Milk Fatty Acid Profile Research Articles

Performance of Holstein dairy cows fed a diet supplemented with rosemary and ginger essential oils: milk production, milk fatty acid, and ruminal fermentation

Abstract The study determined the impact of Rosmarinus officinalis and/or Zingiberene officinalis essential oil (EO) on milk yield, composition, milk fatty acids profile, blood biochemicals, and rumen fermentation in dairy cows. Twenty-eight Holstein lactating cows were distributed into four groups using a completely randomized block design in a 70-d experiment. The control diet consisted of 13 kg of concentrate and 40 kg of fresh berseem clover per head per day, without supplementation. In the other treatments, the control diet was supplemented with 10 mL of EO per head per day, using either ginger EO (GEO treatment), rosemary (REO treatment) EO or a blend of both at a 1:1 v/v ratio (BEO treatment). Supplementation did not affect intake, milk production, or composition. Omega-n3 and omega-n5 were increased with REO (p < 0.05) compared to the control. Both REO and BEO decreased (p = 0.003) serum globulin and increased (p < 0.005) albumin to globulin ratio, high-density lipoprotein cholesterol, and total lipid. Serum total antioxidant capacity was increased (p ˂ 0.001) with the supplementation, without affecting glucose, total protein, albumin, serum cholesterol, low-density lipoprotein cholesterol, alanine aminotransferase, aspartate aminotransferase, and urea concentrations. In conclusion, supplementing Holstein dairy cows with GEO and/ or REO increased the level of omega-3 and omega-5 fatty acids while reduced saturated fatty acids in milk, without affecting feed intake, milk production or milk composition.

Linseed oil supplementation alters milk fatty acid profile, mitigates heat stress, and improves summer milk yield in grazing dairy cows.

Dietary supplementation of fat can be an important source of energy to compensate for the reduction in dry matter intake in dairy cows during heat stress periods. Studies have reported that supplementing dairy cow diets with linseed oil (LO) can increase milk yield and enhance the levels of beneficial fatty acids, such as omega-3 fatty acids, in the milk. The objective of this research was to evaluate the effect of LO supplementation on milk fatty acids profile, milk yield and composition, and physiological parameters of grazing cows. The study was conducted in two seasons, one in spring and one in summer. A 2 × 2 Latin square design was used in each experiment. Twelve Holstein and crossbred Holstein x Jersey cows were involved in each season. Cows were divided into two groups: control (TC) with no supplementation and treatment (TL) supplemented with 400g/day of LO. The results showed that LO supplementation altered the milk fatty acid profile: decreased concentrations of short and medium-chain fatty acids (C10:0 - C17:1) except for C13:0 and increased concentrations of long-chain fatty acids (C18, C18:1 (both trans and cis isomers), C18:2 (specific conjugated linoleic acid - CLA isomers), and C18:3 n3 (omega-3)). Additionally, milk yield increased by 1.5l per day during summer in LO-supplemented cows, while milk fat, protein, and casein content decreased. Milk stability increased by 2.2% in the LO-supplemented group. LO-supplemented cows reduced internal body temperature and heart frequency in the afternoon and increased daily rumination time by 20min. In conclusion, LO supplementation can be an effective strategy to improve the nutritional profile of milk by altering fatty acid composition towards potentially healthier fats, mitigate the negative effects of heat stress on grazing cows during summer, as evidenced by reduced body temperature and heart frequency and increase milk yield.

Erythrocyte membrane and breast milk fatty acid profile in lactating mothers: relationship with infant erythrocyte membrane fatty acid profile.

