Milk Fatty Acid Composition Research Articles

Effect of Feeding Different Levels of Corn Silage on Milk Yield and Quality in Dairy Assaf Ewes

This study aimed to investigate the impact of feeding by different corn silage (CS) proportions on ewes milk yield and fatty acids composition. Twenty-one lactating Assaf ewes were divided into 3 groups (7 ewes each). The following dietary treatments based on increasing the proportion of CS in the total mixed ratio (TMR) were tested; (1) 47 % AH (0 % CS in the TMR) correspond to 0 % CS, (2) 23.5 % AH (23.5 % CS in the TMR) correspond to 50 % CS, and (3) 0 % AH (47 % CS in the TMR) correspond to 100 % CS. After 8 weeks of feeding, the type of diet had no significant effect on milk yield and solid; however, it significantly affects the milk fat. The levels of C8:0 and C14:0 were not affected by different silage levels. While the C10:0 and C12:0 significantly increased when fed on a 100 % CS diet. However, a significantly lower level of C16:0 (33.22 %) was observed in the 100 % CS compared to feeding on silage at 50 and 0 % (40.66 and 37.98 %, respectively). Similar trend was observed for C18:0, the lowest was in 100 % CS compared with the different feeding diets (7.52, 12.69, 10.61 % for 100, 50, 0 %, respectively). Total USFA in milk were decreased (p < 0.05) by feeding 100 and 50 % CS compared to 0 % CS feeding. It can be concluded that the replacement of alfalfa with CS had some influence on milk composition, especially the fatty acids profile.
 HIGHLIGHTS
 
 Utilization of nonconventional feed ingredients is important to reduced feed cost and improving its nutritive value
 Milk composition, especially the fatty acids profile when replaced portions of alfalfa can be affected by feeding corn silage
 More research is needed to confirm our findings

젖소 사육환경과 영양조성에 대한 마케팅 정보가 치즈 선호도에 미치는 영향

The taste preference for cheese is primarily dependent on an individual’s habitual experience, such as personal memories since childhood. Cheese is not a traditional food in Korea, and therefore, the liking of cheese is acquired mainly through the exposure to European natural cheese by frequent travels rather than habitual experience. Although Korean dairy farms started the production of European style natural cheese because of surplus milk undulation, yet its demand has been consistently increasing in the last decade. Most of the mountain cheese variety in Europe are produced during the summer season on mountain pastures, especially in countries surrounded by the Alps. Nevertheless, not only consumers but also mountain cheese producers cannot comprehensively explain the differences in the nutritional properties of the milk from cows that grazed on mountain pasture and cows that were raised indoors. As the demand for cheese consumption is steadily increasing in Korea, it is necessary to study the effects of providing marketing information regarding the health conditions and rearing system of dairy cows in relation to the nutritional composition of cheese. In addition to the marketing focus on health-promoting unsaturated fatty acid composition of milk and cheese, the relationship between providing the marketing information on the raising environments of cows and the overall liking of mountain cheese were also investigated.

The Processes of Nutrition and Metabolism Affecting the Biosynthesis of Milk Components and Vitality of Cows with High- and Low-Fat Milk.

Simple SummaryRumen fermentation, the level of hormones and major metabolites in the blood, and tissue heat production, as well as milk composition, were studied in high-producing cows with different milk fat content. It was found that low milk fat is associated with neither a lack of acetate formation in the rumen, nor a change in the hormonal profile. The result is an increase in the availability of cows for metabolizable energy, the likelihood of ketosis, and the extension of their productive use.In order to clarify the mechanism of the depression of milk fat formation and preserve the health of animals, the aim of the research was to study the characteristics of rumen digestion, energy metabolism, and milk composition in high-producing dairy cows with high and low levels of milk fat that are fed the same diet. Two groups of cows with normal milk fat content (3.94 ± 0.12; n = 10) and low milk fat content (2.95 ± 0.14, n = 10) contained in the same diet were identified. Gas exchange (O2 uptake and CO2 output) was studied in cows and blood samples, rumen contents (pH, NH3-N), and VFA and milk (fat, protein, and fatty acid composition) were collected and analyzed. It was determined that cows with low fat milk are more efficient at using the metabolized energy of their diets due to the tendency to have a decrease in the proportion of heat production (by 6.2 MJ; p = 0.055) and an earlier start of a positive energy balance. At the same time, the fat content in milk did not depend on the level of hormones in the blood or on the formation of acetate in the rumen. An analysis of the duration of the productive use of cows on this farm (n = 650) showed that the number of lactations was inversely correlated with the level of fat in milk (r = −0.68; p < 0.05, n = 1300). These results indicate the advantages of cows that can reduce the fat content of their milk in the first months of lactation.

