Cows Fed Fish Oil Research Articles

Effects of supplementing pomegranate peel with fatty acid sources on oxidative stress, blood metabolites, and milk production of dairy cows fed high-concentrate diets

Primiparous cows are more susceptible to oxidative stress than multiparous cows because of their lower total antioxidant capacity. The objective of this study was to evaluate the effects of fatty acid (FA) source with and without pomegranate peel (PP) as an antioxidant-rich source in the diet on oxidative stress, blood metabolites, lactation performance, and nutrient digestibility in primiparous lactating cows. Twelve Holstein dairy cows in early lactation were randomly assigned to a replicated 4 × 4 Latin square design with a 2 × 2 factorial arrangement of treatments. Each period lasted 28 days with 21 days for feed adjustment and 7 days for data and sample collection. The diets were supplemented with 15 g/kg DM of palmitic acid-enriched fat (enriched in saturated FA) or fish oil (enriched in unsaturated FA) contained 0 or 87 g/kg DM of PP. Pomegranate peels increased total dietary antioxidant concentrations and fish oil reduced the ratio of n-6 to n-3 in the experimental diets. Significant interactions were observed for plasma non-esterified FA and malondialdehyde concentrations, milk fat yield, and apparent total-tract nutrient digestibility. Plasma non-esterified FA concentrations decreased in cows fed palmitic acid-enriched fat when PP was included in the diet. Diets with PP resulted in increased plasma concentrations of malondialdehyde in cows fed fish oil but not in those fed the palmitic acid-enriched fat. In addition, total plasma antioxidant capacity increased in cows fed PP containing diets, whereas blood inflammatory markers were not affected by the by inclusion of PP. Supplementing palmitic acid-enriched fat increased milk fat yield by 10% compared with fish oil, whereas a trend toward a decrease in this variable was observed when fish oil was fed without PP. Also, feed intake increased and milk protein concentration decreased in cows consuming diets containing PP, while milk yield was greater for cows fed fish oil. Cows fed palmitic acid-enriched fat had lower DM and NDF digestibility than in those fed fish oil. The molar fraction of propionate in the rumen decreased and the ratio of acetate to propionate increased in cows fed PP containing diets. Cows fed palmitic acid-enriched fat had a greater molar fraction of propionate but a lower ratio of acetate to propionate than cows fed fish oil. Overall, inclusion of PP in diets containing fish oil or palmitic acid-enriched fat contributed to improved feed intake and antioxidant capacity, while we observed no interaction on oxidative stress and inflammatory markers in dairy cows.

Effects of extruded linseed and level and type of starchy concentrate in a diet containing fish oil on dairy goat performance and milk fatty acid composition

Based on the potential benefits for long-term human health, nutritional strategies have been developed in order to increase the milk fat concentrations of bioactive fatty acids (FA) in ruminants. Dietary supplements of fish oil (FO), extruded linseed (EL) or a mixture of EL and FO increase c9,t11-CLA and n-3 PUFA in milk from bovine and caprine. These supplements associated with a high level of starch from concentrates cause milk fat depression in cows, but information for dairy goats is limited. An experiment was performed to investigate the effects of addition of extruded linseed to a diet containing fish oil in interaction with the type and level of starch concentrate on dairy goat performance and milk fatty acid (FA) profile. Following a 2×3 factorial design, 72 goats were allocated to 6 experimental diets based on alfalfa hay and with concentrates including fish oil (40g/d) without or with extruded linseed (360g/d) and either rich in starch from barley grain or extruded wheat or that were low in starch from barley grain. In contrast to cows, in goats adding extruded linseed to low-or high-starch diets based on hay and containing fish oil increases milk fat content and changes the milk FA composition in particular by increasing some bioactive FA with 18 carbons. In these conditions FA changes were characterized by decreases in SFA (on average 22% decrease) and increases in 18:0, c9-18:1, t11-18:1, c9,t11-CLA and 18:3n-3. The milk t10-18:1 concentration remained low (<1% total FA) and the t11-18:1/t10-18:1 ratio was much higher than in cows fed fish oil with plant oils. The combination of EL and FO induced larger concentrations in t11-18:1 and c9,t11-CLA than FO alone (2.9- and 2.1-fold higher, respectively). The apparent transfer rates of 20:5n-3 and 22:6n-3 from fish oil to milk were lower when EL was added to the diet (on average, 6.6 and 5.4%) compared to FO alone (on average, 8.0 and 7.4%, respectively). Extruded wheat, as the more rapidly degradable starch source in the rumen, decreased milk fat content. Based on the milk FA changes (e.g., c9,t11-CLA,18:2n-6, 18:3n-3, 20:5n-3, 22:6n-3), diets rich in starch from barley grain would induce a lower rumen bacterial biomass and a more extensive biohydrogenation of dietary FA in the rumen than diets rich in starch from extruded wheat. Starch level in the diets had negative effect on milk yield but moderate effects on milk fat and FA content, under these dietary conditions.

