NATURAL BIOACTIVE PRODUCTS AS RUMEN FERMENTATION MODIFIERS
Open Access
- Author:
- Tekippe, Jessica
- Graduate Program:
- Animal Science
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- None
- Committee Members:
- Dr Garbiella Varga, Thesis Advisor/Co-Advisor
Gabriella Anne Varga, Thesis Advisor/Co-Advisor - Keywords:
- methane
dairy cows
rumen - Abstract:
- In experiment 1 medicinal herbs and essential oils were evaluated in a batch culture in vitro screening experiment as potential anti-methanogenic additives for ruminant diets. A total of 88 essential oils and 14 herbs were tested. Rumen inoculum enriched with particle-associated microorganisms was collected from a lactating dairy cow, 2 h before feeding. Incubation was conducted in serum bottles containing 1 g of a feed mixture (0.7 g alfalfa hay, 0.2 g corn starch, and 0.1 g solvent-extracted soybean meal), 1 ml of essential oils (10, 50, and 100 mg/L, final media concentration), 19 ml of McDougall¡¦s buffer with 5 g/L glucose and 2.5 g/L acid-hydrolyzed casein, and 20 ml of ruminal inoculum. Bottles were then flushed with CO2 and incubated at 39„aC for 6 h. Corresponding 50 ml tubes were incubated for 24 h for NDF degradability analysis. Herbs were tested using the same procedure except a portion of the alfalfa hay was replaced with 12.5, 50, 100, and 200 mg of herbs (air-dry basis), and NDF was tested using the DAISY apparatus. Blanks and monensin (5 mg/L, final media concentration) were also incubated. At the end of the incubations, total gas and methane production, VFA and ammonia concentration, and NDF degradability were measured. Treatment by application level interactions were not significant for any of the essential oil treatments. Two of the essential oils increased acetate production, 12 increased propionate production, 10 increased butyrate production, 3 reduced methane production (by 20 to 30%), and 2 decreased ammonia production. With the herbs, 1 increased acetate production, 2 increased propionate production, 1 decreased methane production (by 30%), and 1 decreased ammonia production. Eight of the herbs increased NDF degradability at various inclusion levels. Overall, these results indicated that some essential oils and medicinal herbs may have potential to impact ruminal fermentation in vivo. In experiment 2 there were two cow trials conducted to study the effects of dietary addition of an essential oil product, Xtract 6965 (0 vs. 525 mg/d; EO Pancosama) on ruminal fermentation, total tract digestibility, methane production, manure gas emissions, N losses, and dairy cow performance. In both experiments the EO product was added in the vitamin mineral premix. In trial 1, 20 multiparious Holstein cows (4 of which were ruminally cannulated) were used in a switch over design with 2, 28-d periods. Cows averaged 47 kg/day milk yield (¡Ó7.1 SD), 63 DIM (¡Ó21.4 SD), and 656 kg BW (¡Ó75 SD). Average DMI was 27 kg/d (¡Ó 0.59 SD) and did not differ between treatments (P=0.31). Apparent total tract digestibly of DM, OM, NDF, ADF, crude protein, and total nonstructural carbohydrates were similar between treatments (P = 0.16 to 0.90). Rumen pH and concentration of total VFA, acetate, propionate, butyrate, and valerate, A:P ratio, polysaccharide-degrading activities, and total free amino acid concentration were not affected by treatment (P= 0.15 to 0.97). Isobutyrate (1.12 vs. 0.94 mmol/L; P < 0.0001), isovalerate (1.76 vs. 1.51 mmol/L; P = 0.002), and ammonia concentration (5.4 vs. 3.3 mmol/L; P = 0.0003) were increased by EO compared with the control. Methane concentration was decreased in cows fed the EO diet (38,542 versus 27,975 mg/m3; P = 0.03). Methane production per hour and day and manure emissions of ammonia, methane, and carbon dioxide were not affected by treatment (P= 0.21 to 0.81). Blood glucose concentration was not affected by treatment, while blood urea nitrogen was increased by EO compared with the control (13.37 vs. 11.00 mg/dl; P <0.0001). Average milk yield, fat corrected milk yield, and milk fat, protein, and lactose concentrations were unaffected by diet (P= 0.17 to 0.73). Milk urea nitrogen concentration was greater for EO cows compared with the control (9.55 vs. 8.31 mg/dl; P <0.001). Microbial N flow, urine N%, and urea N were all increased in cows receiving the EO diet (P= to 0.02 to 0.0001). Trial two used 120 primiparious and multiparious Holstein cows grouped in pens of 20 cows/pen (n=3) in a 10 week experiment to study production effects of EO. Cows were blocked by DIM at the beginning of the trial. Dry matter intake (28.5 kg ¡Ó 0.55), milk yield (35.6 kg ¡Ó1.00), components (2.56 kg¡Ó0.02), MUN (11.31 mg/dl¡Ó0.02), feed efficiency (1.26 ¡Ó0.04), and fat corrected milk (34.59 kg¡Ó1.02) were similar among diets (P= 0.13 to 0.97). Results from these studies indicate that supplementing dairy cows with 525 mg/d of Xtract did not improve digestibility of nutrients or milk production and composition under the current experimental conditions. In experiment 3 a lactating cow trial was conducted to study the effects of dietary addition of oregano (Origanum vulgare L.; 0, control vs. 500 g/d, OV) on ruminal fermentation, total tract digestibility, manure emissions, N metabolism, milk taste, and dairy cow performance. Eight primiparious and multiparious Holstein cows (6 of which were ruminally cannulated) were used in a switch over design with 2, 21-d periods. Cows were fed once daily. The OV material was top-dressed on to the TMR. Cows averaged 41 ¡Ó 3.3 SEM kg/d milk yield and 80 ¡Ó 12.5 DIM. Intake of DM averaged 26 ¡Ó 0.83 SEM kg/d and did not differ between treatments. Apparent total tract digestibly of DM, OM, NDF, ADF, CP, and TNC did not differ between treatments. Rumen pH and concentration of total and individual VFA, acetate:propionate ratio, and total free amino acid concentration were also not affected by treatment. Ruminal ammonia concentration was increased by OV compared with the control (5.3 vs. 4.3 mmol/L; P < 0.001). Blood urea N and glucose concentrations were not affected by treatment. Average milk yield, milk fat, protein, and lactose concentrations, MUN, and SCC were unaffected by diet. Milk sensory parameters were also not affected by treatment. Fat-corrected (3.5%) milk yield and 3.5% FCM feed efficiency were increased (P = 0.03 and < 0.001) for OV compared with the control (42.2 vs. 40.7 kg/d and 1.63 vs. 1.53 kg/kg, respectively). Rumen methane production was reduced 40% in the OV treatment (P = 0.004). Ruminal microbial N flow, urinary and fecal N losses, and manure ammonia, methane, and carbon dioxide emissions were unaffected by treatment. Under the current experimental conditions, supplementation of dairy cow diets with 500 g/d of Origanum vulgare did not affect ruminal fermentation, nutrient digestibility, or manure gas emissions. Cow fed OV produced more FCM and had increased feed efficiency that may partially be explained by the decreased ruminal methane production.