Genome-wide associations for heat stress response suggest potential candidate genes underlying milk fatty acid composition in dairy cattle

Contents of milk fatty acids (FA) display remarkable alterations along climatic gradients. Detecting candidate genes underlying such alterations might be beneficial for the exploration of climate sensitivity in dairy cattle. Consequently, we aimed on the definition of FA heat stress indicators, considering FA breeding values in response to temperature-humidity index (THI) alterations. Indicators were used in GWAS, in ongoing gene annotations and for the estimation of chromosome-wide variance components. The phenotypic data set consisted of 39,600 test-day milk FA records from 5,757 first-lactation Holstein dairy cows kept in 16 large-scale German cooperator herds. The FA traits were C18:0, polyunsaturated fatty acids (PUFA), saturated fatty acids (SFA), and unsaturated fatty acids (UFA). After genotype quality control, 40,523 SNP markers from 3,266 cows and 930 sires were considered. Meteorological data from the weather station in closest herd distance were used for the calculation of maximum hourly daily THI, which were allocated to 10 different THI classes. The same FA from 3 stages of lactation were considered as different, but genetically correlated traits. Consequently, a 3-trait reaction norm model was used to estimate genetic parameters and breeding values for FA along THI classes, considering either pedigree (A) or genomic (G) relationship matrices. De-regressed proofs and genomic estimated breeding values at the intermediate THI class 5 and at the extreme THI class 10 were used as pseudophenotypes in ongoing genomic analyses for thermoneutral (TNC) and heat stress conditions (HSC), respectively. The differences in de-regressed proofs and in genomic estimated breeding values from both THI classes were pseudophenotypes for heat stress response (HSR). Genetic correlations between the same FA under TNC and HSC were smallest in the first lactation stage and ranged from 0.20 for PUFA to 0.87 for SFA when modeling with the A matrix, and from 0.35 for UFA to 0.86 for SFA when modeling with the G matrix. In the first lactation stage, larger additive genetic variances under HSC compared with TNC indicate climate sensitivity for C18:0, PUFA, and UFA. Climate sensitivity was also reflected by pronounced chromosome-wide genetic variances for HSR of PUFA and UFA in the first stage of lactation. For all FA under TNC, HSC, and HSR, quite large genetic variance proportions were explained by BTA14. In GWAS, 30 SNP (within or close to 38 potential candidate genes) overlapped for HSR of the different FA. One unique potential candidate gene (AMFR) was detected for HSR of PUFA, 15 for HSR of SFA (ADGRB1, DENND3, DUSP16, EFR3A, EMP1, ENSBTAG00000003838, EPS8, MGP, PIK3C2G, STYK1, TMEM71, GSG1, SMARCE1, CCDC57, and FASN) and 3 for HSR of UFA (ENSBTAG00000048091, PAEP, and EPPK1). The identified unique genes play key roles in milk FA synthesis and are associated with disease resistance in dairy cattle. The results suggest consideration of FA in combination with climatic responses when inferring genetic mechanisms of heat stress in dairy cows.

Effect of replacing soybean meal with peanut meal on milk production and fat composition in lactating dairy cows.

