Fatty acid profile of the milk of cows reared in the mountain region of Poland

Milk Odd- and Branched-Chain Fatty Acids as Biomarkers of Rumen Fermentation

Cow's milk and dairy products are the primary sources of OBCFAs, which have beneficial health properties. The goal of this study was to identify the factors that influence the content of OBCFAs in cow's milk and to indicate which OBCFAs can serve as biomarkers for fermentation processes. The content of OBCFAs in milk depends on the species of ruminants, with studies showing that this varies between 3.33% (in goat's milk) and 5.02% (in buffalo's milk). These differences also stem from the animals' energy balance, lactation phases, forage-to-concentrate ratio, and the presence of bioactive compounds in feeds, as well as management practices and environmental conditions. The OBCFAs in milk fat mainly come from rumen bacteria, but can also be synthesized de novo in the mammary gland, making them potentially useful noninvasive indicators of rumen fermentation. The concentration of BCFA is lower in colostrum and transitional milk than in full lactation milk. The proportions of total OBCFAs are higher in first- and second-parity cows. The most effective predictors of the biohydrogenation of fatty acids in the rumen are likely C18:2 cis-9, trans-11, iso-C16:0, and iso-C13:0. OBCFAs have been identified as potential biomarkers for rumen function, because their synthesis depends on specific bacteria. Strong predictors of subclinical ruminal acidosis include iso-C14:0, iso-C13:0, and C15:0. The concentration of ∑ OBCFA >C16 in milk is associated with fat mobilization and serves as a significant marker of the energy balance in cows.

Effect of Addition of a Mixture of Ethyl Esters of Polyunsaturated Fatty Acid of Linseed Oil to Liquid Feed on Performance and Health of Dairy Calves

This study aimed to determine the effect of supplementing liquid feeds with a mixture of ethyl esters of polyunsaturated fatty acid of linseed oil (EEPUFA; α-linolenic acid-64.5%, linoleic acid-16.1%, and oleic acid-19.4%) on feed intake, body weight gain, feed efficiency, and health of dairy calves. Thirty-six healthy female Holstein-Friesian calves (7 d of age, 41.2 ± 4.0 kg) were assigned to one of two treatment groups (18 calves per group), i.e., control or EEPUFA, and fed liquid feed (whole milk (WM) or milk replacer (MR)) either without or with 10 mL/d of EEPUFA supplementation, respectively, for 56 days (till 63 d of age). Average daily intake of WM and MR was similar between treatments (p = 0.94). Average daily total DM intake and average daily starter feed DM intake were higher for the EEPUFA group (p = 0.05 and p = 0.01, respectively). The average daily body weight gain was also higher for the EEPUFA group (55 g/d; p = 0.03), although final body weight turned out not to be significantly different between groups (75.6 kg vs. 79.0 kg, control vs. EEPUFA, respectively; p = 0.20). Supplementation of liquid feeds with EEPUFA did not affect feed efficiency (p = 0.37) and most of investigated health parameters. However, the percentage of days with diarrhea relative to the number of days receiving treatment was higher in the control group than the EEPUFA group (76 vs. 42, respectively; p = 0.04). Although the results of this preliminary study are promising, further research is needed to establish the dose effect of EEPUFA on the performance and health of calves.

Impact of low-fat and full-fat dairy foods on fasting lipid profile and blood pressure: exploratory endpoints of a randomized controlled trial

BACKGROUND

Dietary guidelines traditionally recommend low-fat dairy because dairy's high saturated fat content is thought to promote cardiovascular disease (CVD). However, emerging evidence indicates that dairy fat may not negatively impact CVD risk factors when consumed in foods with a complex matrix.

OBJECTIVE

The aim was to compare the effects of diets limited in dairy or rich in either low-fat or full-fat dairy on CVD risk factors.

METHODS

In this randomized controlled trial, 72 participants with metabolic syndrome completed a 4-wk run-in period, limiting their dairy intake to ≤3 servings/wk of nonfat milk. Participants were then randomly assigned to 1 of 3 diets, either continuing the limited-dairy diet or switching to a diet containing 3.3 servings/d of either low-fat or full-fat milk, yogurt, and cheese for 12 wk. Exploratory outcome measures included changes in the fasting lipid profile and blood pressure.

RESULTS

In the per-protocol analysis (n = 66), there was no intervention effect on fasting serum total, LDL, and HDL cholesterol; triglycerides; free fatty acids; or cholesterol content in 38 isolated plasma lipoprotein fractions (P > 0.1 for all variables in repeated-measures ANOVA). There was also no intervention effect on diastolic blood pressure, but a significant intervention effect for systolic blood pressure (P = 0.048), with a trend for a decrease in the low-fat dairy diet (-1.6 ± 8.6 mm Hg) compared with the limited-dairy diet (+2.5 ± 8.2 mm Hg) in post hoc testing. Intent-to-treat results were consistent for all endpoints, with the exception that systolic blood pressure became nonsignificant (P = 0.08).

