Effects of Flaxseed Oil and Vitamin E Supplementation on Digestibility and Milk Fatty Composition and Antioxidant Capacity in Water Buffaloes.

This study aimed to evaluate the effects of the supplementation of flaxseed oil and/or vitamin E on dry matter (DM) and nutrient digestibility, milk composition, fatty acid composition, and antioxidant capacity in buffalo milk. Four crossbred female dairy water buffaloes (97 ± 22 days in milk; 6.57 ± 2.2 kg of milk/day, mean ± SD) were distributed in a 4 × 4 Latin square design, with a 2 × 2 factorial arrangement (with or without flaxseed oil at 25 g/kg dry matter; with or without vitamin E at 375 IU/kg dry matter). The experimental period was divided into four periods of 21 days each (16 days for adaptation; five days for data collection). There were four treatments: control diet (no flaxseed oil and no added vitamin E); flaxseed oil diet (flaxseed oil at 25 g/kg DM); vitamin E diet (vitamin E at 375 IU/kg DM), and a combination of both flaxseed oil and vitamin E. The animals were fed total mixed ratios. For all response variables, there was no interaction between flaxseed oil and vitamin E. Flaxseed oil supplementation reduced neutral detergent fiber (NDF) and acid detergent fiber (ADF) apparent total tract digestibility, increased the n-3 fatty acid concentration in milk approximately three-fold while reducing the n-6/n-3 ratio from 9.3:1 to 2.4:1. Vitamin E supplementation increased NDF apparent total tract digestibility and milk total antioxidant capacity. Although there was no interaction between the treatments; flaxseed oil supplementation in lactating buffaloes increased polyunsaturated fatty acid, while vitamin E supplementation increased antioxidant capacity and decreased oxidation products.

Effect of supplementation with Yerba Mate (Ilex paraguariensis) and vitamin E on milk lipoperoxidation in cows receiving diets containing ground soybean seeds.

This research communication addresses the hypothesis that the association of dietary vitamin E and Yerba Mate could help to prevent or decrease oxidation of milk enriched in unsaturated fatty acids (UFA). Four multiparous lactating Holstein cows were used in a 4 × 4 Latin square. Treatments were: (1) control diet with no Yerba Mate or vitamin E; (2) diet containing 375 IU/kg vitamin E; (3) diet containing 30 g/kg Yerba Mate; and (4) diet containing 375 IU/kg vitamin E and 30 g/kg Yerba Mate. To increase unsaturated fatty acids in milk, cows were fed 172 g/kg soybean seeds (on a dry matter basis). There was no interaction between vitamin E and Yerba Mate supplementation for milk antioxidant-related (polyphenols, reducing power, conjugated dienes, and TBARS) analyses. Milk reducing power was increased when cows were supplemented with Yerba Mate. Our results suggest that the association of dietary vitamin E and Yerba Mate does not help to prevent or decrease oxidation of milk in UFA.

Functionality of cow milk naturally enriched with polyunsaturated fatty acids and polyphenols in diets for diabetic rats.

The increasing incidence of diabetes mellitus is becoming a serious threat to human health in various parts of the world. Studies with dairy products have shown a potential beneficial effect against diabetes. This experiment evaluated the supplementation of milk naturally enriched with polyunsaturated fatty acids (PUFA) and polyphenols in rats with streptozotocin-induced diabetes. Forty male 28-day-old Wistar rats were distributed in four experimental treatments of diabetic animals (streptozotocin induction) and a normal group (non-induced). Experimental treatments were: control (water), whole common milk (COM-M), milk enriched with PUFA (PUFA-M), milk enriched with PUFA and polyphenols (PUFA/P-M) through a special diet offered to dairy cows. Milk supplementation at a dose 5 mL/kg body weight was performed for 77 days, 42 days before and 35 days after diabetes induction. The COM-M supplementation increased brown fat deposits, reduced post-induction glucose levels, reduced blood fructosamine levels, and improved glucose tolerance. Milk enriched with PUFA reduced final fasting glucose, LDL levels, and improved blood antioxidant capacity. Milk enriched with PUFA and polyphenols promoted an increase in gastrocnemius muscle mass, and a reduction in mesenteric fat and LDL levels. Milk intake, with an emphasis on milk enriched with PUFA and polyphenols, attenuated the metabolic disorders of streptozotocin-induced diabetes in rats.

Intake, feeding behaviour, digestibility, performance, carcass characteristics and meat quality of lambs fed different levels of semi-purified glycerine in the diet.