During the first thousand days of life, fetus and infant's nutrition depends on mother's diet. Polyunsaturated fatty acids(PUFA) are important substrates in infant neurogenesis. We related erythrocyte membrane (EM) and breast milk fatty acids (FA) profile in lactating mothers with the EM FA profile in exclusively breastfed infants and evaluated maternal fat consumption. We conducted an observational, cross-sectional analytical study. During the 2016-2019 period, milk and blood samples from adult mothers 90 days post-partum and infant's blood were analysed, and FA were determined by GC. A frequency of consumption survey of fatty acids precursor foods and sources was conducted. The sample included forty-five mother-infant EM and forty-five milk samples donated by the same mothers. A low percentage of DHA (0·14 (0·12-0·2)) was found in milk, consistent with mother's low consumption of DHA-rich foods. A significant positive correlation between infant's EM DHA percentage and milk DHA percentage (r = 0·39; P value 0·008), as well as between infant's EM ω-3 fatty acids sum and milk DHA percentage (r = 0·39; P value 0·008), was found. When milk had a DHA percentage greater than or equal to 0·20 %, infants had a significant increase in DHA in their EM. Mother's consumption of DHA precursors and sources was NS. The relation between the DHA percentage distribution found in maternal milk, and the DHA percentage distribution found in infant's and mother's EM was proven in this population. Dietary fatty acid intake is associated with the maternal milk lipid distribution and with mothers' and infant's EM fatty acids percentage.

Milk Production, Milk Composition, Milk Fatty Acid Profile and Nutrient Digestibility of Mehsana Goats Fed Sunflower (Helianthus annus) Oil

A study was conducted during the month of December, 2020 to January, 2021 at Livestock Research Station, Kamdhenu University, Sardarkrushinagar, Gujarat (385506), India to evaluate the effect of dietary sunflower oil supplementation on milk yield, milk fatty acid profile and nutrient digestibility of Mehsana goats. Eighteen lactating Mehsana goats were randomly divided into three treatment groups, viz. Basal diet (control), Basal diet+25 g animal-1 day-1 of sunflower oil and Basal diet+50 g animal-1 day-1 of sunflower oil for a period of 60 days. No significant differences (p>0.05) were found in milk yield in terms of kg d-1, 4% fat corrected milk and energy corrected milk among the treatment groups. The milk constituents and their yields were not affected due to dietary inclusion of sunflower oil. Sunflower oil feeding at the dose of 50 g d-1 increased (p<0.05) concentration of milk short chain fatty acids and polyunsaturated fatty acids in the milk of goats. The intake and digestibility of nitrogen free extract was increased in sunflower oil supplemented groups. The intake and digestibility of dry matter, organic matter, crude protein, ether extract and crude fibre were similar (p>0.05) among the treatment groups. it may be concluded that supplementation of sunflower oil at the dose rate of 25 and 50 g d-1 did not affect feed intake, milk yield, milk constituents and nutrient digestibility in lactating Mehsana goats. However, dietary 50 g d-1 of sunflower oil significantly increased concentration of milk short chain fatty acids and polyunsaturated fatty acids in goats.

Added Value of Products from Endangered Local Sheep Breeds in Mountain Areas.

Local sheep breeds in the Italian eastern Alps passed from ex situ to in situ conservation. These breeds are mainly reared by smallholders in low-input farming systems. To allow the sustainable use of genetic resources, the economic sustainability of farmers must be supported through production guidelines. Analyzing meat and milk composition and fatty acid profile, we aimed to characterize their products based on breed and diet to identify tailormade sales strategies. Results showed that both meat and milk have good nutritional values and can benefit from a pasture-based diet, irrespective of the breed. These results support the redaction of production guidelines based on the peculiar characteristics of these breeds: being multi-purpose breeds adapted to mountain areas and to grazing, thus contributing to the conservation of cultural and landscape heritage.

Supplementation of isoacids to lactating dairy cows fed low or high forage diets: Effects on performance, digestibility, and milk fatty acid profile

