Variation In Fatty Acid Content Research Articles

Modulating Growth and Oil Profile of Sesame (Sesamum indicum L.): Paclobutrazol and Mepiquat Chloride Impacts

AbstractSesame (Sesamum indicum L.) is an important oilseed crop with significant economic importance in many developing countries. This study rigorously investigated the impact of various applications and doses of two specific plant growth regulators, paclobutrazol (PAC) and mepiquat chloride (MC), on the development, yield components, oil content, and fatty acid composition of sesame plants across two consecutive growing seasons. The research revealed that while paclobutrazol application increased the plant height it also resulted in a slight decrease in oil content. The paclobutrazol treatment resulted in the highest seed yield (21.3 g/plant), which was significantly different from both the MC (13.1 g/plant) and PAC + MC (14.6 g/plant) treatments. In contrast, the mepiquat chloride treatment resulted in the lowest oil content. The combined application of both regulators showed intermediate effects. In addition, variations in fatty acid content were observed between applications and doses, with significant differences in saturated and unsaturated fatty acid levels. The findings provide valuable insights into the potential benefits and implications of using growth regulators in sesame cultivation, especially in the context of mechanized harvesting and oil quality optimization.

Comparative analysis of antioxidant and fatty acid composition in avocado (Persea americana Mill.) fruits: Exploring regional and commercial varieties

On Madeira Island, Portugal, the avocado crop benefits from a Mediterranean climate, exhibiting exceptional phytochemical and biochemical properties. Aiming to evaluate the antioxidant quality and fatty acid composition with a commercial avocado, flours were obtained from five varieties (four regional and one commercial Hass) across different tissues (pulp and by-products) and cycles (years and on-tree maturation stages). Results showed that a regional variety with thin purple skin had the highest antioxidant qualities and lipid content, surpassing the other regional and commercial Hass varieties. Oleic acid prevailed in all samples, with regional avocados containing arachidonic acid which is an uncommon occurrence among higher plants. Variations in fatty acid content were influenced by the timing of harvest. These outcomes highlight the promising potential of avocados from Madeira Island.

Effects of different feeding patterns on the rumen bacterial community of tan lambs, based on high-throughput sequencing of 16S rRNA amplicons.

The mutton quality of Chinese Tan lambs (Ovis aries) has declined as feeding patterns have shifted from pasturing to pen rationing. While pen-fed can enhance the growth performance of sheep, it falls short in terms of meat quality attributes such as meat color and tenderness. Furthermore, compared to pen-fed, pasture-fed husbandry increases the proportion of oxidative muscle fibers, decreases the proportion of glycolytic muscle fibers, and reduces LDH (lactate dehydrogenase) activity. Mutton quality is affected by fatty acids, and rumen microorganisms play a role in the synthesis of short-chain fatty acids, long-chain fatty acids, and conjugated linoleic acids. We used 16S rRNA sequencing to analyze the effects of two feeding patterns on the rumen bacteria of Tan lambs. In a randomized block design with 24 newborn Tan lambs, 12 lambs were fed by ewes in pasture and 12 were fed by pen-fed ewes. At 2 months, the biceps femoris and the longissimus dorsi were analyzed by gas chromatography for intramuscular fat content and fatty acids composition, and DNA in the rumen contents was extracted and used to analyze the structure of the bacterial community. Different feeding patterns had no significant effect on the intramuscular fat content of the biceps femoris and longissimus dorsi of the lambs, but there was a significant effect on fatty acids composition. The fatty acids c18:3n3 and c20:5n3 were significantly higher in the biceps femoris and longissimus dorsi of the pasture group than the pen-ration group. The alpha diversity of rumen bacteria was significantly greater in the pasture group compared to the pen-ration group. The ACE index, Chao1 index, Shannon index, and Simpson index were all notably higher in the pasture group than in the pen-ration group. Utilizing beta diversity analysis to examine the differences in rumen bacteria between the pasture group and pen-ration group, it was observed that the homogeneity of bacteria in the pasture group was lower than that in the pen-ration group. Furthermore, the diversity of rumen bacteria in the pasture group was greater than that in the pen-ration group. Twenty-one phyla were identified in the pasture group, and 14 phyla were identified in the pen-ration group. The dominant phyla in the pasture group were Bacteroidetes and Fibrobacteres; the dominant phyla in the pen-ration group were Proteobacteria and Bacteroidetes. The relative abundance of Proteobacteria was significantly higher in the pen-ration group than in the pasture group (p < 0.01). Diversity at the genus level was also higher in the pasture group, with 176 genera in the pasture group and 113 genera in the pen-ration group. The dominant genera in the pasture group were Prevotella_1, Rikenellaceae_RC9_gut_group, and Bacteroidales_BS11_gut_group_Na; the dominant genera in the pen-ration group were Prevotella_1, Prevotella_7, Succinivibrionaceae_UCG-001, and Succinivibrionaceae_NA. The rumen bacterial community of Tan sheep is significantly influenced by pen-ration and pasture-fed conditions, leading to variations in fatty acid content in the muscle, which in turn affects the flavor and nutritional value of the meat to some extent. Pasture-fed conditions have been shown to enhance the diversity of rumen bacterial community structure in Tan sheep, thereby increasing the nutritional value of their meat.

