For this research communication our objective was to investigate to what extent milk coagulation properties and milk fatty acid (FA) composition were affected by different feeding systems, season and their interaction. Eighteen cows in total were subjected to one of three different feeding system treatments: full-time grazing or part-time grazing combined with indoor feeding of fresh grass with low or high concentrate supplementation. Milk was sampled in spring, summer and autumn. Milk coagulation time was 15.0, 19.0 and 17.7 min, coagulation dynamics 1.67, 3.41 and 1.79 min, and curd firmness 52.7, 32.4 and 47.0 mm in spring, summer and autumn, respectively. Thus, milk coagulation properties of the milk were lower during summer. There were strong seasonal effects on milk FA proportions, but there were not always changes with progressing season, or changes were different with respect to the impact of the feeding systems (system × season interaction). The milk fat was favourably rich in oleic acid, conjugated linoleic acid and α-linolenic acid and had a low n-6/n-3 fatty acid ratio in all systems. Factors like seasonal variations in grass composition and the energy balance of the cows were considered relevant for the milk FA composition. Overall, seasonal variations in milk quality were less pronounced with part-time grazing with fresh grass indoors as compared to full-time grazing without concentrate.

The aim of this study was to examine the effect of three different fatty acid (FA)-rich meals enriched in either SFA, MUFA or PUFA on postprandial metabolic responses in premenopausal, normal-weight women. For this randomised, single-blind, crossover study, three high-fat (HF) meals rich in either SFA, MUFA or PUFA (65 % energy from fat; 35 % of participants’ total daily energy needs) were tested. For each visit, anthropometrics and RMR were measured following a 12–15 h fast. Then, participants consumed one of the HF meals, and respiratory gases were collected using indirect calorimetry for 3 h postprandially. Energy expenditure (EE) following a SFA-rich meal was significantly higher than a MUFA-rich meal (P = 0·04; η2 = 0·19), but SFA was not significantly different from PUFA. There was a trend towards significance in EE between PUFA and MUFA (P = 0·06). After adjusting for fat-free mass (FFM), there were no longer condition or time effects for EE, although FFM remained a significant predictor (P = 0·005; η2 = 0·45). There were no significant differences between conditions for dietary-induced thermogenesis or substrate oxidation. The relationship between fat mass (FM) and both total fat oxidation (r 0·62; P = 0·025) and total change in RER following a MUFA-rich meal was observed (r −0·55; P = 0·05). In conclusion, weight loss through increases in EE may be best achieved by increasing FFM rather than selection of FA type. Further, a relationship exists between FM and fat oxidation following a MUFA-rich meal, most likely due to an unidentified mechanism.

Human milk fatty acid composition varies during lactation and is influenced by maternal diet, maternal lifestyle-related factors and genetic background. This is one of the first studies to investigate a period effect, that is, the impact of lifestyle-related changes on human milk fatty acid composition, in two different cohorts. Lactating women were recruited from the general population a decade apart in Ulm, Germany, using similar methodology. Human milk samples collected 6 weeks postpartum were analysed (Ulm Birth Cohort Study (UBCS (2000)), n 567; Ulm SPATZ Health Study (SPATZ (2012)), n 458). Centred log ratio transformation was applied to fatty acid data. Principal component analysis was used to determine study-dependent fatty acid profiles. A general linear model was used to determine the study (or period) effect on fatty acid profiles adjusting for duration of gestation, age, education, delivery mode, smoking and pre-pregnancy BMI. Two principal components were retained (PC1 and PC2). PC1 was associated with UBCS, while PC2 was associated with SPATZ. PC1 comprised high SFA, and low MUFA, n-6 and n-3 long-chain PUFA (LCPUFA). The inverse was true for PC2. Although human milk remains a source of essential fatty acids, infants could be at risk of inadequate n-3 and n-6 LCPUFA intake through human milk. The differences in the human milk fatty acid profiles also reflect changes in maternal dietary habits in the more recent cohort, which may comprise lower intakes of dietary trans-fatty acids and SFA and higher intakes of vegetable oils.