Our objective was to determine the effects of isoacids (ISO) on the lactation performance, digestibility, and milk fatty acid (FA) profile of Holstein cows fed 2 forage NDF levels (FL). The study was 10-wk long (including 2-wk for covariate) utilizing a randomized complete block design. Sixty-four mid-lactating Holstein cows [662 ± 71 kg BW, 119 ± 51 DIM, 2 ± 0.9 parity] were blocked by parity, DIM, and prior milk yield (MY) for multiparous cows or genetic merit for primiparous cows, and randomly assigned to 1 of the 4 diets (n = 16). Diets were arranged as a 2 × 2 factorial, with 2 FL containing 21 (HF) and 17% forage NDF (LF) without (WIA) or with ISO supplementation (IA, 7.85 mmol/kg DM and 3.44 mmol/kg DM for isobutyrate and 2-methylbutyrate, respectively). Diets were balanced for similar NEL (1.58 Mcal/kg DM), CP (16.0%) and total NDF (27.2%). Feed intake and MY were recorded daily. Nutrient digestibility for each cow was determined using indigestible NDF as a marker, and fecal samples were collected at 8-time points (4 h intervals between samples). Individual cow milk samples composited over a 10-wk period were analyzed using gas chromatography for FA profile. The statistical model included FL, ISO, and FL × ISO as fixed effects and block as a random effect (lme4 in R). The ISO did not affect DMI (P = 0.13), while LF had greater DMI than HF diets (27.8 vs. 26.0 kg/d; P < 0.01). However, ISO increased MY (34.7 vs. 37.2 kg/d; P < 0.01) and ECM (41.9 vs. 39.0 kg/d; P < 0.01) by 7% in HF but not in the LF diet, suggesting FL × ISO interaction (P = 0.04). Interestingly, ISO increased ADG (0.4 kg/d) but decreased MUN by 9% only in LF diet as indicated by FL × ISO interaction (P < 0.01). Additionally, ISO increased DM, OM, NDF, and CP digestibility by 10-24% in HF (P < 0.01), but not in LF (FL × ISO; P > 0.05). As expected, ISO increased milk odd chain FA profiles in the IA groups irrespective of FL, e.g., the IA had greater C15:0 (1.87 vs. 1.54 g/100g FA; P = 0.03) and a tendency to be greater C17:0 levels (0.86 vs. 0.76 g/100g FA; P = 0.05) compared with WIA groups. Overall, ISO improved MY and nutrient digestibility in the HF whereas it increased ADG and decreased MUN in LF diet. Additionally, ISO increased milk odd chain FA (C15:0 and C17:0) regardless of FL.

A New Strain of Saccharomyces cerevisiae in Diets of Lactating Holstein Cows Improved Feed Efficiency and Lactation Performance

Abstract This study compared the effects of feeding a new strain of Saccharomyces cerevisiae HSA2020 with a commercial strain on in vitro rumen fermentation and production performance of dairy cows. Permeate was used as a substrate for the laboratory production of the new strain of S. cerevisiae after the hydrolysis by β-galactosidase (5000 µ/mL at 37°C). Two experiments were conducted: in Experiment 1, the effects of three levels (1, 2 and 3 g/kg dry matter) of S. cerevisiae on in vitro ruminal fermentation kinetics were evaluated. In Experiment 2, for 60 days, sixty multiparous Holstein cows (639±24.8 kg BW, 3±1 parity, 7±1 days in milk, with a previous milk production of 23±2.0 kg/d) during the previous lactation, were randomly assigned to 3 treatments in a completely randomized design. Cows were fed without any additives (control treatment) or supplemented with 2 g/kg feed daily of laboratory produced (PY) or commercial (CY) S. cerevisiae. In Experiment 1, inclusion of PY and CY increased (P&lt;0.05) gas production, propionate, and nutrient disappearance, while decreased (P&lt;0.05) methane production and protozoal count. Moreover, in Experiment 2, PY followed by CY increased (P&lt;0.01) nutrient digestibility, and serum concentrations of total protein, albumin, and glucose (P&lt;0.05). Higher daily milk yield, and milk energy output were observed with PY and CY without affecting concentrations of milk components or milk fatty acid profile. Compared to control, increased feed efficiency was observed with PY and CY. Compared to PY, CY increased serum concentrations of urea-N and decreased triglycerides, while PY decreased serum aspartate transaminase and increased concentration of conjugated linoleic acids in milk. In early lactating cow diets, both strains of S. cerevisiae improved production performance at 2 g/kg, and minimal differences between strains were found.