CONCLUSIONS

In men and women with metabolic syndrome, a diet rich in full-fat dairy had no effects on fasting lipid profile or blood pressure compared with diets limited in dairy or rich in low-fat dairy. Therefore, dairy fat, when consumed as part of complex whole foods, does not adversely impact these classic CVD risk factors. This trial was registered at clinicaltrials.gov as NCT02663544.

Effect of Farming System (Organic vs. Conventional) and Season on Composition and Fatty Acid Profile of Bovine, Caprine and Ovine Milk and Retail Halloumi Cheese Produced in Cyprus

The present work aimed to evaluate the effect of farming practices and season on the fat and protein content and fatty acid (FA) profile of milk and Halloumi cheese produced in Cyprus. Over a year, raw bulk-tank milk samples from cow, goat, and sheep farms were collected seasonally from all organic (11) and representative conventional (44) dairy farms, whereas Fresh Halloumi cheese samples were collected monthly from retail outlets (48 organic and 48 conventional samples in total). The different farming practices did not affect the milk fat content of ruminants, while protein levels were decreased in organic bovine and caprine milk. Under organic farming practices, milk and cheese contained increased values of total mono-unsaturated FA (MUFA) and poly-unsaturated FA (PUFA), and specific FA, such as oleic, conjugated linoleic, linoleic, and α-linolenic acids. Total saturated FA (SFA) levels were particularly decreased in organic samples and, consequently, the atherogenic indices of milk and cheese were decreased. Season influenced milk and Halloumi cheese FA profile; spring samples had lower SFA and higher PUFA and MUFA concentrations. Overall, the organic farm practices improved the lipid profile of milk and Halloumi cheese, which is more likely attributed to the different feeding strategies applied in organic dairy farms.

Black Chokeberry Fruit Polyphenols: A Valuable Addition to Reduce Lipid Oxidation of Muffins Containing Xylitol

The study aimed at assessing effects of black chokeberry polyphenol extract (ChPE) added (0.025-0.075%) to xylitol-containing muffins to reduce lipid oxidation, especially in preventing degradation of hydroperoxides throughout the storage period. Among polyphenolic compounds (3092 mg/100 g in total) in ChPE, polymeric procyanidins were the most abundant (1564 mg/100 g). ChPE addition resulted in a significantly increased capacity of scavenging free radicals and markedly inhibited hydroperoxides decomposition, as reflected by low anisidine values (AnV: 3.25-7.52) throughout the storage. On the other hand, sucrose-containing muffins had increased amounts of primary lipid oxidation products and differed significantly from other samples in conjugated diene hydroperoxides (CD values), which was in accordance with the decrease of C18:2 9c12c in those muffins after storage. In addition, sucrose-containing muffins were found to be those with the highest level of contamination with toxic carbonyl lipid oxidation products. Throughout the storage, no yeast or moulds contamination were found in higher enriched muffins. The incorporation of polyphenols to xylitol-containing muffins resulted in preventing decomposition of polyunsaturated fatty acids (PUFAs), and in reducing the content of some toxic aldehydes. ChPE could be regarded as a possible solution to xylitol-containing muffins to extend their shelf life. The results support the use of xylitol in muffin manufacture as being favourable in terms of suitability for diabetics.

The effect of docosahexaenoic acid-rich algae supplementation in milk replacer on performance and selected immune system functions in calves

The aim of this study was to determine the effect of docosahexaenoic acid-rich algae (DHA-RA) supplementation in milk replacer (MR) on performance, selected cytokine expression in lymphocytes, and blood immunoglobulin concentration in newborn dairy calves. Forty female Holstein-Friesian calves (8.6 ± 0.8 d old and 41.1 ± 4.3 kg; mean ± standard deviation) were blocked by date of birth and allocated into 4 experimental groups (10 animals/group): (1) not supplemented with DHA-RA, (2) supplemented with 9 g of DHA-RA/d in MR, (3) supplemented with 18 g of DHA-RA/d in MR, and (4) supplemented with 27 g of DHA-RA/d in MR. Milk replacer was fed in an amount equal to 900 g of MR powder/d (as fed), 2 times a d, for 49 d. Starter mixture (SM) was fed ad libitum beginning on d 15 of the study. Each calf was in the study over a period of 49 d. The MR and SM intake and fecal score were recorded daily and body weight was recorded weekly. Blood samples were collected before the morning feeding, at the beginning of the study, every consecutive week, and at the end of the study for morphology and smear analysis, serum immunoglobulin level (IgG, IgA, and IgM), and lymphocyte isolation. The mRNA isolated from lymphocytes was checked for TNFα, IL-1β, IL-6, and p65 expression. Average daily gain between d 1 to 14 of the study increased quadratically with increasing dose of DHA-RA. However, average daily gain between d 15 to 49 of the study tended to linearly decrease and over the whole study linearly decreased with increasing dose of DHA-RA. The MR intake decreased linearly between d 1 to 14 of the study and over the whole study, and mean SM intake decreased quadratically with increasing dose of DHA-RA. Feed efficiency increased quadratically and fecal score decreased quadratically during the first 14 d of the study. Increasing dose of DHA-RA led to cubic changes in feed efficiency and fecal score between d 15 and 49 of the study. Overall, over the whole study period a tendency was observed for lower fecal score for the DHA-RA supplemented groups. Interleukin-1β mRNA expression decreased linearly, whereas the mRNA expression of p65 and TNFα as well as serum IgG concentration tended to decrease linearly with increasing dose of supplemental DHA-RA. No effect of group was found on IgA and IgM serum level and the majority of blood parameters. Altogether, treatment worsened production variables but seemed to have a beneficial effect on the immune system of calves.