The objective of this study was to evaluate the effects of replacing soybean meal with peanut meal on milk production, chemical and fatty acid composition, nutritional quality indicators of the lipid fraction, and the economic viability of the diets. Twelve crossbred cows in the initial lactation third, with a bodyweight of 545 ± 37kg and average milk production of 28kg/day of milk were distributed in a 4 × 4, triple Latin square design. The treatments consisted of diets with substitution levels of soybean meal for peanut meal (0; 330; 670; and 1000g/kg in DM). The peanut meal inclusion to replace soybean meal in the diets provided a decreasing linear effect for the protein (P = 0.02) and casein (P = 0.01) concentration in milk. Milk production, total solids concentration, feed efficiency, fatty acid composition, and nutritional quality indicators of the milk lipid fraction were not influenced by the substitution levels. The diet cost per kg DM decreased due to the peanut meal inclusion as a protein source. The partial or total substitution of soybean meal for peanut meal in the feedlot cows diet reduces the cost of feed, without affecting milk production and total solids yield.

Performance of dairy cows fed normal- or reduced-starch diets supplemented with an exogenous enzyme preparation

The objective of this study was to investigate the effects of supplementation of an exogenous enzyme preparation (EEP) on performance, total-tract digestibility of nutrients, plasma AA profile, and milk fatty acids composition in lactating dairy cows fed a reduced-starch diet compared with a normal-starch diet (i.e., positive control). Forty-eight Holstein cows (28 primiparous and 20 multiparous) were enrolled in a 10-wk randomized complete block design experiment with 16 cows per treatment. Treatments were as follows: (1) normal-starch diet (control) containing (% dry matter basis) 24.8% starch and 33.0% neutral detergent fiber (NDF), (2) reduced-starch diet (RSD) containing 18.4% starch and 39.1% NDF, or (3) RSD supplemented with 10 g/cow per day of an EEP (ENZ). The EEP contained amylolytic and fibrolytic activities and was top-dressed on the total mixed ration at the time of feeding. Compared with normal-starch diet, dry matter intake and milk and energy-corrected milk (ECM) yields were lower (on average by 7.1, 9.5, and 7.2%, respectively) for cows on the RSD treatments. Concentrations, but not yields, of milk fat and total solids were increased by RSD. Energy-corrected milk feed efficiency did not differ among treatments. Total-tract digestibility of NDF tended to increase by RSD treatments. Plasma AA concentrations were not affected by treatment, except that of 3-methylhistidine was increased by ENZ, compared with RSD. Blood glucose concentration tended to be lower in cows on the RSD treatments, but ENZ increased glucose and tended to increase insulin concentrations at 4 h after feeding when compared with RSD. Cows on the RSD treatments had decreased concentrations of de novo fatty acids and tended to have increased concentrations of preformed fatty acids in milk. Overall, decreasing dietary starch concentration by 26% decreased dry matter intake, milk, and ECM yields, but ECM feed efficiency was not different among treatments. The negative effects of reducing dietary starch on production were not attenuated by the EEP.

Human milk fatty acid composition and its association with maternal blood and adipose tissue fatty acid content in a cohort of women from Europe

