concentration of t10,c12 CLA. Such inhibitory effects were also observed in the mRNA expression of SREBP1-regulated genes including SREBP1, fatty acid synthetase, stearoyl-CoA desaturase, and Insig1. Compared with no CLA group, 60 µM or higher concentration of t10,c12 CLA increased Insig1 protein expression over 2-fold in cells transfected with FLAG-tagged Insig1. This stimulatory effect was not specific to t10,c12 CLA but also other polyunsaturated fatty acids including cis-9,trans-11 CLA and linoleic acid. Oleic acid had no effect on Insig1 protein expression, whereas palmitic acid decreased Insig1 protein expression. Further investigation revealed that increased abundance of FLAG-Insig1 with t10,c12 CLA was due to the inhibition of the proteasomal degradation of Insig1. The t10,c12 CLA delayed the Insig1 decay when protein synthesis was blocked. Immunoprecipitation also confirmed that the interaction between ubiquitin-like domain-containing protein 8 and Insig1, the key step of removing Insig1 from ER and freeing SREBP1 for proteolytic processing, was inhibited by t10,c12 CLA, but not palmitic acid. These findings suggested that t10,c12 CLA played a role in regulating SREBP1 activation by reducing proteasomal degradation of Insig1. We concluded that stabilized Insig1 retained SREBP1 in the ER from activation, thus reducing lipogenic gene transcription.

Meta-analysis to evaluate the effect of including molasses in the diet for dairy cows on performance, milk fat synthesis and milk fatty acid

Different types of molasses have been included in diets for ruminant animals, mainly as a substitute for energetic ingredients, such as corn and sorghum. However, the positive effect of this inclusion on the performance, fatty acid profile and composition of cows’ milk is not yet clear. In this sense, this study aimed to evaluate by meta-analysis the effect of including molasses in diets for dairy cows on the milk fatty content and fatty acid in milk. The eleven peer-reviewed publications with 52 treatments means were included in data set. The effect of including molasses in the diet of dairy cows were evaluated using random effect models to examine the weighted mean differences (WMD) between molasses treatment (diets with molasses inclusion) and control treatment (without molasses inclusion in the diet). Heterogeneity was explored by meta-regression and subgroup analysis considering genetic group, days in milk, molasses in the diet (g/kg DM), type of molasses, concentrate in the diet (g/kg DM). The covariates genetic group and days in milk influenced most the variability of responses to the inclusion of molasses in the diet for dairy cows. Molasses supplementation to dairy cow diets negatively impacted animal performance and milk composition by reducing milk yield and milk protein, lactose yield and concentration (with inclusions levels of molasses greater than 60 g/kg of DM). However, inclusions of molasses up to 120 g/kg of DM in diet, did not affect the yield and concentration of fat in milk. The inclusions of molasses in the diet caused a reduction in the concentration of unsaturated fatty acids (Total UFA -10.67%); however, it increased the concentration of omega-3 fatty acids in milk (11.52%), without affecting total of polyunsaturated fatty acids and C18: 2 cis-9, trans-11 CLA.

Targeted assessment of the metabolome in skeletal muscle and in serum of dairy cows supplemented with conjugated linoleic acid during early lactation

