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Veerle Fievez - One of the best experts on this subject based on the ideXlab platform.

  • Origin of starch in dairy concentrates provokes differences in Milk Fatty Acids related to lifestyle diseases.
    Communications in agricultural and applied biological sciences, 2020
    Co-Authors: Bruno Vlaeminck, A.m. Van Vuuren, Daniël Demeyer, Veerle Fievez
    Abstract:

    The aim of this study was to evaluate whether Milk Fatty Acids were affected by dietary starch source. Four Holstein-Friesian cows were fed 4 diets in a 4×4 latin square design. Cows either received a control diet (CON; grass silage, ensiled beet pulp and concentrate mixture with 70% dried beet pulp) or diets in which the dried beet pulp of the concentrate was replaced with either native potato starch (PS), maize meal (MS) or wheat meal (WS). Short chain Fatty Acids in Milk (

  • Milk Fatty Acids as possible biomarkers to diagnose hyperketonemia in early lactation
    Journal of Dairy Science, 2015
    Co-Authors: S. Jorjong, Bernard De Baets, A.t.m. Van Knegsel, Jan Verwaeren, Rupert M. Bruckmaier, Bas Kemp, Veerle Fievez
    Abstract:

    Abstract The aim of this study was to assess the potential of Milk Fatty Acids as diagnostic tool for hyperketonemia of 93 dairy cows in a 3×2 factorial arrangement. Cows were fed a glucogenic or lipogenic diet and originally were intended to be subjected to a 0-, 30-, or 60-d dry period. Nevertheless, some of the cows, which were intended for inclusion in the 0-d dry period group, dried off spontaneously. Milk was collected in wk 2, 3, 4, and 8 of lactation for Milk fat analysis. Blood was sampled from wk 2 to 8 after parturition for β-hydroxybutyrate (BHBA) analysis. Cases were classified into 2 groups: hyperketonemia (BHBA ≥1.2mmol/L) and nonhyperketonemia (BHBA anteiso C15:0-to- anteiso C17:0 and C18:1 cis -9-to-C15:0 were subjected to a logistic regression analysis (stepwise forward method). The Milk fat C18:1 cis -9-to-C15:0 ratio revealed the most discriminating factor for diagnosis of hyperketonemia. Ninety percent of nonhyperketonemia cases showed a Milk fat C18:1 cis -9-to-C15:0 ratio of 40 or lower, whereas 70% of cows suffering from hyperketonemia showed Milk fat C18:1 cis -9-to-C15:0 ratios exceeding 40. Additionally, cows with a Milk fat ratio C18:1 cis -9-to-C15:0 of at least 45 in wk 2 after parturition had about 50% chance to encounter blood plasma BHBA values of 1.2mmol/L or more during the first 8 wk of lactation. Of the cows not suffering from hyperketonemia during the first 2 mo of lactation, only 9% exceeded this wk 2 threshold. Practical implementation requires routine analysis of both Milk Fatty Acids, which currently is lacking for C15:0. The inclusion of other variables, such as test-day information and a more frequent sampling protocol should be considered to further improve diagnostic performance of this biomarker.

  • Prediction of subacute ruminal acidosis based on Milk Fatty Acids
    Computers and Electronics in Agriculture, 2015
    Co-Authors: E. Colman, Willem Waegeman, Bernard De Baets, Veerle Fievez
    Abstract:

    Diagnostic models based on Milk Fatty Acids should include experimental information.Radial kernel-based SVM are superior to develop models based on all Milk Fatty Acids.Expert knowledge allowed to select key Milk Fatty Acids.Linear models are preferred when relying on a selected subset of Milk Fatty Acids. Subacute ruminal acidosis (SARA), characterized by low rumen pH, is one of the most important metabolic disorders in dairy cattle. As dairy cows experiencing SARA often do not exhibit overt clinical symptoms, diagnostic biomarkers in Milk are of interest. Data of six acidosis induction experiments with rumen-fistulated dairy cows were combined to assess the potential of Milk Fatty Acids (FA) to identify acidotic cases, based on three threshold values often reported in literature, i.e. time pH

  • Prediction of subacute ruminal acidosis based on Milk Fatty Acids: A comparison of linear discriminant and support vector machine approaches for model development
    Computers and Electronics in Agriculture, 2015
    Co-Authors: E. Colman, Willem Waegeman, Bernard De Baets, Veerle Fievez
    Abstract:

    Subacute ruminal acidosis (SARA), characterized by low rumen pH, is one of the most important metabolic disorders in dairy cattle. As dairy cows experiencing SARA often do not exhibit overt clinical symptoms, diagnostic biomarkers in Milk are of interest. Data of six acidosis induction experiments with rumen-fistulated dairy cows were combined to assess the potential of Milk Fatty Acids (FA) to identify acidotic cases, based on three threshold values often reported in literature, i.e. time pH < 5.6 of 180. min/d and 283. min/d and time pH below 5.8 of 475. min/d (N = 442 cases, of which 111-165 acidotic cases, depending on the applied threshold value). Both linear discriminant analysis (LDA) as well as support vector machines (SVM) were used to develop classification models, with SVM based on two common types of kernel functions (linear kernels and Gaussian radial basis function kernels) and including either the whole Milk FA profile (41-69 Milk FA, depending on the experiment) or a selected number of Milk FA (i.e. both odd and branched chain FA and biohydrogenation derivates of poly-unsaturated FA, 13-16 FA). Both evaluation of the performance of individual classification models as well as comparison of models was based on the area under the receiver operating characteristic (ROC) curve. Non-linear models developed through a radial kernel based SVM approach seemed of particular interest when including all Milk FA as model features. However, linear models based on the selected group of Milk FA most often performed as good as the non-linear models including all Milk FA, with the former being least time consuming and more cost-effective, both from a computational as well as an analytical perspective. However, combination of all data sets only resulted in good classification models when including data of each dataset upon training the model, whereas model performance decreased dramatically in case of cross-dataset cross-validation. This indicates an important impact of the origin of the datasets on the performance of the model which should be taken into account in further exploration of prediction models of SARA.

  • Milk Fatty Acids as possible biomarkers to early diagnose elevated concentrations of blood plasma nonesterified Fatty Acids in dairy cows
    Journal of Dairy Science, 2014
    Co-Authors: S. Jorjong, Bernard De Baets, A.t.m. Van Knegsel, Jan Verwaeren, M. Val Lahoz, Rupert M. Bruckmaier, Bas Kemp, Veerle Fievez
    Abstract:

    Most cows encounter a state of negative energy balance during the periparturient period, which may lead to metabolic disorders and impaired fertility. The aim of this study was to assess the potential of Milk Fatty Acids as diagnostic tools of detrimental levels of blood plasma nonesterified Fatty Acids (NEFA), defined as NEFA concentrations beyond 0.6 mmol/L, in a data set of 92 early lactating cows fed a glucogenic or lipogenic diet and subjected to 0-, 30-, or 60-d dry period before parturition. Milk was collected in wk 2, 3, 4, and 8 (n = 368) and blood was sampled weekly from wk 2 to 8 after parturition. Milk was analyzed for Milk Fatty Acids and blood plasma for NEFA. Data were classified as “at risk of detrimental blood plasma NEFA” (NEFA ≥0.6 mmol/L) and “not at risk of detrimental blood plasma NEFA” (NEFA

Sheila M Innis - One of the best experts on this subject based on the ideXlab platform.

  • Impact of maternal diet on human Milk composition and neurological development of infants
    American Journal of Clinical Nutrition, 2014
    Co-Authors: Sheila M Innis
    Abstract:

    Maternal nutrition has little or no effect on many nutrients in human Milk; for others, human Milk may not be designed as a primary nu- tritional source for the infant; and for a few, maternal nutrition can lead to substantial variations in human Milk quality. Human Milk Fatty Acids are among the nutrients that show extreme sensitivity to maternal nutrition and are implicated in neurological develop- ment. Extensive development occurs in the infant brain, with growth from w350 g at birth to 925 g at 1 y, with this growth including extensive dendritic and axonal arborization. Transfer of n–6 (omega-6) and n–3 (omega-3) Fatty Acids from the maternal diet into human Milk occurs with little interconversion of 18:2n–6 to 20:4n–6 or 18:3n–3 to docosahexaenoic acid (DHA) and little ev- idence of mammary gland regulation to maintain individual Fatty Acids constant with varying maternal Fatty acid nutrition. DHA has gained attention because of its high concentrations and roles in the brain and retina. Studies addressing DHA intakes by lactating women or human Milk amounts of DHA at levels above those typical in the United States and Canada on infant outcomes are inconsistent. However, separating effects of the Fatty acid supply in gestation or in the weaning diet from effects on neurodevelop- ment solely due to human Milk Fatty Acids is complex, particularly when neurodevelopment is assessed after the period of exclusive human Milk feeding. Information on infant Fatty acid intakes, in- cluding Milk volume consumed and energy density, will aid in un- derstanding of the human Milk Fatty Acids that best support neurological development.