PurposeHuman milk (HM) composition is influenced by factors, like maternal diet and body stores, among other factors. For evaluating the influence of maternal fatty acid (FA) status on milk FA composition, the correlation between FA content in HM and in maternal plasma, erythrocytes, and adipose tissue was investigated.Methods223 European women who delivered at term, provided HM samples over first four months of lactation. Venous blood and adipose tissue (only from mothers who consented and underwent a C-section delivery) were sampled at delivery. FAs were assessed in plasma, erythrocytes, adipose tissue, and HM. Evolution of HM FAs over lactation and correlations between FA content in milk and tissues and between mother’s blood and cord blood were established.ResultsDuring lactation, arachidonic acid (ARA) and docosahexaenoic acid (DHA) significantly decreased, while linoleic acid (LA), alpha-linolenic acid (ALA), and eicosapentaenoic acid (EPA) remained stable. Positive correlations were observed between HM and adipose tissue for palmitic, stearic, oleic, and polyunsaturated fatty acids (PUFAs). Correlations were found between milk and plasma for oleic, LA, ARA, ALA, DHA, monounsaturated fatty acids (MUFAs), and PUFAs. No correlation was observed between erythrocytes and HM FAs. LA and ALA were more concentrated in maternal blood than in infant blood, contrary to ARA and DHA, supporting that biomagnification of LCPUFAs may have occurred during pregnancy.ConclusionsThese data show that maternal adipose tissue rather than erythrocytes may serve as reservoir of PUFAs and LCPUFAs for human milk. Plasma also supplies PUFAs and LCPUFAs to maternal milk. If both, adipose tissue and plasma PUFAs, are reflection of dietary intake, it is necessary to provide PUFAs and LCPUFAs during pregnancy or even before conception and lactation to ensure availability for mothers and enough supply for the infant via HM.

Milk Fat Depression and Trans-11 to Trans-10 C18:1 Shift in Milk of Two Cattle Farming Systems

Milk fat depression (MFD) syndrome, a consistent decrease in milk fat content, is related to important changes in fatty acid composition due to feed imbalances and the consequent ruminal metabolism alteration. Milk produced in two different farming systems was compared: Holstein Friesian fed with unified in intensive production and Podolica raised on a pasture in an extensive system. Milk chemical characteristics and fatty acid composition were determined comparing milk with a normal fat level (&gt;3.8%) to milk with a low fat level (&lt;3.2%) in each breeding system. Holstein Friesian milk showed the decrease in trans-11 and increase in trans-10 C18:1 (shift from trans-11 to trans-10 C18:1) in low fat with respect to normal fat milk with a consequent decrease in the trans-11/trans-10 C18:1 ratio. Even conjugated linoleic acid (CLA), C18:2 cis-9, trans-11, was lower while CLA trans-10, cis-12 was higher in low fat milk than in normal fat milk from Holstein Friesian. These changes, that are indicators of MFD syndrome, were not found in Podolica milk between fat levels. Holstein Friesian milk showed less short-chain fatty acids (9.48 % vs. 11.05%, p &lt; 0.001), trans vaccenic acid (C18:1 trans-11, 0.51% vs. 3.39%, p &lt; 0.001), rumenic acid (CLA C18:2 cis-9, trans-11, 0.32% vs. 1.45%, p &lt; 0.001) and total CLA (0.53% vs. 1.91%, p &lt; 0.001) contents than Podolica milk. Further losses of these human healthy nutrients in low fat Friesian milk reduced the nutritional quality of the milk, while the milk from animals raised on the pasture was of better quality even when the level of fat was low.

Effects of the herbal preparation AyuFertin, used for anestrus overcome, on fatty acids composition of milk in Bulgarian Murrah buffaloes

The herbal protocols, used instead of hormones in buffalo breeding for reproduction optimisation, do not provide information of their effect on the milk quality of treated animals. This research analysed whether the herbal preparation AyuFertin (Indian Herbs Specialities Pvt. Ltd, Saharanpur), applied in postpartum period for recovering the ovary cycling, had a side effect on the milk composition. The experiment was conducted with buffaloes of the Bulgarian Murrah breed at average age of 50 months during May-June 2019, divided into control (n=6) and experimental (n=7) groups. The experimental buffaloes received AyuFertin orally for three consecutive days at a dose of 3 g/100 kg live weight since the 21st postpartum day. The animals without signs of estrus were treated again after 10 days. The milk samples were collected at test-days, before and after treatments. The fatty acid composition of the milk and Ayufertin was evaluated by gas chromatography-mass spectrometry analysis. Quantification of the identified fatty acids in milk was made by the area normalisation method. In general, the fatty acids composition did not differ after the treatment with AyuFertin. Deviation in the amounts of some fatty acids was established. The content of medium-chain fatty acids such as lauric and capric was decreased, while the amount of long-chain acids such as 11-hexadecanoic and stearic was increased in the experimental group. The main active components of AyuFertin - trienoic acids were not transferred into the milk of treated animals. In conclusion, due to the ability of AyuFertin to affect the fatty acids amount in the milk of treated buffaloes, farmers should strictly follow the manufacturer’s recommendation for the dose and duration of AyuFertin treatment to avoid negative effects on milk quality.

