Milk Fatty Acid Profile Research Articles

The Effect of Increasing the Proportion of Dietary Roughage Based on the Partial Replacement of Low-Quality Roughage with Alfalfa Hay on the Fatty Acid Profile of Donkey Milk

As a lactation source, donkey milk contains a higher percentage of n-3 polyunsaturated fatty acids in the milk fatty acid profile than cow’s milk, especially the percentage of α-linolenic acid (ALA). We hypothesized that the ratio of dietary concentrate/roughage could influence the composition of the fatty acid (FA) profile of donkey milk, and that the substitution of low-quality roughage with high-quality roughage could improve the composition of the polyunsaturated fatty acid profile of donkey milk. The purpose of this experiment was to investigate the effects of the partial dietary replacement of low-quality roughage with alfalfa hay to increase the proportion of roughage in the diet on the FA profiles in the milk of lactating donkeys, with the goal of optimizing the FA profiles of donkey milk. The trial design was a single-factor randomized design. Sixteen Dezhou donkeys of similar age, weight, parity, and lactation days were selected and equally divided (n = 8 per group) into a low alfalfa hay group (LG, 40 concentrate/60 roughage, alfalfa hay: 44.85 g/kg dry matter) and a high alfalfa hay group (HG, 30 concentrate/70 roughage, alfalfa hay: 179.48 g/kg dry matter). The trial lasted 8 weeks and the energy and protein levels of the two diets were identical. The results showed that the profile of milk ALA increased (p = 0.048) and the n-6/n-3 ratio and index of thrombogenicity were decreased (p = 0.019 and p = 0.002) in the HG. Partial replacement of low-quality roughage with alfalfa hay and increasing the percentage of dietary roughage from 60% to 70% optimized the FA quality of donkey milk fat.

Protected palmitic acid to mitigate milk fat depression in grazing Holstein cows in the Mexican Highlands

ABSTRACT The cis-9 trans-11 and trans-10 cis-12 isomers of conjugated linoleic acid (CLA) are associated with anticancer and lipolytic effects in tissues, respectively, but in lactating cows, the latter isomer reduces the milk fat concentration, a detrimental aspect for the dairy industry, as it reduces the yield of milk derivatives. Therefore, the objective of this study was to evaluate the effect of providing protected palmitic acid (PA P ) to grazing lactating Holstein cows supplemented with soybean oil as a source of conjugated linoleic acid, on milk production, fat concentration and mitigation of milk fat depression. Nine multiparous Holstein cows were used, distributed in three groups of three cows each, with initial means of days in milk, live weight, milk production, and number of calvings: 124 ± 16 days, 494 ± 53 kg, 20.9 ± 1.3 kg, and 3.2 ± 2.2, respectively. A crossover design with three treatments was used: control (base diet, BD, = grazing +4 kg concentrate without soybean oil + 2.5 kg corn silage), soybean oil (BD with inclusion of 300 g dry basis soybean oil cow−1 day−1), and soybean oil + PA P (BD with inclusion of 300 g dry basis soybean oil and 412 g PA P cow−1 day−1). The groups of cows were on rotational grazing in a mixed pasture of Alfalfa (Medicago sativa) and Orchard grass (Dactylis glomerata). The variables evaluated were as follows: dry matter intake (DM), milk production, concentration of protein, fat and lactose in milk, and milk fat profile. Statistical analysis was through PROC MIXED and comparison of means with Tukey’s test (p < 0.05). There were no differences (p > 0.05) between treatments in dry matter intake, milk production or milk protein and lactose content. But the addition of PA P in the cow diet increased fat-corrected milk production (p = 0.010), yield (p = 0.030) and fat concentration (p = 0.040), and improved the milk fatty acid profile, by increasing (p = 0.010) the concentration of cis-9, trans-11 CLA in milk fat. Soybean oil supplementation in the diet of grazing lactating cows showed no differences in productive variables, and did not cause the expected milk fat depression. However, combining soybean oil with PA P improved the fatty acid profile, increasing the cis-9, trans-11 isomer CLA and palmitic acid in milk fat, with higher yield and fat concentration.

Milk Performance and Grazing Behaviour of Cinisara Cows Supplemented with Low- and High-Polyphenols Faba Bean Varieties