Performance, bioenergetic status, and indicators of oxidative stress of environmentally heat-loaded Holstein cows in response to diets inducing milk fat depression

Effects of grain type and dietary oil supplement on production performance, energy balance, metabolic heat production, and markers of liver function of heat-loaded lactating dairy cows were evaluated using 8 multiparous Holstein cows (77.0d in milk) in a duplicated 4×4 Latin square design with a 2×2 factorial arrangement of treatments. Experimental diets contained either ground barley or ground corn supplemented with either fish oil or soybean oil at 2% of dietary dry matter. Mean daily maximum temperature, minimum relative humidity, and maximum temperature–humidity index were 35.3°C, 11.3%, and 77.0, respectively. Dietary treatment did not affect rectal temperature (38.9°C), but respiration rate tended to decrease in cows fed fish oil versus soybean oil. Dry matter intake decreased for the fish oil–supplemented diets (21.1 vs. 24.3kg/d), which was negatively correlated with plasma concentrations of alkaline phosphatase (r=–0.45; n=32) and malondialdehyde (r=–0.26; n=32). Actual milk yield (41.9kg/d) and energy-corrected milk yield (36.6kg/d) were not affected by grain type, whereas feeding fish oil decreased milk yield as compared with soybean oil (40.4 vs. 43.4kg/d). Milk fat depression occurred in all dietary treatments, especially when cows were fed fish oil because of the presence of polyunsaturated FA in the diets. trans-10 C18:1 was negatively correlated with milk fat yield (r=–0.38; n=32). Daily milk cis-9,trans-11 C18:2 secretion was 29.6% less in cows fed barley- versus corn-based diets but 31.8% greater in cows fed fish oil as compared with cows fed soybean oil. Because of a lower dry matter intake, metabolic heat production was decreased in cows fed fish oil relative to cows fed soybean oil. Although feeding fish oil versus soybean oil decreased net energy for both maintenance and lactation, net energy balance remained unchanged across treatments. In vivo plasma lipoperoxidation was greater in cows fed fish oil versus soybean oil, which substantiated increased susceptibility of plasma lipoperoxidation when cows were fed fish oil. Plasma concentration of malondialdehyde was positively correlated with plasma aspartate aminotransferase (r=0.38; n=32), which is an indicator of liver function in heat-loaded cows. Results suggest that in heat-loaded cows fed diets supplemented with soybean oil versus fish oil, biosynthesis in the mammary gland was prioritized over anabolism and oxidation in peripheral adipose and muscle tissues regardless of type of grain used.

Interaction between fish oil and plant oils or starchy concentrates in the diet: Effects on dairy performance and milk fatty acid composition in goats