Plantain and chicory are interesting forage species since they present good nutritional quality and are more resistant to drought than many temperate grasses. The fatty acid (FA) profile in milk and meat is related to a growing concern for the consumption of healthy foods, that is, with a lower content of saturated FA, higher polyunsaturated FA (PUFA) and a favourable n-6 : n-3 FAs ratio. Our objective was to evaluate the FA content in ewe’s milk and lamb’s meat fed a plantain–chicory mixture (PCH) or a grass-based permanent sward (GBS) dominated by perennial ryegrass. Eighteen Austral ewes in mid-lactation were allocated to PCH and GBS treatments. Milk samples were obtained during September (spring). Thirty weaned lambs were finished on both treatments from November to December (7 weeks), slaughtered and their meat sampled. Fat from milk and meat samples was extracted and stored until analysed by gas chromatography. Milk fat from GBS was higher than from PCH (P < 0.05) in C18:0 (11 385 v. 5874 mg/100 g FA), 9c-18:1 (15 750 v. 8565 mg/100 g FA), 11 t-18:1 (4576 v. 2703 mg/100 g FA) and 9c,11 t-18:2 (1405 v. 921 mg/100 g FA) and lower in 18:2n-6 (827 v. 1529 mg/100 g FA) and 18:3n-3 (943 v. 1318 mg/100 g FA) FA. Total mono-unsaturated FA was higher in GBS than PCH (P < 0.05). Meat fat from PCH swards presented a higher (P < 0.05) content than GBS for 18:2n-6 (46.8 v. 28.2 mg/100 g FA), linolenic (24.6 v. 14.2 mg/100 g FA), polyunsaturated FA (119.7 v. 73.4 mg/100 g FA), n-6 (65.9 v. 40.8 mg/100 g FA) and n-3 (53.8 v. 32.5 mg/100 g FA), respectively. No effect of treatment (P > 0.05) was detected for 9c-18:1 (283.9 v. 205.8 mg/100 g FA), 11 t-18:1 (26.2 v. 19.3 mg/100 g FA) and 9c,11 t-18:2 (10.1 v. 7.6 mg/100 g FA), for PCH and GBS. These results suggest that grazing a PCH mixture results in a higher concentration of PUFA in ewes’ milk and in lambs’ fat, as compared to a GBS sward.

Human donor milk (DM) is Holder pasteurised (62·5°C, 30 min) to ensure its microbiological safety for infant consumption. In low-resource settings, flash heating is used to pasteurise milk. Although there is considerable interest in non-thermal alternatives (high hydrostatic pressure processing (HHP) and UVC irradiation) for pasteurisation, their effect on the fatty acid composition is not well understood. Of particular interest is the effect of pasteurisation on the generation of oxylipins. DM from eight mothers containing bacteria >5 × 107 colony-forming units/l was used. In a paired design, each pool of milk underwent four pasteurisation techniques: Holder; flash heating; UVC (250 nm, 25 min) and HHP (500 MPa, 8 min). Fatty acids were quantified by GC-flame ionisation detection and oxylipins derived from arachidonic acid; 18-carbon PUFA (α-linolenic acid, linoleic acid and γ-linolenic acid) and EPA/DHA were measured by liquid chromatography-tandem MS in aliquots of raw and processed milk. There were no significant changes to the composition of fatty acids following all pasteurisation techniques compared with raw milk. The n-6:n-3 ratio remained constant ranging from 6·4 to 6·6. Several arachidonic acid-derived oxylipins were highest post-UVC and elevated post-HHP compared with raw milk. Several oxylipins derived from 18-carbon PUFA (linoleic and α-linolenic acids) were elevated in UVC-treated milk. EPA/DHA-derived oxylipins were on average, unaffected by pasteurisation. Although some PUFA-derived oxylipins were increased following UVC and HHP, no method affected the fatty acid composition of human DM. Further research is needed to determine if varying levels of oxylipins in human DM as a result of processing can potentially mediate cellular signalling; proliferation and apoptosis, especially important for preterm infant development.

