Relationship between the Methane Production and the CNCPS Carbohydrate Fractions of Rations with Various Concentrate/roughage Ratios Evaluated Using <italic>In vitro</italic> Incubation Technique

Abstract

The objective of the trial was to study the relationship between the methane (CH4) production and the Cornell Net Carbohydrate and Protein System (CNCPS) carbohydrate fractions of feeds for cattle and the suitability of CNCPS carbohydrate fractions as the dietary variables in modeling the CH4 production in rumen fermentation. Forty-five rations for cattle with the concentrate/roughage ratios of 10:90, 20:80, 30:70, 40:60, and 50:50 were formulated as feed samples. The Menke and Steingass’s gas test was used for the measurement of CH4 production. The feed samples were incubated for 48 h and the CH4 production was analyzed using gas chromatography. Statistical analysis indicated that the CH4 production (mL) was closely correlated with the CNCPS carbohydrate fractions (g), i.e. CA (sugars); CB1 (starch and pectin); CB2 (available cell wall) in a multiple linear pattern: CH4 = (89.16±14.93) CA+ (124.10±13.90) CB1+(30.58±11.72) CB2+(3.28±7.19), R2 = 0.81, p<0.0001, n = 45. Validation of the model using 10 rations indicated that the CH4 production of the rations for cattle could accurately be predicted based on the CNCPS carbohydrate fractions. The trial indicated that the CNCPS carbohydrate fractions CA, CB1 and CB2 were suitable dietary variables for predicting the CH4 production in rumen fermentation in vitro.

Effect of different forage-to-concentrate ratios on ruminal bacterial structure and real-time methane production in sheep

“…In the current models established for the same rumen microflora to predict methane production, nutritional indicators had been used as parameters [16–21]. A large number of calibration parameters are required for the models to adapt to plentiful situations, thereby limiting the scope of these models.…”

“…Simple devices for in vitro fermentation have been used to establish the prediction models [21]. However, in such cases, methane production could only be detected either at specific time points or at the final time point, and therefore, did not reveal the overall fermentation status well.…”

Predicting In Vitro Rumen VFA Production Using CNCPS Carbohydrate Fractions with Multiple Linear Models and Artificial Neural Networks

“…Dong and Zhao (2013) reported that the CNCPS carbohydrate fractions CA, CB 1 , and CB 2 were closely correlated to the in vitro rumen total gas and methane production in a multiple linear model and concluded that the CNCPS fractions CA, CB 1 , and CB 2 were suitable input variables for predicting in vitro rumen gas production [14] . Since gas and VFA were produced simultaneously when dietary carbohydrates were fermented in the rumen, it could be presumed that CNCPS CA, CB 1 , and CB 2 could also be suitable variables for predicting VFA production.…”

“…The fractionation of dietary carbohydrates by CNCPS reflected not only the carbohydrate composition but also the fermentative characteristics in the rumen. Dong and Zhao (2013) reported that the CNCPS carbohydrate fractions CA, CB 1 , and CB 2 were closely correlated to the in vitro rumen total gas and methane production in a multiple linear pattern [14] . Since gas and VFA were produced simultaneously when dietary carbohydrates were fermented in the rumen, it could be speculated that CNCPS carbohydrate fractions CA, CB 1 , and CB 2 could be suitable variables for predicting VFA production.…”

Physiological and rumen microbial responses of Angus cattle (Bos taurus) following exposure to heat load

“…Methanogenic archaea can form methane, automatically, from CO2 and H2 derived from the fermentation of carbon sources (Lopez & Newbold 2007). Ruminants contribute about 15% to the total atmospheric methane emissions (McAllister et al 1996), which depend on the amount of carbohydrate apparently digested (Dong & Zhao 2013). The metabolic hydrogen is converted to H2 by hydrogenase-expressing bacterial species, and the H2 converted to CH4 by Archaea in the combined reaction (Kamra et al 2015).…”