Variation in fatty acid content among benthic invertebrates in a seasonally driven system

AbstractAt temperate latitudes where seasonal changing environmental conditions strongly affect the magnitude, duration and species composition of pelagic primary production, macrobenthic organisms living below the photic zone rely on the sedimentation of organic matter as their primary energy source. The succession from nutritious spring blooms to summer cyanobacteria is assumed to reduce food quality for benthic primary consumers and their fatty acid (FA) profiles. In contrast, we find low seasonal variability in FA content of five benthic macroinvertebrates spanning two trophic levels in the Baltic Sea, a system with high seasonal variation in phytoplankton species composition. However, levels of the major FA groups vary greatly between benthic species. The results suggest that benthic macroinvertebrates have evolved FA metabolism adapted to degraded sedimenting material. Moreover, our study shows that species composition of benthic macrofauna rather than seasonal changing conditions affect availability of essential nutrients to higher trophic levels.

Development of Intron Polymorphism Markers and Their Association With Fatty Acid Component Variation in Oil Palm.

Oil palm (Elaeis guineensis Jacq.) is a tropical woody oil crop of the palm family and is known as “the oil king of the world,” but its palm oil contains about 50% palmitic acid, which is considered unhealthy for humans. Intron polymorphisms (IP) are highly efficient and easily examined molecular markers located adjacent to exon regions of functional genes, thus may be associated with targeted trait variation. In order to speed up the breeding of oil palm fatty acid composition, the current study identified a total of 310 introns located within 52 candidate genes involved in fatty acid biosynthesis in the oil palm genome. Based on the intron sequences, 205 primer pairs were designed, 64 of which showed polymorphism among 70 oil palm individuals. Phenotypic variation of fatty acid content in the 70 oil palm individuals was also investigated. Association analysis revealed that 13 IP markers were significantly associated with fatty acid content variation, and these IP markers were located on chromosomes 2, 5, 6, 8, 9, and 10 of oil palm. The development of such IP markers may be useful for the genetic improvement of fatty acid composition in oil palm.

Genome-Wide Association Study for Fatty Acid Composition in American Angus Cattle.