Fatty acid composition of milk from mothers giving birth at extremely low gestation in Sweden

Abstract Preterm infants show postnatal deficits of long-chain polyunsaturated fatty acids (LCPUFAs) which are essential for adequate growth and neurodevelopment. Human milk is a primary source of fatty acids (FAs) for the preterm infant, and therefore, knowledge about milk FA levels is required to design appropriate supplementation strategies. Here, we expanded on our previous study (Nilsson et al., 2018, Acta Paediatrica, 107, 1020–1027) determining FA composition in milk obtained from mothers of extremely low gestational age (&lt;28 weeks) infants on three occasions during lactation. There was a clear difference in FA composition in milk collected at Day 7 and milk collected at postmenstrual weeks (PMW) 32 or PMW 40. Notably, the proportion of LCPUFAs was low and declined significantly during milk maturation. These results strengthen previous data that the content of FAs required by the preterm infant is not supplied in sufficient amounts when the mother’s own milk is the sole source of these essential nutrients.

Survey on fatty acid profiles of retail pasteurised cow’s milk and cow’s yogurt in Bulgaria

Assessing the consumer’s awareness of the diet-health relationship, this study presents the fatty acid composition of cow’s milk available on Bulgarian market. Over a 5-year period, 100 samples of pasteurised cow’s milk and 135 samples cow’s yogurt were analysed by gas chromatography (ISO 15885:2002). The saturated fatty acids predominated - average amount 70.1% for milk and 71.1% for yogurt. The unsaturated fatty acids proportions were 29.9% and 28.9% respectively. Seasonal variations in the fatty acid composition of milk were detected, due to feeding practices. Non-milk fat was identified in 5 yogurt samples, while all pasteurised milk samples were not adulterated. This study provides the first scientific information for fatty acid composition of cow’s milk on Bulgarian market with respect to dietary intake estimation.

Near-Infrared Reflectance Spectroscopy (NIRS) detection to differentiate morning and afternoon milk based on nutrient contents and fatty acid profiles

Milking time is one of the factors that affect milk quality. The objective of this study was to differentiate morning milk from afternoon based on milk fatty acid profile and create a prediction model using Near-Infrared Reflectance Spectroscopy (NIRS). This study used explorative research and post-observation analysis. Milk sampling was collected from three different dairy farm locations in West Java Provinces (Pangalengan district of Bandung Regency, Cibungbulang District of Bogor Regency, and Tanah Sareal District of Bogor Municipality). Milk quality observed in this study included milk fat, protein, lactose, solid non-fat (SNF), and fatty acid compositions. Milk fat, protein, lactose, and SNF were analyzed using Lactoscan. Fatty acid compositions were identified using gas chromatography (GC). Sample spectrums were collected using NIRSflex 500. The difference between morning and afternoon milking was tested using a t-test carried out by SPSS ver. 25. Qualitative calibration of milk quality was conducted using NIRSCal v5.6 by applying the cluster (CLU) method. The results from lactoscan and GC showed that milk fat, caprylic acid, and myristoleic acid, and total SFA were significantly different (Sig. (2-tailed) < 0.05) in morning and afternoon milk. However, NIRS failed to generate a sophisticated model for the milk quality differentiation, which shows a low Q-value (0.0011231). The quantitative analysis accurately produced milk fat and total SFA predictions but failed to accurately predict caprylic acid and myristoleic acid. This study concluded that morning milk could be differentiated from afternoon milk based on milk fat, caprylic acid, myristoleic acid, and total SFA content. The NIRS technology can differentiate between morning and afternoon milk based on quantitative calibration of total fat and SFA.