Fatty acid (FA) composition is a key component of sheep milk nutritional quality. However, breeding for FA composition in dairy sheep is hampered by the logistic and phenotyping costs. This study was aimed at estimating genetic parameters for sheep milk FA and to test the feasibility of their routine measurement by using Fourier-transform IR (FTIR) spectroscopy. Milk FA composition of 989 Sarda ewes farmed in 48 flocks was measured by gas chromatography (FAGC). Moreover, FTIR spectrum was collected for each sample, and it was used to predict FA composition (FAFTIR) by partial least squares regression: 700 ewes were used for estimating model parameters, whereas the remaining 289 animals were used to validate the model. One hundred replicates were performed by randomly assigning animals to estimation and validation data set, respectively. Variance components for both measured and predicted traits were estimated with an animal model that included the fixed effects of parity, days in milking interval, lambing month, province, altitude of flock location, the random effects of flock-test-date and animal genetic additive. Genetic correlations among FAGC, and between corresponding FAGC and FAFTIR were estimated by bivariate analysis. Coefficients of determination between FAGC and FAFTIR ranged from moderate (about 0.50 for odd- and branched-chain FA) to high (about 0.90 for de novo FA) values. Low-to-moderate heritabilities were observed for individual FA (ranging from 0.01 to 0.47). The largest value was observed for GC measured C16:0. Low–to-moderate heritabilities were estimated for FA groups. In most of cases, heritabilites were slightly larger for FAGC than FAFTIR. Estimates of genetic correlations among FAGC showed a large variability in magnitude and sign. The genetic correlation between FAFTIR and FAGC was higher than 60% for all investigated traits. Results of the present study confirm the existence of genetic variability of the FA composition in sheep and suggest the feasibility of using FAFTIR as proxies for these traits in large scale breeding programs.

It has been well established that milk yield is affected both by milking frequency and due to the removal of residual milk, but the influence of a combination of these factors is unclear. In this study, four mid-lactation cows were used in a 4 × 4 Latin square design to test the hypothesis that the effects of more frequent milking and residual milk removal on milk yield and composition are additive and alter milk fatty acid composition. Treatments comprised two or four times daily milking in combination with (or without) residual milk removal over a 96 h interval preceded by a 2 d pretreatment period and followed by a 8 d washout in each 14 d experimental period. Milk was sampled at each milking for the analysis of gross composition and SCC. Samples of available and residual milk collected on the last milking during each treatment period were collected and submitted for fatty acid composition analysis. Increases in milking frequency and residual milk removal alone or in combination had no effect on milk yield or on the secretion of lactose and protein in milk. However, residual milk removal during more frequent milking increased milk fat yield. Milking treatments had no major influence on the fatty acid composition of available milk, but resulted in rather small changes in the relative abundance of specific fatty acids, with no evidence that the additive effects of treatments were due to higher utilisation of preformed fatty acids relative to fatty acid synthesis de novo. For all treatments, fat composition of available and residual milk was rather similar indicating a highly uniform fatty acid composition of milk fat within the mammary gland.

A total of 48 sub-adult hares and adult reproducing farmed hares were used to characterize carcass and meat traits according to the age and gender of animals. With respect to carcass traits, when age increased, the carcass weight significantly increased (2022 to 3391 g; P<0.001), but dressing out percentages did not change. The dissectible fat (1.3% to 2.2%; P<0.05) and Longissimus lumborum (LL) proportions (13.5% to 14.5%; P<0.001) and muscle-to-bone ratio of hind legs (5.11 to 6.23; P<0.001) increased, whereas the hind leg proportions decreased (37.3% to 36.3%; P=0.01). As for the meat quality, the pH of hind leg (5.74 to 5.83; P<0.001) and LL (5.53 to 5.69; P<0.001) increased with age, while the L* index decreased in both cuts (42.9 to 34.4 in hind leg; 45.1 to 40.3 in LL; P<0.001). The redness index increased at the hind leg (4.07 to 5.76; P<0.001), while it decreased at LL (3.03 to 1.46; P<0.001). In the case of the hind leg, meat thawing losses decreased (1.58% to 1.02%), and shear force increased (2.97 to 4.02 kg/g). In the case of LL, thawing losses decreased (8.79% to 4.91%; P<0.001) in the adult hares compared with the sub-adult ones. Meat water and protein contents decreased in the hind leg and LL of the adult hares compared with the sub-adult ones, whereas ether extract increased in a restricted range in LL only (0.92% to 1.11%; P<0.001). In the case of the hind leg, the rate of the saturated fatty acids (SFA) decreased (41.0% to 26.7%), and the rate of the polyunsaturated fatty acids (PUFA) increased (34.0% to 45.3%) (P<0.001). In the case of LL, SFA (38.6% to 42.9%) and monounsaturated fatty acids (19.4% to 27.2%) increased, whereas PUFA decreased (42.0% to 30.1%) when the age increased (P<0.001). Gender affected only the slaughter results and carcass traits. In conclusion, farmed hares have favourable slaughter results (high dressing percentage), carcass traits (high hind legs and loins rates), and meat nutritional value (high-protein, low-fat meat). This fact would offer additional commercial opportunities, in addition to restocking, to hare farmers.

