Contrasted effects of dietary extruded linseed supplementation on carotenoid and liposoluble vitamin status in lactating Holstein or Montbéliarde cows fed hay or corn silage.

Cow milk and dairy products have a good nutritional value that could be improved by increasing the concentrations of several compounds such as carotenoids and liposoluble vitamins A and E. Their concentrations in milk are dependent on their respective dietary intakes, but the transfer from feeds to milk seems to be limited by dietary, digestive, or metabolic factors linked to lipids that could differ between dairy breeds. The effect of dietary fat supplement (provided as extruded linseed) on carotenoid, vitamin E, and vitamin A status as well as their transfer from diet to milk were explored in mid-lactating dairy cows (Holstein or Montbéliarde breed) receiving either corn silage or hay as the main forage. Carotenoid and tocopherol status were higher in cows fed hay than in those fed corn silage, both at the plasma and milk level. The transfer rate for carotenoids was the same regardless of forage, whereas the transfer rate for tocopherols was greater (1.71 vs. 1.20%, respectively) for cows fed hay compared with corn silage. Cows fed extruded linseed had greater plasma concentrations of tocopherols (+25%) compared with those that did not, regardless of forage, but linseed treatment only changed xanthophyll (+35%) concentrations. This would suggest that the lipid supplement increased the availability of xanthophylls and tocopherols for the cows. However, carotenoid transfer into milk remained low and unaffected by the lipid supplement, whatever the forage nature, suggesting a limiting unknown process. Carotenoid status was marginally different between breeds because plasma concentrations were higher in Montbéliarde cows besides lower intakes. In milk, 13-E-ß-carotene concentration was also higher for Montbéliarde cows because of a 2-fold higher transfer rate than for Holstein cows. In contrast, Holstein cows had higher transfer rates of α-tocopherol and vitamin A activity, linked to higher milk fat yield. For the first time, this study proposed an evaluation of the transfer rate of lipid micronutrients from diet to milk in cows. The study highlighted that these compounds follow distinct patterns of regulation during their transfer. However, in these experimental conditions, it was not possible to show that a dietary fat supplement could increase the concentration of these compounds in milk fat.

Nutrigenetics of carotenoid metabolism in the chicken: a polymorphism at the ß,ß-carotene 15,15'-mono-oxygenase 1 (BCMO1) locus affects the response to dietary ß-carotene.

The enzyme ß,ß-carotene-15,15'-mono-oxygenase 1 (BCMO1) is responsible for the symmetrical cleavage of ß-carotene into retinal. We identified a polymorphism in the promoter of the BCMO1 gene, inducing differences in BCMO1 mRNA levels (high in adenines (AA) and low in guanines (GG)) and colour in chicken breast muscle. The present study was designed to test whether this polymorphism could affect the response to dietary ß-carotene. Dietary ß-carotene supplementation did not change the effects of the genotypes on breast muscle properties: BCMO1 mRNA levels were lower and xanthophyll contents higher in GG than in AA chickens. Lower vitamin E levels in the plasma and duodenum, plasma cholesterol levels and body weight were also observed in GG than in AA chickens. In both genotypes, dietary ß-carotene increased vitamin A storage in the liver; however, it reduced numerous parameters such as SCARB1 (scavenger receptor class B type I) in the duodenum, BCMO1 in the liver, vitamin E levels in the plasma and tissues, xanthophyll contents in the pectoralis major muscle and carcass adiposity. However, several diet × genotype interactions were observed. In the GG genotype, dietary ß-carotene increased ISX (intestine-specific homeobox) and decreased BCMO1 mRNA levels in the duodenum, decreased xanthophyll concentrations in the duodenum, liver and plasma, and decreased colour index and HDL-cholesterol concentration in the plasma. Retinol accumulation following dietary ß-carotene supplementation was observed in the duodenum of AA chickens only. Therefore, the negative feedback control on ß-carotene conversion through ISX appears as functional in the duodenum of GG but not of AA chickens. This could result in a higher availability of ß-carotene in the duodenum of GG chickens, reducing the uptake of xanthophylls, liposoluble vitamins and cholesterol.

Long-chain fatty acids differentially alter lipogenesis in bovine and caprine mammary slices.