Chemical composition and seasonal changes in the fatty acid profile of Uruguayan “Colonia” Cheeses

The basic chemical composition and the fatty acid (FA) profile of Uruguayan Colonia cheese, consumed in the Mercosur region, were determined. 24 cheeses from different dairy farms: 10 elaborated in autumn and 14 in spring, were analyzed. Those cheeses are made from cow´s milk, whose diet was composed of 50% pasture system, 25% concentrate, and 25% silage reserves. The cheese making and ripening time were similar. Seasonal differences emerged in the profiles of saturated FA (SFA), unsaturated FA (UFA) and polyunsaturated FA (PUFA). The seasonal comparation of polyunsaturated FA (PUFA) as well as the CLA isomer such as C18:2 t10c12 showed significant differences (p < 0.05). CLA isomer such as C18:2 c9t11, showed no differences (p > 0.05). The atherogenesis index (AI) = 2.21 and thrombogenicity (IT) = 2.84, were calculated and discussed.

Comparison of Fatty Acid Composition of Milk from Simmental and Polish Holstein-Friesian Cows in Different Production Seasons

The aim of this study was to determine the fatty acid (FA) profile of Simmental cow milk in relation to lipid intake in feeds and their composition, and to compare it with FA composition of milk from cows of Polish Holstein-Friesian (PHF) breed. To this end, 104 milk samples were collected from Simmental cows and 52 milk samples derived from PHF breed were taken over a 2-year period. The season significantly influenced both contents of lipid, dry matter and crude protein as well as FA content in lipids extracted from forages. Winter and autumn seasons were characterized by a significantly higher intake of lipids with forages resulting from the intake of fresh silages, compared with the other seasons when the animals were fed stored silages. This was reflected in the highest content of conjugated linoleic acid (CLA) c-9 t-11 C18:2 in milk from the autumn season. Compared with PHF, milk from Simmentals had a higher content of short-chain saturated FAs (SCSFAs) and was characterized by great differences in FA contents determined in the group of odd- and branched-chain FAs (OBCFAs). Milk from Simmental cows had the butyric acid C4:0 and iso C15:0 content of 4.99 and 1.20 g/100 g FA on average, respectively, which have been associated with benefits for human health.

Effects of replacing extracted soybean meal with rapeseed cake in corn grass silage-based diet for dairy cows

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.

Differentiation of geographical origin of cream products in Poland according to their fatty acid profile

Fatty acid (FA) composition of bovine milk fat from cream samples, originating from three regions of Poland (one mountainous and two lowland ones) and collected within 2 years, was analysed aiming at identifying the region of production by applying principal component analysis (PCA). From the 44 FAs identified by gas chromatography, two groups were discerned: seasonally variable (n=17) and non-seasonal (n=7). The biplots showed that different FAs could serve as markers of geographical origin of cream samples. The CLA, vaccenic acid, C18:39c12c15c, total C18:1 trans and C18:39c12c15c n-6 (GLA) were found indicative of mountainous regions, and the short-chain saturated FAs (SCFA; C4:0-C11:0) - of the lowland ones. The Opole province was characterised by a high content of linoleic acid. It was concluded that the origin of a cream sample could be fairly well identified by gas chromatography combined with chemometric analysis of milk fat FAs.

Effect of rearing system (mountain pasture vs. indoor) of Simmental cows on milk composition and Montasio cheese characteristics

Dairy cattle in the Alps are traditionally maintained on high altitude pastures during summer. In recent decades, however, many farmers prefer to maintain the cows always indoor with a hay-based diet. Many authors have shown that the forage type is able to modify the characteristics of milk and cheese. Recently the product specification of PDO Montasio allowed differentiation between mountain cheeses and other products. Aim of this trial is to study the effect of rearing system on the characteristics of milk and cheese produced in this context. One hundred and twenty Simmental dairy cows were considered, 60 grazed on high altitude pasture, and 60 kept indoor and fed a hay-based diet. Cheese production was repeated in two periods (early July and late August) and ripened two and six months. Pasture-derived milk and cheese presented higher fat and lower protein content than hay-derived ones. Rearing systems also affected cheese colour. Textural parameters, hardness, gumminess and chewiness were found to be higher in pasture-derived cheese. In addition, it showed lower level of total saturated fatty acids, and higher level of mono and polyunsaturated fatty acids than hay-derived cheeses. Consumers perceived the difference of cheeses in terms of colour and holes, but they express a similar overall liking. More limited effects of period and ripening time were observed.