Simple SummaryAlmost everybody depends on livestock for various reasons directly or indirectly. Consequently, improving livestock production means improving human life. Meat plays important role in human life, as it is good source of protein and energy. Meat composition depends on breed’s genetics and environmental factors. Fatty acids (FA) play important role in human diet and health. FA add flavor and taste to meat. Fatty acid composition of meat is a complex polygenic trait that is controlled by genetics and environmental factors. Therefore, the objective of the present study was to identify genomic regions associated with FA composition in American Angus. Thirty-six different genomic regions were identified associated with variation in at least one FA. The genomic regions associated with more than one FA and high genetic variance, harbor good candidate genes (e.g., FABP2, FASN, FADS2, FADS3 and SCD). The identified makers could be used to select for altered FA profile and help to increase the understanding of the genetic basis of FA composition. Furthermore, findings from the present study could help to devise effective breeding plans and selection strategies for the improvement of beef FA profile.Livestock is an important commodity playing a major role in the global economy. Red meat plays an important role in human life, as it is a good source of animal protein and energy. The fatty acid content of beef has been shown to impact the eating experience and nutritional value of beef. Therefore, this study aimed to identify genomic regions which can account for genetic variation in meat fatty acid content. Genotypes imputed to the Illumina BovineHD 770K BeadChip were used in this study. Thirty-six 1-Mb genomic regions with a posterior probability of inclusion (PPI) greater than 0.90 were identified to be associated with variation in the content of at least one fatty acid. The genomic regions (1Mb) which were associated with more than one fatty acid trait with high genetic variance and harbored good candidate genes were on Chromosome (Chr) 6 (fatty acid binding protein 2), Chr 19 (thyroid hormone receptor alpha, fatty acid synthase), Chr 26 (stearoyl-CoA desaturase), and Chr 29 (thyroid hormone responsive, fatty acid desaturase 2, and fatty acid desaturase 3). Further studies are required to identify the causal variants within the identified genomic regions. Findings from the present study will help to increase understanding of the variation in fatty acid content of beef and help to enhance selection for beef with improved fatty acid composition.

Genome-wide discovery and characterization of long noncoding RNAs in African oil palm (Elaeis guineensis Jacq.).

Long noncoding RNAs (lncRNAs) are an important class of genes and play important roles in a range of biological processes. However, few reports have described the identification of lncRNAs in oil palm. In this study, we applied strand specific RNA-seq with rRNA removal to identify 1,363 lncRNAs from the equally mixed tissues of oil palm spear leaf and six different developmental stages of mesocarp (8–24 weeks). Based on strand specific RNA-seq data and 18 released oil palm transcriptomes, we systematically characterized the expression patterns of lncRNA loci and their target genes. A total of 875 uniq target genes for natural antisense lncRNAs (NAT-lncRNA, 712), long intergenic noncoding RNAs (lincRNAs, 92), intronic-lncRNAs (33), and sense-lncRNAs (52) were predicted. A majority of lncRNA loci (77.8%–89.6%) had low expression in 18 transcriptomes, while only 89 lncRNA loci had medium to high expression in at least one transcriptome. Coexpression analysis between lncRNAs and their target genes indicated that 6% of lncRNAs had expression patterns positively correlated with those of target genes. Based on single nucleotide polymorphism (SNP) markers derived from our previous research, 6,882 SNPs were detected for lncRNAs and 28 SNPs belonging to 21 lncRNAs were associated with the variation of fatty acid contents. Moreover, seven lncRNAs showed expression patterns positively correlated expression pattern with those of genes in de novo fatty acid synthesis pathways. Our study identified a collection of lncRNAs for oil palm and provided clues for further research into lncRNAs that may regulate mesocarp development and lipid metabolism.

SSR based association mapping analysis for fatty acid content in coconut flesh and exploration of the elite alleles in Cocos nucifera L

Exploring the elite alleles based on the association mapping related to fatty acid content in coconut flesh will expedite the breeding of coconut varieties for human welfare. In the present study, a total of eighty representative Cocos nucifera accessions belonging to 6 populations (Red dwarf, Yellow dwarf, Hainan red, Hainan tall, MAWA and Aromatica green dwarf) were selected from China as an association mapping population. The fatty acid content in mature flesh of the selected coconut accessions was measured by gas chromatography-mass spectrometry (GCMS). Ninety one SSR (simple sequence repeat) markers distributed across the 16 chromosomes of coconut were adopted for association mapping analysis with the aim to explore the elite alleles for the fatty acid content related traits. The results clearly showed the significant variation in fatty acid content among the analyzed coconut accessions. Based on the population structure analysis, we categorized eighty accessions in to two subgroups, the higher-fatty acid containing germplasm subgroup (HFA) and the lower-fatty acid containing germplasm subgroup (LFA). An admixed population structure was also observed through the PCoA (two groups), and UPGMA (two clusters). A Total of 10 SSR loci associated with fatty acid content of coconut flesh, were identified by the general linear model (GLM) and mixed linear model (MLM), with the maximum number of association loci across the chromosome 14. SSR loci with high explanation of phenotypic variation and stable expression were selected from the comparative analysis, with the phenotypic effect of their elite alleles ranging from -1.02～3.12. Among the identified elite alleles, CnFatB3-359 demonstrated the strongest positive effect with (mean of 2.35) the typical carrier material of Aromatica green dwarf, while CnFatB2-830 had the strongest negative effect (mean of -0.65) with the carrier material of MAWA. The present research detected favorable quantitative trait loci’s alleles and typical accessions for fatty acid content associated traits for breeding nutritional rich coconut varieties

