There is an increasing interest in low-input, multispecies swards as a sustainable forage for ruminant production, but the impact of grazing these over extended periods of time on meat nutritional quality (fatty acid (FA) profile, trace minerals and oxidisability risk) and sensory properties is unclear. Thirty lambs were grazed for 133 days on either a perennial ryegrass (PRG) or botanically diverse (containing twelve plant species, BD), pasture. The effects on the FA composition of musculus longissimus thoracis (lean and subcutaneous fat), zinc and iron content (lean), glutathione perioxidase (GSH-Px) activity (lean and plasma) and thiobarbituric acid reactive substances (TBARS) content (lean) were determined, and cooked meat was assessed for sensory properties using a trained sensory panel. BD lambs were lighter (P = 0.014) and had a lower weekly live weight gain (P = 0.017) than PRG, which was probably due to the nutritional quality of the pasture. BD pasture increased (P < 0.05) 18:2 n-6 content in lean and subcutaneous fat, and there was no effect (P > 0.05) on other polyunsaturated FA (PUFA), GSH-Px activity or TBARS content. BD pasture increased (P = 0.038) lean tissue zinc content compared with PRG but did not affect iron (P > 0.05). Pasture type had no impact (P > 0.05) on meat aroma and flavour sensory properties. It was concluded that grazing BD for an extended period did not negatively affect the nutritional and eating quality of lamb meat compared with PRG, and as such is suitable for finishing lambs. In order to benefit economically from including a BD pasture in a lamb finishing system, producers may need to consider an earlier slaughter target weight, depending on live weight gain.

Soyabean is considered an unsustainable protein source for livestock feeds because of the large quantity of input and energy required to cultivate and process it. Other protein-based agro-industrial co-products that are less input-intensive, can mitigate methane (CH4) production and may therefore be more sustainable options instead soyabean. The objective of this study was to compare the effect of replacing the same amount of protein (40 g/kg DM crude protein) as soyabean meal (SBM) with low-carbon local agro-industrial co-products, (brewers' spent grains, BSG; dried wheat distillers' grains, WDG; dried corn distillers' grains, CDG and corn steep liquor CSL), on in vitro rumen degradation, fermentation and gas and methane production. The study used a 72-hour in vitro gas production method with a basal substrate of dried, ground grass silage and wheat. Gas volumes were measured at ten different specific intervals, and CH4 concentrations were analysed via gas chromatography. After 72 hours, in vitro DM degradability (IVDMD) and volatile fatty acid (VFA) concentrations were assessed. Gas and CH4 production curve profiles were fitted to models to determine asymptote production, the extent of degradation in rumen proper (RoP), and the fractional degradation rate (mu) (h(-1)) in the halfway 50 % of the asymptote production. The IVDMD and estimated RoP at 0.04 h and 0.025 h were lower (P<0.05) for BSG compared to the other treatments, by 4.9-6.6 %; 5.8-9.9 %; 5.2-9.0 %. Gas and CH4 yield (mL/g substrate and mL/g substrate degraded), and pH (SB = 6.77, BSG = 6.80, WDG = 6.74, CDG = 6.84, and CSL = 6.73; P>0.05), were not significantly affected by treatment. Butyrate and valerate were lower (P<0.05) for BSG compared to CSL, and caproate was lower (P<0.001) for BSG compared to the other treatments and in CSL compared to SBM. The results regarding degradability and VFAs concentrations of this study demonstrated that dried wheat distillers' grains, dried corn distillers' grains, and corn steep liquor have the potential to replace soyabean meal as protein sources for ruminants, but further reduction of CH4 emissions as a result of such practice may not be expected. Although slightly less degradable, based on their nutrient composition and the fact they did not affect rumen fermentation characteristics, brewers' spent grains can still play a complementary role in ruminant diets, especially in regions where they are locally readily available.

Milk is a fundamental food matrix that is widely consumed. Milk fat is important for producing dairy products such as butter, cream, cheese and whole milk powder. Aside from flavour, it has been linked to human health and its chemistry can be modulated by various means towards a more healthy fatty acid profile. Industry and stakeholders have different interests in milk fat, based on specific policies which reflect the type of research and funding initiatives currently performed in different countries. This position paper summarizes the current state-of-the-art with regards to milk fat research and industry as well as stakeholder initiatives, and then highlights new developments based on information gathered from North America (United States and Mexico), Europe (United Kingdom, Spain, Italy, and Finland), Africa (Egypt), Asia (China and Bangladesh) and Oceania (New Zealand). South America is an important contributor to the dairy industry but will not be considered here and thus this paper must be considered cross-continental rather than global. This manuscript intends to show a wide 'picture' of milk fat from different angles in different parts of the globe.

