Ruminal fermentation kinetics of by-products using the semi-automatic technique of in-vitro gas production

Abstract

The objective of this study was to develop a specific equation for the conversion of pressure values (psi) to volume (ml) for the Laboratory of Bromatology of the Federal University of Western Pará. To this end, the ruminal fermentation kinetics of regional feedstuffs were evaluated using the semi-automatic technique of in-vitro gas production. To set up the targeted equation, samples of ground corn, soybean meal, rice bran, Mombasa grass, cupuassu pie, cassava residues, and banana leaves were incubated and the pressure and volumes of the gases produced during the fermentation process were measured at predetermined times and related. These data on the volume of produced gases were used to determine, by applying the bi-compartmental logistic model, the ruminal fermentation kinetics parameters. The equation found for the laboratory was V = 0.3757P2 + 1.5972P + 0.2189. Ground corn and cassava residue showed a higher degradation rate of non-fibrous carbohydrates (0.120 and 0.163 %/h respectively) and higher final gas volume (228.91 and 273.17 ml/g of DM, respectively). As for the degradation rate of fibrous carbohydrates, ground corn (0.023 %/h), rice bran (0.023 %/h), and cassava residue (0.021 %/h) presented the highest degradation rate. Thus, a specific equation to be used at the Laboratory of Bromatology of the Federal University of Western Pará was identified, according to the method applied and the altitude of the premises. Ruminal fermentation kinetics of cassava residue and rice bran showed the same parameters as corn, which may suggest the possibility of replacing corn in the diet of ruminant animals.

In vitro Inoculation of Fresh or Frozen Rumen Fluid Distinguishes Contrasting Microbial Communities and Fermentation Induced by Increasing Forage to Concentrate Ratio

“…Furthermore, it avoids the effect of host interference factors, such as rumen passage rate and absorption, on the fermentation process (2). Based on the aforementioned advantages, in vitro rumen batch culture has been widely employed in ruminant nutrition research to evaluate rumen degradation of feedstuffs (3), the efficiency of rumenprotect protocols (i.e., amino acids and unsaturated fatty acids), and fast screening of methane inhibitors (4)(5)(6)(7).…”