Impact of oil type and savory plant on nutrient digestibility and rumen fermentation, milk yield, and milk fatty acid profile in dairy cows

Fat supplements are well known for their multiple beneficial effects on ruminant health, reproduction and productivity, and as a source for certain bioactive compounds in ruminant products. On the other hand, numerous phytochemicals have demonstrated the potential to improve rumen fermentation through modifying the volatile fatty acid (VFA) pattern to favour those with greater energy efficiency, boosting microbial protein synthesis, and decreasing methane emission and ruminal ammonia concentration. Savory is an aromatic plant rich in various phytochemicals (mainly carvacrol and flavonoids) that can alter ruminal metabolism of dietary fatty acids, potentially increasing the production of some bioactive compounds such as conjugated linoleic acids (CLAs). This study aimed to investigate combined effects of oil type (fish oil (FO) versus soybean oil (SO)) and the inclusion of savory (Satureja khuzistanica) plant (SP) in the diet on total tract digestibility of nutrients, rumen fermentation, milk yield and milk fatty acid profile in dairy cattle. Eight multiparous lactating Holstein cows were used in a replicated 4 × 4 Latin square design experiment with four diets and four 21-d periods. During each experimental period consisted of 14 days of adaptation and a 7-day sampling period, cows were randomly assigned to one of the four dietary treatments: the diet supplemented with 2% (DM basis) fish oil (FOD) or soybean oil (SOD), the FOD or SOD plus 370 g DM/d/head SP (FODs, SODs, respectively). The experimental diets were arranged in a 2 × 2 factorial design, with the fat sources as the first and SP as the second factor. The FO-supplemented diets had lower dry matter intake (DMI) and higher total tract digestibility than SO-supplemented diets (P < 0.05), and including SP in the diet improved total tract digestibility of dry matter (DM), organic matter (OM), ether extract (EE), and non-fibrous carbohydrates (NFC) (P < 0.05) without negatively affecting DMI. Rumen pH was lower with SO than with FO diets (P < 0.01) and increased with SP inclusion in the diet (P < 0.05). Total protozoa count and ruminal ammonia concentration decreased, and the branched-chain VFA (BCVFA) proportion increased with SP inclusion in the diet (P < 0.05). Milk production, as well as the concentration and yield of milk components (except lactose concentration) were higher with SO than with FO diets (P < 0.05), but these variables remained unaffected by SP. The milk concentrations of both non-esterified fatty acids (NEFA) and beta-hydroxybutyrate (BHB) were lower with SO compared to FO diets, and these variables were reduced by SP (P < 0.01). The proportions of both mono- and polyunsaturated FA (MUFA and PUFA, respectively) in milk were higher with FO than with SO diets (P < 0.01), and their proportions increased by SP at the expense of saturated FA (SFA) (P < 0.01). Including SP in the diet increased the proportions of all the milk n-3 FA (C18:3c, C20:5, and C22:6) by 21%, 40%, and 97%, respectively, and those of conjugated linoleic acids (C18:2 (c9,t11-CLA) and C18:2 (t10,c12-CLA)) by 23% and 62%, respectively. There was no interaction between oil type and SP for the assessed variables. Fish oil, despite reducing milk production and milk components, was more effective than soybean oil in enriching milk with healthy FA. These findings also show promise for SP as a feed additive with the potential to improve total tract digestibility, rumen fermentation and milk FA composition.

The Characteristics of Milk Fatty Acid Profile Predicted by Fourier-Transform Mid-Infrared Spectroscopy (FT-MIRS) in Chinese Holstein Cows.