A field trial evaluated the effects of tree species, plant fractions, and season on the dry matter degradability (DMd) and tannin profiles of three tree species (Salix caprea, goat willow (GW); Quercus robur, common oak; Acer campestre., maple). Leaf and twig samples were collected monthly from five trees per species between June and September in Berkshire, UK. Total condensed tannins (CTs) concentrations were determined using a Butanol-HCl assay and tannin profiling (mean degree of polymerization (mDP), and concentrations of procyanidins (PC), prodelphinidins (PD), and cis- and trans- flavan-3-ols) were measured via in situ thiolysis assay. In vitro total DMd was determined using the ANKOM Daisy II system. Data were analysed using linear mixed models with tree species, plant fractions, month, and their interactions as fixed factors, and tree ID (nested within species) as a random factor. Goat willow had the highest (P < 0.05) DMd, total CTs concentrations, mDP, and trans flavan-3-ols. Oak had the highest (P < 0.001) PD concentrations. Maple had the highest final DM, soluble losses, and concentrations of PC, and cis flavan-3-ols. Across all tree species, leaves had a higher (P < 0.001) DMd, soluble losses, and total CTs concentrations, and lower DM (P < 0.001) and mDP (P = 0.043) concentrations than twigs. Soluble losses and DMd increased (P < 0.001) with season, from June to September, while the highest (P = 0.001) DM content was observed in August. Tannin profiles did not vary with seasons, except for the highest (P < 0.001) mDP concentrations in June compared with other months. The impacts of high-PC (96 % in CTs; HPC) and high-PD (73 % in CTs; HPD) GW on total gas and methane (CH4) production were assessed in vitro. Experimental diets were 100 % grass silage (GS, control), HPC (80:20 grass silage:HPC GW), HPD (80:20 grass silage: HPD GW), plus two diets with the addition of polyethylene glycol (PEG) in the HPC and HPD to neutralise tannins. Diets were incubated for 72 h in rumen fluid: medium at 1:9 v/v in triplicate. Gas pressure (psi transducer) and CH4 concentrations (gas chromatography) were measured throughout. Volatile fatty acids (VFA) concentrations and DMd were assessed at 72 h. Data were analysed by linear mixed models using dietary treatment as a fixed factor and batch run (1-3) as a random factor. HPC, HPD, HPC+PEG, and HPD+PEG diets had lower (P < 0.001) DMd and 72 h production of cumulative gas and CH4 than Grass silage (GS). Grass silage produced more (P < 0.001) total VFA and acetic acid concentrations than the four GW diets and less (P < 0.001) butyric acid than HPD. This study concludes that the inclusion of GW reduced in vitro CH4 production, partly due to its tannin content, with PC showing an improved potential. Species and fraction-specific differences in tannin profiles influenced the nutritive value and CH4 mitigation potential of tree fodder, and these need to be accounted for when tree fodder is introduced into animal diets.

This study investigated the effects of different protein sources on feed intake, nutrient, and energy utilization, growth performance, and enteric methane (CH4) emissions in growing beef cattle, also evaluated against a pasture-based diet. Thirty-two Holstein x Angus growing beef were allocated to four dietary treatments: a total mixed ration (TMR) including solvent-extracted soybean meal as the main protein source (n = 8), TMR with local brewers' spent grains (n = 8), TMR with local field beans (n = 8), and a diet consisting solely of fresh-cut Italian ryegrass (GRA; n = 8). Every 4 wk, animals were moved to digestibility stalls within respiration chambers to measure nutrient intakes, energy and nitrogen (N) utilization, and enteric CH4 emissions. Feed intake (Calan gates), nutrient intakes, and CH4 emissions (GreenFeed) were also measured when animals were group-housed. In respiratory chambers, enteric CH4 yield per kg of dry matter intake (DMI), per kg of organic matter intake (OMI), and per kg body weight were lower (P < 0.05) for GRA. Feces and urine energy outputs were higher (P = 0.007 and P < 0.001, respectively) for GRA steers than concentrate-fed steers. Urinary nitrogen output (UNO, P = 0.026), manure (feces + urine) nitrogen output (MNO, P = 0.034), UNO/nitrogen intake (P = 0.002), and MNO/nitrogen intake (P = 0.006) were higher for GRA. During group-housing periods, CH4 emissions, measured by GreenFeed, were similar to those measured in chambers. Similar CH4 yield between treatments, expressed per kg digestible DMI and digestible OMI, may indicate that the lower diet digestibility was likely the reason for the reduced enteric CH4 emissions in pasture-based diets. The higher energy output and nitrogen losses, and the reduced nitrogen utilization for steers fed the fresh-cut ryegrass diet indicate less efficient energy and nitrogen utilization, which can be considered environmentally undesirable. The lower growth rates in the pasture-based system should also be accounted for when this is adopted for reducing production costs.