Indirect comparisons from studies in vivo have suggested that caprine mammary tissue is less sensitive than bovine mammary tissue to the anti-lipogenic effect of long-chain fatty acids (LCFA), including specific rumen biohydrogenation (RBH) intermediates of polyunsaturated fatty acids (PUFA). Our objective was to investigate the effects on lipogenesis of 18-carbon LCFA differing in the degree of unsaturation and/or double bond conformation using cultured slices of bovine and caprine mammary tissues. Mammary tissues were collected from five multiparous Holstein × Normande cows and six multiparous Alpine goats in mid lactation. The expression of genes involved in milk component synthesis was measured in tissues collected at slaughter and after slice preparation: FASN, SCD1, CD36, SREBF1 and PPARG1 mRNA levels were higher in bovine than caprine samples, whereas the opposite was observed for CSN2 mRNA levels. Bovine and caprine mammary slices were incubated for 20 h in a medium with BSA (control), cis-9-18 : 1, 18 : 2n-6, 18 : 3n-3, cis-9, trans-11-CLA, or trans-10, cis-12-CLA (the latter at 3 increasing concentrations: C1 (0.11 mm), C2 (0.16 mm), C3 (0.37 mm)). Lipogenesis was estimated by measuring the incorporation of 14C-acetate into total lipid. Significant differences of individual LCFA (P < 0.05) were observed between species: bovine tissue showed a decrease in total lipogenesis with 18 : 2n-6, 18 : 3n-3, trans-10,cis-12-CLA (C2 and C3) while caprine tissue showed an increase after treatment with 18 : 3n-3, cis-9, trans-11-CLA or trans-10, cis-12-CLA (C3). These results were not related to the mRNA abundance of our set of genes in the mammary slices after incubation. In conclusion, this study demonstrates that caprine mammary slices reacted differently from bovine mammary slices to the anti-lipogenic activity of specific LCFA and suggests that regulation of lipogenesis via other genes and/or at protein level and enzyme activity may be involved.

Vitamin B2 concentration in cow milk: Quantification by a new UHPLC method and prediction by visible and near-infrared spectral analysis.

Until now, there are few information on vitamin B2 concentration variability in milk. In this study, a novel analytical method to quantify total vitamin B2 in milk was developed and applied on 676 samples. In parallel, spectral analysis (colorimetry and near infrared spectroscopy) were performed to develop prediction models of vitamin B2 concentration in milk. The analytical method includes an acid and enzymatic extraction followed by vitamin B2 quantification by Ultra High Performance Liquid Chromatography coupled with fluorimetry. Samples analysis showed a wide range of concentration from 0.78 to 4.58 mg/L with a mean of 2.09 ± 0.48 mg/L. Two prediction models based on colorimetric analysis allow estimation of vitamin B2 concentration in milk. Thus, this work shows an analytical method and, for the first time, a prediction method to enable enhancement of researches on vitamin B2 content of milk and its variation factors.

Common and diet-specific metabolic pathways underlying residual feed intake in fattening Charolais yearling bulls.

Residual feed intake (RFI) is one of the preferred traits for feed efficiency animal breeding. However, RFI measurement is expensive and time-consuming and animal ranking may depend on the nature of the diets. We aimed to explore RFI plasma biomarkers and to unravel the underlying metabolic pathways in yearling bulls fed either a corn-silage diet rich in starch (corn diet) or a grass-silage diet rich in fiber (grass diet). Forty-eight extreme RFI animals (Low-RFI, n = 24, versus High-RFI, n = 24, balanced per diet) were selected from a population of 364 Charolais bulls and their plasma was subjected to a targeted LC-MS metabolomic approach together with classical metabolite and hormonal plasma analyses. Greater lean body mass and nitrogen use efficiency, and lower protein turnover were identified as common mechanisms underlying RFI irrespective of the diet. On the other hand, greater adiposity and plasma concentrations of branched-chain amino acids (BCAA) together with lower insulin sensitivity in High-RFI animals were only observed with corn diet. Conversely, greater plasma concentrations of BCAA and total triglycerides, but similar insulin concentrations were noted in efficient RFI cattle with grass diet. Our data suggest that there are diet-specific mechanisms explaining RFI differences in fattening Charolais yearling bulls.

Carotenoid, Tocopherol, and Phenolic Compound Content and Composition in Cover Crops Used as Forage.

Secondary compounds of grassland and forage plant species such as vitamins or phenolic compounds are involved in different health-promoting effects in animals. However, information on their concentration and composition in forage plant species remains scarce. The objective of this study was to characterize the composition of secondary compounds of seven grazed cover crop plant species harvested at two stages of growth. Carotenoids and tocopherols were characterized and quantified using ultraperformance liquid chromatography with a photodiode array, and soluble phenolic compounds were characterized using high-performance liquid chromatography with diode-array detection. All species were rich in carotenoids, especially at the vegetative stage, even if the concentrations varied between plant species. Variations in tocopherol concentrations and phenolic composition were more important between plant species than between stages within species. Among the plant species tested, sainfoin (Onobrychis viciifolia Scop) contained the most secondary metabolites.

Comparison of the Potential Abilities of Three Spectroscopy Methods: Near-Infrared, Mid-Infrared, and Molecular Fluorescence, to Predict Carotenoid, Vitamin and Fatty Acid Contents in Cow Milk.