The aim of this study was to evaluate the effect of different inclusion levels of semi-purified glycerine in the diet of feedlot lambs on feeding behaviour, nutrient intake and digestibility, carcass characteristics, meat quality and in vitro degradability. Thirty-two Dorper × (Texel × Suffolk) crossbred intact male lambs (22.2 ± 5.51 kg) were fed glycerine (90% purity) at 0, 120, 240 or 360 g/kg dry matter (DM) in a total mixed ration with a roughage to concentrate ratio of 40:60 for 84 d. In vitro degradability was not affected by glycerine supplementation. Feeding behaviour and digestibility of DM, crude protein and fibre and production performance were similar among treatments. Ether extract digestibility was lower at the highest inclusion level. Glycerine level had no effect on ruminal pH, carcass characteristics and meat quality, except for subcutaneous fat thickness which was lower for lambs fed glycerine at 240 and 360 g/kg DM. Scores for unpleasant taste, unpleasant odour, succulence and softness of meat were not affected by dietary glycerine level. These data suggest that there are no adverse effects on carcass quality and performance when semi-purified glycerine is provided up to 360 g/kg DM in the diet of growing lambs fed a forage to concentrate ratio of 40:60.

Supplementation of cow milk naturally enriched in polyunsaturated fatty acids and polyphenols to growing rats.

This study investigated whether intake of cow milk, naturally enriched with polyunsaturated fatty acids (PUFA, omega-3) and polyphenols (from propolis extract and vitamin E), from manipulation of cow's diet, would result in positive metabolic effects in rats from weaning until adulthood. Male Wistar rats were fed a standard chow diet or a hypercaloric diet (metabolically disturbed rats, obese) which was supplemented with either whole common milk, milk enriched with PUFA (PUFA-M) or milk enriched with PUFA and polyphenols (PUFA/P-M), at 5mL/kg body weight,having water as control. Whole milk supplementation increased initial weight gain and reduced gain in the adulthood of rats. Intake of common milk reduced cholesterol levels in non-obese rats and reduced insulin resistance in obese rats. PUFA-milk showed a decreasing effect on plasma triacylglycerol and VLDL concentrations, increasing plasma HDL concentration and reducing adipocyte size of non-obese rats, but no effect was observed in obese rats. PUFA/P-milk in obese rats resulted in greater deposition of muscle mass and mesenteric fat, with a tendency to lower LDL levels, and resulted a visceral fat accumulation in non-obese rats. Thus, whole common milk and PUFA-rich milk have shown to be beneficial in a normal metabolic condition, whereas common milk and milk enriched with PUFA and polyphenols improve metabolic effects of obesity.

Brazilian propolis extract used as an additive to decrease methane emissions from the rumen microbial population in vitro.

Propolis is a product that is rich in phenolic compounds and can be utilized in animal nutrition as a dietary additive. In this study, the effects of a Brazilian green propolis extract on rumen fermentation and gas production were determined. The fate of propolis phenolic compounds in the rumen medium was also investigated. Fermentation was done in 24-h batches over three periods. Inoculates were obtained from cows fed on grassland hay and concentrate. Propolis extract in a hydroalcoholic solution was applied at increasing doses to the substrate (1 to 56 g/kg). The fermentation substrate consisted on a mixture of alfalfa hay, soybean meal, and wheat grain mixture in dry matter. After 24 h of fermentation, seven new compounds were observed in the medium in amounts that correlated to the propolis dose. The dose of propolis extract linearly decreased the pH of the medium and linearly increased propionate production, which reduced the acetate-to-propionate ratio and influenced the total production of short-chain fatty acids. Propolis also linearly reduced methane production and increased the carbon dioxide-to-methane ratio. Ammonia nitrogen levels and in vitro digestibility of organic matter were similar among the treatments. The combination of increased propionate production and decreased methane production suggests better energy utilization from the feed.

Pelleting in Associated with Sodium Monensin Increases the Conjugated Linoleic Acids Concentration in the Milk of Dairy Cows Fed Canola Seeds.