We estimated the heritabilities (h2) and genetic and phenotypic correlations among individual and groups of fatty acids, as well as their correlations with six important carcass and meat-quality traits in Korean Hanwoo cattle. Meat samples were collected from the longissimus dorsi muscles of 1000 Hanwoo steers that were 30-month-old (progeny of 85 proven Hanwoo bulls) to determine intramuscular fatty acid profiles. Phenotypic data on carcass weight (CWT), eye muscle area (EMA), back fat thickness (BFT), marbling score (MS), Warner–Bratzler shear force (WBSF) and intramuscular fat content (IMF) were also investigated using this half-sib population. Variance and covari.ance components were estimated using restricted maximum likelihood procedures under univariate and pairwise bivariate animal models. Oleic acid (C18:1n-9) was the most abundant fatty acid, accounting for 50.69% of all investigated fatty acids, followed by palmitic (C16:0; 27.33%) and stearic acid (C18:0; 10.96%). The contents of saturated fatty acids (SFAs), monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) were 41.64%, 56.24% and 2.10%, respectively, and the MUFA/SFA ratio, PUFA/SFA ratio, desaturation index (DI) and elongation index (EI) were 1.36, 0.05, 0.59 and 0.66, respectively. The h2 estimates for individual fatty acids ranged from very low to high (0.03±0.14 to 0.63±0.14). The h2 estimates for SFAs, MUFAs, PUFAs, DI and EI were 0.53±0.14, 0.49±0.14, 0.23±0.10, 0.51±0.13 and 0.53±0.13, respectively. The genetic and phenotypic correlations among individual fatty acids and fatty acid classes varied widely (−0.99 to 0.99). Notably, C18:1n-9 had favourable (negative) genetic correlations with two detrimental fatty acids, C14:0 (−0.76) and C16:0 (−0.92). Genetic correlations of individual and group fatty acids with CWT, EMA, BFT, MS, WBSF and IMF ranged from low to moderate (both positive and negative) with the exception of low-concentration PUFAs. Low or near-zero phenotypic correlations reflected potential non-genetic contributions. This study provides insights on genetic variability and correlations among intramuscular fatty acids as well as correlations between fatty acids and carcass and meat-quality traits, which could be used in Hanwoo breeding programmes to improve fatty acid compositions in meat.

The present study aims to assess the effects of pig’s genotype (lean v. fatty) and dietary protein level (control v. reduced) on intramuscular fat (IMF) content, fatty acid composition and fibre profile of psoas major, a representative red muscle in pig’s carcass scarcely studied relative to white longissimus lumborum. The experiment was conducted on 40 intact male pigs (20 Alentejana purebred and 20 Large White×Landrace×Pietrain crossbred) from 60 to 93 kg of live weight. Pigs were divided and allocated to four dietary groups: control protein diet equilibrated for lysine (17.5% of CP and 0.7% of lysine) and reduced protein diet (RPD) not equilibrated for lysine (13.1% of crude protein and 0.4% of lysine) within a 2×2 factorial arrangement (two genotypes and two diets). Alentejana purebred had higher IMF content (15.7%) and monounsaturated fatty acids (MUFA) (8.9%), whereas crossbred pigs had higher PM weight (46.3%) and polyunsaturated fatty acids (PUFA) (20.1%). The genotype also affected colour with higher lightness (15.1%) and yellowness (33.8%) and lower redness (9.9%) scores in crossbred pigs. In line with this, fatty pigs displayed more oxidative fibres (29.5%), whilst lean pigs had more glycolytic (54.4%). Relative to fatty acids, RPD increased MUFA (5.2%) and SFA (3.2%) but decreased PUFA (14.8%). Ultimately, RPD increased IMF content (15.7%) in the red muscle under study, with no impact on glycolytic to oxidative fibre type transformation.