The objective of this work is to compare the ability of three spectroscopy techniques: molecular fluorescence, near-infrared (NIR), and mid-infrared with attenuated total reflectance (MIR-ATR) spectroscopy to predict the concentrations of 8 carotenoids, 6 vitamins and 22 fatty acids (FA) in cow's milk. A dataset was built through the analysis of 242 frozen milk samples from different experiments. The milk compounds were analysed using reference methods and by NIR, MIR-ATR, and fluorescence to establish different predictive models. NIR spectroscopy allowed for better prediction of cis9-ß-carotene, ß-cryptoxanthin and the sum of carotenoids than the other techniques, with a coefficient of cross-validation in calibration (R2CV) > 0.60 and a coefficient of determination in validation (R2V) > 0.50. Their standard errors of prediction (SEP) were equal to 0.01, except for the sum of carotenoids (SEP = 0.15). However, MIR-ATR and fluorescence seem usable for the prediction of lutein and all-trans-ß-carotene, respectively. These three spectroscopy methods did not allow us to predict (R2CV < 0.30) vitamin contents except, for vitamin A (the best R²CV = 0.65 with NIR and SEP = 0.15) and α-tocopherol (the best R²CV = 0.56 with MIR-ATR and SEP = 0.41), but all R²V were <0.30. NIR spectroscopy yielded the best prediction of the selected milk FA.

Butter serums and buttermilks as sources of bioactive lipids from the milk fat globule membrane: Differences in their lipid composition and potentialities of cow diet to increase n-3 PUFA.

Improving the nutritional and health properties of food products, e.g. infant milk formula, by the addition of functional ingredients is of primary importance. This study focused on bioactive milk polar lipids (PLs) recovered from dietary sources that are of increasing interest. The chemical compositions of buttermilks and butter serums were determined and the modulation of the fatty acid composition of milk PLs was investigated. Butter serums contain a higher amount of milk PLs than buttermilks (88 vs. 13-18g/kg dry matter), with a higher proportion of sphingomyelin (34 vs. 19% of PLs, respectively) interestingly close to human milk PL profile. Butter serums are also interesting sources of choline, an important nutrient for infant brain development. We demonstrated that the unsaturated fatty acid content of milk PLs recovered in the buttermilks and the butter serums, mainly the amount of C18:3n-3 and C22:6n-3 (DHA) that are of nutritional interest, can be increased by dietary strategies. This work opens perspectives for a better valorization of milk PLs in human nutrition (both infants and adults) to benefit their functional, nutritional and health properties.

Exploration of Biological Markers of Feed Efficiency in Young Bulls.

The efficiency with which ruminants convert feed to desirable products is difficult to measure under normal commercial settings. We explored the use of potential biological markers from easily obtainable samples, that is, blood, hair, and feces, to characterize potential causes of divergent efficiency when considered as residual feed intake (RFI) or feed conversion efficiency (FCE). A total of 54 Charolais bulls, 20 in period 1 and 34 in period 2, were examined for individual dry matter intake (DMI) and growth. Bulls were offered a diet of 70:30 wrapped grass silage to concentrate for 99 d. At the conclusion of the test period, blood samples were collected for the determination of vitamins B2 and B6, and plasma used for the determination of metabolites, natural isotopic 15N abundance (15N NIA, expressed as δ15N ‰) and fractionation (Δ15Nplasma proteins-diet and Δ13Cplasma proteins-diet) and near-infrared spectroscopy (NIRS). Feces were analyzed by NIRS. Bulls were slaughtered at 15-17 months of age and carcass characteristics determined. Bulls were ranked according to RFI with extremes (SD ± 0.5; n = 31) classified as either efficient (Neg-RFI) or inefficient (Pos-RFI). Extreme bulls were then classified for FCE (high vs low FCE), changing the groups. Pos-RFI bulls consumed 14% more feed than Neg-RFI bulls for the same level of weight gain. Low FCE bulls tended to eat more, but had lower weight gains than high FCE bulls. No differences were detected in carcass conformation, fat scores, hot carcass weight, or dressing percentage. Yet, heart and bladder weights were heavier in Pos-RFI, and rumen weight tended to be heavier in Pos-RFI bulls. RFI did not affect bulk 15N or 13C fractionation. A negative correlation was observed between FCE and Δ15Nplasma proteins-diet. Inefficient bulls (Pos-RFI) had higher δ15N in glycine compared to Neg-RFI bulls. Similarly, metabolomic analysis showed a tendency for concentrations of glycine and sarcosine to be elevated in Pos-RFI bulls, whereas aspartic acid and carnosine tended to be elevated, and serine tended to be lower in High FCE. Among vitamins, only flavin adenine dinucleotide concentration was higher in the blood of bulls with High FCE. These results suggest that the two feed efficiency metrics differ in the underlying mechanisms of metabolism, where RFI is driven by differences in the energetic requirements of visceral organs and the extent of AA catabolism.