Fatty acid is an important factor affecting the nutritional quality of milk. In this study, we collected and assessed 78,086 milk samples from 12,065 Chinese Holstein cows from 11 farms in Northern China from November 2019 to September 2022. The contents of eight fatty acid groups were predicted using FT-MIRS-based models. The contents of TFAs, SFAs, UFAs, MUFAs, PUFAs, and LCFAs in milk reached the highest at 96-125 DIM, and SCFA and MCFA contents reached the highest at 276-305 DIM. With the increase in somatic cell score, the contents of various fatty acid groups in milk gradually decreased, and the nutritional value of milk and flavor of dairy products gradually deteriorated. The contents of high-quality fatty acids in milk, particularly UFAs and MUFAs, were significantly higher in the non-pregnant state than in the pregnant state. However, SCFA and MCFA contents exhibited the opposite pattern. Our findings provided valuable information on the content and distribution range of fatty acid groups in milk from Chinese Holstein cows. Further analysis is warranted to explore the breeding of Chinese Holstein cows providing milk with abundant beneficial fatty acids.

The Effects of Hemp Hay (Canapa sativa L.) in the Diets of Grazing Goats on Milk Production and Fatty Acid Profile.

Hemp (Cannabis sativa L.) is a cosmopolitan annual herbaceous plant used in the past as a source of textile fiber. Currently, hemp is receiving great interest as animal feed due to its chemical and nutritional properties. The aim of this study was to explore the effects of supplementing goats' diets with hemp hay on the milk yield, chemical composition, and fatty acid profile. Twenty multiparous goats, immediately after kidding, were divided into two homogenous groups (C: control vs. H: hemp); the goats had free access to the pasture, and both groups received a supplement of 500 g/head/day of a barley and corn meal mixture (50/50). In addition, group H was given 250 g/head/day of hemp hay while group C received the same amount of alfalfa hay. The milk yield was measured daily, and milk samples were collected monthly 4 times to evaluate the milk composition and fatty acid profile. The milk yield was significantly (p < 0.05) higher in the experimental group, while no differences were found in the milk chemical composition. Concerning the fatty acid profile, the milk from group H was characterized by significantly lower concentrations of C11:0, C12:0, C13:0, C14:0, C15:0, and C17:0 and higher C16:0 and C18:0. Among the polyunsaturated FA, C18:2 n6 and C20:4 were significantly (p < 0.001) lower, and C20:5 n3 was significantly (p < 0.05) higher in the milk from group H than that from group C. The n6/n3, LA/ALA and AA/EPA ratios were significantly (p < 0.001) lower in the milk from group H, while the CLAs were unaffected by the treatment.

The Effects of Two Selected Single Nucleotide Polymorphisms of the Fatty Acid Synthase Gene on the Fat Content and Fatty Acid Profile of Cow's Milk from the Polish Holstein-Friesian Red-and-White Breed versus Two Polish Red-and-White and Polish Red Conservation Breeds Kept in Poland.

Fatty acid synthase (FASN) is a metabolic enzyme responsible for the synthesis of fatty acids in milk and meat. The SNPs g.841G/C and g.17924A/G of the FASN gene significantly influence the fat and fatty acid content of milk from cows of various breeds. Therefore, these SNPs were selected for this study. This study aimed to analyze the relationship of SNPs and their genotypes with the fat content and fatty acid profile of milk from Polish Red-and-White (ZR), Polish Red (RP), and Polish Holstein-Friesian Red-and-White (RW) cows. Milk samples were obtained during a milking trial. SNP genotyping was performed using the real-time PCR (HRM) method. It was shown that SNPs (with specific genotypes) were significantly associated with the presence of fatty acids such as C18:1n9t and C18:2n6c in milk. In addition, it was found that the milk fat from the ZR (genotypic variant A/G, AA) and RP (genotypic variant GG, A/G) breeds often exhibited a more attractive fatty acids profile than the milk fat from RW cows. This information can be used by both cattle breeders and people interested in consuming functional foods.

Utilising fatty acid prediction equations and mid‐infrared spectroscopy to estimate the seasonality changes in bovine milk from pasture‐based systems

The aim of this study was to utilise mid‐infrared spectroscopy with fatty acid (FA) predictions to characterise the seasonality‐associated changes to the FA profile of milk from Irish spring‐calving pasture‐based dairy cow production systems. A total of 546 454 individual milk records were collected from the Years 2015 to 2020, from 264 003 cows in 2400 commercial dairy farms. Significant changes occur to the predicted FA profile of milk across the year, such as increases in unsaturated FAs including C18:1 n‐9 until April. This can be associated with the increasing proportion of fresh pasture in the cows' diet, and a decrease between September and October as the cows begin to transition indoors for the winter period. The opposite trend was noted for saturated FAs and in particular C16:0, where proportions decreased until April and increased between September and November. Milk produced between April and September also coincided with the lowest spreadability index, indicating a more beneficial milk FA profile for more spreadable butter texture during this period. This work provides a valuable reference resource at a national level of the FA profile of milk from pasture‐based spring‐calving dairy systems.