Safflower is a traditional oilseed crop in the world. Its seed oil is a healthy edible oil containing high amount of unsaturated fatty acids. Genetically diverse exotic cultivars are valuable germplasm for introducing new diversity in safflower improvement programmes. In this study, we characterized safflower cultivars of India (30) and Mexico (23) comprising varieties, hybrids and advanced lines developed over 50 years for genetic distinctiveness using 38 simple sequence repeat (SSR) loci. Genetic diversity estimates across cultivar groups (total, India and Mexico) were as follows: mean number of alleles (3.2, 3.1, 2.6), expected heterozygosity (0.42, 0.37, 0.37) and polymorphism information content (0.36, 0.33, 0.32) respectively, which suggested narrow SSR allelic diversity within and between cultivar groups. However, distance-based cluster analysis (neighbour-joining tree) and model-based STRUCTURE analysis revealed that safflower cultivars of India and Mexico, with the exception of a few, form two genetically distinct groups. High level of genetic variation explained between the populations (40%) and Fst estimate (0.4) suggested that the cultivar groups were highly differentiated with limited gene flow supporting a strong genetic structuring. High oil (~38%) and high oleic (73–79%) contents of a subset of Mexican safflower varieties and advanced lines were confirmed in field trials in India. These exotic sources from Mexico are valuable for safflower breeding programmes in India to develop new cultivars with high oil yielding potential and high oleic acid content, which is the current market demand.

The influence of genotype (lean v. fatty) and dietary protein level (normal v. reduced) on plasma metabolites, hepatic fatty acid composition and mRNA levels of lipid-sensitive factors is reported for the first time, using the pig as an experimental model. The experiment was conducted on forty entire male pigs (twenty lean pigs of Large White×Landrace×Pietrain cross-breed and twenty fatty pigs of Alentejana purebreed) from 60 to 93 kg of live weight. Each pig genotype was divided into two subgroups, which were fed the following diets: a normal protein diet (NPD) equilibrated for lysine (17·5 % crude protein and 0·7 % lysine) and a reduced protein diet (RPD) not equilibrated for lysine (13·1 % crude protein and 0·4 % lysine). The majority of plasma metabolites were affected by genotype, with lean pigs having higher contents of lipids, whereas fatty pigs presented higher insulin, leptin and urea levels. RPD increased plasma TAG, free fatty acids and VLDL-cholesterol compared with NPD. Hepatic total lipids were higher in fatty pigs than in the lean genotype. RPD affected hepatic fatty acid composition but had a slight influence on gene expression levels in the liver. Sterol regulatory element-binding factor 1 was down-regulated by RPD, and fatty acid desaturase 1 (FADS1) and fatty acid binding protein 4 (FABP4) were affected by the interaction between genotype and diet. In pigs fed RPD, FADS1 was up-regulated in the lean genotype, whereas FABP4 increased in the fatty genotype. Although there is a genotype-specific effect of dietary protein restriction on hepatic lipid metabolism, lipogenesis is not promoted in the liver of lean or fatty pigs.

The isolated or combined effects of betaine and arginine supplementation of reduced protein diets (RPD) on fat content, fatty acid composition and mRNA levels of genes controlling lipid metabolism in pig m. longissimus lumborum and subcutaneous adipose tissue (SAT) were assessed. The experiment was performed on forty intact male pigs (Duroc×Large White×Landrace cross-breed) with initial and final live weights of 60 and 93 kg, respectively. Pigs were randomly assigned to one of the following five diets (n 8): 16·0 % of crude protein (control), 13·0 % of crude protein (RPD), RPD supplemented with 0·33 % of betaine, RPD supplemented with 1·5 % of arginine and RPD supplemented with 0·33 % of betaine and 1·5 % of arginine. Data confirmed that RPD increase intramuscular fat (IMF) content and total fat content in SAT. The increased total fat content in SAT was accompanied by higher GLUT type 4, lipoprotein lipase and stearoyl-CoA desaturase mRNA expression levels. In addition, the supplementation of RPD with betaine and/or arginine did not affect either IMF or total fat in SAT. However, dietary betaine supplementation slightly affected fatty acid composition in both muscle and SAT. This effect was associated with an increase of carnitine O-acetyltransferase mRNA levels in SAT but not in muscle, which suggests that betaine might be involved in the differential regulation of some key genes of lipid metabolism in pig muscle and SAT. Although the arginine-supplemented diet decreased the mRNA expression level of PPARG in muscle and SAT, it did not influence fat content or fatty acid composition in any of these pig tissues.

