Acid Composition Of Milk Fat Research Articles

Effect of processing of cow milk by high pressures under conditions up to 900 MPa on the composition of neutral, polar lipids and fatty acids

Thermal processing of milk promotes oxidation reactions and changes in organoleptic characteristics. Application of High Pressure Processing (HPP) is a promising alternative but little is known about the impact on milk compounds, mainly lipids. This research aims to study the possible alteration of the composition of milk lipids and fatty acids as result of HPP using 250–900 MPa. Thus, two cow milk batches were assayed and the composition in tri-., di-., monoacylglycerols, cholesterol, cholesterol esters, free fatty acids, phospholipids and fatty acids analysed. It was found differences (p < 0.05) among batches in the distribution of triacylglycerols (CN34, CN50 and CN54) and also in the concentration of diacylglycerols, monoacylglycerols, cholesterol, phosphatidylethanolamine and phosphatidylinositol and unsaturated fatty acids (C18:1 10t, C18:1 9c, C18:1 11c, C18:1 16t+14c, C18:2 9c,12c, C18:2 9c,11t and C20:1 9c). Data from the current study showed that processing by HPP up to 900 MPa did not produce significant changes to the lipid classes or fatty acid composition of milk fat.

Fatty acid composition of milk fat in milk of Tzigay sheep and their F2 cross-breeds with Chios

The study was conducted on aggregate milk samples, which were taken every month during the milking period from Tzigay sheep and their F2 cross-breeds of Chios, raised in the conditions of the Central Balkan Mountain. The fat extraction of milk samples was done by the Rose-Gottlieb method. Fatty acid composition was determined on a gas chromatograph with flame ionization detector and capillary column. The aim of the study was to follow the changes in the composition of fatty acids in the milk fat of milk of Tzigay sheep and their F2 cross-breeds. The saturated fatty acids in milk of the two groups had high values during both consecutive years, as they varied from 67.05% in milk of Tzigay sheep in the second lactation up to 70.87% at their F2 cross-breeds. The content of myristic acid was correspondingly 8.22-8.88% at Tzigay sheep and 8.45-8.74% at their F2 cross-breeds. The total amount of polyunsaturated fatty acids in the examined milk for the two types of sheep was comparatively low with near concentrations (4.39-5.20%) in the period of the two years. The milk of the two groups had high values of the correlation SFA/PUSFA (15.71 and 13.17) and low values of PUSFA/SFA (0.06-0.08). Mon?unsaturated fatty acids, represented mainly by the oleic acid (C18:1) varied during both periods from 21.92% to 25.32% and appeared as a substratum in the synthesis of CLA. The short-chain fatty acids (C4:0-C11:0) had higher values in Tzigay sheep in comparison with F2 cross-breeds of Chios. The long-chain fatty acids (C17iso-C25:0) maintained close concentration in the milk of Tzigay breed, while their content in the milk of F2 cross-breeds was increased.

Effect of lactation period on the fatty acid composition in mares’ milk from different breeds

Abstract. Analyses were carried out on the fatty acid composition of milk fat originating from mares of three breeds: Polish Cold-Blooded, Wielkopolski and Konik Polski. Milk was collected from mares in the early, mid and late lactation. Determination of fatty acids was conducted with the gas chromatography method. The analysis of the fatty acid composition demonstrated that over the entire lactation period unsaturated fatty acids (from 52.96 % to 62.46 %), represented mainly by linolenic (22.15 %) and oleic (19.98 %) acid, were predominantly present only in samples originating from mares of the Wielkopolski breed. In milk of mares of Konik Polski, saturated fatty acids appeared to predominate (51.95 % and 52.95 %) in the early and mid lactation, whereas unsaturated fatty acids (62.28 %) predominated in the late lactation. In the case of milk samples of the Polish Cold-Blooded mares, saturated fatty acids (represented mainly by palmitic acid) were observed to prevail in the early and late lactation (55.77 % and 61.31 %), whereas unsaturated fatty acids (52.20 %) were found to negligibly prevail in the mid lactation. The study confirmed that fatty acid composition was determined by the period of lactation and breed of the mares.