Differences in Milk Fatty Acids Profile of Two Breeds of Water Buffaloes Explained by Their Gastrointestinal Microbiota.

This experiment investigated gastrointestinal microbes' role in milk fatty acid differences between Murrah and Nili-Ravi buffaloes. After 30 days of a basal diet, rumen microbial diversity was similar, but Murrah buffaloes had greater partially unsaturated fatty acids like C18:2c9t11. Rumen bacteria like Acetobacter, Ruminococcus, and Prevotellaceae_YAB2003_group correlated positively with milk fatty acids C22:5n-6 and C18:3 in Murrah. Fecal microbial beta diversity differed, with UCG-005 and Prevolla positively correlated with C18:2c9t11 and C22:5n-6. The greater quantity of milk fatty acids C18:3, C18:2c9t11, and C22:5n-6 in Murrah milk was linked to rumen and fecal microbes. This suggests that gastrointestinal microbes like Acetobacter, Ruminococcus, and UCG_005 regulate milk fatty acid concentrations in buffaloes.

Selection of the most informative wavenumbers to improve prediction accuracy of milk fatty acid profile based on milk mid‐infrared spectra data

AbstractMilk mid‐infrared (MIR) spectra have been shown to provide valuable information on a wide range of traits to be used in dairy cattle breeding programs. Selecting the most informative variables from complex data can improve the prediction accuracy and model robustness and, consequently, the interpretability of MIR spectra. Thus, we aimed to investigate the prediction performance of feature selection methods based on MIR spectra data, using the milk fatty acid (FA) profile as an example to illustrate the evaluated procedure. Data of MIR spectra, milk test‐day records, and reference FA concentrations of 155 first‐parity Holstein cows were used in the analyses. Four models comprising different explanatory variables and three feature selection methods were evaluated. The results indicated that competitive adaptive reweighted sampling (CARS) method can effectively select the most informative variables from the MIR spectra, resulting in higher prediction accuracies than other variable selection approaches. The model including selected MIR spectra and cow information variables yielded the best FA profile predictions based on partial least square regression. C8:0, C10:0, C14:1, C17:0 isomers, C18:1, C18:1 isomer, medium‐chain FA, unsaturation FA, monounsaturated FA, and polyunsaturated FA presented accuracies based on the determination coefficient ranging from 0.66 to 0.85 in internal validation and from 0.65 to 0.84 in external validation. The most related wavenumbers to 35 FAs were found within 1003 to 1145 cm−1. Generally, using CARS and cow information improved predictions of FAs based on MIR spectra in Chinese Holstein dairy cows. Additional validation studies should be conducted as larger datasets become available.

Animal and Farm Factors Affecting the Fatty Acid Profile and Amyloid A Concentration of Milk on Quebec Dairy Farms

Relationships between farm and animal factors and the fatty acid (FA) profile and milk amyloid A (MAA) content of milk were determined in 336 Holstein dairy cows on 24 Quebec farms using multiple regression. Cows with a somatic cell count (SCC) above 200,000, and farms feeding palm oil were excluded. Independent factors of the regression models included days in milk (DIM), parity, yield, fat and protein contents of milk, SCC, and the dietary contents of neutral detergent fibre (NDF) and crude fat (CFAT). Non- significant variables with P-values &gt;0.25 were stepwise removed. Models with high fits were those of total short chain FA, medium chain FA, odd- and branched-chain FA (OBCFA), and saturated long chain FA with R2 of 0.33, 0.36, 0.34, and 0.41, respectively. The fat and protein contents and yield of milk did not affect the milk FA profile. Higher NDF increased the milk fat proportions of short chain FA and OBCFA and decreased those of monounsaturated (MUFA) and polyunsaturated FA (PUFA). Higher CFAT reduced this proportion of short chain FA but increased those of MUFA and PUFA. Increasing DIM reduced this proportion of short chain FA and increased that of medium chain FA. Higher SCC increased MAA.