Fatty acid composition of maize silages from different hybrids

Fatty acid composition of maize silages from different hybrids

Kernel oil content and oil composition in walnut (Juglans regia L.) accessions from north-eastern Italy.

Walnut oil use is currently limited by its poor oxidative stability due to the high percentage of polyunsaturated fatty acids. Modifying the oil composition may be a goal in walnut breeding to increase interest in this crop. Exploring natural variability and identifying the main environmental factors affecting oil quality are necessary in crop selection. Therefore 190 wild accessions were collected and evaluated during 2013 and 2014 for oil content and its fatty acid profile and compared with five commercial cultivars as references. High variation in kernel oil content and fatty acid composition was found in the native walnut. Kernel oil content ranged from 54.2 to 72.2% (w/w). The major fatty acids were linoleic (range 46.9-68.6%), oleic (10.0-25.1%), linolenic (6.9-17.6%), palmitic (3.9-11.4%) and stearic (1.1-5.2%) acids. Some accessions had oil with a fatty acid ratio very different from the reference commercial cultivars, especially the oleic acid/polyunsaturated fatty acid (PUFA) ratio. A significant linear relationship and positive correlation between the daily minimum temperature and oleic acid content was observed in the wild walnuts. The wide variation in fatty acid content and composition allows superior accessions to be selected for diffusion among growers. A suitable strategy would be to make a selection against PUFA content rather than just for high oleic acid. In addition, the selected high oleic accessions, before being utilized per se or as donor parents in breeding programs, have to demonstrate they are not adversely affected by the environment. © 2017 Society of Chemical Industry.

Using a gradient in food quality to infer drivers of fatty acid content in two filter-feeding aquatic consumers

Inferences about ecological structure and function are often made using elemental or macromolecular tracers of food web structure. For example, inferences about food chain length are often made using stable isotope ratios of top predators and consumer food sources are often inferred from both stable isotopes and fatty acid (FA) content in consumer tissues. The use of FAs as tracers implies some degree of macromolecular conservation across trophic interactions, but many FAs are subject to physiological alteration and animals may produce those FAs from precursors in response to food deficiencies. We measured 41 individual FAs and several aggregate FA metrics in two filter-feeding taxa to (1) assess ecological variation in food availability and (2) identify potential drivers of among-site variation in FA content. These taxa were filter feeding caddisflies (Family Hydropyschidae) and dreissenid mussels (Genus Dreissena), which both consume seston. Stable isotopic composition (C and N) in these taxa co-varied across 13 sites in the Great Lakes region of North America, indicating they fed on very similar food resources. However, co-variation in FA content was very limited, with only one common FA co-varying across this gradient (α-linolenic acid; ALA), suggesting these taxa accumulate FAs very differently even when exposed to the same foods. Based on these results, among-site variation in ALA content in both consumers does appear to be driven by food resources, along with several other FAs in dreissenid mussels. We conclude that single-taxa measurements of FA content cannot be used to infer FA availability in food resources.