Purpose Longer-term intake of fatty acid (FA)-modified dairy products (SFA-reduced, MUFA-enriched) was reported to attenuate postprandial endothelial function in humans, relative to conventional (control) dairy. Thus, we performed an in vitro study in human aortic endothelial cells (HAEC) to investigate mechanisms underlying the effects observed in vivo. Methods This sub-study was conducted within the framework of the RESET study, a 12-week randomised controlled crossover trial with FA-modified and control dairy diets. HAEC were incubated for 24 h with post-intervention plasma samples from eleven adults (age: 57.5 ± 6.0 years; BMI: 25.7 ± 2.7 kg/m 2 ) at moderate cardiovascular disease risk following representative sequential mixed meals. Markers of endothelial function and lipid regulation were assessed. Results Relative to control, HAEC incubation with plasma following the FA-modified treatment increased postprandial NOx production ( P -interaction = 0.019), yet up-regulated relative E-selectin mRNA gene expression ( P -interaction = 0.011). There was no impact on other genes measured. Conclusion Incubation of HAEC with human plasma collected after longer-term dairy fat manipulation had a beneficial impact on postprandial NOx production. Further ex vivo research is needed to understand the impact of partial replacement of SFA with unsaturated fatty acids in dairy foods on pathways involved in endothelial function.

Selenium (Se) plays a crucial role in protecting biological materials from oxidative damage through the action of the selenoprotein glutathione peroxidase (GSH-Px), and the effectiveness of this protection is often dependent upon Se supply. Recent evidence has indicated that GSH-Px mRNA expression can be upregulated in response to potential oxidative damage risk, and that this upregulation is independent of Se supply. The current study aimed to determine the effect of Se supplementation, stocking rate and tissue fatty acid profile on GSH-Px activity in breast and thigh tissue of commercial broilers. A total of 168 Ross 308 broiler chicks were enrolled onto the study. Prior to enrolment, birds were brooded as a single group and received a starter diet containing no additional Se. The study was a 2 × 2 factorial design comprising of two levels of dietary Se (high Se, 0.5 mg/kg total Se, low Se background Se only), and two stocking rates (high, 30 kg/m2, and low, 15 kg/m2). At 15 days of age, birds were blocked by live weight and randomly allocated to one of the four treatments, with six pen replicates per treatment. At 42 days of age, one bird was randomly selected from each pen replicate, euthanased and breast and thigh tissue harvested. GSH-Px activity, thiobarbituric acid reactive substances (TBARS), and fatty acid (FA) content of these tissues were determined. There was no effect (P > 0.05) of stocking rate on GSH-Px activity or TBARS. GSH-Px activity did not differ between tissue types but was greater in high Se birds (P < 0.001) compared to low Se. TBARS concentrations were greater in thigh tissue (P < 0.001), and these thigh concentrations were greater in high Se birds (P < 0.05). There were marked differences between breast and thigh tissue in most FAs (P < 0.001), with breast generally containing greater proportions of polyunsaturated FA, so that breast tissue had a higher (P < 0.001) peroxidisability index (PI) than thigh. A positive correlation between GSH-Px activity and PI in the thigh tissue of high Se birds (Pearson Correlation 0.668; P = 0.025) may indicate that increasing susceptibility to peroxidisation in lipid-rich tissues may also upregulate GSH-Px activity in Se-replete birds. This study suggests that ensuring adequate dietary selenium could be a useful tool to mitigate adverse effects on meat quality caused by oxidation, particularly in lipid-rich meat.