In the dairy cow, late gestation and early lactation are characterized by a complexity of metabolic processes required for the homeorhetic adaptation to the needs of fetal growth and milk production. Skeletal muscle plays an important role in this adaptation. The objective of this study was to characterize the metabolome in skeletal muscle (semitendinosus muscle) and in serum of dairy cows in the context of the physiological changes occurring in early lactation and to test the effects of dietary supplementation (from d 1 in milk onwards) with conjugated linoleic acids (sCLA; 100 g/d; supplying 7.6 g of cis-9,trans-11 CLA and 7.6 g of trans-10,cis-12 CLA per cow/d; n = 11) compared with control fat-supplemented cows (CTR; n = 10). The metabolome was characterized in skeletal muscle samples collected on d 21 and 70 after calving in conjunction with their serum counterpart using a targeted metabolomics approach (AbsoluteIDQ p180 kit; Biocrates Life Sciences AG, Innsbruck, Austria). Thereby 188 metabolites from 6 different compound classes (acylcarnitines, amino acids, biogenic amines, glycerophospholipids, sphingolipids, and hexoses) were quantified in both sample types. In both groups, dry matter intake increased after calving. It was lower in sCLA than in CTR on d 21, which resulted in reduced calculated net energy and metabolizable protein balances. On d 21, the concentrations of dopamine, Ala, and hexoses in the skeletal muscle were higher in sCLA than in CTR. On d 21, the changed metabolites in serum were mainly long-chain (>C24) diacyl phosphatidylcholine PC (PC-aa) and acyl-alkyl phosphatidylcholine (PC-ae), along with lysophosphatidylcholine acyl (lysoPC-a) C26:1 that were all lower in sCLA than in CTR. Supplementation with CLA affected the muscle concentrations of 22 metabolites on d 70 including 10 long-chain (>C22) sphingomyelin (SM), hydroxysphingomyelin [SM(OH)], PC-aa, and PC-ae along with 9 long-chain (>C16) lysoPC-a and 3 metabolites related to amino acids (spermine, citrulline, and Asp). On d 70, the concentrations of lysoPC-a C18:2 and C26:0 in serum were higher in the sCLA cows than in the CTR cows. Regardless of treatment, the concentrations of Ile, Leu, Phe, Lys, His, Met, Trp, and hydroxybutyrylcarnitine (C4-OH) decreased, whereas those of ornithine, Gln, and trans-4-hydroxyproline (t4-OH-Pro) increased from d 21 to 70 in muscle. The significantly changed metabolites in serum with time of lactation were 28 long-chain (>C30) PC-ae and PC-aa, 7 long-chain (>C16) SM and SM(OH), along with lysoPC-a C20:3 that were all increased. In conclusion, in addition to other significantly changed metabolites, CLA supplementation mainly led to changes in muscle and serum concentrations of glycerophospholipids and sphingolipids that might reflect the phospholipid compositional changes in muscle. The metabolome changes observed in sCLA on d 21 seem to be, at least in part, due to the lower DMI in these cows. The changes in the muscle concentrations of AA from d 21 to 70, which coincided with the steady energy and MP balances, might reflect a shift of protein synthesis/degradation balance toward synthesis.

Prebiotic dietary fibre intervention improves fecal markers related to inflammation in obese patients: results from the Food4Gut randomized placebo-controlled trial

PurposeInulin-type fructans (ITF) are prebiotic dietary fibre (DF) that may confer beneficial health effects, by interacting with the gut microbiota. We have tested the hypothesis that a dietary intervention promoting inulin intake versus placebo influences fecal microbial-derived metabolites and markers related to gut integrity and inflammation in obese patients.MethodsMicrobiota (16S rRNA sequencing), long- and short-chain fatty acids (LCFA, SCFA), bile acids, zonulin, and calprotectin were analyzed in fecal samples obtained from obese patients included in a randomized, placebo-controlled trial. Participants received either 16 g/d native inulin (prebiotic n = 12) versus maltodextrin (placebo n = 12), coupled to dietary advice to consume inulin-rich versus inulin-poor vegetables for 3 months, in addition to dietary caloric restriction.ResultsBoth placebo and prebiotic interventions lowered energy and protein intake. A substantial increase in Bifidobacterium was detected after ITF treatment (q = 0.049) supporting our recent data obtained in a larger cohort. Interestingly, fecal calprotectin, a marker of gut inflammation, was reduced upon ITF treatment. Both prebiotic and placebo interventions increased the ratio of tauro-conjugated/free bile acids in feces. Prebiotic treatment did not significantly modify fecal SCFA content but it increased fecal rumenic acid, a conjugated linoleic acid (cis-9, trans-11 CLA) with immunomodulatory properties, that correlated notably to the expansion of Bifidobacterium (p = 0.031; r = 0.052).ConclusionsOur study demonstrates that ITF-prebiotic intake during 3 months decreases a fecal marker of intestinal inflammation in obese patients. Our data point to a potential contribution of microbial lipid-derived metabolites in gastro-intestinal dysfunction related to obesity.ClinicalTrials.gov IdentifierNCT03852069 (February 22, 2019 retrospectively, registered).