Multivariate data analysis for finding the relevant fatty acids contributing to the melting fractions of cream

The melting behaviour and fatty acid composition of cream from a total of 33 cows from four farms were analysed. Multivariate data analysis was used to identify the fatty acids that contributed most to the melting points and to differentiate between creams from different practical feeding regimes. It was demonstrated that the melting point of the medium melting fraction of milk fat was positively correlated with palmitic acid (C16:0), whereas it was negatively correlated with oleic acid (C18:1 cis9), conjugated linoleic acid (CLA cis9 trans11), vaccenic acid (C18:1 trans11), elaic acid (C18:1 trans9) and myristoleic acid (C14:1). The melting points of the high melting fractions could not be related to the fatty acid composition. Addition of palmitic acid-based fat supplement to the feeding ration in combination with a lower forage intake increased the amount of C16:0 and palmitoleic acid (C16:1) in milk fat, whereas it decreased the amount of stearic acid (C18:0) and C18:1 trans fatty acid. Average data on the melting behaviour of cream separated the farms into two groups where the main differences in feeding were the amounts of maize silage and rapeseed cake used. Multivariate analysis of data from individual cows identified the most relevant fatty acids contributing to the melting point of the medium melting fraction of cream. The fatty acid composition of milk fat could differentiate cream from different feeding strategies; however, owing to individual cow variation, it was not possible to extract clear correlations between feeding regime and melting behaviour of cream.

Milk yield, milk composition and somatic cell count of dairy goats given n-3 unsaturated fatty acids diet supplement

Research of the effects of n-3 unsaturated fatty acids (PUFA, particularly eicosapentaenoic acid-EPA; -linoleic acid-ALA; docosahexaenoic acid-DHA) on goat’s milk production (daily milk yield; daily fat, protein and lactose content) and somatic cell count and the persistence of this effect after terminated supplementation was conducted on 62 machine-milked Alpine breed goats kept at an indoor Alpine farm. After adoption period the animals were randomly allocated according to supplement addition into control group (G-4) with no added supplement and test groups (G-1; G-2; G-3) where a supplement containing PUFA was added over a period of five days. Measurements of milk yield and sampling (70 mL) for analysis of milk composition during the adoption period, supplementation period and first five days after supplementation were done every day at each milking (morning and evening). From the 5 th to the 50 th day of the after supplementation period, measurements and sampling occurred every fifth day. Based on the obtained results it could be concluded that the PUFA dietary addition alters the quantity and the quality of produced milk. DHA and EPA supplementation increase daily milk yield, while ALA supplementation induces a decrease of milk yield. When milk content is taken into consideration, the effects are contrary. Regarding somatic cell count, the highest effect on reduction was determined when ALA supplement was added. The mentioned effects persisted after the dietary supplement was withdrawn. The obtained results could be used in dietary supplementation planning in respect to the desired effects. Further research with the aim of determining the fatty acid composition of milk fat is needed.

Determination of the adulteration of butter

AbstractThe adulteration of butter is a serious problem due to economic advantages taken by replacing expensive milk fat with cheaper oil without informing the customers. The authentication of milk fat methods include analysis of bulk components, especially triacylglycerols, fatty acids, sterols and tocopherols. Fatty acid and sterol composition was analysed by using GC‐MS. TAG and tocopherol profiles were examined by HPLC with diode array (DAD) and fluorescence detectors (FLDs). In addition, identification of selected TAG of butter fat was conducted by LC‐atmospheric pressure chemical ionisation (APCI)/MS technique. The lipid composition of 16 different butters available on Polish market were investigated. The cholesterol content in butter fat ranged from 176.8 to 264.8 mg/100 g of fat and in two samples of milk fat β‐sitosterol was found. The total saturated fatty acid (SFA) content in milk fat was 67.1–73.5%, monounsaturated fatty acid 24.5–30.5% and polyunsaturated fatty acid was 1.2–2.0%. Abnormalities in fatty acid profiles, e.g. high concentration of linoleic fatty acid, were found in two butters. These abnormalities were also determined in TAG profiles. The examination of tocopherols in butter fat confirmed that two products were adulterated by the addition of plant oils because they contained δ‐tocopherol which is typical for plant origin foodstuffs. The methods described are useful for investigating milk fat adulterations, and the most efficient are analysis of sterols and tocopherols composition.Practical applications: The described methods are useful for investigating adulteration of milk fat. Traditional strategies rely on examination of fatty acids methyl esters and TAG; these methods have some disadvantages. Due to the variability of fatty acid composition of milk fat and because TAG analysis is complex and time consuming, FA analysis is not an efficient approach for butter authentication. The most efficient method for butter authentication is qualitative and quantitative analysis of sterols and tocopherols. This analysis will determine if components of plant origin were used for butter production.