Chemical composition and fatty acid profile in meat from grazing lamb diets supplemented with ryegrass hay, fishmeal and soya bean meal as PUFA sources

ABSTRACT: This study examined the characteristics of the fatty acids profile in the meat of lambs fed grazing and supplemented with different PUFA sources. Thirty Suffolk lambs were used (37.2±5.4kg BW), grazing on perennial ryegrass (Lolium perenne) (12h d-1) and supplemented (30g kg-1 BW0.75) with ryegrass hay (RGH), or supplements formulated with fishmeal (FHM) or soybean meal (SBM). Lambs were used in a completely randomized design. Results showed an effect on total SFA, with SBM higher than RGH (P=0.033), and SBM and FHM showing higher MUFA content compared with RGH (P=0.001). Total PUFA content was higher for RGH, followed by FHM and with the lowest content for SBM (P=0.001). Concluding that there is a variation in fatty acid content depending on the lipid-protein source used in supplementation in grazing sheep, the content of PUFA was higher for grazing lambs supplemented with RGH compared with those supplemented with FHM or SBM.

Epistatic interactions associated with fatty acid concentrations of beef from angus sired beef cattle.

BackgroundConsumers are becoming increasingly conscientious about the nutritional value of their food. Consumption of some fatty acids has been associated with human health traits such as blood pressure and cardiovascular disease. Therefore, it is important to investigate genetic variation in content of fatty acids present in meat. Previously publications reported regions of the cattle genome that are additively associated with variation in fatty acid content. This study evaluated epistatic interactions, which could account for additional genetic variation in fatty acid content.ResultsEpistatic interactions for 44 fatty acid traits in a population of Angus beef cattle were evaluated with EpiSNPmpi. False discovery rate (FDR) was controlled at 5 % and was limited to well-represented genotypic combinations. Epistatic interactions were detected for 37 triacylglyceride (TAG), 36 phospholipid (PL) fatty acid traits, and three weight traits. A total of 6,181, 7,168, and 0 significant epistatic interactions (FDR < 0.05, 50-animals per genotype combination) were associated with Triacylglyceride fatty acids, Phospholipid fatty acids, and weight traits respectively and most were additive-by-additive interactions. A large number of interactions occurred in potential regions of regulatory control along the chromosomes where genes related to fatty acid metabolism reside.ConclusionsMany fatty acids were associated with epistatic interactions. Despite a large number of significant interactions, there are a limited number of genomic locations that harbored these interactions. While larger population sizes are needed to accurately validate and quantify these epistatic interactions, the current findings point towards additional genetic variance that can be accounted for within these fatty acid traits.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-016-3235-8) contains supplementary material, which is available to authorized users.

Screening of Cotton Genotypes for Protein Content, Oil and Fatty Acid Composition

&lt;p&gt;The increase in the population at the global level necessitates to explore promising approaches to increase food supply, including protein and oil, to meet the needs of the people. Cotton is one of the most important oil producing crops and cottonseed meal provides important protein nutrients as animal feed. However, information on the genetic basis of cottonseed oil and protein contents is lacking. In this study; protein contents, oil and fatty acid composition of 124 cotton genotypes were observed for developing new cultivars. Accelerated Solvent Extraction method used for determining fat ratio; Gas Chromatography employed for fatty acid analysis while protein contents were analyzed by Kjeldahl method. Average crude oil 31.0%, total fat contents varied from 23.11 to 37.70% while mean protein content 38.0% were observed among genotypes. The dominating fatty acids included linoleic acid, palmitic acid and oleic acid (46.91, 25.73 and 20.21%) respectively, while linolenic acid (0.13%), r-linolenic (0.33%), palmitoleic acid (0.64%), myristic acid (0.88%), nervonic acid (1%) and stearic acid (2.38%) had variations in fatty acid contents. Frequency distribution of the parameters showed a normal distribution and differences among genotypes for the traits studied were statistically highly significant. Prinicipal component analysis showed a complex opposite relationship with a total protein and oil contents. Genotypes; Fantom for protein, Cirpan 60 for total crude oil, Stoneville 468 and YB195 for higher amount of fatty acids especially oleic acid; can be used for improvement of cottonseed quality in breeding programs.&lt;/p&gt;