Two experiments were performed to investigate the effects of supplementing a diet with fish oil either alone or with plant oils on dairy goat performance and milk fatty acid (FA) profile (Experiment 1), and the interaction between fish oil with the type and level of starch concentrate (Experiment 2). In Experiment 1, 84 goats were allocated to 7 experimental diets without a lipid supplement or with a low or high dose of fish oil (20 or 40g/d, respectively) either alone or with linseed or sunflower-seed oils (the combinations included 130g/d of oil supplements). In Experiment 2, 72 goats were allocated to 6 experimental diets without a lipid supplement and with a concentrate rich in corn and barley grain starch or with the high dose of fish oil (40g/d) and concentrates rich in starch from barley grain, corn grain or both; or that were low in starch from barley grain or corn grain. In contrast to cows, in goats, fish oil supplements modulated milk FA composition without decreasing the milk fat content; this result may have been related to specific milk FA responses, such as a lack of or a small reduction in 18:0 and c9-18:1 (Experiment 1) or a moderate reduction compensated through increases in short-chain FA (Experiment 2) and limited increases in t10-18:1. The combinations of fish oil with sunflower-seed oil were more efficient than either fish oil plus linseed oil or fish oil alone at increasing (P<0.05) milk c9,t11-18:2 and t11-18:1 concentrations (up to 24- and 35-fold increases, respectively), simultaneously decreasing (P<0.05) medium-chain saturated FA (on average, 40% decrease). Based on the milk FA changes (e.g., 18:2n-6, 18:3n-3, t11-18:1 and 18:0) in Experiment 2, diets rich in barley grain starch with fish oil would induce less extensive ruminal dietary FA biohydrogenation and better inhibit the trans 18:1 reduction than diets that are supplemented with the same level of fish oil but are low in barley grain starch or rich in corn grain starch. The apparent transfer rates of 20:5n-3 and 22:6n-3 from fish oil to milk were low (on average, 2.8% and 2.4%, respectively; Experiment 1) but were slightly higher in barley-grain treatments (on average, 5.1% and 7.6%, respectively) compared with corn-grain-only treatments (on average, 2.5% and 3.7%, respectively; Experiment 2). The milk t10-18:1 concentration remained low (≤1.1% total FA) and the t10-18:1/t11-18:1 ratio was much lower than in cows fed fish oil with plant oils.

Dietary grain source and oil supplement: Feeding behavior and lactational performance of Holstein cows

Effects of grain source and dietary oil supplement on dry matter intake (DMI), feeding, chewing behavior, and production performance of lactating dairy cows were evaluated using eight multiparous Holstein cows (77±22.1 days in milk; mean±SD) in a duplicated 4×4 Latin square design with a 2×2 factorial arrangement of treatments. Experimental diets contained either ground barley or ground corn supplemented with either fish oil or soybean oil at 2% of dietary dry matter (DM). Geometric mean particle size of dietary treatments was 4.1mm. Dry matter intake tended (P=0.09) to be greater for barley- vs. corn-based diets (23.2 vs. 22.3kg/d), but was reduced for the fish oil compared to soybean oil supplemented diets (21.1 vs. 24.3kg/d; P<0.001). This reduction in DMI was attributed to smaller meal size (1.24 vs. 1.55kg of DM; P=0.004) and slower eating rate (0.082 vs. 0.098kg of DM/min; P<0.001) for fish oil compared to soybean oil supplemented diets. Main treatment effects interacted (P=0.005) for DMI of particles retained on 19mm sieve but not for sorting index. Eating rate (0.090kg of DM/min) was similar between barley- and corn-based diets, however, rumination time was greater for barley- compared to corn-based diets as result of longer rumination bout duration (32.5 vs. 28.5min/bout; P=0.01). Barley- compared to corn-based diets increased total chewing time by 71min (709 vs. 638min) for cows fed fish oil, but not for cows fed soybean oil. Grain source did not affect milk yield or milk composition. Compared to soybean oil, fish oil negatively affected milk yield (40.4 vs. 43.4kg/d; P=0.01), and thereby, both milk fat (0.91 vs. 1.26kg/d; P<0.001) and protein (1.23 vs. 1.33kg/d; P=0.007) production. However, feed efficiency (milk yield/DMI) was greater in fish oil compared to soybean oil supplemented diets (1.94 vs. 1.80; P=0.003). Results indicated that grain source and oil supplement can interact to affect feeding and chewing behavior, but not lactational performance of lactating cows.