The high degradability of crude protein (CP) from fresh grass can impair its utilization in ruminants. The presence of a moderate level of polyphenolic substances in the diet of grazing animals could help to overcome this problem. The study aimed to evaluate the effects of supplementation with two varieties of faba bean, with different polyphenol contents, on milk yield and quality, as well as on grazing behaviour, in Cinisara grazing cows. A total of 30 cows, homogeneous per days in milk (61 ± 29) and milk yield (12.9 kg ± 3.2), fed on a mixed pasture (CP 17.9% DM) and supplied with grains (an equal mixture of barley, oats, and wheat) and mixed hay (CP 10.2% DM), were assigned to three dietary treatments and supplemented as follows: control group (C, 10 cows), 1 kg of hay, 6 kg of grains mixture, and 0.4 kg soybean meal; low polyphenols group (LP, 10 cows), 1 kg of hay, 4 kg of grains mixture, and 2 kg/d of faba bean var. Torrelama (total polyphenols 4.4 mg GAE/g DM; CP 28.4% DM); high polyphenols group (HP, 10 cows), 2 kg of hay, 4 kg of grains mixture, and 2 kg/d of faba bean var. Fanfare (total polyphenols 16.4 mg GAE/g DM; CP 28.9% DM). All groups were allowed to graze for 20 h/d on natural pasture forage. The HP supplement tended to increase the milk yield compared to that of the LP and C groups (17.1 vs. 15.3 and 14.6 kg/d, respectively; p = 0.057) but reduced the protein (3.20 vs. 3.39 and 3.47%; p = 0.009) and casein proportions (2.45 vs. 2.67 and 2.74%, respectively; p = 0.007) compared to those from the LP and C treatments. HP milk also showed a higher milk urea nitrogen (MUN) value compared to that of C milk, while an intermediate level was measured in LP milk (25.5 vs. 22.9 and 20.9 mg/dl, respectively; p = 0.036). No dietary effect was evident in the milk fatty acid profile. Eating time at pasture and biting rate were not affected by supplementation. The results do not seem to suggest a difference in the efficiency of use of supplements with different polyphenol contents. In any case, they seem to demonstrate that the use of faba beans, regardless of their polyphenol content, represents a valid alternative to soyabeans, also taking into account the tendency for an increased milk yield found by integrating pasture grazing with faba beans possessing a high level of polyphenols, without significant worsening of the qualitative characteristics of the milk or negatively affecting grazing behaviour.

Exploring the Role of Salt Supplementation on Milk Composition, Fatty Acids, and Insulin Response in Lactating Camels.

Camel milk is a valuable food source with unique nutritional properties and potential health benefits. This study investigated the influence of high dietary salt on milk composition and fatty acid (FA) profile as well as insulin regulation in dairy camels. Twelve multiparous female camels were used in a crossover design with two treatments: control concentrate (CON; 1.3% salt) and high-salt concentrate (SAL; 3.9% salt). Each period lasted 3 weeks, with camels switched between treatments in the second period. The measured variables included milk yield, milk composition, blood metabolites, and insulin levels in blood and milk. The SAL group exhibited higher (p < 0.01) water consumption. Nevertheless, milk yield and composition (fat, protein, lactose) remained unaffected. Notably, SAL camels had elevated blood insulin levels (p < 0.05) compared to the CON group, suggesting enhanced pancreatic activity possibly driven by osmotic balance changes. Milk FA profiles revealed a reduction in unsaturated fatty acids (UFA, p < 0.04), particularly monounsaturated (MUFA, p < 0.05) and odd-chain fatty acids (OCFA, p < 0.05). Furthermore, lipid quality indices such as the atherogenic index (p < 0.01) and the hypocholesterolemic/hypercholesterolemic FA ratio (h/H, p < 0.01) indicated a less favorable milk fat profile in the SAL group. These findings suggest that while moderate salt supplementation may not negatively impact milk yield in dairy camels, it alters both metabolic and milk fat composition variables, with potential implications for the nutritional quality of milk.

Preserving Mediterranean Donkeys: A Study on Milk Production and Nutritional Benefits.

The aim of the study was to model lactation curves and assess the physicochemical properties, amino acid, and fatty acid profiles of milk from two Mediterranean donkey populations, Masri (n = 14) and North African (n = 14), using the Wood model. Over a lactation period of 205 ± 12.5 days, North African donkeys produced more milk (188.66 ± 7.19 kg) than Masri donkeys (163.42 ± 7.21 kg, p < 0.05). Peak milk yields occurred on day 57 for North African donkeys (1.212 kg/day) and day 59 for Masri donkeys (0.991 kg/day), with similar persistency indices of 7.19 and 7.21, respectively. North African donkey milk had significantly higher protein (1.45 ± 0.03 g/100 g) and β-lactoglobulin (4.75 ± 0.06 mg/mL) contents, while Masri donkey milk contained more fat (1.16 ± 0.05 g/100 g). Amino acid analysis revealed higher glutamate (0.27 ± 0.12 g/100 g) in North African donkey milk, while Masri donkey milk had more aspartate (0.16 ± 0.04 g/100 g). North African donkey milk had higher palmitic acid (20.1 ± 0.07 g/100 g), while Masri donkey milk had more oleic acid (21.4 ± 0.42 g/100 g). Lactation curve fitting yielded R2 values of 93.8% for Masri donkeys and 95.7% for North African donkeys. These findings suggest that both populations are well-suited for milk production, particularly for human consumption or food applications. North African donkeys exhibited superior yields and nutrient profiles suitable for functional food applications.

Can dietary palmitic supplementation and milking frequency modify the cheesemaking properties of milk?