Grape seed oil in the diet of primiparous Jersey cows before and after parturition: effects on performance, health, rumen environment, and milk quality.

The objective of the study was to determine whether adding grape seed oil (GSO) to the diet of primiparous Jersey breeds during the transition period would improve animal health by measuring effects on the rumen environment, serum biochemistry, oxidative response, and the composition and quality of milk. We used 14 Jersey heifers, weighing an average of 430kg and 240days of gestation. The animals were divided into two groups and offered a basal diet, including GSO in the concentrate for the GSO group (dose of 25mL per animal day) and the same dose of soybean oil (SO) for the control group. The animals were allocated and maintained in a compost barn system, receiving an anionic diet (pre-partum) and a diet for postpartum lactating animals. Dry matter intake (DMI), milk production, serum biochemistry, serum and milk oxidative stability, ruminal fluid and milk fatty acid profile, milk qualitative aspects, and ruminal parameters such as pH, bacterial activity, and protozoan count were evaluated. The addition of GSO had a positive effect on the health of the cows, especially on the oxidative stability of the cows, by increasing total thiols (P = 0.03), higher plasma ferric reducing capacity (FRAP) (P = 0.01), and total antioxidant capacity (TAC) (P = 0.01). In the oxidative stability of the milk produced by the treated animals, there was also an increase in TAC (P = 0.05) and FRAP (P = 0.03). Discreet changes were observed in the ruminal environment with a decreasing trend in pH (P = 0.04) but an increase in bacterial activity (P = 0.05) and protozoa counts (P = 0.07) in cows that consumed the additive. GSO consumption affected the fatty acid profile in milk, increasing saturated fatty acids (SFA) (P = 0.05) and reducing unsaturated fatty acids (UFA) (P = 0.03). The oil did not affect milk production or efficiency in the postpartum period. Based on this information, it is concluded that the addition of GSO positively affects the cow's antioxidant system.

Fatty Acid Profile of Milk of Various Indigenous Cattle Breeds in Hot-Arid Region of Rajasthan

The bioactive components refer to compounds either naturally existing in food or introduced during food processing that may have physiological and biochemical functions when consumed by humans and have crucial impacts on human metabolism and beneficial effects on human health, that guard neonates and adults against pathogens and illnesses and Antioxidants may positively affect human health by protecting the body against damage caused by reactive oxygen species, which attack membrane lipids, protein and DNA. Bioactive components encompass proteins, peptides, carbohydrates, lipids, glycolipids and other minor biomolecules i.e. vitamins, lactoferrin, enzymes, immunoglobulin and growth factors. The present study was conducted on fatty acids in milk of various indigenous cattle breeds viz. Kankrej, Sahiwal and Rathi. For fatty acids, 36 milk samples (12 from each breed) were collected from different Livestock Research Station, Bikaner. Fatty acids were measured by GC-MS. The analysis of variance revealed monounsaturated fatty acids and Poly unsaturated fatty acids significantly differed in different indigenous cattle breeds whereas saturated fatty acids did not differ. The present study concluded that the milk from the indigenous cattle breeds viz. Kankrej, Sahiwal, and Rathi have distinct compositions and quantities of different active components which can be harnessed for the promotion of different functional foods based on indigenous cattle milk and further pharmaceutical preparations can be promoted for the benefit of farmers and entrepreneurs.