Variation of Fatty Acid Content in Zamorano-Type Ovine Cheese According to the Milk Conjugated Linoleic Acid Content

A total of 30 Zamorano-type cheeses were manufactured in order to study the effects of milk conjugated linoleic acid (CLA) content, ripening time, and interactions between both effects on fatty acid (FA) profile. Cheeses elaborated from milk with a high CLA content showed higher contents of vaccenic, oleic, alpha-linolenic (ALA), CLA, monounsaturated (MUFA) and polyunsaturated (PUFA) FA, and lower contents of capric, lauric, myristic, palmitic, estearic, linoleic, and saturated (SFA) FA than cheese from milk with a low CLA content. Content of unsaturated C18 FA along with MUFA and PUFA groups increased throughout the ripening, while SFA content decreased. The interactions between milk CLA content and ripening time were significant for palmitic, linoleic, CLA, SFA, and omega-6/omega-3 ratio in Zamorano-type cheese. Decreases in cheese omega-6/omega-3 ratio were obtained from milk with a high CLA content; this ratio worsened over ripening in cheeses from low-CLA milk. In conclusion, these results emphasize the importance of the initial CLA content in milk with regard to improve the lipid profile in cheese for consumption.

Seasonal and within-plant variation in fatty acid content and composition in the brown seaweed Spatoglossum macrodontum (Dictyotales, Phaeophyceae)

We investigated seasonal and within-plant variation in total fatty acids (TFAs) and biomass increase in the tropical brown seaweed Spatoglossum macrodontum which was sampled from Magnetic Island (Queensland, Australia) at monthly intervals over 1 year. In this habitat, S. macrodontum is an annual species with a growth period from June to September where mean biomass changed from 8- to 136-g fresh weight. Although TFA content and fatty acid (FA) composition were not directly correlated to individual plant size, there was clear seasonal variation in TFA content with a peak in July (82.7 mg g−1 dry weight (dw)) followed by a 30 % decline in August and little subsequent variation from September to November (65.9–55.5 mg g−1 dw). The FA profile was rich in polyunsaturated FAs (PUFAs) (39 %); however, there was a change to a higher percentage of saturated FAs (SFAs) (42 %) and reduced PUFA (31 %) as plants reached the end of the growth period. Averaged across sampling periods, TFA content ranged from 77 mg g−1 dw in the tips to 30 mg g−1 dw in the base section. While PUFA content (37–38 %) was similar across sections, the base had less SFAs and a higher content of monounsaturated FAs (MUFAs) (29 %). These results are the first data on the seasonal biomass increase and the temporal and internal variations in FAs for this species with important implications when targeting large brown seaweeds as a source of FAs for nutraceuticals (PUFA(n-3), 21.8 % of TFA) or chemicals (C18:1 (n-9), 17.6 % of TFA).

Fatty Acid Composition at the Base of Aquatic Food Webs Is Influenced by Habitat Type and Watershed Land Use

Spatial variation in food resources strongly influences many aspects of aquatic consumer ecology. Although large-scale controls over spatial variation in many aspects of food resources are well known, others have received little study. Here we investigated variation in the fatty acid (FA) composition of seston and primary consumers within (i.e., among habitats) and among tributary systems of Lake Michigan, USA. FA composition of food is important because all metazoans require certain FAs for proper growth and development that cannot be produced de novo, including many polyunsaturated fatty acids (PUFAs). Here we sampled three habitat types (river, rivermouth and nearshore zone) in 11 tributaries of Lake Michigan to assess the amount of FA in seston and primary consumers of seston. We hypothesize that among-system and among-habitat variation in FAs at the base of food webs would be related to algal production, which in turn is influenced by three land cover characteristics: 1) combined agriculture and urban lands (an indication of anthropogenic nutrient inputs that fuel algal production), 2) the proportion of surface waters (an indication of water residence times that allow algal producers to accumulate) and 3) the extent of riparian forested buffers (an indication of stream shading that reduces algal production). Of these three land cover characteristics, only intense land use appeared to strongly related to seston and consumer FA and this effect was only strong in rivermouth and nearshore lake sites. River seston and consumer FA composition was highly variable, but that variation does not appear to be driven by the watershed land cover characteristics investigated here. Whether the spatial variation in FA content at the base of these food webs significantly influences the production of economically important species higher in the food web should be a focus of future research.