Olive mill wastewater microconstituents composition according to olive variety and extraction process.

Olive oil production yields a considerable amount of wastewater, a powerful pollutant that is currently discarded but could be considered as a potential source of valuable natural products due to its content in phenolic compounds and other natural antioxidants. The aim of this work was to explore the variability in olive mill wastewater composition from Algerian olive oil mills considering extraction processes (traditional discontinuous press vs 3-phases centrifugal system) and olive varieties (Azerraj, Sigoise, Chemlal). Whereas pH, dry or organic matter content didn't vary, there was a significant difference in ash content according to extraction process and olive variety. Carotenoid content was 2.2-fold higher with 3-phases than with press systems whereas tocopherol content was not significantly different. Among the phenolic compounds quantified, tyrosol was usually the most abundant whereas oleuropein concentrations were highly variable. Differences in phenolic compound concentrations were more pronounced between olive varieties than between processes.

Identification of quinoline, carboline and glycinamide compounds in cow milk using HRMS and NMR.

The aim of this work was to characterise new UV-absorbing compounds (UAC) in cow milk in order to gain an overview of the molecular diversity of the minor bioactive constituents, that could be used to trace animal feed or that potentially affect milk quality. UAC were extracted from lyophilized milks, partitioned using SPE C-18 cartridges, purified by semi-preparative HPLC then analysed by HPLC/DAD/HRMS in both ESI(-) and ESI(+) ionisation mode. Compounds that remained unidentified after comparison with UV and MS databases were analysed by 1D and 2D NMR techniques. The identification and structural elucidation of N-cinnamoylglycine, 2,4-, 2,6-, 2,8-quinolinediols, and 1-methyl-3-carboxy-beta-carboline are described.

Detection of a Cis [corrected] eQTL controlling BCMO1 gene expression leads to the identification of a QTG for chicken breast meat color.

Classical quantitative trait loci (QTL) analysis and gene expression QTL (eQTL) were combined to identify the causal gene (or QTG) underlying a highly significant QTL controlling the variation of breast meat color in a F2 cross between divergent high-growth (HG) and low-growth (LG) chicken lines. Within this meat quality QTL, BCMO1 (Accession number GenBank: AJ271386), encoding the ß-carotene 15, 15'-monooxygenase, a key enzyme in the conversion of ß-carotene into colorless retinal, was a good functional candidate. Analysis of the abundance of BCMO1 mRNA in breast muscle of the HG x LG F2 population allowed for the identification of a strong cis eQTL. Moreover, reevaluation of the color QTL taking BCMO1 mRNA levels as a covariate indicated that BCMO1 mRNA levels entirely explained the variations in meat color. Two fully-linked single nucleotide polymorphisms (SNP) located within the proximal promoter of BCMO1 gene were identified. Haplotype substitution resulted in a marked difference in BCMO1 promoter activity in vitro. The association study in the F2 population revealed a three-fold difference in BCMO1 expression leading to a difference of 1 standard deviation in yellow color between the homozygous birds at this haplotype. This difference in meat yellow color was fully consistent with the difference in carotenoid content (i.e. lutein and zeaxanthin) evidenced between the two alternative haplotypes. A significant association between the haplotype, the level of BCMO1 expression and the yellow color of the meat was also recovered in an unrelated commercial broiler population. The mutation could be of economic importance for poultry production by making possible a gene-assisted selection for color, a determining aspect of meat quality. Moreover, this natural genetic diversity constitutes a new model for the study of ß-carotene metabolism which may act upon diverse biological processes as precursor of the vitamin A.

Variation in content and composition of phenolic compounds in permanent pastures according to botanical variation.

Phenolic compounds contribute to the micronutrient composition of pasture, which in turn may affect animal product composition. To assess the importance and variations in content of these compounds, the polyphenolic and botanical compositions of 24 permanent pastures located in one lowland and two upland regions were studied at equivalent stages of growth. Phenolic fractions were characterized and quantified using HPLC-PDA-ESI-QToF, and the total content was determined by colorimetry over each whole pasture. A rise in altitude was accompanied by a marked increase in total phenolic content, linked to changes in botanical composition, but did not have any influence on the distribution according to molecular class. For all of the pastures, significantly different patterns due to qualitative and quantitative differences among the 92 separate peaks were observed with 31 compounds identified. The involvement of certain plants in the variations of content and composition in phenolic compounds of pastures was statistically evaluated.