The increasing use of unconventional feedstuffs in chicken’s diets results in the substitution of starch by lipids as the main dietary energy source. To evaluate the responses of genetically fat or lean chickens to these diets, males of two experimental lines divergently selected for abdominal fat content were fed isocaloric, isonitrogenous diets with either high lipid (80 g/kg), high fiber (64 g/kg) contents (HL), or low lipid (20 g/kg), low fiber (21 g/kg) contents (LL) from 22 to 63 days of age. The diet had no effect on growth performance and did not affect body composition evaluated at 63 days of age. Glycolytic and oxidative energy metabolisms in the liver and glycogen storage in liver and Sartorius muscle at 63 days of age were greater in chicken fed LL diet compared with chicken fed HL diet. In Pectoralis major (PM) muscle, energy metabolisms and glycogen content were not different between diets. There were no dietary-associated differences in lipid contents of the liver, muscles and abdominal fat. However, the percentages of saturated (SFA) and monounsaturated fatty acids (MUFA) in tissue lipids were generally higher, whereas percentages of polyunsaturated fatty acids (PUFA) were lower for diet LL than for diet HL. The fat line had a greater feed intake and average daily gain, but gain to feed ratio was lower in that line compared with the lean line. Fat chickens were heavier than lean chickens at 63 days of age. Their carcass fatness was higher and their muscle yield was lower than those of lean chickens. The oxidative enzyme activities in the liver were lower in the fat line than in the lean line, but line did not affect energy metabolism in muscles. The hepatic glycogen content was not different between lines, whereas glycogen content and glycolytic potential were higher in the PM muscle of fat chickens compared with lean chickens. Lipid contents in the liver, muscles and abdominal fat did not differ between lines, but fat chickens stored less MUFA and more PUFA in abdominal fat and muscles than lean chickens. Except for the fatty acid composition of liver and abdominal fat, no interaction between line and diet was observed. In conclusion, the amount of lipids stored in muscles and fatty tissues by lean or fat chickens did not depend on the dietary energy source.

The present study was conducted to investigate the effects of dietary arachidonic acid (ARA) on growth performance, fatty acid composition and ARA metabolism-related gene expression in larval half-smooth tongue sole (Cynoglossus semilaevis). Larvae (35 d after hatching, 54 (sem 1) mg) were fed diets with graded concentrations of ARA (0·01, 0·39, 0·70, 1·07, 1·42 and 2·86 % dry weight) five times per d to apparent satiation for 30 d. Results showed that increased dietary ARA concentration caused a significant non-linear rise to a plateau in survival rate, final body weight and thermal growth coefficient, and the maximum values occurred with the 1·42 % ARA treatment. As dietary ARA increased to 1·07 or 1·42 %, activities of trypsin, leucine aminopeptidase and alkaline phosphatase levels increased, but they decreased with higher ARA concentrations. The fatty acid composition of tongue sole larvae was almost well correlated with their dietary fatty acid profiles, and the EPA content of the larvae decreased with increasing dietary ARA. Meanwhile, the partial sequences of COX-1a (cyclo-oxygenase-1a), COX-1b (cyclo-oxygenase-1b), COX-2 (cyclo-oxygenase-2), 5-LOX (5-lipoxygenase) and CYP2J6-like (cytochrome P450 2J6-like) were also obtained. Both COX-2 and 5-LOX mRNA expression levels significantly increased to a plateau in an ‘L’-shaped manner as dietary ARA increased to 1·07 or 1·42 %, but no significant differences were found in the gene expression of COX-1a, COX-1b or CYP2J6-like. These results suggest that 1·07–1·42 % dietary ARA was beneficial to the growth performance of larval tongue sole, and the regulation of dietary ARA on the growth performance of larvae was probably involved in altering the mRNA expression of COX-2 and 5-LOX.