The potential of milk fat for the synthesis of valuable derivatives

The overall decline in milk fat consumption experienced in the last decades has promoted global research efforts seeking for alternate uses of this valuable natural fat. Milk fat possesses a pleasant flavor and a rich chemical composition, including a range of bioactive, health beneficial minor components. The main drawbacks of milk fat from the consumer point of view are its poor spreadability at refrigeration temperature and its high content in saturated fatty acids, which raises health concerns. However, the rich fatty acid composition of milk fat could be utilized for the production of a wide range of added-value derivatives in the food and cosmetic industries, including nutritionally enhanced modified fats, food emulsifiers, flavors, and tailor-made lipids. A promising strategy for the revalorization of milk fat encompasses the isolation and commercialization of the valuable minor components of milk fat, coupled with a broader utilization of physically or nutritionally improved milk fat fractions and derivative products.

THE PHYSICAL AND CHEMICAL PROPERTIES OF CAMEL'S AND SHEEP'S MILK IN QENA GOVERNORATE

This study was carried out to evaluate some physical properties and chemical composition of some lactating animals in Qena governorate, Egypt. Composite samples of camels' and sheep’s (Ossimi breed) milks were collected from twelve individual farms in Qena. Physical parameter used to monitor the quality of milk samples was specific gravity. The samples were also analysed for the gross chemical composition, fatty acids composition of milk fat and minerals contents. Sheep’s milk has higher specific gravity than Camel milk and the contents of fat, protein, lactose, ash and total solids in sheep’s milk were significantly (p < 0.05) higher than camel milk. Fatty acid composition of camel milk fat differed significantly (p < 0.05) from that of sheep “ossimi” milk fat analysed, it contained higher content of (C16:0, C16:1, C18:0 and C18:2) than sheep “ossimi” milk fat, while, sheep “ossimi” milk fat were significantly (p < 0.05) higher of (C6:0 – C12:0) and (C18:1) than camel milk fats. The levels of Ca, P and K in the sheep “ossimi” milk ash were significantly higher (P < 0.05) than those in the camel milk ash, while, the level of Na and Fe in the camel milk ash were significantly higher (P < 0.05) than those in the sheep “ossimi” milks ash.

Effect of breed and nutrition on milk quality of sheep

Sheep breeding has a relevant economic and environmental role in the Alps, where cheese production is often obtained from local breeds. Recent studies have emphasized the role of fatty acid composition and CLA content of fat because of its considerable contribution to the final nutritional characteristics of cheese and to the quality of fat intake in the diet of consumers. Aim of the study was to evaluate the breed and nutrition effects on fatty acid composition and CLA content of milk fat during lactation of four Alpine sheep breeds (Frabosana, Delle Langhe, Savoiarda and Lacaune). At beginning of lactation, animals were stabled and fed hay and concentrate (pea and corn meal). From 60 to 90 days in milk, all the ewes of the four breeds grazed on the same valley pastures, and from middle to late lactation on the same alpine pastures. Feed samples of hay, concentrate and pasture grass were analysed for chemical composition and fatty acid composition. Milk samples were collected from 4 animals of each breed at different stage of lactation, and analysed for fatty acid composition of fat and CLA. Data were analysed with the “Statistica” package for Principal Components Analysis (PCA). Results showed that two main principal components (PC) explained more than 50% of cumulative variance. The first PC was positively correlated to SFA amount and negatively correlated to MUFA and PUFA of milk fat; the second PC was negatively correlated to the total CLA of milk fat. The analysis scattered the 4 different breeds during the stabled phase (beginning of lactation), showing that the breed has an influence on fatty acid composition of milk fat and CLA when animal are fed the same diet. From 60 days in milk to end of lactation, when sheep grazed on valley or alpine pastures, the differences in fatty acid composition and CLA were influenced only by the diet. Further studies are needed to better understand the interaction between nutrition and lactation stage on characteristics of fatty acid composition and CLA content.

