Nutritional Quality and In Vitro Rumen Fermentation Characteristics of Silage Prepared with Lucerne, Sweet Maize Stalk, and Their Mixtures

The objective of this work was to evaluate the pH, chemical composition, minerals, vitamins, and in vitro rumen fermentation characteristics of silage prepared with lucerne, sweet maize stalk (MS), and their mixtures. Freshly chopped lucerne and MS were combined in ratios of 100:0 (M0, control), 80:20 (M20), 60:40 (M40), 40:60 (M60), 20:80 (M80), and 0:100 (M100) on a fresh matter basis. Each treatment was prepared in triplicate, and a total of eighteen silos were fermented for 65 days. After 65 days of fermentation, the pH values in M0, M20, M40, M60, M80, and M100 silages were 5.47, 4.84, 4.23, 4.13, 3.79, and 3.61, respectively. As the MS proportion in the mixtures increased, silage K, Ca, P, Na, Fe, and Cu concentrations linearly decreased (p < 0.001) and so did vitamins B5 and K1 and α-tocopherol. In vitro rumen dry matter and organic matter degradability, pH, ammonia, total volatile fatty acid, and gas production linearly decreased (p < 0.01), while neutral detergent fiber concentration linearly increased (p < 0.001), with increasing proportion of MS. The in vitro dry matter and organic matter degradability rapidly decreased when the MS percentage was ≥60%. In conclusion, the M40 silage is the most suitable for livestock utilization in local forage production considering the balance of silage pH, nutritional quality, and in vitro ruminal fermentation characteristics.

Dietary treatment with omega fatty acids mediates in vitro rumen fermentation kinetics and reduce methane emission in water buffalo

Purpose: To investigate the effect of dietary supplementation of two omega fatty acids on in vitro rumen fermentation, microbial populations, total gas and methane (CH4) production．Methods: Both linoleic and linolenic acids were supplemented at 0 (control), 1, 3, 5 and 7 % of dry matter (DM) in a ration with a high roughage to concentrate ratio (70: 30). Total gas and CH4 were measured at 3, 6, 9, 12 and 24 h of fermentation while pH, volatile fatty acids (VFA), and ammonia nitrogen (NH3-N) concentrations were measured at 24 h using buffalo rumen fluid in an in vitro batch culture system. Microbial populations were determined using 16S-rDNA gene primers by RT-PCR.Results: The results revealed that linoleic acid at 3, 5 and 7 % decreased the concentration of NH3-N (p< 0.05) but linolenic acid at 5 and 7 % increased NH3-N (p < 0.05). A linear decrease (p <0.001) in acetate and butyrate, coupled with linear increase (p <0.001) in propionate was observed in response to treatment. Furthermore, supplementation of 3, 5 and 7 % of both fatty acids linearly (p < 0.001) decreased total gas and CH4 production when compared to the control. The addition of linoleic acid linearly (p < 0.001) decreased the number of protozoa without affecting methanogens, while linolenic acid linearly and quadratically (p < 0.001) reduced the population of both protozoa and methanogens (p < 0.05).Conclusion: Linolenic acid is more effective at a 3 % level in reducing methane production (up to 63 %) in high roughage diets.

Effect of Alfalfa Hay Substitution by Raw Garlic Leaves on In vitro Gas Methane Production and Ruminal Fermentation

Background: The aim of present research was to evaluate under in vitro conditions, the effect of alfalfa hay substitution by raw garlic leaves on ruminal fermentation patterns and methane production in diets ruminants. Methods: Four treatments were evaluated: (T1) alfalfa hay (50%); (T2) alfalfa hay (33%) + raw garlic leaves (17%); (T3) alfalfa hay (17%) + raw garlic leaves (33%) and (T4) raw garlic leaves (50%). Result: The highest values of fractional rate of gas production (kd), ammonia-nitrogen (NH3-N), propionate and microbial biomass synthesis (MBS) was recorded in T4 and the lowest in T1 (P less than 0.05). In contrast, the highest methane production was recorded in T1 and the lowest in T4 (P less than 0.05). It was concluded that the substitution of alfalfa hay by raw garlic leaves in diet with 50% roughages and 50% concentrate result in an improvement in vitro rumen fermentation pattern and decreases the methane production.

Effects of elevated CO₂ and extreme climatic events on forage quality and in vitro rumen fermentation in permanent grassland

The aim of this study was to analyze changes in botanical and chemical composition, as well as in vitro rumen fermentation characteristics of an upland grassland exposed to climate changes in controlled CO2 concentration, air temperature and precipitation conditions. Grassland was exposed to a future climate scenario coupled with CO2 treatments (390 and 520 ppm) from the beginning of spring. During summer, an extreme climatic event (ECE; 2 weeks of a +6 ∘C increase in temperature, together with severe drought) was applied and then followed by a recovery period. Three cutting dates were considered, i.e. in April, June and November. The results indicate that increases in greenness, nitrogen (N) content and changes in water-soluble carbohydrate profile in association with botanical composition changes for the November cut lead to higher in vitro dry matter degradability (IVDMD) in the rumen. The neutral detergent fiber : nitrogen (NDF:N) ratio appeared to be a key driver of forage quality, which was affected in opposite ways by elevated CO2 and ECE, with a strong impact on rumen fermentation. Atmospheric CO2 concentration in interaction with ECE tended to affect IVDMD, indicating that the effects of elevated CO2 and ECE may partly offset each other. Our findings indicate that the various factors of climate change need to be considered together in order to properly characterize their effects on forage quality and use by ruminants.