Effect of crude glycerine in supplement on the intake, rumen fermentation, and microbial profile of Nellore steers grazing tropical grass

Abstract

a b s t r a c tThe objective of this study was to evaluate the effect of crude glycerine (CG) inclusion in feed supplement (0, 70, 140, 210 and 280 g/kg DM basis of supplement) on the forage intake and digestibility, ruminal fermentation parameters, kinetics of fibre degradation, and rumen microbial profile of Nellore steers grazing on tropical grass. Ten ruminally cannulated Nellore steers [490 kg 7 47 body weight (BW)] were used in a replicated 5 Â 5 Latin square design with 14-d periods. Steers were individually supplemented at the rate of 300 g/100 kg of BW. Inclusion of CG in the supplement did not affect (P40.05) dry matter intake, apparent total tract digestibility, ruminal pH (P ¼0.784) or total ruminal VFA (P ¼0.291), but linearly decreased the NH 3 -N concentration (P ¼0.021). The inclusion of CG in the supplement linearly increased (P o 0.001) the molar proportions of butyrate and valerate; linearly decreased the acetate (P ¼0.007) concentration, thus reducing the acetate to propionate ratio (Po 0.001); and did not affect the molar proportions of propionate and isobutyrate. Inclusion of GC had a quadratic effect (P ¼0.010) on the in situ potential degradable fraction of NDF and rate of fibre degradation (P¼ 0.006). Addition of CG linearly decreased the number of protozoa of the genera Entodinium (P ¼ 0.015) and Isotricha (P ¼0.058) and the relative proportions of Ruminococcus albus (P ¼0.047) and Ruminococcus flavefaciens in the rumen (P ¼0.036), but did not affect Fibrobacter succinogenes (P¼ 0.420) or the methanogens (P ¼0.150). The inclusion of CG in the supplement up to 280 g/kg DM altered ruminal fermentation and negatively affected in situ fibre degradation and the gram-positive cellulolytic bacterial population, but did not affect intake and apparent total tract digestibility for Nellore steers grazing tropical grass.

Combining Crude Glycerin with Chitosan Can Manipulate In Vitro Ruminal Efficiency and Inhibit Methane Synthesis

“…Methane concentration was inhibited by 39.65% when 21% crude glycerin was included in TMR, compared to the TMR group with 0% crude glycerin. Regarding the influence of crude glycerin on in vitro CH 4 synthesis, Vito et al [21] indicated that concentration of CH 4 could be reduced with glycerin addition because of the adverse influence of glycerin on methanogen populatios. Vito et al [21] also suggested that supplementation of 28% of crude glycerin in Nellore steers grazing on tropical grass reduced methanogen population by 55.93% compared to the control group.…”

“…Regarding the influence of crude glycerin on in vitro CH 4 synthesis, Vito et al [21] indicated that concentration of CH 4 could be reduced with glycerin addition because of the adverse influence of glycerin on methanogen populatios. Vito et al [21] also suggested that supplementation of 28% of crude glycerin in Nellore steers grazing on tropical grass reduced methanogen population by 55.93% compared to the control group. This might occur because the crude glycerin can modify the cell membrane permeability of methanogens, thus inhibiting the CH 4 production.…”

“…This might occur because the crude glycerin can modify the cell membrane permeability of methanogens, thus inhibiting the CH 4 production. Furthermore, Vito et al [21] found that the linear reduction in the number of protozoa of the genera Entodinium and Isotricha when the increasing level of crude glycerin could affect CH 4 reduction. In addition, Lee et al [5] demonstrated that glycerin has the potential to inhibit in vitro CH 4 synthesis in the rumen, suggesting an advantageous impact of glycerin on enhancing energy utilization.…”

Characterization of ruminal bacteria in grazing Nellore steers

“…Several experimental studies under similar conditions in Nellore cattle grazing quantified F . succinogenes by real time PCR showed that, even with low abundance in the rumen microbiota (<5%), these bacteria are important for forage degradation (San Vito et al ., 2016;Carvalho et al ., 2017;Neto et al ., 2017).…”

Does partial replacement of corn with glycerin in beef cattle diets affect in vitro ruminal fermentation, gas production kinetic, and enteric greenhouse gas emissions?

“…Therefore, glycerin has the potential to be used as a sustainable alternative to replace corn as energy source in beef cattle finishing diets. Previous in vitro [ 3 , 8 ] and in vivo [ 9 , 10 ] studies have reported positive effects on ruminal fermentation when glycerin was included in beef cattle finishing diets. However, there is still controversy regarding the effects of glycerin on total gas production (GP) and enteric CH 4 production [ 11 ], NDF digestibility [ 2 ], the recommended levels of glycerin inclusion in beef cattle finishing diets [ 9 , 10 ], and its impact on ruminal fermentation of high fiber feeds [ 12 , 13 ].…”