Influence of milk fatty acid composition and process parameters on the quality of ice cream

There has been considerable interest in recent years in altering the fatty acid composition of milk fat in dairy products to improve the long-term health of consumers. The objective of this study was to investigate the influence of altering the fatty acid composition and varying two process parameters (homogenization pressure and ageing temperature) on the quality of ice cream. The quality of ice cream (8% fat) was monitored before and after heat shock by assessing fat droplet size, solvent extractable fat content, texture analysis, meltdown tests and sensory analyses. The results suggest that a high solid fat content and low homogenization pressure correlated well with large particles and high amounts of solvent extractable fat, which resulted in firm ice cream with slow melting behaviour and good structure retention. In contrast, ageing temperature did not significantly influence fat destabilization. Following heat shock, the results suggested that the hardness of ice cream was not determined by any of the parameters investigated, but was probably dominated by the amount of ice crystals. A good melting behaviour was retained after heat shock, provided that a strong matrix of destabilized fat was produced during the freezing process. Even though differences could be observed in hardness and melting behaviour for different milk fats or process conditions, these differences were hardly identified by trained sensory panels. These results suggest that high-quality ice cream can be produced with an altered fatty acid composition without any alteration in the conventional production process, provided that ice cream is stored and consumed under ideal circumstances.

Effect of mare's breed on the fatty acid composition of milk fat

Gas chromatography and IDF Standard method (1999) were used to analyze the fatty acid composition of milk fat of mares originating from the following breeds: 10 of Wielkopolska breed, 10 Konik Polski Horses, and 9 Polish Cold-blooded Horses. Eighty-seven mare’s milk samples were collected in the years 2000–2002. Unsaturated fatty acids were shown to prevail in the milk fat of mares of Wielkopolska breed (61.32%) and of Konik Polski mares (52.58%) whereas saturated acids prevailed in the milk fat of Cold Blooded mares (54.95%). The study revealed that the fatty acid composition of the investigated groups of mares was breed-specific. Of course, the impact of other uncontrolled factors such as nutrition is not excluded, either.

Effects of strain of Holstein-Friesian and concentrate supplementation on the fatty acid composition of milk fat of dairy cows grazing pasture in early lactation

The effect of a grain-based concentrate supplement on fatty acid (FA) intake and concentration of milk FA in early lactation was investigated in grazing dairy cows that differed in their country of origin and in their estimated breeding value for milk yield. It was hypothesized that Holstein-Friesian cows of North American (NA) origin would produce milk lower in milk fat than those of New Zealand (NZ) origin, and that the difference would be associated with lower de novo synthesis of FA. In comparison, increasing the intake of concentrates should have the same effect on the FA composition of the milk from both strains. Fifty-four cows were randomly assigned in a factorial arrangement to treatments including 3 amounts of concentrate daily [0, 3, and 6kg of dry matter (DM)/cow] and the 2 strains. The barley/steam-flaked corn concentrate contained 3.5% DM FA, with C18:2, C16:0, and C18:1 contributing 48, 18, and 16% of the total FA. The pasture consumed by the cows contained 4.6% DM FA with C18:3, C16:0, and C18:1 contributing 51, 10, and 10% of the FA, respectively. Pasture DM intake decreased linearly with supplementation, but total DM intake was not different between concentrate or strain treatments, averaging 16.2kg of DM/cow, with cows consuming 720g of total FA/d. Cows of the NA strain had lesser concentrations of milk fat compared with NZ cows (3.58 vs. 3.95%). Milk fat from the NA cows had lesser concentrations of C6:0, C8:0, C10:0, C12:0, C14:0, and C16:0, and greater concentrations of cis-9 C18:1, C18:2, and cis-9, trans-11 C18:2, than NZ cows. These changes indicated that in milk from NA cows had a lesser concentration of de novo synthesized FA and a greater concentration of FA of dietary origin. Milk fat concentration was not affected by concentrate supplementation. Increasing concentrate intake resulted in linear increases in the concentrations of C10:0, C12:0, C14:0, and C18:2 FA in milk fat, and a linear decrease in the concentration of C4:0 FA. The combination of NA cows fed pasture alone resulted in a FA composition of milk that was potentially most beneficial from a human health perspective; however, this would need to be balanced against other aspects of the productivity of these animals.