Causes of variation in fatty acid content and composition in grass and maize silages

The aim of this study was to quantify the variation in fatty acid (FA) content and composition in grass and maize silages and to identify key management factors during plant growth and the ensiling process that cause this variation. Samples of grass (n=101) and maize (n=96) silages were randomly collected from commercial dairy farms in The Netherlands in 2007 and 2008. Multivariate analysis was computed on data related to agronomic conditions, harvest-maturity, wilting management (grass only), chemical composition and feeding value of the individual silages to search for variables which cause the variation in FA contents. Total FA content was highly variable in grass (8.10–32.47g/kg DM) and maize (12.37–35.25g/kg DM) silages, and contents of all major individual FA also had a high variation. The content of C18:3n-3 had large variation (3.57–20.53g/kg DM) in grass silages, while C18:2n-6 had large variation (6.89–22.41g/kg DM) in maize silages. Redundancy analysis (i.e., a combination of principal components analysis and multiple regression) showed that variables related to plant maturity at harvest explained most of the variation in FA content, with silages from young grass and young maize having high contents of C18:3n-3. Plant cell wall components and digestibility are related to the maturity at harvest and were strong predictors of the FA contents in grass and maize silages. Regression equations based on nutrient composition provided relatively good estimations of the contents of C18:3n-3 (R2=0.73) and total FA (R2=0.65) in grass silages. Regression equations based on nutrient composition and feeding values gave relatively good estimations of the contents of C18:2n-6 (R2=0.51) and total FA (R2=0.48) in maize silages. Bruising (i.e., removing of the waxy layer of leaves and stem), silage pH and ammonia–N content did not affect the FA content in the grass silages.

Factors influencing variation of fatty acid content in ovine milk

Between January 2006 and December 2007, a total of 4,579 test-day observations for contents of milk fatty acids (FA) were obtained from 2,218 lactations of 1,109 ewes belonging to 14 Churra dairy flocks. The 36 analyzed FA were quantified as grams per 100g of total FA and were grouped as 18 dependent variables: 10 FA, 6 groups of FA, and 2 FA indexes. Flock, day of testing within flock (TD), ewe age, stage of lactation, and season effects contributed significantly to variations in FA. The 2 most important variation factors were flock (3 to 30% of total variance) and TD (35 to 70% of total variance). The percentage of variance explained by the TD effect for conjugated linoleic acid (CLA, C18:2 cis-9, trans-11) and linolenic acid (C18:3 cis-9, cis-12, cis-15) was particularly high: 60.7 and 68.2%, respectively. The season effect was also a very important variation factor, closely linked to feeding. The most significant seasonal variations were observed in polyunsaturated FA, with the highest values occurring in spring and summer and the lowest in winter. More specifically, CLA and linolenic acid contents were 44 and 30% higher in spring-summer than in winter. As the age of the ewe increased, the monounsaturated and polyunsaturated FA decreased and the short- and medium-chain saturated FA increased. The CLA and the CLA/C18:1 trans-11 Δ9-desaturase index increased significantly throughout lactation. The correlation coefficient between rumenic acid (CLA) and vaccenic acid was high (0.47) because of the precursor-product relationship via the Δ9-desaturase enzyme. The correlation coefficients were high between C10:0 and C12:0 (0.79), C12:0 and C14:0 (0.73), and C14:0 and C16:0 (0.29), probably because of their similar metabolic origin. Positive correlations were also obtained among the C18 FA family. All the studied factors of FA variation would be considered as fixed effects in the statistical models used for estimation of genetic and phenotypic parameters from test-day records of commercial flocks.

Seasonal Variations of Fatty Acid Contents of Saccostrea cucullata at Intertidal Zone of Chabahar Bay

Seasonal Variations of Fatty Acid Contents of Saccostrea cucullata at Intertidal Zone of Chabahar Bay