Fatty acid composition of milk from Holstein cows fed fish oil, canola oil, or their combination in early lactation

Fatty acid composition of milk from Holstein cows fed fish oil, canola oil, or their combination in early lactation

Effects of ruminal or duodenal supply of fish oil on milk fat secretion and profiles of trans-fatty acids and conjugated linoleic acid isomers in dairy cows fed maize silage

Milk fat secretion and profiles of conjugated linoleic acids (CLA) and trans-18:1 isomers in milk fat due to a ruminal or duodenal supply of fish oil (FO; EPA = 22% of total fatty acids, DHA = 7%) were evaluated using six lactating Holstein cows with cannulas in their rumen and duodenum. Cows were fed a control diet based on corn silage (66% of DM), or the control plus 300 mL FO/d into the rumen (FO-R) or duodenum (FO-D) for 4 weeks in a replicated 3 × 3 Latin square design. Dry matter intake was higher with the control (19.8 kg/d), intermediate with FO-D (18.0 kg/d), and lower with FO-R (16.2 kg/d). Yield of milk (22.7 kg/d), lactose (1.09 kg/d), or crude protein (0.70 kg/d) was not affected by treatments. Content of crude protein, true protein, and casein was lower in response to FO-R compared with the control. Despite similar jugular concentration compared with the control, jugular–mammary venous difference for β-OH-butyrate was 54% lower with FO-R or FO-D. Milk fat content and yield were lowest with FO-R (25 g/kg, 567 g/d) compared with FO-D (32 g/kg, 737 g/d) or the control (35 g/kg, 783 g/d). Percentage of trans5-, trans6 + 7 + 8-, trans9-, trans10-, trans11-, trans12-, and trans13 + 14-18:1 in milk fat was greater due to FO-R (0.05, 0.44, 0.48, 1.8, 9.2, 0.70, and 0.82%, respectively) compared with the control or FO-D (0.02, 0.22, 0.19, 0.27, 1.1, 0.35, and 0.40%). Although 18:0 and cis9-18:1 percentage was markedly lower in response to FO-R, percentage of cis11-, cis13-, and cis15-18:1 was greater compared with the control or FO-D. Cis9, trans11-CLA (87–95% of total CLA) averaged 3.2% in response to FO-R compared with 0.51% for control or FO-D. Trans10, cis12-18:2 was not detected. Among non-conjugated 18:2 isomers, cis9, cis12-18:2 was lower but cis9, trans13-, trans9, cis12-, and trans11, cis15-18:2 greater when FO-R was compared with the control or FO-D. There was high correlation ( r = 0.94–0.99) among data obtained by GLC versus HPLC for most trans-18:1 isomers and cis9, trans11-18:2, suggesting GLC alone with our chromatographic conditions provided adequate separation of isomers. Milk 20:5 n-3 (EPA) and 22:6 n-3 (DHA) were 0.08 and 0.04% with the control, increased to 0.36 and 0.17% with FO-R, and were 1.47 and 0.47% with FO-D. Data indicate, ruminal supply of FO led to hydrogenation of EPA and DHA and enhanced percentage of various trans-18:1, cis-18:1, non-conjugated 18:2, and cis9, trans11-18:2 in milk fat. Combined increases in trans-18:1 along with reduced availability of 18:0 for endogenous synthesis of cis9-18:1 may play a key role in reduced milk fat synthesis in cows fed fish oil.

Effects of Dry Matter Intake, Addition of Buffer, and Source of Fat on Duodenal Flow and Concentration of Conjugated Linoleic Acid and Trans-11 C18:1 in Milk

The primary objective of the study was to investigate the effects of DM intake, addition of buffer, and fish vs. soybean oil on duodenal flows and milk concentrations of conjugated linoleic acid (CLA) and trans-11C18:1. Four ruminally and duodenally cannulated multiparous cows averaging 106±17 d in milk at the start of the trial were used in a 4×4 Latin square design with treatments as follows: 1) control=diet contained 2% fish oil and fed ad libitum, 2) buffer addition (BUFF)=control diet with 0.8% of NaHCO3 added, 3) low DM intake (LDMI)=DMI restricted to 80% of the control but concentration of fish oil was increased to 2.5% to provide for similar fatty acids (FA) intake, and 4) soybean oil (SBO)=same as control except 2% soybean oil was substituted for fish oil. The diets consisted of 36.2% forage and 63.8% concentrate. Each period consisted of 18 d, with the last 7 d devoted to data collection and the first 4 d used to determine the appropriate amount of feed to be offered to the cow on LDMI. Duodenal flows of CLA and trans-C18:1 were lower for SBO than for diets with fish oil. Feeding buffer did not affect ruminal pH or duodenal flows of trans-11C18:1 and CLA. Restriction of DMI decreased duodenal flow of trans-11C18:1 but did not decrease duodenal flow of CLA compared with control. In milk, CLA concentration was lower for SBO (24.5, 17.9, 18.5, and 10.1 mg/g of FA for control, BUFF, LDMI, and SBO, respectively). Cows fed fish oil had higher duodenal flow and milk concentration of n-3 polyunsaturated fatty acids than the cows fed SBO. Compared with SBO, fish oil is more effective in increasing duodenal flows of CLA and trans-11C18:1, and thus, concentration of CLA in milk.