Milk Fatty Acids II: Prediction of the Production of Individual Fatty Acids in Bovine Milk

Previously observed relationships between dietary composition and production of a small number of individual milk fatty acids were the motivation to examine whether equations could be developed to predict production of all the major individual milk fatty acids. Such equations could be incorporated into ration formulation programs and used to examine factors that influence milk fat composition. Data from 29 published experiments on Holstein cows that provided 120 dietary treatments were entered into CPM-Dairy to obtain estimates of amounts of individual long-chain fatty acids (LCFA) absorbed from the intestines. These derived data and other dietary and animal data including the reported fatty acid composition of milk fat were entered into a spreadsheet. Descriptors of diet included daily intake of dry matter, total fermentable carbohydrate, total fatty acids, and profile of dietary fatty acids, intake of neutral detergent fiber, supplemental fish-oil, buffer, and magnesium oxide. Cow data included body weight and days in milk (DIM). Multiple linear regression was used to develop equations to predict the production (g/d) of each of 26 major LCFA. The equations developed generally had R2 values in excess of 0.5. Production (g/d) of total de novo fatty acids (C4:0 to C15:0) (PTdenovo) was found to be positively related to the intake of fermentable carbohydrate, and negatively related to the intake of fish oil fatty acids and the estimated total amount of unsaturated fatty acids absorbed from the intestines. The PTdenovo was greater in pasture-fed cows than total mixed ration-fed cows and was negatively related to the square root of DIM. Production of each individual de novo fatty acid was described by a fixed proportion of PTdenovo. These proportions were 0.12±0.006 (C4:0), 0.083±0.0039 (C6:0), 0.0516±0.0025 (C8:0), 0.111±0.003 (C10:0), 0.134±0.0037 (C12:0), 0.441±0.007 (C14:0), 0.046±0.0024 (C14:1), and 0.0432±0.0017 (C15:0). Separate independent equations were developed to describe the daily production of C16:0, C16:1, and the main individual preformed fatty acids (>C16). The productions of each of the main individual pre-formed fatty acids were generally strongly related to the corresponding estimated amount (g/d) of specific fatty acids absorbed from the intestines. Percentage estimates for the direct transfer of the major absorbed LCFA to their corresponding LCFA in milk were 42% (C16:0); 9.5% (C18:0); 47.5% (cis-9 C18:1); 16.1% (all isomers of trans-C18:1), 38% (cis-9, cis-12 C18:2); and 31% (cis-9, cis-12, cis15 C18:3). High dietary intake of fish oil fatty acids was negatively associated with the production of all of the major individual preformed fatty acids with the exception of C20:5 and C22:6. In some instances, particular dietary factors were found to have positive influences on production of one fatty acid and negative influences on another. For example, high levels of dietary magnesium oxide were positively associated with production of C17 fatty acids but negatively associated with production of C18:0 and cis-9, trans-11 C18:2 (conjugated linoleic acid). This analysis quantified effects of major dietary and cow factors on production of individual fatty acids in milk.

Comparative potential of white and red clover to modify the milk fatty acid profile of cows fed ryegrass‐based diets from zero‐grazing and silage systems

AbstractBACKGROUND: Two experiments were conducted to compare the effects of white and red clover on the fatty acid composition of milk fat from cows fed ryegrass‐based diets. In experiment 1, fresh ryegrass was mixed with white or red clover (60/40, on a dry matter (DM) basis). Experiment 2 involved similar mixed diets in ensiled form, and one ryegrass‐silage diet without the addition of clover.RESULTS: Total DM intake, milk yield and milk fat content were not affected by dietary treatments. Feeding freshly cut white versus red clover supplemented diets resulted in a higher proportion of n‐3 fatty acids, especially α‐linolenic acid, in milk fat. Addition of any clover silage to ryegrass silage increased the proportions of n‐3 fatty acids in milk fat, and reduced the proportions of conjugated linoleic acids (CLA), including C18:2 c9t11, and C18:1cis isomers. The n‐6/n‐3 ratio was elevated compared to the diet not supplemented with clover.CONCLUSION: White clover seemed to be slightly superior to red clover supplementation, but the effects of clover supplementation as such were generally larger than that of clover type. However, a higher concentration of n‐3 fatty acids with clover supplementation coincided with a lower concentration of CLA in the milk fat. Copyright © 2007 Society of Chemical Industry

Production Performance and Milk Composition of Dairy Cows Fed Whole or Ground Flaxseed With or Without Monensin