The aim of the study was to assess the effects of partial replacement of soybean meal with a protein-equivalent amount of rapeseed cake in the diet on milking parameters and fatty acid (FA) composition of milk in dairy cows. Two groups of Holstein-Friesian cows, 8 each, consisting of randomised blocks were studied: a control group (C) was given a traditional high-protein supplement (extracted soybean meal) and the experimental group (E), had part of extracted soybean meal replaced with rapeseed cake. Dry matter intake and milk yield in both groups were not affected by the diet but milk fat percentage and yield were decreased in both groups. Rapeseed cake had no effect on milk acidity or on protein (including casein) and lactose contents. A lower concentration of urea in milk in E group indicated a proper ratio of protein to energy in the fodder. Health condition of mammary gland and indicators of metabolic profile were not affected by rapeseed cake supplementation. In E group, the share of atherogenic saturated fatty acids (FA) was reduced after 11 weeks: palmitic, by 26% and myristic, by 22%; moreover, as compared with control cows, the content of monounsaturated FA in milk increased by 44% after 3 weeks and by 68% after 11 weeks, t-18:1 and c-9 t-11 isomer of CLA increased about 2·5-fold after 11 weeks. In E group, the atherogenic index (AI) was significantly (P < 0·001) lower than in C (by 54% on average) and the decrease with time was considerable (by 29%, P < 0·001). Contents of odd- and branched- chain FA in milk were not significantly affected thus reflecting proper rumen function. Partial replacement of soybean meal with rapeseed cake in the diet of cows may improve both milking indices and FA profile of milk.

The objectives of this study were to determine the effects of conjugated linoleic acid (CLA) or betaine on the growth performance, carcass characteristics and fatty acid composition in backfat and belly fat of pigs fed distillers dried grains with solubles (DDGS). Thirty-two (60±2 kg) crossbred barrows (Duroc×Landrace×Yorkshine) were assigned to one of four diets randomly: (1) the control diet containing no corn DDGS (control group); (2) the diet containing 30% corn DDGS (DDGS-fed group); (3) the diet containing 30% corn DDGS and 10 g/kg CLA (CLA-fed group); (4) the diet containing 30% corn DDGS and 1 g/kg BET (BET-fed group). The pigs fed DDGS showed that the percentages of C18:2, polyunsaturated fatty acid (PUFA) and iodine value (IV) increased, while C18:1, saturated fatty acid (SFA) and monounsaturated fatty acid (MUFA) decreased. Pigs fed the DDGS+CLA or DDGS+betaine diets showed the increased percentage of SFA, and the decreased percentage of C18:2, PUFA and IV. In conclusion, results confirmed that the diets containing 30% DDGS had no detrimental effects on growth performance, but increased the percentage of PUFA and IV and decreased the percentage of SFA and MUFA in the backfat and belly fat. However, supplementation with CLA or BET can part reverse these effects on carcass fat in finishing pigs.

There are very few studies in ruminants characterizing mammary and adipose tissue (AT) expression of genes and gene networks for diets causing variations in milk fatty acid (FA) composition without altering milk fat secretion, and even less complementing this information with data on tissue FA profiles. This work was conducted in sheep in order to investigate the response of the mammary gland and the subcutaneous and perirenal AT, in terms of FA profile and mRNA abundance of genes involved in lipid metabolism, to a diet known to modify milk FA composition. Ten lactating Assaf ewes were randomly assigned to two treatments consisting of a total mixed ration based on alfalfa hay and a concentrate (60 : 40) supplemented with 0 (control diet) or 25 (SO diet) g of sunflower oil/kg of diet dry matter for 7 weeks. Milk composition, including FA profile, was analysed after 48 days on treatments. On day 49, the animals were euthanized and tissue samples were collected to analyse FA and mRNA abundance of 16 candidate genes. Feeding SO did not affect animal performance but modified milk FA composition. Major changes included decreases in the concentration of FA derived from de novo synthesis (e.g. 12:0, 14:0 and 16:0) and increases in that of long-chain FA (e.g. 18:0, c9-18:1, trans-18:1 isomers and c9,t11-CLA); however, they were not accompanied by significant variations in the mRNA abundance of the studied lipogenic genes (i.e. ACACA, FASN, LPL, CD36, FABP3, SCD1 and SCD5) and transcription factors (SREBF1 and PPARG), or in the constituent FA of mammary tissue. Regarding the FA composition of AT, the little influence of SO did not appear to be linked to changes in gene mRNA abundance (decreases of GPAM and SREBF1 in both tissues, and of PPARG in the subcutaneous depot). Similarly, the great variation between AT (higher contents of saturated FA and trans-18:1 isomers in the perirenal, and of cis-18:1, c9,t11-CLA and n-3 PUFA in the subcutaneous AT) could not be related to differences in gene mRNA abundance due to tissue site (higher LPL and CD36, and lower SREBF1 in perirenal than in subcutaneous AT). Overall, these results suggest a marginal contribution of gene expression to the nutritional regulation of lipid metabolism in these tissues, at least with the examined diets and after 7 weeks on treatments. It cannot be ruled out, however, that the response to SO is mediated by other genes or post-transcriptional mechanisms.