  • genetic variants of the fads1 fads2 gene cluster are associated with altered n 6 and n 3 essential Fatty Acids in plasma and erythrocyte phospholipids in women during pregnancy and in breast Milk during lactation
    Journal of Nutrition, 2008
    Co-Authors: Sheila M Innis
    Abstract:

    The enzymes encoded by Fatty acid desaturase (FADS) 1 and FADS2 are rate-limiting enzymes in the desaturation of linoleic acid [LA; 18:2(n-6)] to arachidonic acid [ARA; 20:4(n-6)], and α-linolenic acid [ALA; 18:3(n-3)] to eicosapentaenoic acid [EPA; 20:5(n-3)] and docosahexaenoic acid [DHA; 22:6(n-3)]. ARA, EPA, and DHA play central roles in infant growth, neural development, and immune function. The maternal ARA, EPA, and DHA status in gestation influences maternal-to-infant transfer and breast Milk provides Fatty Acids for infants after birth. We determined if single nucleotide polymorphisms in FADS1 and FADS2 influence plasma phospholipid and erythrocyte ethanolamine phosphoglyceride (EPG) (n-6) and (n-3) Fatty Acids of women in pregnancy or their breast Milk during lactation. We genotyped rs174553, rs99780, rs174575, and rs174583 in the FADS1 FADS2 gene cluster and analyzed plasma and erythrocyte Fatty Acids and dietary intake for 69 pregnant women and breast Milk for a subset of 54 women exclusively breast-feeding at 1 mo postpartum. Minor allele homozygotes of rs174553(GG), rs99780(TT), and rs174583(TT) had lower ARA but higher LA in plasma phospholipids and erythrocyte EPG and decreased (n-6) and (n-3) Fatty acid product:precursor ratios at 16 and 36 wk of gestation. Breast Milk Fatty Acids were influenced by genotype, with significantly lower 14:0, ARA, and EPA but higher 20:2(n-6) in the minor allele homozygotes of rs174553(GG), rs99780(TT), and rs174583(TT) and lower ARA, EPA, 22:5(n-3), and DHA in the minor allele homozygotes G/G of rs174575. We showed that genetic variants of FADS1 and FADS2 influence blood lipid and breast Milk essential Fatty Acids in pregnancy and lactation.

  • trans Fatty Acids in human Milk are inversely associated with concentrations of essential all cis n 6 and n 3 Fatty Acids and determine trans but not n 6 and n 3 Fatty Acids in plasma lipids of breast fed infants
    The American Journal of Clinical Nutrition, 1999
    Co-Authors: Sheila M Innis, D J King
    Abstract:

    Background: Human Milk Fatty Acids vary with maternal dietary fat composition. Hydrogenated dietary oils with trans Fatty Acids may displace cis n-6 and n-3 unsaturated Fatty Acids or have adverse effects on their metabolism. The effects of Milk trans, n-6, and n-3 Fatty Acids in breast-fed infants are unclear, although n-6 and n-3 Fatty Acids are important in infant growth and development. Objective: We sought to determine the relations between trans and cis unsaturated Fatty Acids in Milk and plasma phospholipids and triacylglycerols of breast-fed infants, and to identify the major maternal dietary sources of trans Fatty Acids. Design: We collected Milk from 103 mothers with exclusively breast-fed 2-mo-old infants, blood from 62 infants, and 3-d dietary records from 21 mothers. Results: Mean (±SEM) percentages of trans Fatty Acids were as follows: Milk, 7.1 ± 0.32%; infants' triacylglycerols, 6.5 ± 0.33%; and infants' phospholipids, 3.7 ± 0.16%. Milk trans Fatty Acids, α-linolenic acid (18:3n-3), arachidonic acid (20:4n-6), docosahexaenoic acid (22:6n-3) (P <0.001), and linoleic acid (18:2n-6) (P = 0.007) were each related to the same Fatty acid in infant plasma phospholipids. Milk trans Fatty Acids were inversely related to Milk 18:2n-6 and 18:3n-3, but not to Milk or infant plasma 20:4n-6 or 22:6n-3. trans Fatty Acids represented 7.7% of maternal total fat intake (2.5% of total energy); the major dietary sources were bakery products and breads (32%), snacks (14%), fast foods (11%), and margarines and shortenings (11%). Conclusions: There were comparable concentrations of trans Fatty Acids in the maternal diet, breast Milk, and plasma triacylglycerols of breast-fed infants. Prepared foods were the major dietary source of trans Fatty Acids.

  • Evidence that palmitic acid is absorbed assn-2 monoacylglycerol from human Milk by breast-fed infants
    Lipids, 1994
    Co-Authors: Sheila M Innis, Roger Dyer, Carolanne M. Nelson
    Abstract:

    Milk Fatty Acids consist of about 20–25% palmitic acid (16∶0), with about 70% of 16∶0 esterified to the sn -2 position of the Milk triacylglycerols. Hydrolysis of dietary triacylglycerols by endogenous lipases produces sn -2 monoacylglycerols and free Fatty Acids, which are absorbed, reesterified, and then secreted into plasma. Unesterified 16∶0 is not well absorbed and readily forms soaps with calcium in the intestine. The positioning of 16∶0 at the sn -2 position of Milk triacylglycerols could explain the high coefficient of absorption of Milk fat. However, the Milk lipase, bile salt-stimulated lipase, has been suggested to complete the hydrolysis of Milk fat to free Fatty Acids and glycerol. These studies determined whether 16∶0 is absorbed from human Milk as sn -2 monopalmitin by comparison of the plasma triacylglycerol total and sn -2 position Fatty acid composition between breast-fed and formula-fed term gestation infants. The human Milk and formula had 21.0 and 22.3% of 16∶0, respectively, with 54.2 and 4.8% 16∶0 in the Fatty Acids esterified to the 2 position. The plasma triacylglycerol total Fatty Acids had 26.0±0.6 and 26.2±0.6% of 16∶0, and the sn -2 position Fatty Acids had 23.3±3.3 and 7.4±0.7% of 16∶0 in the three-month-old exclusively breast-fed (n=17) and formula-fed (n=18) infants, respectively. Marked differences were found in the plasma total and the 2 position phospholipid percentage of 20∶4ω6, i.e., 11.6±0.3 and 6.9±0.6 (total), 17.7±1.4 and 9.7±0.6 ( sn -2 position) and percentage of 22∶6ω3, 4.6±0.3 and 2.1±0.3 (total), 5.6±0.6 and 2.0±0.2 ( sn -2 position) for the breast-fed and formula-fed infants, respectively. These studies provide convincing evidence that 16∶0 is absorbed from human Milk as sn -2 monoacyl-glycerol. The metabolic significance of the differences in positional distribution of Fatty Acids in the plasma lipids of breast-fed and formula-fed infants is not known.

Henk Bovenhuis - One of the best experts on this subject based on the ideXlab platform.

  • exploring causal networks of bovine Milk Fatty Acids in a multivariate mixed model context
    Genetics Selection Evolution, 2014
    Co-Authors: Aniek C Bouwman, Henk Bovenhuis, Luc Janss, B D Valente, G J M Rosa
    Abstract:

    Background Knowledge regarding causal relationships among traits is important to understand complex biological systems. Structural equation models (SEM) can be used to quantify the causal relations between traits, which allow prediction of outcomes to interventions applied to such a network. Such models are fitted conditionally on a causal structure among traits, represented by a directed acyclic graph and an Inductive Causation (IC) algorithm can be used to search for causal structures. The aim of this study was to explore the space of causal structures involving bovine Milk Fatty Acids and to select a network supported by data as the structure of a SEM.

  • genomic regions associated with bovine Milk Fatty Acids in both summer and winter Milk samples
    BMC Genetics, 2012
    Co-Authors: Aniek C Bouwman, Marleen Hpw Visker, Johan A M Van Arendonk, Henk Bovenhuis
    Abstract:

    Background In this study we perform a genome-wide association study (GWAS) for bovine Milk Fatty Acids from summer Milk samples. This study replicates a previous study where we performed a GWAS for bovine Milk Fatty Acids based on winter Milk samples from the same population. Fatty Acids from summer and winter Milk are genetically similar traits and we therefore compare the regions detected in summer Milk to the regions previously detected in winter Milk GWAS to discover regions that explain genetic variation in both summer and winter Milk.

  • Genome-wide association of Milk Fatty Acids in Dutch dairy cattle
    BMC Genetics, 2011
    Co-Authors: Aniek C Bouwman, Henk Bovenhuis, Marleen Hpw Visker, Johan Am Van Arendonk
    Abstract:

    BackgroundIdentifying genomic regions, and preferably individual genes, responsible for genetic variation in Milk fat composition of bovine Milk will enhance the understanding of biological pathways involved in Fatty acid synthesis and may point to opportunities for changing Milk fat composition via selective breeding. An association study of 50,000 single nucleotide polymorphisms (SNPs) was performed for even-chain saturated Fatty Acids (C4:0-C18:0), even-chain monounsaturated Fatty Acids (C10:1-C18:1), and the polyunsaturated C18:2 cis9,trans11 (CLA) to identify genomic regions associated with individual Fatty Acids in bovine Milk.ResultsThe two-step single SNP association analysis found a total of 54 regions on 29 chromosomes that were significantly associated with one or more Fatty Acids. Bos taurus autosomes (BTA) 14, 19, and 26 showed highly significant associations with seven to ten traits, explaining a relatively large percentage of the total additive genetic variation. Many additional regions were significantly associated with the Fatty Acids. Some of the regions harbor genes that are known to be involved in fat synthesis or were previously identified as underlying quantitative trait loci for fat yield or content, such as ABCG2 and PPARGC1A on BTA 6; ACSS2 on BTA 13; DGAT1 on BTA 14; ACLY , SREBF1 , STAT5A , GH , and FASN on BTA 19; SCD1 on BTA26; and AGPAT6 on BTA 27.ConclusionsMedium chain and unsaturated Fatty Acids are strongly influenced by polymorphisms in DGAT1 and SCD1 . Other regions also showed significant associations with the Fatty Acids studied. These additional regions explain a relatively small percentage of the total additive genetic variance, but they are relevant to the total genetic merit of an individual and in unraveling the genetic background of Milk fat composition. Regions identified in this study can be fine mapped to find causal mutations. The results also create opportunities for changing Milk fat composition through breeding by selecting individuals based on their genetic merit for Milk fat composition.