Conjugated Linoleic Acid and Vaccenic Acid in Rumen, Plasma, and Milk of Cows Fed Fish Oil and Fats Differing in Saturation of 18 Carbon Fatty Acids

The objective of this study was to examine the effect of feeding fish oil (FO) along with fat sources that varied in saturation of 18 carbon fatty acids (high stearic, high oleic, high linoleic, or high linolenic acids) on rumen, plasma, and milk fatty acid profiles. Four primiparous Holstein cows at 85 d in milk (± 40) were assigned to 4×4 Latin squares with 4-wk periods. Treatment diets were 1) 1% FO plus 2% commercial fat high in stearic acid (HS); 2) 1% FO plus 2% fat from high oleic acid sunflower seeds (HO); 3) 1% FO plus 2% fat from high linoleic acid sunflower seeds (HLO); and 4) 1% FO plus 2% fat from flax seeds (high linolenic; HLN). Diets were formulated to contain 18% crude protein and were composed of 50% (dry basis) concentrate mix, 25% corn silage, 12.5% alfalfa silage, and 12.5% alfalfa hay. Milk production, milk protein percentages and yields, and dry matter intake were similar across diets. Milk fat concentrations and yields were least for HO and HLO diets. The proportion of milk cis-9, trans-11 conjugated linoleic acid (CLA; 0.71, 0.99, 1.71, and 1.12 g/100g fatty acids, respectively), and vaccenic acid (TVA; 1.85, 2.60, 4.14, and 2.16 g/100g fatty acids, respectively) were greatest with the HLO diet. The proportions of ruminal cis-9, trans-11 CLA (0.09, 0.16, 0.18, and 0.16 g/100g fatty acids, respectively) were similar for the HO, HLO, and HLN diets and all were higher than for the HS diet. The proportions of TVA (2.85, 4.36, 8.69, and 4.64 g/100g fatty acids, respectively) increased with the HO, HLO, and HLN diets compared with the HS diets, and the increase was greatest with the HLO diet. The effects of fat supplements on ruminal TVA concentrations were also reflected in plasma triglycerides, (2.75, 4.64, 8.77, and 5.42 g/100g fatty acids, respectively); however, there were no differences in the proportion of cis-9, trans-11 CLA (0.06, 0.07, 0.06, and 0.07 g/100g fatty acids, respectively). This study further supports the significant role for mammary delta-9 desaturase in milk cis-9, trans-11 CLA production.

Fatty Acid Profiles of Milk and Rumen Digesta From Cows Fed Fish Oil, Extruded Soybeans or Their Blend