BACKGROUND:Longer-term consumption of SFA-reduced, MUFA-enriched dairy products has been reported to improve fasting flow-mediated dilatation (FMD). Yet, their impact on endothelial function in the postprandial state warrants investigation. OBJECTIVES:The aim was to compare the impact of a fatty acid (FA) modified with a conventional (control) dairy diet on the postprandial %FMD (primary outcome) and systemic cardiometabolic responses to representative meals, and retrospectively explore whether treatment effects differ by apolipoprotein E (APOE) or endothelial NO synthase (eNOS) Glu298Asp gene polymorphisms. METHODS:In a crossover-design randomized controlled study, 52 adults with moderate cardiovascular disease risk consumed dairy products [38% of total energy intake (%TE) from fat: FA-modified (target: 16%TE SFAs; 14%TE MUFAs) or control (19%TE SFAs; 11%TE MUFAs)] for 12 wk, separated by an 8-wk washout. Blood sampling and FMD measurements (0-480 min) were performed pre- and postintervention after sequential mixed meals that were representative of the assigned dairy diets (0 min, ∼50 g fat; 330 min, ∼30 g fat). RESULTS:Relative to preintervention (∆), the FA-modified dairy diet and meals (treatment) attenuated the increase in the incremental AUC (iAUC), but not AUC, for the %FMD response observed with the conventional treatment (-135 ± 69% vs. +199 ± 82% × min; P = 0.005). The ∆ iAUC, but not AUC, for the apoB response decreased after the FA-modified treatment yet increased after the conventional treatment (-4 ± 3 vs. +3 ± 3 mg/mL × min; P = 0.004). The ∆ iAUC decreased for plasma total SFAs (P = 0.003) and trans 18:1 (P < 0.0001) and increased for cis-MUFAs (P < 0.0001) following the conventional relative to the FA-modified treatment. No treatment × APOE or eNOS genotype interactions were evident for any outcome. CONCLUSIONS:This study provides novel insights into the longer-term effects of FA-modified dairy food consumption on postprandial cardiometabolic responses.

Methane (CH4) emission from enteric fermentation of ruminant livestock is a source of greenhouse gases (GHG) and has become a significant concern for global warming. Enteric methane emission is also associated with poor feed efficiency. Therefore, research has focused on identifying dietary mitigation strategies to decrease CH4 emissions from ruminants. In recent years, plant-derived bioactive compounds have been investigated for their potential to reduce CH4 emissions from ruminant livestock. The organosulphur compounds of garlic have been observed to decrease CH4 emission and increase propionate concentration in anaerobic fermentations (in vitro) and in the rumen (in vivo). However, the mode of action of CH4 reduction is not completely clear, and the response in vivo is inconsistent. It might be affected by variations in the concentration and effect of individual substances in garlic. The composition of the diet that is being fed to the animal may also contribute to these differences. This review provides a summary of the effect of garlic and its bioactive compounds on CH4 emissions by ruminants. Additionally, this review aims to provide insight into garlic and its bioactive compounds in terms of enteric CH4 mitigation efficacy, consistency in afficacy, possible mode of action, and safety deriving data from both in vivo and in vitro studies.

Background: Chronic consumption of dairy products with an SFA-reduced, MUFA-enriched content was shown to impact favorably on brachial artery flow-mediated dilatation (FMD). However, their acute effect on postprandial cardiometabolic risk biomarkers requires investigation. Objective: The effects of sequential high-fat mixed meals rich in fatty acid (FA)-modified or conventional (control) dairy products on postprandial FMD (primary outcome) and systemic cardiometabolic biomarkers in adults with moderate cardiovascular risk (>= 50% above the population mean) were compared. Methods: In a randomized crossover trial, 52 participants [mean +/- SEM age: 53 +/- 2 y; BMI (kg/m(2)) 25.9 +/- 0.51 consumed a high-dairy-fat breakfast (0 min; similar to 50 g total fat: modified: 25 g SFAs, 20 g MUFAs; control: 32 g SFAs, 12 g MUFAs) and lunch (330 min; similar to 30 g total fat; modified: 15 g SFAs, 12 g MUFAs; control: 19 g SFAs, 7 g MUFAs). Blood samples were obtained before and until 480 min after breakfast, with FMD assessed at 0, 180, 300, and 420 min. Data were analyzed by linear mixed models. Results: Postprandial changes in cardiometabolic biomarkers were comparable between the different dairy meals, with the exception of a tendency for a 4% higher AUC for the %FMD response following the modified-dairy-fat meals (P= 0.075). Plasma total lipid FA analysis revealed that incremental AUC responses were 53% lower for total SFAs, 214% and 258% higher for total cis-MUFAs (predominantly cis-9 18:1), and trans-18:1, respectively, following the modified relative to the control dairy meals (all P < 0.0001). Conclusions: In adults at moderate cardiovascular risk, acute consumption of sequential high-fat meals containing FA-modified dairy products had little impact on postprandial endothelial function or systemic cardiometabolic biomarkers, but a differential effect on the plasma total lipid FA profile, relative to conventional dairy fat meals.