To evaluate the effects of the pelleting and the addition of sodium monensin on production, the chemical and lipid composition of milk and butter physical characteristics, 4 Holstein dairy cows (135 days of lactation) with an average milk production of 14.7 kg/d, were supplemented with a concentrate containing ground canola seeds. The cows were assigned to a 4×4 Latin square design with a 2×2 factorial arrangement of treatments: i) ground maize, soybean meal, mineral and vitamin supplements, and ground canola seeds (CG); ii) CG concentrate with 31.5 mg of monensin added per kg of dry matter (DM); iii) CG pelleted concentrate; iv) CG concentrate with monensin addition pelleted. There was no difference in milk production and composition. The addition of monensin increased milk concentration of polyunsaturated fatty acids (PUFA), the PUFA/saturated fatty acids (SFA) ratio, and omega 6. The pelleting increased the concentration of monounsaturated fatty acids, the PUFA/SFA ratio, and the omega 6/omega 3 ratio, but decreased the concentration of SFA. The association between pelleting and the addition of monensin increased the concentration of conjugated linoleic acids by 46.9%. The physical characteristics of butter were not affected by the evaluated diets. We concluded that the concentrate with 31.5 mg of monensin added per kg DM basis combined with the pelleting improves the lipid composition of milk from Holstein cows that are on pasture and supplemented with ground canola seeds, without changing the production, milk composition, and spreadability of butter.

Effects of abomasal infusion of flaxseed (Linum usitatissimum) oil on microbial ß-glucuronidase activity and concentration of the mammalian lignan enterolactone in ruminal fluid, plasma, urine and milk of dairy cows.

Ruminal microbiota plays an important role in the conversion of plant lignans into mammalian lignans. The main mammalian lignan present in the milk of dairy cows fed flax products is enterolactone (EL). The objectives of the present study were to investigate the effects of abomasal infusion of flax oil on the metabolism of flax lignans and concentrations of EL in biological fluids of dairy cows. A total of six rumen-cannulated dairy cows were assigned within a 2 × 3 factorial arrangement of six treatments utilising flax hulls (0 and 15·9 % of DM) and abomasal infusion of flax oil (0, 250 and 500 g/d). There were six periods of 21 d each. Samples were collected during the last 7 d of each period and subjected to chemical analysis. Flax hull supplementation increased concentrations of EL in ruminal fluid, plasma, urine and milk, while flax oil infusion had no effect. Post-feeding, ß-glucuronidase activity in the ruminal fluid of cows infused with 250 g flax oil was significantly lower for cows fed hulls than for those fed the control diet. The present study demonstrated that the presence of a rich source of n-3 fatty acids such as flax oil in the small intestine does not interfere with the absorption of the mammalian lignan EL and that lower ruminal ß-glucuronidase activity had no effect on the conversion of flax lignans into EL in the rumen of dairy cows.

Intake and digestibility of fatty acids in late-lactating dairy cows fed flaxseed hulls supplemented with monensin.

Flaxseed hull, a co-product obtained from flax processing, is a rich source of n-3 fatty acids but there is little information on digestibility of its nutrients by dairy cows. Four rumen-cannulated multiparous Holstein cows averaging 665 ± 21 kg of body weight and 190 ± 5 d in milk at the beginning of the experiment were assigned to a 4 × 4 Latin square design with four 28-d experimental periods to determine the effects of feeding monensin and flaxseed hulls on total tract apparent digestibility of nutrients and fatty acids. The four treatments were: (1) diet CO: control with neither flaxseed hulls nor monensin added; (2) diet FH containing 19·8 g flaxseed hulls/100 g dry matter (DM); (3) diet MO with 16 mg monensin/kg DM; (4) diet HM containing 19·8 g flaxseed hulls/100 g DM and 16 mg monensin/kg DM. Diets provided similar amounts of protein and net energy of lactation. Digestibility of crude protein was higher for diets containing flaxseed hulls and for diets supplemented with monensin. Flaxseed hulls supplementation decreased digestibility of acid and neutral detergent fibre. Significantly higher digestibility of ether extract and individual fatty acids was observed for treatments with flaxseed hulls compared with treatments without flaxseed hulls. A combination of flaxseed hulls and monensin did not result in better fatty acid digestibility than when feeding only flaxseed hulls.

Digestion, milk production and milk fatty acid profile of dairy cows fed flax hulls and infused with flax oil in the abomasum.