Meta-analysis of the effect of glycerin inclusion in dairy cattle diet on milk fatty acid profile.

The use of glycerin in diets for dairy cows initially emerged as an alternative for the prevention and control of ketosis. However, despite some controversy, there are still several studies associating glycerin with increases in daily milk yield, with possible changes in its constituents. Therefore, the objective of this study was to evaluate, using a meta-analysis approach, the effect of glycerin inclusion in dairy cow diets on milk fatty acid. Twenty-two peer-reviewed publications with 66 treatment means were included in data set. The effect of glycerin inclusion in diet (treatment) were evaluated using random-effect models to examine the weighted mean differences (WMD) between a control diet (without glycerin in the diet) and the treatment diet. Heterogeneity was explored by meta-regression and subgroup analysis performed for: genetic type; days in milk; experimental period; glycerin in diet; glycerin type and concentrate in diet. Inclusion of glycerin in the diet increased the digestibility of dry matter and protein, as well as ruminal propionate. It did not affect dry matter intake (P = 0.351) and milk yield (P = 0.730). The effect of glycerin inclusion on the milk fat yield is dependent on the genetic group, in which Holstein (WMD = −0.04 kg/d; P = 0.010) and Holstein-crossbreed (WMD = −0.10 kg/d; P < 0.0001) cows produced less fat in milk compared to Jersey cows, when glycerin was included in the diets. Glycine inclusions of up to 100 g/kg in the diet of dairy cows did not negatively affect milk production and composition. However, inclusions above 150 g/kg of glycerin in the diet reduced the concentration of fat, and of unsaturated, monounsaturated, polyunsaturated fatty acids and conjugated linoleic acid (CLA C18: 2 cis-9 and trans-11) in milk. The results reported in our meta-analysis does not demonstrate the effectiveness of glycerin in improving the composition of milk and a group of fatty acids of importance for human health such as C18: 2 cis-9, trans-11 CLA.

Partially replacing sorghum silage with cactus (Opuntia stricta) cladodes in a soybean oil-supplemented diet markedly increases trans-11 18:1, cis-9, trans-11 CLA and 18:2 n-6 contents in cow milk.

Based on low 18:0 contents observed in milk fat of cows fed cactus cladodes (CC), we hypothesized that including Opuntia stricta cladodes in a soybean oil (SO)-supplemented diet would promote incomplete rumen biohydrogenation of supplemental PUFA, leading to increased trans-11 18:1 and cis-9, trans-11 CLA contents in milk. Twelve Holstein cows were used in a two-period study: (a) Baseline: all cows received a total mixed ration (TMR) composed of sorghum silage (SS) and a concentrate containing no SO for 14days; (b) Treatment: cows received one of the following SO-supplemented diets for 21days: (1) SS-TMR: a TMR composed of SS and a SO-enriched concentrate, (2) CC-TMR: a TMR containing CC as a partial substitute for SS plus the SO-enriched concentrate, and (3) CC-PMR: same diet as in treatment 2, but CC were mixed with the SO-enriched concentrate and fed as a partial mixed ration (PMR). Both CC diets increased relative abundances of trans-11 18:1, cis-9, trans-11 CLA, and 18:2 n-6 in milk fat, whereas opposite effects were observed on 18:0 and cis-9 18:1. Proportion of 18:2 n-6 increased, and cis-9, trans-11 CLA tended to increase with CC-PMR as compared to CC-TMR, whereas 18:3 n-3 was higher with CC-PMR than with SS-TMR. Proportions of several odd- and branched-chain fatty acids, certain 18:1 isomers, and trans-9, cis-11 CLA changed with CC diets, notably with CC-PMR. Milk yield and intake of most nutrients (except fibre) increased or tended to increase with the CC diets, whereas gross milk composition was unaltered. Stearoyl-CoA desaturase-1 index for C18 (SCD18 ) was higher with CC-PMR than with SS-TMR, and milk n-6:n-3 FA ratio and apparent transfer of 18:2 n-6 to milk increased with CC diets. These results indicate that Opuntia stricta cladodes can be a valuable feed ingredient for improving the nutraceutical value of milk fat.