Four fistulated primiparous cows (two Holstein and two Brown Swiss) averaging 102 DIM were used in a 4×4 Latin square with 3-wk periods to determine the effect of feeding fish oil, extruded soybeans, or their combination on fatty acid profiles of milk and rumen digesta. Experimental diets consisted of: 1) control diet; 2) a diet with 2% (DM basis) added fat from menhaden fish oil; 3) a diet with 2% added fat from extruded soybeans; and 4) a diet with 1% added fat from fish oil and 1% fat from extruded soybeans. All diets consisted of 25% corn silage, 25% alfalfa hay, and 50% concentrate. Milk yields (28.6, 29.7, 29.2, and 28.1 kg/d for control, fish oil, extruded soybeans, and combination diets, respectively) were similar for all fat supplements and control. Milk fat and protein percentages (3.49, 3.08; 3.25, 2.96; 3.47, 3.01; 3.48, 2.99 for diets 1, 2, 3, and 4, respectively) were not affected by fat supplements compared with control. Dry matter intake (23.0, 21.6, 22.7, and 21.6kg/d) was reduced when diets containing fish oil were fed. Concentrations of conjugated linoleic acid [CLA; cis-9, trans-11 CLA, 0.40, 0.88, 0.87, and 0.80g/100g fatty acids (FA)] and transvaccenic acid (TVA, 1.02, 2.34, 2.41, and 2.06g/100g of FA) were increased in milk fat by all fat supplements, with no differences in milk CLA and TVA observed among fat supplements. As with milk fat, proportions of ruminal CLA (0.09, 0.26, 0.18, and 0.21g/100g of FA) and TVA (2.61, 4.56, 4.61, and 4.39g/100g of FA) increased with fat supplements. The effects of fat supplements on ruminal TVA and CLA concentrations were also reflected in rumen FA-salts, free fatty acids, and neutral lipids. The higher TVA to CLA ratio in the rumen compared with milk indicated that fat supplements increased milk CLA concentration mainly by increasing ruminal production of TVA, which also implied the significant role that mammary delta-9 desaturase plays in milk CLA concentrations.

Composition and Flavor of Milk and Butter from Cows Fed Fish Oil, Extruded Soybeans, or Their Combination

Milk was collected from eight multiparous Holstein and four multiparous Brown Swiss cows that were distributed into four groups and arranged in a randomized complete block design with four 4-wk periods. The four treatments included a control diet of a 50:50 ratio of forage-to-concentrate; a fish oil diet of the control diet with 2% (on dry matter basis) added fat from menhaden fish oil; a fish oil with extruded soybean diet of the control diet with 1% (on dry matter basis) added fat from menhaden fish oil and 1% (on dry matter basis) added fat from extruded soybeans; and an extruded soybean diet of the control diet with 2% (on dry matter basis) added fat from extruded soybeans. Milk from cows fed control, fish oil, fish oil with extruded soybean, and extruded soybean diets contained 3.31, 2.58, 2.94, and 3.47% fat, respectively. Concentrations of conjugated linoleic acid in milk were highest in the fish oil (2.30 g/100g of fatty acids) and fish oil with extruded soybean (2.17 g/100g of fatty acids) diets compared with the control (0.56 g/100g fatty acids) diet. Milk, cream, butter, and buttermilk from the fish oil, fish oil with extruded soybean, and extruded soybean diets had higher concentrations of transvaccenic acid and unsaturated fatty acids compared with the controls. Butter made from the extruded soybean diet was softest compared with all treatments. An experienced sensory panel found no flavor differences in milks or butters.

Composition and Properties of Milk and Butter from Cows Fed Fish Oil

A control diet and a fish oil diet were fed to 12 multiparous Holstein cows to determine how the incorporation of Menhaden fish oil in the diet would influence the fatty acid composition, especially the conjugated linoleic acid and transvaccenic acid, contents of milk and butter. The control diet consisted of a 50:50 ratio of forage to concentrate, and the fish oil diet consisted of the control diet with 2% (on a dry matter basis) added fish oil. Milk from cows fed the control diet contained higher average concentrations of milk fat (3.37%) compared with milk from cows fed the fish oil diet (2.29%). Milk from cows fed fish oil contained higher concentrations of conjugated linoleic acid, transvaccenic acid, and total unsaturated fatty acids (0.68 and 2.51; 1.42 and 6.28; and 30.47 and 41.71 g/100g of fat, respectively). Butter made from the fish oil diet milk also had higher concentrations of conjugated linoleic acid, transvaccenic acid, and unsaturated fatty acids. Penetrometer readings indicated fish oil diet butters were softer at 4 and 20°C than the control diet butters. Acid degree values were similar in the fish oil butters compared with the control butters. No significant difference was found in the flavor characteristics of milk and butter from cows fed the control and fish oil diets. Production of milk and butter with increased amounts of conjugated linoleic acid, transvaccenic acid, and other beneficial fatty acids may have a desirable impact on the health of consumers and lead to increased sales.