The popularity of plant-based dairy alternatives (PBDAs) products has grown exponentially in recent years creating a new market of PBDA. The aim of this study was to compare the nutritional content of plant-based alternatives of milk, yogurt and cheese with dairy equivalents and the impact on nutritional intake across the lifespan when they are substituted into UK diets. Nutritional information from cow’s milk, yogurt, cheese and PBDAs available on the UK market was collected via manufacturers information. The products were categorised according to primary plant-based ingredient/s and compared with the equivalent dairy product. The National Diet and Nutrition Survey data was used to calculate the intake of milk, yogurt and cheese across all age groups and the energy and nutrient intake was calculated. Plant-based milk, cheese and yogurt alternative categories were then substituted for dairy intakes, and energy and nutrient intakes were calculated and compared to UK Dietary Reference Values. A total of 299 PBDA products were identified consisting of 136 milk alternatives, 55 yogurt alternatives and 109 cheese alternatives. All PBDAs were more expensive than dairy products. Milk contained more energy, saturated fat, carbohydrates, protein, vitamin B2, vitamin B12 and iodine, and less fibre and free sugars, than plant-based milk alternatives (P < 0.05). There were significant differences between yogurt and cheese and their corresponding PBDAs for energy, fat, saturated fat, carbohydrate, sugars, fibre protein, salt, and calcium (P < 0.05). These differences were reflected in the nutrient intakes of different age groups and the results demonstrated that PBDA may be useful as practical replacements of dairy products but cannot be considered nutritional replacements.

This chapter describes the association between dietary fatty acids that are commonly found in dairy products and human cardiometabolic health. It discusses how saturated fatty acids in dairy milk can be partially replaced with unsaturated fatty acids through supplementation of the cow's diet with plant oils/oilseeds and fish oils. Since the dietary supplementation process may result in increased concentrations of ruminant trans-fatty acids in milk fat, the current understanding of their cardiovascular health effects is briefly reviewed. In addition, the evidence base of human randomised controlled trials examining the cardiometabolic health effects of consuming dairy products with an increased proportion of unsaturated fatty acids and conjugated linoleic acids is summarised. Finally, this chapter highlights that the possible interaction between the dairy 'food matrix' and the effects of changing the fatty acid composition of dairy foods should be considered in future studies to ensure a more accurate insight into cardiometabolic health-dairy food associations.

Abstract The aims of the study were to determine the long-term effects of dietary supplementation with microalgae (SCIM) on milk and blood fatty acid (FA) composition and reproductive hormones in early lactation dairy cows. Sixty Holstein–Friesian dairy cows (30 per treatment) were unsupplemented (Control) or supplemented with 100 g of SCIM (Schizochytrium limacinum sp.) per cow per day from 25 ± 0.5 d post-partum for 98 d. Intake and milk yield were recorded daily, with milk samples collected at weeks 0, 1, 2, 4, 8 and 14, and blood samples collected from 12 representative pairs per treatment at weeks 0, 2, 4, 8, and 14 for subsequent analysis of FA, β-hydroxybutyrate, non-esterified fatty acids and glucose. At 33 ± 0.9 d postpartum the oestrus cycle of 24 cows (12 per treatment) were synchronized and plasma 13,14-dihydro-15-keto PGF2α (PGFM) concentrations determined following an oxytocin challenge. Data were analysed by repeated measures analysis of variance. There was no effect of treatment on dry matter intake, milk yield or milk fat content, with mean values across treatments of 22.1 and 40.6, and 37.2 g/kg respectively. Milk fat concentration of C22:6 n-3 increased rapidly in cows receiving SCIM, reaching a maximum of 0.38 g/100 g FA by week 14. Similarly, blood concentration of C22:6 n-3 increased to 1.6 g/100 g FA by week 14 in cows fed SCIM. There was no effect of treatment on plasma metabolites, but plasma glucose was lower in cows fed SCIM compared to the Control at week 2, and higher in week 8. There was no effect of treatment on peak plasma PGFM concentration or area under the curve. It is concluded that feeding SCIM rapidly increases blood and milk concentrations of C22:6 n-3 which are maintained over time, but does not improve plasma PGFM in dairy cows.