  • short communication genome wide scan for bovine Milk fat composition ii quantitative trait loci for long chain Fatty Acids
    Journal of Dairy Science, 2009
    Co-Authors: A Schennink, Henk Bovenhuis, Marleen Hpw Visker, W M Stoop, J J Van Der Poel, J A M Van Arendonk
    Abstract:

    We present the results of a genome-wide scan to identify quantitative trait loci (QTL) that contribute to genetic variation in long-chain Milk Fatty Acids. Milk-fat composition phenotypes were available on 1,905 Dutch Holstein-Friesian cows. A total of 849 cows and their 7 sires were genotyped for 1,341 single nucleotide polymorphisms across all Bos taurus autosomes (BTA). We detected significant QTL on BTA14, BTA15, and BTA16: for C18:1 cis-9, C18:1 cis-12, C18:2 cis-9,12, CLA cis-9,trans-11, C18:3 cis-9,12,15, the C18 index, the total index, total saturated Fatty Acids, total unsaturated Fatty Acids (UFA), and the ratio of saturated Fatty Acids:unsaturated Fatty Acids on BTA14; for C18:1 trans Fatty Acids on BTA15; and for the C18 and CLA indices on BTA16. The QTL explained 3 to 19% of the phenotypic variance. Suggestive QTL were found on 16 other chromosomes. The diacylglycerol acyltransferase 1 (DGAT1) K232A polymorphism on BTA14, which is known to influence Fatty acid composition, most likely explains the QTL that was detected on BTA14.

  • genetic parameters for major Milk Fatty Acids and Milk production traits of dutch holstein friesians
    Journal of Dairy Science, 2008
    Co-Authors: W M Stoop, J A M Van Arendonk, J M L Heck, H J F Van Valenberg, Henk Bovenhuis
    Abstract:

    Abstract The objective of this study was to estimate genetic parameters for major Milk Fatty Acids and Milk production traits. One morning Milk sample was collected from 1,918 Holstein-Friesian heifers located in 398 commercial herds in the Netherlands. Each sample was analyzed for total percentages of fat and protein, and for detailed Fatty acid percentages (computed as Fatty acid weight as a proportion of total fat weight). Intraherd heritabilities were high for C4:0 to C16:0, ranging from 0.42 for C4:0 to 0.71 for C10:0. Saturated and unsaturated C18 Fatty Acids had intraherd heritability estimates of approximately 0.25, except for C18:2 cis -9, trans -11, which was 0.42. Standard errors of the heritabilities were between 0.07 and 0.12. Genetic correlations were high and positive among C4:0 to C14:0, as well as among unsaturated C18, but correlations of C4:0 to C14:0 with unsaturated C18 were generally weak. The genetic correlation of C16:0 with fat percentage was positive (0.65), implying that selection for fat percentage should result in a correlated increase of C16:0, whereas unsaturated C18 Fatty Acids decreased with increasing fat percentage (−0.74). Milk fat composition can be changed by means of selective breeding, which offers opportunities to meet consumer demands regarding health and technological aspects.

Giovanni Bittante - One of the best experts on this subject based on the ideXlab platform.

  • effects of candidate gene polymorphisms on the detailed Fatty Acids profile determined by gas chromatography in bovine Milk
    Journal of Dairy Science, 2016
    Co-Authors: Sara Pegolo, A Cecchinato, Giuseppe Conte, Stefano Schiavon, Maria Mele, Giovanni Bittante
    Abstract:

    Abstract Association analyses between candidate genes and bovine Milk Fatty Acids can improve our understanding of genetic variation in Milk Fatty acid profiles and reveal potential opportunities to tailor Milk fat composition through selection strategies. In this work, we investigated the association of 51 single nucleotide polymorphisms (SNP) selected from 37 candidate genes using a functional and positional approach, with 47 Fatty Acids, 9 Fatty acid groups, and 5 Δ 9 -desaturation indices in Milk samples from Brown Swiss cows. Individual Milk samples were collected from 1,158 Italian Brown Swiss cows, and gas chromatography was used to obtain detailed Milk Fatty acid compositions. A GoldenGate assay system (Illumina, San Diego, CA) was used to perform genotype 96 selected SNP located in 54 genes across 22 chromosomes. In total, 51 polymorphic SNP in 37 candidate genes were retained for the association analysis. A Bayesian linear animal model was used to estimate the contribution of each SNP. A total of 129 tests indicated relevant additive effects between a given SNP and a single Fatty acid trait; 38 SNP belonging to 30 genes were relevant for a total of 57 Fatty acid traits. Most of the studied Fatty acid traits (~81%) were relevantly associated with multiple SNP. Relevantly associated SNP were mainly found in genes related to fat metabolism, linked to or contained in previously identified quantitative trait loci for fat yield or content, or associated with genes previously identified in association analyses with Milk Fatty acid profiles in other cow breeds. The most representative candidate genes were LEP , PRL , STAT5A , CCL3 , ACACA , GHR , ADRB2 , LPIN1 , STAT1 , FABP4 , and CSN2 . In particular, relevant associations with SNP located on bovine chromosome 19 (BTA19) were found. Two candidate genes on BTA19 ( CCL3 and ACACA) were relevantly associated with de novo short- and medium-chain Fatty Acids, likely explaining the high heritability values found for these Fatty Acids (with the exception of C6:0). Two additional genes on BTA19 ( CCL2 and GH1 ) showed associations with saturated and branched-chain Fatty Acids. Our findings provide basic information on genes and SNP affecting the Milk Fatty acid composition of dairy cows. These results may support the possibility of using genetic selection to modify Milk Fatty acid profiles to promote beneficial health-related effects.