Total Fatty Acid and Polar Lipid Species Composition of Human Milk.

Human milk lipids are essential for infant health. However, little is known about the relationship between total milk fatty acid (FA) composition and polar lipid species composition. Therefore, we aimed to characterize the relationship between the FA and polar lipid species composition in human milk, with a focus on differences between milk with higher or lower milk fat content. From the Norwegian Human Milk Study (HUMIS, 2002–2009), a subset of 664 milk samples were analyzed for FA and polar lipid composition. Milk samples did not differ in major FA, phosphatidylcholine, or sphingomyelin species percentages between the highest and lowest quartiles of total FA concentration. However, milk in the highest FA quartile had a lower phospholipid-to-total-FA ratio and a lower sphingomyelin-to-phosphatidylcholine ratio than the lowest quartile. The only FAs associated with total phosphatidylcholine or sphingomyelin were behenic and tridecanoic acids, respectively. Milk FA and phosphatidylcholine and sphingomyelin species containing these FAs showed modest correlations. Associations of arachidonic and docosahexaenoic acids with percentages of phosphatidylcholine species carrying these FAs support the conclusion that the availability of these FAs limits the synthesis of phospholipid species containing them.

Fatty acid composition of drinking cow's milk trade networks of Kyiv

Introduction. There are several important aspects requiring a control of fatty acid composition in drinking milk distributed across the retail stores: milk is one of the main consumer products; fatty acids are the main energy substrates, involved in the synthesis of cellular structural components, whereas their interaction might impact the intensity of body growth and development; the fatty acid composition of milk varies depending on the diet and the animal's specific physiological state; in case of udder diseases, a change milk composition may occur; prevention of product counterfeiting distributed across the retail stores. &#x0D; Material and methods. The present research examined milk samples from five dairy producers that distribute their products across the retailing chains in Kyiv. Milk samples were collected to determine the fatty acid composition. Milk fat was extracted following the Folch method. The milk fatty acid content assessment was carried out by gas chromatography. &#x0D; Results. 20 fatty acids were identified in the tested milk samples. A higher level of saturated fatty acids was recorded in milk from "Ferma" and "Selyanskoye for kids" dairy producers. The highest content of unsaturated fatty acids was registered in products of “Ukrainskoe” and “Molokia” dairy trademarks. &#x0D; Conclusions. The fatty acid composition of the drinking cow’s milk distributed across trading networks in Kiev was found to be heterogeneous, by differing in the content of both long-chain saturated fatty acids and unsaturated fatty acids.

The effects of dietary resin acid inclusion on productive, physiological and rumen microbiome responses of dairy cows during early lactation

Dairy cows have intense fluctuations in digestive, metabolic and hormonal systems around calving which predispose them to various disorders and health problems. The aim of the current experiment was to investigate feed and nutrient intake, rumen fermentation, rumen bacterial communities, milk production, milk fatty acid composition and plasma biomarker profiles of dairy cows to assess the modulation of these functions by in-feed resin acid inclusion. Thirty-six Nordic Red cows were used in a continuous feeding trial starting 3 weeks prepartum and lasting for 10 weeks into the lactation. The cows were fed grass silage ad libitum and the dietary treatments were 1) control with basal concentrate (CON), 2) CON supplemented with tall oil fatty acids (TOFA; 90% fatty acids and 9% resin acids) at 7.0 g/cow/day and 3) CON supplemented with resin acid concentrate (RAC; 37.5% resin acids) at 1.7 g/cow/day. The mixture of resin acids in TOFA and RAC, consisting mostly of abietic and dehydroabietic acids, originated from coniferous tree species Pinus sylvestris L. and Picea abies L.Feed intake and milk production were measured throughout the experimental period. Milk and blood samples were collected at weeks 2, 3, 6 and 10, and rumen fluid was sampled at weeks 2 and 10 of lactation to analyse rumen fermentation and rumen bacterial communities. The dynamics in feed intake and milk production with progressing lactation showed typical curvilinear trends (P for time <0.001). The time effect was also significant for most other measured parameters including plasma metabolites, immunological biomarkers, rumen pH and a number of ruminal bacterial species. Diet organic matter and neutral detergent fibre digestibility of TOFA was higher (P < 0.05) than those of the other diets. TOFA also resulted in mild immunomodulatory effects but in general there were no major effects of in-feed resin acid supplementation or diet × time interactions on the measured parameters. This indicates that under the conditions of the current experiment, the dietary supplements were not able to modulate the performance of dairy cows.