Background: Modifying dairy fat composition by increasing the MUFA content is a potential strategy to reduce dietary SFA intake for cardiovascular disease (CVD) prevention in the population. Objectives: To determine the effects of consuming SFA-reduced, MUFA-enriched (modified) dairy products, compared with conventional dairy products (control), on the fasting cholesterol profile (primary outcome), endothelial function assessed by flow-mediated dilatation (FMD; key secondary outcome), and other cardiometabolic risk markers. Methods: A double-blind, randomized, controlled crossover 12-wk intervention was conducted. Participants with a 1.5-fold higher (moderate) CVD risk than the population mean replaced habitual dairy products with study products (milk, cheese, and butter) to achieve a high-fat, high-dairy isoenergetic daily dietary exchange [38% of total energy intake (%TE) from fat: control (dietary target: 19%TE SFA; 11%TE MUFA) and modified (16%TE SFA; 14%TE MUFA) diet]. Results: Fifty-four participants (57.4% men; mean +/- SEM age: 52 +/- 3 y; BMI: 25.8 +/- 0.5 kg/m(2)) completed the study. The modified diet attenuated the rise in fasting LDL cholesterol observed with the control diet (0.03 +/- 0.06 mmol/L and 0.19 +/- 0.05 mmol/L, respectively; P = 0.03). Relative to baseline, the %FMD response increased after the modified diet (0.35% +/- 0.15%), whereas a decrease was observed after the control diet (-0.51% +/- 0.15%; P < 0.0001). In addition, fasting plasma nitrite concentrations increased after the modified diet, yet decreased after the control diet (0.02 +/- 0.01 mu mol/L and -0.03 +/- 0.02 mu mol/L, respectively; P = 0.01). Conclusions: In adults at moderate CVD risk, consumption of a high-fat diet containing SFA-reduced, MUFA-enriched dairy products for 12 wk showed beneficial effects on fasting LDL cholesterol and endothelial function compared with conventional dairy products. Our findings indicate that fatty acid modification of dairy products may have potential as a public health strategy aimed at CVD risk reduction.

Isoenergetic replacement of dietary saturated fatty acids (SFA) with cis-monounsaturated fatty acids (MUFA) and polyunsaturated fatty acids (PUFA) can reduce cardiovascular disease risk. Supplementing dairy cow diets with plant oils lowers milk fat SFA concentrations. However, this feeding strategy can also increase milk fat trans fatty acids (FA) and negatively affect rumen fermentation. Protection of oil supplements from the rumen environment is therefore needed. In the present study a whey protein gel (WPG) of rapeseed oil (RO) was produced for feeding to dairy cows, in 2 experiments. In experiment 1, four multiparous Holstein-Friesian cows in mid-lactation were used in a change-over experiment, with 8-d treatment periods separated by a 5-d washout period. Total mixed ration diets containing 420 g of RO or WPG providing 420 g of RO were fed and the effects on milk production, composition, and FA concentration were measured. Experiment 2 involved 4 multiparous mid-lactation Holstein-Friesian cows in a 4 × 4 Latin square design experiment, with 28-d periods, to investigate the effect of incremental dietary inclusion (0, 271, 617, and 814 g/d supplemental oil) of WPG on milk production, composition, and FA concentration in the last week of each period. Whey protein gel had minimal effects on milk FA profile in experiment 1, but trans-18:1 and total trans-MUFA were higher after 8 d of supplementation with RO than with WPG. Incremental diet inclusion of WPG in experiment 2 resulted in linear increases in milk yield, cis- and trans-MUFA and PUFA, and linear decreases in SFA (from 73 to 58 g/100 g of FA) and milk fat concentration. The WPG supplement was effective at decreasing milk SFA concentration by replacement with MUFA and PUFA in experiment 2, but the increase in trans FA suggested that protection was incomplete.

This study investigated the effect of UK dairy production system, month, and their interaction, on retail milk fatty acid (FA) profile throughout the year. Milk samples (n= 120) from four conventional (CON), four organic (ORG) and two free-range (FR) brands were collected monthly. ORG milk had more nutritionally-desirable polyunsaturated FA, including rumenic acid and the omega-3 PUFA alpha-linolenic, eicosapentaenoic and docosapentaenoic acids, and less of the nutritionally-undesirable palmitic acid. Milk FA profile was similar between FR and CON systems, but FR milk had less saturated FA (SFA) and/or palmitic acid, and/or greater alpha-linolenic and rumenic acids in certain months within the peak-grazing season. According to the measured milk FA profiles and UK milk fat intakes, milk and dairy products contribute around one-third of the maximum recommended SFA intake. A small increased intake of beneficial PUFA may be expected by consuming ORG milk but human health implications from such differences are unknown.