Effects of lignocellulolytic enzymes on the fermentation profile, chemical composition, and in situ ruminal disappearance of whole-plant corn silage.

The objective of this study was to examine the enzyme activities of an enzymatic complex produced by Pleurotus ostreatus in different pH and the effects of adding increased application rates of this enzymatic complex on the fermentation profile, chemical composition, and in situ ruminal disappearance of whole-plant corn silage (WPCS) at the onset of fermentation and 30 d after ensiling. The lignocellulolytic enzymatic complex was obtained through in vitro cultivation of P. ostreatus. In the first experiment, the activities of laccase, lignin peroxidase (LiP), manganese peroxidase, endo- and exo-glucanase, xylanase, and mannanase were determined at pH 3, 4, 5, and 6. In the second experiment, five application rates of enzymatic complex were tested in a randomized complete block design (0, 9, 18, 27, and 36 mg of lignocellulosic enzymes/kg of fresh whole-plant corn [WPC], corresponding to 0, 0.587, 1.156, 1.734, and 2.312 g of enzymatic complex/kg of fresh WPC, respectively). There were four replicates per treatment (vacuum-sealed bags) per opening time. Bags were opened 1, 2, 3, and 7 d after ensiling (onset of fermentation period) and 30 d after ensiling to evaluate the fermentation profile, chemical composition, and in situ dry matter and neutral fiber detergent disappearance of WPCS. Laccase had the greatest activity at pH 5 (P < 0.01), whereas manganese peroxidase and LiP had the greatest activity at pH 4 (P < 0.01; P < 0.01). There was no effect of the rate of application of enzymatic complex, at the onset of fermentation, on the fermentation profile (P > 0.21), and chemical composition (P > 0.36). The concentration of water-soluble carbohydrate quadratically decreased (P < 0.01) over the ensiling time at the onset of fermentation, leading to a quadratic increase of lactic acid (P = 0.02) and a linear increase of acetic acid (P = 0.02) throughout fermentation. Consequently, pH quadratically decreased (P < 0.01). Lignin concentration linearly decreased (P = 0.04) with the enzymatic complex application rates at 30 d of storage; however, other nutrients and fermentation profiles did not change (P > 0.11) with the enzymatic complex application rates. Addition of lignocellulolytic enzymatic complex from P. ostreatus cultivation to WPC at ensiling decreased WPCS lignin concentration 30 d after ensiling; however, it was not sufficient to improve in situ disappearance of fiber and dry matter.

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.

Influence of basil (Ocimum basilicum Lamiaceae) addition on functional, technological and sensorial characteristics of fresh cheeses made with organic buffalo milk.

The inclusion of basil in the development of fresh cheeses made with organic buffalo milk was studied. The treatments were: 0 (without basil), 2.5, 5.0 and 7.5 g dried basil/kg of cheese. The cheeses were stored under refrigeration at 4 ± 1 °C during 21 days. The addition of basil did not modify fat, protein, moisture and mineral content of cheeses. The total polyphenol content and antioxidant activity of cheeses increased with basil addition at day one, with a significant reduction in cheeses with 21 days of storage. Cheeses with basil presented higher antioxidant activity and lower pH. The inclusion of basil changed hardness and chewiness, but not influenced springiness and cohesiveness. The microstructure was less homogeneous in cheeses with basil. Cheese with 2.5 and 5.0 g dried basil/kg cheese were preferred by consumers. Thus, the basil improves functional and modify technological characteristics of fresh cheeses and presented good acceptability.

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.

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.

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.

The interaction of monensin and flaxseed hulls on ruminal and milk concentration of the mammalian lignan enterolactone in late-lactating dairy cows.

Four ruminally fistulated multiparous Holstein cows were assigned to a 4x4 Latin square design with a 2x2 factorial arrangement of treatments to study the effects of dietary supplementation of monensin and flaxseed hulls on ruminal and milk concentration of the mammalian lignan enterolactone (EL) and ruminal and faecal activity of beta-glucuronidase. The hypothesis was that monensin supplementation has no effect on the incorporation of EL into milk when cows are fed flaxseed hulls. Treatments were: 1) control, neither flaxseed hulls nor monensin (CO); 2) diet containing (dry matter basis) 20% flaxseed hulls (FH); 3) diet with monensin (16 mg/kg of dry matter; MO); 4) diet containing 20% (dry matter basis) flaxseed hulls and 16 mg/kg monensin (HM). Intake of dry matter was higher for CO and MO than for FH and HM and monensin had no effect. Milk production decreased in cows fed flaxseed hulls while monensin had no effect. Production of 4% fat-corrected milk and concentrations of milk fat, lactose, urea N, and total solids were similar among treatments. Although there was a decrease in ruminal activity of beta-glucuronidase when feeding flaxseed hulls, the metabolism of plant into mammalian lignans may be increased as shown by enhanced concentration of EL in the rumen and milk. Supplementation with flaxseed hulls then may contribute to favourably change milk composition for better human health by enhancing mammalian lignan EL concentration.