Identifying and exploring biohydrogenating rumen bacteria with emphasis on pathways including trans-10 intermediates

BackgroundBacteria involved in ruminal formation of trans-10 intermediates are unclear. Therefore, this study aimed at identifying rumen bacteria that produce trans-10 intermediates from 18-carbon unsaturated fatty acids.ResultsPure cultures of 28 rumen bacterial species were incubated individually in the presence of 40 μg/mL 18:3n-3, 18:2n-6 or trans-11 18:1 under control or lactate-enriched (200 mM Na lactate) conditions for 24 h. Of the 28 strains, Cutibacterium acnes (formerly Propionibacterium acnes) was the only bacterium found to produce trans-10 intermediates from 18:3n-3 and 18:2n-6, irrespective of the growth condition. To further assess the potential importance of this species in the trans-11 to trans-10 shift, different biomass ratios of Butyrivibrio fibrisolvens (as a trans-11 producer) and C. acnes were incubated in different growth media (control, low pH and 22:6n-3 enriched media) containing 40 μg/mL 18:2n-6. Under control conditions, a trans-10 shift, defined in the current study as trans-10/trans-11 ≥ 0.9, occurred when the biomass of C. acnes represented between 90 and 98% of the inoculum. A low pH or addition of 22:6n-3 inhibited cis-9, trans-11 CLA and trans-10, cis-12 CLA formation by B. fibrisolvens and C. acnes, respectively, whereby C. acnes seemed to be more tolerant. This resulted in a decreased biomass of C. acnes required at inoculation to induce a trans-10 shift to 50% (low pH) and 90% (22:6n-3 addition).ConclusionsAmong the bacterial species studied,C. acnes was the only bacterium that have the metabolic ability to produce trans-10 intermediates from 18:3n-3 and 18:2n-6. Nevertheless, this experiment revealed that it is unlikely that C. acnes is the only or predominant species involved in the trans-11 to trans-10 shift in vivo.

Effects of Dietary Fatty Acids on Bovine Oocyte Competence and Granulosa Cells.

Here we assessed the effects of dietary essential fatty acids on the developmental competence of oocytes in cows and on the functionality of follicular granulosa cells (GC). Lactating German Holstein cows were supplemented from week 9 ante partum (ap) until week 8 post-partum (pp) in four dietary groups designed as (i) control (CTRL: coconut oil), (ii) essential fatty acid (EFA: linseed and safflower oil), (iii) conjugated linoleic acid (CLA: Lutalin®), and (iv) EFA+CLA (mixture of linseed oil, safflower oil and Lutalin®). EFA, CLA or EFA+CLA supplementation did not improve in vitro embryo production. However, higher proportions of α-linolenic acid (ALA) and cis-9, trans-11 CLA were observed in the follicular fluid suggesting the exposure of GC to relatively high levels of ALA and cis-9, trans-11 CLA. Consequently, we tested different concentrations of ALA and cis-9, trans-11 CLA in a bovine GC culture model for their effects on steroid production, marker gene expression and viability. Both fatty acids upregulated CD36 and downregulated the expression of FOXL2, while ALA significantly increased SOX 9 transcript levels. Both ALA and cis-9, trans-11 CLA reduced the CCND2 expression and cis-9, trans-11 CLA induced apoptosis. ALA and cis-9, trans-11 CLA significantly down-regulated the expression of STAR, CYP19A1, FSHR, LHCGR and decreased the 17β-Estradiol (E2) and progesterone (P4) production. In conclusion, dietary lipids did not improve in vitro embryo production, while ALA and cis-9, trans-11 CLA affected the morphology and functionality of GC. This could suggestively lead to compromised follicle development and ovarian cyclicity in dairy cows.