  • genetic and environmental relationships of detailed Milk Fatty Acids profile determined by gas chromatography in brown swiss cows
    Journal of Dairy Science, 2016
    Co-Authors: Sara Pegolo, A Cecchinato, J Casellas, Giuseppe Conte, Marcello Mele, Stefano Schiavon, Giovanni Bittante
    Abstract:

    Abstract The aim of this study was to characterize the profile of 47 Fatty Acids, including conjugated linoleic acid (CLA), 13 Fatty acid groups, and 5 Δ 9 -desaturation indices in Milk samples from Brown Swiss cows. The genetic variation was assessed and the statistical relevance of the genetic background for each trait was evaluated using the Bayes factor test. The additive genetic, herd-date, and residual relationships were also estimated among all single Fatty Acids and groups of Fatty Acids. Individual Milk samples were collected from 1,158 Italian Brown Swiss cows and a detailed analysis of fat percentages and Milk Fatty acid compositions was performed by gas chromatography. Bayesian animal models were used for (co)variance components estimation. Exploitable genetic variation was observed for most of the de novo synthesized Fatty Acids and saturated Fatty Acids, except for C4:0 and C6:0, whereas long-chain Fatty Acids and unsaturated Fatty Acids (including CLA) were mainly influenced by herd-date effects. Herd-date effect explained large portions of the total phenotypic variance for C18:2 cis- 9, cis- 12 (0.668), C18:3 cis- 9, cis- 12, cis- 15 (0.631), and the biohydrogenation and elongation products of these Fatty Acids. The desaturation ratios showed higher heritability estimates than the individual Fatty Acids, except for CLA desaturation index (0.098). Among the medium-chain Fatty Acids, C12:0 had greater heritability than C14:0 (0.243 vs. 0.097, respectively). Both C14:0 and C16:0 showed negative additive genetic correlations with the main monounsaturated and polyunsaturated Fatty Acids of Milk fat, suggesting that their synthesis in the mammary gland may be influenced by the presence of unsaturated Fatty Acids. No correlation was observed between C4:0 and the other short-chain Fatty Acids (except for C6:0), confirming the independence of C4:0 from de novo mammary Fatty acid synthesis. Among the genetic correlations dealing with potentially beneficial Fatty Acids, C18:0 was positively correlated with vaccenic and rumenic Acids and negatively with linoleic acid. Finally, Fatty Acids C6:0 through C14:0 showed relevant correlations due to unknown environmental effects, suggesting the potential existence of genetic variances in micro-environmental sensitivity. This study allowed us to acquire new knowledge about the genetic and the environmental relationships among Fatty Acids. Likewise, the existence of genetic variation for most of de novo synthetized Fatty Acids and saturated Fatty Acids was also observed. Overall, these results provide useful information to combine feeding with genetic selection strategies for obtaining a desirable Milk Fatty Acids profile, depending on the origin of Fatty Acids in Milk.

  • genetic parameters for conjugated linoleic acid selected Milk Fatty Acids and Milk Fatty acid unsaturation of italian holstein friesian cows
    Journal of Dairy Science, 2009
    Co-Authors: Marcello Mele, Martino Cassandro, Giuseppe Conte, Giovanni Bittante, Andrea Serra, Dal R Zotto, A Buccioni, Pier Lorenzo Secchiari
    Abstract:

    Abstract The objective of this study was to estimate genetic parameters for conjugated linoleic acid (CLA) and other selected Milk Fatty acid (FA) content and for unsaturation ratios in the Italian Holstein Friesian population. Furthermore, the relationship of Milk FA with Milk fat and protein content was considered. One morning Milk sample was collected from 990 Italian Holstein Friesian cows randomly sampled from 54 half-sib families, located in 34 commercial herds in the North-eastern part of Italy. Each sample was analyzed for Milk percentages of fat and protein, and for single FA percentages (computed as FA weight as a proportion of total fat weight). Heritabilities were moderate for unsaturated FA, ranging from 0.14 for C16:1 to 0.19 for C14:1. Less than 10% of heritability was estimated for each saturated FA content. Heritability for index of desaturation, monounsaturated FA and CLA/ trans -11 18:1 ratio were 0.15, 0.14, and 0.15, respectively. Standard errors of the heritability values ranged from 0.02 to 0.06. Genetic correlations were high and negative between C16:0 and C18:0, as well as between C14:0 and C18:0. Genetic correlations of index of desaturation were high and negative with C14:0 and C16:0 (−0.70 and −0.72, respectively), and close to zero (0.03) with C18:0. The genetic correlation of C16:0 with fat percentage was positive (0.74), implying that selection for fat percentage should result in a correlated increase of C16:0, whereas trans -11 C18:1 and cis- 9, trans- 11 C18:2 contents decreased with increasing fat percentage (−0.69 and −0.55, respectively). Genetic correlations of fat percentage with 14:1/14 and 16:1/16 ratios were positive, whereas genetic correlations of fat percentage with 18:1/18 and CLA/ trans -11 18:1 ratios were negative. These results suggest that it is possible to change the Milk FA composition by genetic selection, which offers opportunities to meet consumer demands regarding health aspects of Milk and dairy products.

Bernard De Baets - One of the best experts on this subject based on the ideXlab platform.

  • Milk Fatty Acids as possible biomarkers to diagnose hyperketonemia in early lactation
    Journal of Dairy Science, 2015
    Co-Authors: S. Jorjong, Bernard De Baets, A.t.m. Van Knegsel, Jan Verwaeren, Rupert M. Bruckmaier, Bas Kemp, Veerle Fievez
    Abstract:

    Abstract The aim of this study was to assess the potential of Milk Fatty Acids as diagnostic tool for hyperketonemia of 93 dairy cows in a 3×2 factorial arrangement. Cows were fed a glucogenic or lipogenic diet and originally were intended to be subjected to a 0-, 30-, or 60-d dry period. Nevertheless, some of the cows, which were intended for inclusion in the 0-d dry period group, dried off spontaneously. Milk was collected in wk 2, 3, 4, and 8 of lactation for Milk fat analysis. Blood was sampled from wk 2 to 8 after parturition for β-hydroxybutyrate (BHBA) analysis. Cases were classified into 2 groups: hyperketonemia (BHBA ≥1.2mmol/L) and nonhyperketonemia (BHBA anteiso C15:0-to- anteiso C17:0 and C18:1 cis -9-to-C15:0 were subjected to a logistic regression analysis (stepwise forward method). The Milk fat C18:1 cis -9-to-C15:0 ratio revealed the most discriminating factor for diagnosis of hyperketonemia. Ninety percent of nonhyperketonemia cases showed a Milk fat C18:1 cis -9-to-C15:0 ratio of 40 or lower, whereas 70% of cows suffering from hyperketonemia showed Milk fat C18:1 cis -9-to-C15:0 ratios exceeding 40. Additionally, cows with a Milk fat ratio C18:1 cis -9-to-C15:0 of at least 45 in wk 2 after parturition had about 50% chance to encounter blood plasma BHBA values of 1.2mmol/L or more during the first 8 wk of lactation. Of the cows not suffering from hyperketonemia during the first 2 mo of lactation, only 9% exceeded this wk 2 threshold. Practical implementation requires routine analysis of both Milk Fatty Acids, which currently is lacking for C15:0. The inclusion of other variables, such as test-day information and a more frequent sampling protocol should be considered to further improve diagnostic performance of this biomarker.

  • Prediction of subacute ruminal acidosis based on Milk Fatty Acids
    Computers and Electronics in Agriculture, 2015
    Co-Authors: E. Colman, Willem Waegeman, Bernard De Baets, Veerle Fievez
    Abstract:

    Diagnostic models based on Milk Fatty Acids should include experimental information.Radial kernel-based SVM are superior to develop models based on all Milk Fatty Acids.Expert knowledge allowed to select key Milk Fatty Acids.Linear models are preferred when relying on a selected subset of Milk Fatty Acids. Subacute ruminal acidosis (SARA), characterized by low rumen pH, is one of the most important metabolic disorders in dairy cattle. As dairy cows experiencing SARA often do not exhibit overt clinical symptoms, diagnostic biomarkers in Milk are of interest. Data of six acidosis induction experiments with rumen-fistulated dairy cows were combined to assess the potential of Milk Fatty Acids (FA) to identify acidotic cases, based on three threshold values often reported in literature, i.e. time pH

  • Prediction of subacute ruminal acidosis based on Milk Fatty Acids: A comparison of linear discriminant and support vector machine approaches for model development
    Computers and Electronics in Agriculture, 2015
    Co-Authors: E. Colman, Willem Waegeman, Bernard De Baets, Veerle Fievez
    Abstract:

