Effects of different forage combinations in total mixed rations on in vitro gas production kinetics, ruminal and milk fatty acid profiles of lactating cows

Abstract

This study aimed to determine the effects of different forage combinations on in vitro gas production (GP) kinetics, ruminal and milk fatty acid profiles. Forty-five lactating cows were randomly arranged into three groups and fed three total mixed rations (TMRs) with different forage combinations: TMR1, 23% alfalfa hay, 7% Chinese wild ryegrass hay and 15% whole corn silage; TMR2, 30% corn stover plus 15% whole corn silage; TMR3, 30% rice straw plus 15% whole corn silage. In vitro dry matter disappearance ranked: TMR1 > TMR2 > TMR3, and highest cumulative GP and asymptotic GP occurred in TMR1 while no difference occurred between TMR2 and TMR3. The average GP rate ranked: TMR1 > TMR2 > TMR3. TMR1 in comparison with TMR2 and TMR3 presented lower rumen contents of acetate and butyrate and greater rumen contents of propionate, valerate, C13:0, C14:0, C15:0, C18:1cis-9, C18:2n-6, C18:3n-3, C20:0 and C22:0 as well as milk C18:2n-6 and C18:3n-3 proportions. Transfer efficiencies of C18:2n-6 and C18:3n-3 from diet to milk ranked: TMR1 > TMR2 > TMR3. The findings suggest TMRs containing alfalfa hay and Chinese wild ryegrass hay in comparison with corn stover or rice straw improve rumen fermentation and transfer efficiency of C18:2n-6 and C18:3n-3.

In Vitro Fermentation Characteristics for Different Ratios of Soluble to Insoluble Dietary Fiber by Fresh Fecal Microbiota from Growing Pigs

“…Throughout the whole incubation, all the bottles were sealed with Hungate’s stoppers and screw caps and connected to gas channel inlets of an automated trace gas recording system (AGRS-III, China Agricultural University, Beijing, China) through medical transfusion tubes and needles to continuously record cumulative gas production. 39…”

Effects of Different Parts on the Chemical Composition, Silage Fermentation Profile, In Vitro and In Situ Digestibility of Paper Mulberry

“…The leaf, stem, and whole plant PM silage were taken for in vitro digestibility experiment. The in vitro gas production was determined using an Automated Trace Gas Recording System (AGRS) for microbial fermentation, as described by Bai et al [19,20]. Briefly, 500 mg (DM basis) of representative samples (four replicates) of each treatment group were weighed into 120 mL glass bottles, and 50 mL of a freshly prepared buffer solution was added to each bottle [20].…”

A Combination of Lactic Acid Bacteria and Molasses Improves Fermentation Quality, Chemical Composition, Physicochemical Structure, in vitro Degradability and Rumen Microbiota Colonization of Rice Straw

“…The in vitro gas production was determined using an automated trace gas recording system (AGRS) for microbial fermentation, as described previously ( 16 ). Briefly, 500 mg (DM basis) of representative samples (rice straw samples had been fermented for 45 days) (6 replicates) of each treatment group was weighed and placed in 120-ml glass bottles.…”