Use of Cold-Pressed Sunflower Cake in the Concentrate as a Low-Input Local Strategy to Modify the Milk Fatty Acid Profile of Dairy Cows.

Simple SummaryConsumers demand healthier dairy products. Supplementing plant lipids, rich in poliunsaturated fatty acids, results in improved milk fatty acid profile, but these oils could enter into competition with human food needs and compromise animal performance. The aim of this study was to test the feasibility of formulating cold-pressed sunflower cake (CPSC, high-fat by-product) in a dairy cows’ concentrate to improve milk fatty acid profile. Cold-pressed sunflower cake increased total trans-mono unsaturated fatty acids (21%), total conjugated linoleic acid (31%), and polyunsaturated fatty acids to saturated fatty acids ratio (18%), but did not affect milk production, digestibility, intake, and milk composition. However, reduced fat yield (9%) and fat corrected milk (7%) were observed. Feeding CPSC improved overall acceptability of milk by improving flavor. In conclusion, CPSC could modify milk FA profile without observing a detrimental effect on digestibility, production performance, or milk acceptance. Adopting feeding systems based on the use of cheaper and local alternative feedstuffs rich in polyunsaturated fatty acids would represent a good strategy to change milk fatty acid profile and contribute the promotion of low-input production systems.Cold-pressed sunflower cake (CPSC) is a cheap by-product of oil-manufacturing. Supplementing diets with CPSC, rich in fat and linoleic acid, could be an effective tool for increasing healthy fatty acids (FA) in milk. To test this hypothesis, 10 cows were used in a crossover design with two experimental diets fed during two 63-day periods. Cows’ milk production was recorded and samples were taken for fat, protein, lactose, and for FA composition analysis. Dry matter intake (DMI) and dry matter apparent digestibility (DMD) were estimated using two markers. Milk acceptance test was carried out. CPSC decreased milk C12:0 (10%, p = 0.023) and C16:0 (5%, p = 0.035) and increased C18:1 cis-12 (37%, p = 0.006), C18:1 trans-11 (32%, p = 0.005), C18:2 cis-9 cis-12 (13%, p = 0.004), and cis-9 trans-11 CLA (35%, p = 0.004). CPSC increased total trans-monounsaturated FA (21%, p = 0.003), total CLA (31%, p = 0.007), and PUFA:SFA ratio (18%, p = 0.006). CPSC did not affect milk production, DMD, DMI and milk composition, but reduced fat yield (9%, p = 0.013) and FCM (7%, p = 0.013). CPSC improved milk overall acceptability. In conclusion, CPSC could modify milk FA profile without a detrimental effect on digestibility, production performance, or milk acceptance.

CONJUGATED LINOLEIC ACID AND CANCER IN HUMANS-IS THERE A ROLE OR NOT? A REVIEW OF THE SCIENTIFIC EVIDENCE

Conjugated linoleic acids are naturally occurring fatty acids that are found predominantly in ruminant meat, milk and dairy products. They are composed mainly of two isomers: cis-9, trans-11 and trans-10, cis-12 fatty acid. Their synthesis occurs mainly by the action of ruminal bacteria, Butyrivibrio Fibrisolvens, and a host of lactic acid bacteria, which isomerize linoleic acid to CLA or by synthesis via α9-desaturase of 11-trans octadecanoic acid, and, through desaturation of free linoleic acid or other unsaturated fatty acids. Although cis-9, trans-11 and trans-9, trans-11 CLA isomers have consistently shown anti-carcinogenicity on animal models and on cancerous human cells, results from clinical trials are inconclusive and conflicting. Despite most of the data on humans being mainly from epidemiological studies, a few clinical studies with breast and colorectal cancer sufferers have shown some promise. Controlled, long-term, racial and gender diverse, geographically spread clinical studies are required to understand the link between CLA intake and incidence of human cancers.