Review of equations to predict methane emissions in dairy cows from milk fatty acid profiles and their application to commercial dairy farms

Greenhouse gas emission from the activities of all productive sectors is currently a topic of foremost importance. The major contributors in the livestock sector are ruminants, especially dairy cows. This study aimed to evaluate and compare 21 equations for predicting enteric methane emissions (EME) developed on the basis of milk traits and fatty acid profiles, which were selected from 46 retrieved through a literature review. We compiled a reference database of the detailed fatty acid profiles, determined by GC, of 992 lactating cows from 85 herds under 4 different dairy management systems. The cows were classified according to DIM, parity order, and dairy system. This database was the basis on which we estimated EME using the selected equations. The EME traits estimated were methane yield (20.63 ± 2.26 g/kg DMI, 7 equations), methane intensity (16.05 ± 2.76 g/kg of corrected milk, 4 equations), and daily methane production (385.4 ± 68.2 g/d, 10 equations). Methane production was also indirectly calculated by multiplying the daily corrected milk yield by the methane intensity (416.6 ± 134.7 g/d, 4 equations). We also tested for the effects of DIM, parity, and dairy system (as a correction factor) on the estimates. In general, we observed little consistency among the EME estimates obtained from the different equations, with exception of those obtained from meta-analyses of a range of data from different research centers. We found all the EME predictions to be highly affected by the sources of variation included in the statistical model: DIM significantly affected the results of 19 of the 21 equations, and parity order influenced the results of 13. Different patterns were observed for different equations with only some of them in accordance with expectations based on the cow's physiology. Finally, the best predictions of daily methane production were obtained when a measure of milk yield was included in the equation or when the estimate was indirectly calculated from daily milk yield and methane intensity.

Effect of the Replacement of Wheat Straw by Spent Mushroom Substrate in the Diet of Dairy Ewes during Late Lactation on Milk Production, Composition, Oxidation Stability and Udder Health

The aim of the present study was to investigate the effects of different dietary levels of spent mushroom substrate (SMS) at the expense of wheat straw (WS) on milk characteristics in dairy sheep. Thirty ewes at their final stage of lactation (145 ± 5 days after parturition) were randomly assigned into three groups; control (C), provided with a diet consisting of concentrates, alfalfa hay and WS, and SMS1 and SMS2, where WS was replaced by SMS at 50 or 100%, respectively. The experiment lasted for 28 days, and milk yield, composition, somatic cell count (SCC) and oxidative stability were monitored weekly, while milk fatty acid and immune cell profile were also determined on day 28. No significant differences were found in produced milk quantity, fat, protein, lactose, total solids non-fat, SCC and fatty acid profile between the experimental groups. However, milk oxidative stability was significantly improved as an effect of SMS (p &lt; 0.001). At the same time, milk polymorphonuclear leukocyte percentage was decreased in SMS2 group (p &lt; 0.05). As indicated, SMS seems to be a promising agro-industrial by-product for ewes’ diet that could improve milk oxidative stability, without negatively affecting milk yield, composition and ewe health status, contributing in the context of sustainability, circular economy and protection of natural resources.

Composition and fatty acid profile of milk from cows fed diets supplemented with raw and n-3 PUFA-enriched fish oil

Dietary supplementation of ruminants with fish oil is a strategy for favorably modifying the fatty acid composition of milk fat. This study investigated the effect of supplementing cows’ diet with fish oil after low-temperature crystallisation (LTC-FO) compared to its raw form (FO) on milk yield, milk components (fat, protein, and lactose), and milk fatty acid profile. Twenty-four mid-lactating multiparous Polish Holstein–Friesian cows fed a total-mix ration were randomly assigned to two homogeneous groups (n = 12 cows each) and supplemented with LTC-FO or FO at 1% of dry matter. Milk samples were collected on days 14 and 30 of the 30-day experiment. No significant differences between the groups in terms of milk yield, milk protein, and lactose content were found, however, the fat yield and content decreased in the LTC-FO group. Milk fat from cows in the LTC-FO group contained significantly higher levels of C18:1 trans-11, C18:2 cis-9, trans-11, C18:3n − 3, C20:5, and C22:6, and lower levels of saturated fatty acids compared to the FO group (p < 0.05). Therefore, LTC-FO may be a more efficient feed additive than FO and may serve as a practical way to modify the fatty acid composition of milk fat.