The cumulative effects of dietary arginine, leucine and protein levels on fat content, fatty acid composition and mRNA levels of genes controlling lipid metabolism in pig longissimus lumborum muscle and subcutaneous adipose tissue (SAT) were investigated. The experiment was performed on fifty-four intact male pigs (Duroc × Pietrain × Large White × Landrace crossbred), with a live weight ranging from 59 to 92 kg. The pigs were randomly assigned to one of six experimental treatments (n 9). The treatments followed a 2 × 3 factorial arrangement, with two levels of arginine supplementation (0 v. 1 %) and three levels of a basal diet (normal protein diet, NPD; reduced protein diet, RPD; reduced protein diet to achieve 2 % of leucine, RPDL). The results showed that dietary arginine supplementation did not affect the intramuscular fat (IMF) content and back fat thickness, but increased the total fat in SAT. This effect was associated with an increase in fatty acid synthase (FASN) and stearoyl-CoA desaturase (SCD) mRNA levels in SAT, which suggests that arginine might be involved in the differential regulation of some key lipogenic genes in pig muscle and SAT. The increase in IMF content under the RPD, with or without leucine supplementation, was accompanied by increased FASN and SCD mRNA levels. Arginine supplementation did not influence the percentage of main fatty acids, while the RPD had a significant effect on fatty acid composition in both tissues. Leucine supplementation of RPD did not change IMF, total fat of SAT and back fat thickness, but increased 16 : 0 and 18 : 1cis-9 and decreased 18 : 2n-6 in muscle.

The present study assessed the effect of pig genotype (fatty v. lean) and dietary protein and lysine (Lys) levels (normal v. reduced) on intramuscular fat (IMF) content, subcutaneous adipose tissue (SAT) deposition, fatty acid composition and mRNA levels of genes controlling lipid metabolism. The experiment was conducted on sixty intact male pigs (thirty Alentejana purebred and thirty Large White × Landrace × Pietrain crossbred), from 60 to 93 kg of live weight. Animals were divided into three groups fed with the following diets: control diet equilibrated for Lys (17·5 % crude protein (CP) and 0·7 % Lys), reduced protein diet (RPD) equilibrated for Lys (13·2 % CP and 0·6 % Lys) and RPD not equilibrated for Lys (13·1 % CP and 0·4 % Lys). It was shown that the RPD increased fat deposition in the longissimus lumborum muscle in the lean but not in the fatty pig genotype. It is strongly suggested that the effect of RPD on the longissimus lumborum muscle of crossbred pigs is mediated via Lys restriction. The increase in IMF content under the RPD was accompanied by increased stearoyl-CoA desaturase (SCD) and PPARG mRNA levels. RPD did not alter backfat thickness, but increased the total fatty acid content in both lean and fatty pig genotype. The higher amount of SAT in fatty pigs, when compared with the lean ones, was associated with the higher expression levels of ACACA, CEBPA, FASN and SCD genes. Taken together, the data indicate that the mechanisms regulating fat deposition in pigs are genotype and tissue specific, and are associated with the expression regulation of the key lipogenic genes.