Flax hull, a co-product obtained from flax processing, is a rich source of n-3 fatty acids (FA) but there is little information on digestion of flax hull based diets and nutritive value of flax hull for dairy production. Flax oil is rich in α-linolenic acid (LNA) and rumen bypass of flax oil contributes to increase n-3 FA proportions in milk. Therefore, the main objective of the experiment was to determine the effects of abomasal infusion of increasing amounts of flax oil on apparent digestibility, dry matter (DM) intake, milk production, milk composition, and milk FA profile with emphasis on the proportion of LNA when cows were supplemented or not with another source of LNA such as flax hull. Six multiparous Holstein cows averaging 650±36 kg body weight and 95±20 d in milk were assigned to a 6×6 Latin square design (21-d experimental periods) with a 2×3 factorial arrangement of treatments. Treatments were: 1) control, neither flax hull nor flax oil (CON), 2) diet containing (DM basis) 15·9% flaxseed hull (FHU); 3) CON with abomasal infusion of 250 g/d flax oil; 4) CON with abomasal infusion of 500 g/d flax oil; 5) FHU with abomasal infusion of 250 g/d flax oil; 6) FHU with abomasal infusion of 500 g/d flax oil. Infusion of flax oil in the abomasum resulted in a more pronounce decrease in DM intake for cows fed the CON diets than for those fed the FHU diets. Abomasal infusion of flax oil had little effect on digestibility and FHU supplementation increased digestibility of DM and crude protein. Milk yield was not changed by abomasal infusion of flax oil where it was decreased with FHU supplementation. Cows fed FHU had higher proportions of 18:0, cis9-18:1, trans dienes, trans monoenes and total trans in milk fat than those fed CON. Proportion of LNA was similar in milk fat of cows infused with 250 and 500 g/d flax oil in the abomasum. Independently of the basal diet, abomasal infusion of flax oil resulted in the lowest n-6:n-3 FA ratio in milk fat, suggesting that the most important factor for modification of milk FA profile was the amount of n-3 FA bypassing the rumen and not the amount of flax hull fed to dairy cows. Moreover, these data suggest that there is no advantage to supply more than 250 g/d of flax oil in the abomasum to increase the proportion of LNA in milk fat.

Ruminal fermentation characteristics and fatty acid profile of ruminal fluid and milk of dairy cows fed flaxseed hulls supplemented with monensin.

Flaxseed hull, a co-product obtained from flax processing, is a rich source of n-3 fatty acids (FA) but there is little information on its value for dairy production. Monensin supplementation is known to modify biohydrogenation of FA by rumen microbes. Therefore, the main objective of the experiment was to determine the effect of feeding a combination of monensin and flaxseed hulls on ruminal fermentation characteristics and FA profile of ruminal fluid and milk. Four ruminally fistulated multiparous Holstein cows averaging 665 ± 21 kg body weight and 190 ± 5 d in milk were assigned to a 4×4 Latin square design (28-d experimental periods) with a 2×2 factorial arrangement of treatments. Treatments were: 1) control, neither flaxseed hulls nor monensin; 2) diet containing (dry matter basis) 19·8% flaxseed hulls; 3) diet with monensin (16 mg/kg dry matter); 4) diet containing 19·8% (dry matter basis) flaxseed hulls and 16 mg monensin/kg. Flaxseed hull supplementation decreased the acetate to propionate ratio in ruminal fluid and monensin had no effect. Concentrations of trans-18:1 isomers (trans9,trans11,trans13/14+6/8) and cis9,12,15-18:3 in ruminal fluid and milk fat were higher and those of cis9,12-18:2 in milk fat tended (P=0·07) to be higher for cows supplemented with flaxseed hulls than for cows fed no flaxseed hulls. Monensin had little effect on milk fatty acid profile. A combination of flaxseed hulls and monensin did not result in better milk fatty acid profile than when feeding only flaxseed hulls.

Ruminal metabolism of flaxseed ( Linum usitatissimum) lignans to the mammalian lignan enterolactone and its concentration in ruminal fluid, plasma, urine and milk of dairy cows.

Secoisolariciresinol diglucoside is the main flax (Linum usitatissimum) lignan that is converted to the mammalian lignans enterodiol (ED) and enterolactone (EL) by gastrointestinal microbiota. The objectives of the present study were to investigate the role of ruminal microbiota and the effects of flax oil on in vivo metabolism of flax lignans and concentration of EL in biological fluids. Four rumen-cannulated dairy cows were used in a 4 x 4 Latin square design. There were four periods of 21 d each and four treatments utilising flax hulls (1800 g/d) and oil (400 g/d) supplements. The treatments were: (1) oil and hulls administered in the rumen and abomasal infusion of water; (2) oil and hulls administered in the abomasum; (3) oil infused in the abomasum and hulls placed in the rumen; (4) oil placed in the rumen and hulls administered in the abomasum. Samples were collected during the last week of each period and subjected to chemical analysis. The site of supplementation of oil and hulls had no effect on ruminal EL concentration. Supplementing flax oil in the rumen and the abomasum led to similar EL concentrations in urine, plasma and milk. Concentrations of EL were higher in the urine, plasma and milk of cows supplemented with hulls in the rumen than in those placed with hulls in the abomasum. The present study demonstrated that ruminal microbiota play an important role in the metabolism of flax lignans.