Changes in the Spectrum of Free Fatty Acids in Blood Serum of Dairy Cows during a Prolonged Summer Heat Wave.

Simple SummaryHeat stress leads to poor welfare, decreased productivity, and poor product quality. It is known that the content of fatty acids in the blood can reflect the physiological state of the body under normal and pathological conditions. They can be biomarkers for the state of biomembranes associated with inflammation and indicate the state of energy imbalance during chronic heat stress. They perform various functions in the body; therefore, the determination of the spectrum of free fatty acids can be used as biomarkers of these processes. The changes in the spectrum of free fatty acids in the blood serum of dairy cows revealed in our study will make it possible to better understand the physiological state of the organism and possibly indicate ways to maintain the health and milk productivity of animals under conditions of prolonged hyperthermia.This experiment was conducted to study the effect of a prolonged hot period on the fatty acid (FA) composition in blood serum of dairy cows. Eighteen multiparous Holstein cows were randomly assigned to the hyperthermia group (HYP, n = 8) in August (summer season) and the control group (CON, n = 10) in October (autumn season). Blood from animals of the HYP group was collected in one heat wave, which was preceded by a long period of heat stress (HS, temperature-humidity index (THI ≥ 72)). Blood from cows of the CON group was collected under thermal comfort conditions (THI < 68). The spectrum of free fatty acids (FFA) in the blood serum was analyzed by gas chromatography. The concentration of FFA increased, including saturated FAs and monounsaturated FAs, in the blood serum of cows under conditions of prolonged HS. This was associated with the mobilization of FA into the bloodstream from adipose tissue, as a consequence of negative energy balance. An increase in the ratio of n-6/n-3 polyunsaturated FAs may indicate biomembrane dysfunction and adversely affect dairy cows. This study showed that prolonged periods of heat can affect the FA composition of blood. How much this leads to changes in the FA composition of milk and the quality of food products remains to be seen in further research.

Fatty Acid Composition and Nutritional Indices/Ratios of Colostrum and Milk from Murrah and “Murrah × Carabao” Crossbred Buffaloes

This study aims to determine the fatty acid (FA) composition and compare FA-based nutritional indices/ratios of colostrum and milk obtained on the 30th, 60th, and 90th day of lactation from 27 Murrah and 18 “Murrah × Carabao” crossbred buffaloes. The major saturated FA (SFA) in colostrum and milk is palmitic acid (C16:0), comprising 32–33% by weight of total FAs. Other important SFAs – myristic acid (C14:0), stearic acid (C18:0), and lauric acid (C12:0) – were lower (P &lt; 0.05) in colostrum than in milk. Oleic acid (C18:1-n9c), a monounsaturated fatty acid (MUFA), is the second most abundant FA in colostrum (28.5%) and milk (18.0–18.8%). Arachidonic acid (C20:4-n6, AA) is the dominant polyunsaturated fatty acid (PUFA) in colostrum (0.92%) and milk (0.42–0.45%). Conjugated linoleic acid (C18:2-c9t11, CLA) was higher in colostrum (0.64%) than in milk (0.14–0.16%). Colostrum and milk had a very low PUFA/SFA ratio (0.02–0.06: 1). The linoleic acid (C18:2-n6, LA) to α-linolenic acid (C18:3-n3, ALA) ratio was higher in colostrum (3.21: 1) than in milk (0.62–1.55: 1). The omega-6 (LA and AA) to omega-3 [ALA and docosahexaenoic acid (C22:6-n3, DHA)] or n-6/n-3 ratio was more balanced for milk (1.76-2.34: 1) than colostrum (3.37: 1). Colostrum had lower atherogenicity (2.53 vs. 4.50–4.66), lower thrombogenicity (2.68 vs. 4.48–4.59), and higher health-promoting index (0.39 vs. 0.21–0.22) than milk. The hypocholesterolemic/hypercholesterolemic (h/H) ratio was higher for colostrum (0.64: 1) than milk (0.34–0.36: 1). Except for AA, the FA composition of colostrum and milk were not significantly different between Murrah and “Murrah × Carabao” crosses (P &gt; 0.05).