Eight multiparous Holstein cows averaging 570±43kg of body weight and 60±20 d in milk were used in a double Latin square design with four 21-d experimental periods to determine the effects of feeding ground or whole flaxseed with or without monensin supplementation (0.02% on a dry matter basis) on milk production and composition, feed intake, digestion, blood composition, and fatty acid profile of milk. Intake of dry matter was similar among treatments. Cows fed whole flaxseed had higher digestibility of acid detergent fiber but lower digestibilities of crude protein and ether extract than those fed ground flaxseed; monensin had no effect on digestibility. Milk production tended to be greater for cows fed ground flaxseed (22.8kg/d) compared with those fed whole flaxseed (21.4kg/d). Processing of flaxseed had no effect on 4% fat-corrected milk yield and milk protein and lactose concentrations. Monensin supplementation had no effect on milk production but decreased 4% fat-corrected milk yield as a result of a decrease in milk fat concentration. Feeding ground compared with whole flaxseed decreased concentrations of 16:0, 17:0, and cis6-20:4 and increased those of cis6-18:2, cis9, trans11-18:2, and cis3-18:3 in milk fat. As a result, there was a decrease in concentrations of medium-chain and saturated fatty acids and a trend for higher concentrations of long-chain fatty acids in milk fat when feeding ground compared with whole flaxseed. Monensin supplementation increased concentrations of cis9 and trans11-18:2 and decreased concentrations of saturated fatty acids in milk fat. There was an interaction between flaxseed processing and monensin supplementation, with higher milk fat concentration of trans11-18:1 for cows fed ground flaxseed with monensin than for those fed the other diets. Flaxseed processing and monensin supplementation successfully modified the fatty acid composition of milk fat that might favor nutritional value for consumers.

Fatty acid composition of Mediterranean buffalo milk fat

The purpose of this research was to investigate the variation in fatty acid composition of milk fat from four buffalo (Bubalus bubalis) herds under different feeding management and ration composition. Changes in milk fatty acid composition were monitored on a weekly basis. Saturated fatty acids (65.5%) predominated in buffalo milk fat; monounsaturated and polyunsaturated fatty acids were 27.0% and 4.5%, respectively. Of saturated fatty acids, the content of palmitic acid was the highest (30.6%) followed by stearic acid (12.0%) and myristic acid (10.7%). Of the unsaturated fatty acids the content of oleic acid was the highest (26.6%). The average content of conjugated linoleic acid (0.76±0.33) was higher than the maximal values generally reported for dairy cow.

Effect of breed and nutrition on milk quality of sheep

Sheep breeding has a relevant economic and environmental role in the Alps, where cheese production is often obtained from local breeds. Recent studies have emphasized the role of fatty acid composition and CLA content of fat because of its considerable contribution to the final nutritional characteristics of cheese and to the quality of fat intake in the diet of consumers. Aim of the study was to evaluate the breed and nutrition effects on fatty acid composition and CLA content of milk fat during lactation of four Alpine sheep breeds (Frabosana, Delle Langhe, Savoiarda and Lacaune). At beginning of lactation, animals were stabled and fed hay and concentrate (pea and corn meal). From 60 to 90 days in milk, all the ewes of the four breeds grazed on the same valley pastures, and from middle to late lactation on the same alpine pastures. Feed samples of hay, concentrate and pasture grass were analysed for chemical composition and fatty acid composition. Milk samples were collected from 4 animals of each breed at different stage of lactation, and analysed for fatty acid composition of fat and CLA. Data were analysed with the “Statistica” package for Principal Components Analysis (PCA). Results showed that two main principal components (PC) explained more than 50% of cumulative variance. The first PC was positively correlated to SFA amount and negatively correlated to MUFA and PUFA of milk fat; the second PC was negatively correlated to the total CLA of milk fat. The analysis scattered the 4 different breeds during the stabled phase (beginning of lactation), showing that the breed has an influence on fatty acid composition of milk fat and CLA when animal are fed the same diet. From 60 days in milk to end of lactation, when sheep grazed on valley or alpine pastures, the differences in fatty acid composition and CLA were influenced only by the diet. Further studies are needed to better understand the interaction between nutrition and lactation stage on characteristics of fatty acid composition and CLA content.