Palmitic acid (PA) supplementation and greater milking frequency can increase milk production and fat yield in dairy cows. However, the technological impacts of those practices on cheesemaking still need to be determined. This work aimed to evaluate, with Holstein dairy cows, the effects of dietary PA, thrice-daily milking frequency, and their interaction on cheese yield and composition. Before cheesemaking, milks were standardized to a casein-to-fat ratio of 0.78 ± 0.02 and targets of 3.27 ± 0.03 and 4.20 ± 0.05% wt/wt, for casein and fat concentrations, respectively. Rennet coagulation properties of standardized milk, cheese composition, curd draining properties, free fatty acid (FFA) content, and proteolysis during ripening were analyzed. Dietary PA supplementation modified the milk fatty acid profile but did not affect coagulation and draining properties, cheese composition, and proteolysis. The moisture-adjusted yield and fat and protein recoveries were also similar between treatments. The greater milking frequency did not affect process performance. However, increasing milking frequency led to a significantly higher FFA content in cheese at the end of ripening of 1.4 ± 0.2 vs. 0.8 ± 0.2 mEq/kg of cheese fat for thrice- and twice-daily milkings, respectively. Consequently, dietary supplementation of PA to dairy cows only had a limited effect on the cheesemaking process under the standardized conditions tested. However, the effect of FFA on cheese sensory properties should be considered if the milking frequency is increased.

The Health-Related Fatty Acid Profile of Milk from Holstein-Friesian Cows as Influenced by Production System and Lactation Stage.

This study aimed to evaluate the effect of production system and lactation stage (LS) on the yield, centesimal composition, and fatty acid profile of milk from Holstein-Friesian cows. A total of 539 milk samples were collected in winter from cows in six certified organic dairy herds (ODHs) and eight conventional dairy herds (CDHs). The samples were collected randomly from up to 30% of cows at a given stage of lactation (7-45, 46-90, 91-135, 136-180, 181-225, 226-270, 271-315, and 316-360 days after calving). Milk samples were analyzed for proximate composition and the concentrations of fatty acids. The average daily milk yield was 11.4 kg higher (p < 0.01) in CDHs than in ODHs (28.1 kg vs. 16.7 kg). The concentrations of milk fat, protein, and lactose were also higher in CDHs than in ODHs. The fatty acid profile of milk fat was more desirable in ODHs than in CDHs (higher concentrations of polyunsaturated fatty acids (PUFAs), including n-3 PUFAs, trans-vaccenic acid, linolenic acid, and conjugated linoleic acid, and a higher desaturase index). Milk yield decreased (the decrease was more pronounced in ODHs), the concentrations of milk constituents increased, and the proportion of short-chain fatty acids in milk fat decreased (p < 0.05) with advancing lactation.

Differential effects of 3-nitrooxypropanol supplementation on milk fatty acids profiles in three different dairy breeds

Differential effects of 3-nitrooxypropanol supplementation on milk fatty acids profiles in three different dairy breeds

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 &lt; 0.05) compared to the control. Both REO and BEO decreased (p = 0.003) serum globulin and increased (p &lt; 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.

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&gt;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&lt;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&gt;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.

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.

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.

Diet supplementation with hemp (Cannabis sativa L.) inflorescences: effects on quanti-qualitative milk yield and fatty acid profile on grazing dairy goats

Hemp (Cannabis sativa L.) is an annual plant belonging to the family of Cannabaceae with several varieties characterized by different fatty acid profile, content in flavonoids, polyphenols, and cannabinoid compounds. Hemp is mostly used in livestock nutrition as oil or as protein cake, but not as inflorescences. The aim of this study was to evaluate the effect of dietary hemp inflorescences on milk yield and composition in grazing dairy goats. Twenty Camosciata delle Alpi goats at their 3rd parity and with a mean body weight of 45.2 ± 2.0 kg, immediately after kidding, were equally allocated into two groups (G: Grazing and GH: grazing and hemp). For three months, all goats were fed on a permanent pasture and received 700/head/day of concentrate; diet of group GH was supplemented with 20 g/head/day of hemp inflorescences. Goats’ body weight did not change during the trial. Individual milk yield was daily recorded and samples collected every 20 days for chemical composition and fatty acid profile analysis. No significant differences were found for milk yield and chemical composition. Caproic (C6:0) (1.80 vs. 1.74%; p < 0.01) and lauric acids (C12:0) were significantly higher in milk of group GH (4.83 vs. 4.32%; p < 0.01) as well as linoleic (C18:2) (2.04 vs. 1.93%; p < 0.05), adrenic acid (C22:4) (0.046 vs. 0.031%, p < 0.05), omega-6/omega-3 ratio (3.17 vs. 2.93, p < 0.05) and total conjugated linoleic acids (CLAs) (0.435 vs. 0.417%; p < 0.01). The results of this study suggest that the supplementation of grazing goats’ diet with hemp inflorescences may enhance the milk nutritional characteristics by increasing its content of CLAs and other beneficial fatty acids.

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.