Detailed knowledge of maternal and infant factors and human milk composition could inform recommendations for optimal composition.

Breastfeeding is best for infants, but quantitative associations between specific milk components and infant biomarkers remain unclear. Methodological limitations include missing milk volume intake, variable milk composition and that standardised, fasted state blood sampling is impossible in infants. Milk protein and fat content appear marginally related to infant serum amino acid and phospholipid concentrations, with some association between milk fatty acid composition and lipid species levels. CONCLUSION: Detailed simultaneous examinations of maternal factors, milk composition and infant biomarkers or outcomes could identify the mechanistic basis of human milk effects and help develop dietary recommendations for optimal human milk composition.

Explore Gastric Lipolysis and Lipid Oxidation of Conventional versus Pasture-Based Milk by a Semi-dynamic In Vitro Digestion Model.

Research on gastric lipolysis of commercial cow's milk with different fatty acid (FA) compositions is scarce. Gastric lipase exhibits specificity for the sn-3 chain position of triacylglycerols, whose structure is influenced by milk FA composition. Therefore, during gastric digestion of conventional (C) vs pasture-based (P) milk, differences may occur on lipolysis, which has impact on free FA available, influencing their absorption/metabolism rate and physiological hormonal responses. Those two milk types were subjected to the INFOGEST semi-dynamic digestion model. Five gastric emptying points were analyzed for oxidative degradation of polyunsaturated fatty acids (PUFA) and individual free FA. The relative release of medium-chain FA (C8:0-C12:0) was higher than that of longer-chain FA (C14:0-C18:0), and a linear increase in markers of PUFA oxidative degradation occurred along gastric digestion. Quantitatively, C8:0, C18:2n-6, C18:3n-3, and CLAc9t11 were higher (P < 0.001) in P milk when compared with C milk.

Changes in milk ketone and fatty acid concentrations during early lactation in Holstein and Fleckvieh cows

The aim of this study was to compare the changes in milk composition postpartum, especially ketones and milk fatty acids (FAs), in Holstein and Fleckvieh cows kept under identical management conditions. Milk composite samples were collected from 66 cows during afternoon milking, at weekly intervals from one to eight weeks postpartum, and their components were determined by Fourier transform infrared spectroscopy. The Holstein cows had higher (P &amp;lt; 0.05) concentrations of long-chain FAs (ranging from 6% to 16% in different weeks), monounsaturated FAs (6% to 12%), and C18:1 (5% to 16%), as well as lower (P &amp;lt; 0.05) concentrations of saturated FAs (3% to 8%) and short-chain FAs (7% to 17%) in their milk than the Fleckvieh cows for almost the entire monitored period. These differences can be explained by pronounced lipomobilization, due to a negative energy balance, when mainly long-chain FAs from adipose tissue are incorporated into milk and significantly inhibit the de novo synthesis of FAs in the mammary gland. In conclusion, it can be assumed that breed-related metabolic changes during the first weeks of lactation have a large effect on the milk FA composition. This reflection of the metabolic load changes and lipomobilization in differing milk FA profiles would allow for the use of selected milk FAs to detect energy imbalances and their associated diseases in early lactation cows.