Efficacy of a Novel Whey Protein Gel Complex to Increase the Unsaturated Fatty Acid Composition of Bovine Milk Fat

A novel whey protein emulsion gel (WPEG) complex was developed to protect dietary unsaturated fatty acids from rumen biohydrogenation with the goal of modifying the fatty acid composition of milk fat. Three experiments were conducted with WPEG complexes made from either whey protein concentrate containing 80% crude protein, whey protein isolate, or whey protein concentrate high-gel capacity. Each experiment lasted 3 wk. All cows received a basal total mixed ration (TMR). During wk 1 and 3, all cows received only the TMR. During wk 2, 3 control cows received 330g/d of soybean oil added to the TMR, and the other 3 cows received 330g/d of soybean oil in one of the WPEG complexes. During wk 2, C18:2 increased from 3.29 to 5.88g/100g of fat in Experiment 1, 2.91 to 7.42g/100g of fat in Experiment 2, and 3.57 to 6.56g/100g of fat in Experiment 3 for WPEG cows. Fatty acid C18:3 increased from 0.51 to 0.84, 0.52 to 1.15, and 0.51 to 0.97g/100g of fat for Experiments 1, 2, and 3, respectively, for WPEG cows. Higher proportions of C18:1 trans-9 in milk fat of control cows compared with WPEG cows were seen in all experiments. The proportion of C18:1 trans-11 was also higher in control cows in Experiments 1 and 2, but not in Experiment 3. The WPEG complexes successfully protected unsaturated fatty acids from rumen biohydrogenation and resulted in an increase in the unsaturated fatty acid composition of milk fat produced by Holstein cows without increasing the trans 18-carbon monoenes.

Impact of a basal diet of hay and fodder beet supplemented with rapeseed, linseed and sunflowerseed on the fatty acid composition of milk fat

Abstract The content of fatty acids (FAs) in milk from cows fed a control diet comprised of hay ad libitum and 15 kg fodder beet, supplemented with either 1 kg ground rapeseed (RAP1), 1 or 1.4 kg ground linseed (LIN1 or LIN1.4), or 1 or 1.4 kg ground sunflowerseed (SUN1 or SUN1.4), was determined using high resolution gas chromatography. The concentration of saturated fatty acids (SFAs) in milk fat from cows fed the control diet was very high and decreased almost linearly as a function of increased daily intake of oleic, linoleic and α -linolenic acids of the oilseeds. The highest concentrations of unsaturated fatty acids (UFAs) and conjugated linoleic acids (CLAs) were found in milk from cows fed the SUN1.4 diet. A supplement of linseed induced the highest content of α -linolenic acid in milk fat. Sunflowerseed was the best of the three oilseeds studied for counterbalancing the high content of SFAs and the relatively low content of UFAs in milk fat.

Production Response of Lactating Cows Fed Dried Versus Wet Brewers’ Grain in Diets with Similar Dry Matter Content ,

Twenty-four Holstein-Friesian dairy cows (20 intact and 4 fitted with rumen cannula) during early lactation (56±25.3 d in milk) were assigned to two treatments to determine intake and production responses to feeding dried and wet brewers’ grain. There were two cows fitted with a rumen cannula in each treatment. Cows were fed a total mixed ration twice daily containing either dried or wet brewers’ grain at 15% of the dietary dry matter (DM). The diet contained 47% forage and 53% concentrate. The experimental design was a replicated 2×2 Latin square with two periods of 5 wk each. First 2 wk in each period were considered as adaptation to diets and data from the last 3 wk were used for treatment comparisons. Dried and wet brewers’ diets contained 68.0 and 66.5% DM, respectively. Feeding brewers’ grain dry or wet to dairy cows had no influence on feed intake (25.6 vs. 25.1 kg/d), fat corrected milk yield (40.1 vs. 40.7 kg/d), milk composition and feed consumption. The pH, ammonia, total volatile fatty acids and molar ratios of volatile fatty acids in the rumen fluid were not different between treatments. Fatty acid composition of milk fat from cows fed diets containing dry or wet brewers’ grain was identical, except C18:2 and C18:3 fatty acids were lower in milk fat from cows fed wet brewers’ grain compared with dried brewers’ grain. The results from the present study suggest that the performance of cows fed either dried or wet brewers’ grain at 15% of dietary DM was similar when diets had the same DM. The average price for dried and wet brewers’ grain in the United States from July 2001 to June 2002 was $145.3 and $96.9/metric tonne DM, respectively. Using wet instead of dried brewers’ grain will save $49/metric tonne minus the difference in storage costs. Wet brewers’ grain can be fed to dairy cows in areas that are close to the brewery and provides nutritive value similar to the dried brewers’ grain.