    Subacute ruminal acidosis (SARA), characterized by low rumen pH, is one of the most important metabolic disorders in dairy cattle. As dairy cows experiencing SARA often do not exhibit overt clinical symptoms, diagnostic biomarkers in Milk are of interest. Data of six acidosis induction experiments with rumen-fistulated dairy cows were combined to assess the potential of Milk Fatty Acids (FA) to identify acidotic cases, based on three threshold values often reported in literature, i.e. time pH < 5.6 of 180. min/d and 283. min/d and time pH below 5.8 of 475. min/d (N = 442 cases, of which 111-165 acidotic cases, depending on the applied threshold value). Both linear discriminant analysis (LDA) as well as support vector machines (SVM) were used to develop classification models, with SVM based on two common types of kernel functions (linear kernels and Gaussian radial basis function kernels) and including either the whole Milk FA profile (41-69 Milk FA, depending on the experiment) or a selected number of Milk FA (i.e. both odd and branched chain FA and biohydrogenation derivates of poly-unsaturated FA, 13-16 FA). Both evaluation of the performance of individual classification models as well as comparison of models was based on the area under the receiver operating characteristic (ROC) curve. Non-linear models developed through a radial kernel based SVM approach seemed of particular interest when including all Milk FA as model features. However, linear models based on the selected group of Milk FA most often performed as good as the non-linear models including all Milk FA, with the former being least time consuming and more cost-effective, both from a computational as well as an analytical perspective. However, combination of all data sets only resulted in good classification models when including data of each dataset upon training the model, whereas model performance decreased dramatically in case of cross-dataset cross-validation. This indicates an important impact of the origin of the datasets on the performance of the model which should be taken into account in further exploration of prediction models of SARA.

  • Milk Fatty Acids as possible biomarkers to early diagnose elevated concentrations of blood plasma nonesterified Fatty Acids in dairy cows
    Journal of Dairy Science, 2014
    Co-Authors: S. Jorjong, Bernard De Baets, A.t.m. Van Knegsel, Jan Verwaeren, M. Val Lahoz, Rupert M. Bruckmaier, Bas Kemp, Veerle Fievez
    Abstract:

    Most cows encounter a state of negative energy balance during the periparturient period, which may lead to metabolic disorders and impaired fertility. The aim of this study was to assess the potential of Milk Fatty Acids as diagnostic tools of detrimental levels of blood plasma nonesterified Fatty Acids (NEFA), defined as NEFA concentrations beyond 0.6 mmol/L, in a data set of 92 early lactating cows fed a glucogenic or lipogenic diet and subjected to 0-, 30-, or 60-d dry period before parturition. Milk was collected in wk 2, 3, 4, and 8 (n = 368) and blood was sampled weekly from wk 2 to 8 after parturition. Milk was analyzed for Milk Fatty Acids and blood plasma for NEFA. Data were classified as “at risk of detrimental blood plasma NEFA” (NEFA ≥0.6 mmol/L) and “not at risk of detrimental blood plasma NEFA” (NEFA

  • Grain-based versus alfalfa-based subacute ruminal acidosis induction experiments: Similarities and differences between changes in Milk Fatty Acids.
    Journal of dairy science, 2013
    Co-Authors: E. Colman, Bruno Vlaeminck, Ehsan Khafipour, J C Plaizier, Bernard De Baets, Veerle Fievez
    Abstract:

    Subacute ruminal acidosis (SARA) is one of the most important metabolic disorders, traditionally characterized by low rumen pH, which might be induced by an increase in the dietary proportion of grains as well as by a reduction of structural fiber. Both approaches were used in earlier published experiments in which SARA was induced by replacing part of the ration by a grain mixture or alfalfa hay by alfalfa pellets. The main differences between both experiments were the presence of blood lipopolysaccharide and Escherichia coli and associated effects on the rumen microbial population in the rumen of grain-based induced SARA animals as well as a great amount of quickly fermentable carbohydrates in the grain-based SARA induction experiment. Both induction approaches changed rumen pH although the pH decrease was more substantial in the alfalfa-based SARA induction protocol. The goal of the current analysis was to assess whether both acidosis induction approaches provoked similar shifts in the Milk Fatty acid (FA) profile. Similar changes of the odd- and branched-chain FA and the C18 biohydrogenation intermediates were observed in the alfalfa-based SARA induction experiment and the grain-based SARA induction experiment, although they were more pronounced in the former. The proportion of trans-10 C18:1 in the last week of the alfalfa-based induction experiment was 6 times higher than the proportion measured during the control week. The main difference between both induction experiments under similar rumen pH changes was the decreasing sum of iso FA during the grain-based SARA induction experiment whereas the sum of iso FA remained stable during the alfalfa-based SARA induction experiment. The cellulolytic bacterial community seemed to be negatively affected by either the presence of E. coli and the associated lipopolysaccharide accumulation in the rumen or by the amount of starch and quickly fermentable carbohydrates in the diet. In general, changes in the Milk FA profile were related to changes in rumen pH. Nevertheless, feed characteristics (low in structural fiber vs. high in starch) also affected the Milk FA profile and, as such, both effects should be taken into account when subacute acidosis occurs.