Mathematical models describing disappearance of Lucerne hay in the rumen using the nylon bag technique

Abstract

It is essential to study the dynamics of rumen degradation of feeds before their potential use in formulating diets for ruminants. Various mathematical models have been developed to describe this degradation. The non-lagged exponential model (Model I), the lagged exponential model (Model II), the Gompertz model (Model III), and the generalized Mitscherlich model (Model IV) were examined using two alternative software (SAS and MATLAB) to determine their efficacy in accounting for variation in ruminal disappearance of dry matter (DM) and crude protein (CP) of lucerne hay from three cuttings. All models described DM degradability well (R2 >0.98). Only Models I and II converged when fitted to CP degradability data (R2 >0.98). It was concluded that any of these models could be used to describe the degradation of DM, whereas only Models I and II could be used to describe the degradation of CP from three cuttings of Lucerne hay. All the models that were fitted to the DM degradation data performed reasonably well, with only minor differences in goodness of fit. However, these models differed in values of the parameter estimates. Additionally, SAS failed to converge in the analyses of CP with Models III and IV, and MATLAB converged to nonsensical values with Model III. Model I might be recommended because it fitted the data well and required estimates of the fewest parameters
 Keywords: alfalfa hay, in situ digestion, model selection, nonlinear regression

Identification of Ruminal Fermentation Curves of Some Legume Forages Using Particle Swarm Optimization

“…Another study [ 34 ] showed that alfalfa hay had 56.1% of the slowly fermentable fraction, which is consistent with our findings. These achievements are in agreement with the reports of Palangi et al [ 23 ], who noted that the fermentation curves for legume forages vary according to their maturity and chemical composition. As previously discussed by Bayatkouhsar et al [ 35 ], cutting alfalfa in the afternoon as opposed to in the morning may result in higher concentrations of soluble carbohydrates, leaf content, and true protein, which may impact the fermentation pattern using the gas production method.…”

“…From the collected data using the in vitro approach, various mathematical models were created as prospective candidates to characterize the kinetics of feed fermentation. The behavior of the model was examined using the first-order kinetics model (without and with a lag phase) [ 23 ]. The mathematical definition is as follows:…”

Essential oil and apple pomace affect fermentation and aerobic stability of alfalfa silage

“…In vitro DM degradation of treatments was measured in three replicate bottles. The percentage of degradability (Y) of DM over time (t) was described by the exponential equation: fitted to the data by iterative regression analysis (Palangi & Macit, 2019;Palangi et al, 2020). The effective degradability (ED) of DM and CP for feedstuffs was estimated as:…”

Comparative effects of extracted polyphenols from black and green tea wastes on in-vitro fermentability of feed ingredients

“…In this study, four different digestion models which has already been described by Palangi, Macit and Bayat. (2020) and were compared to investigate the digestion process.…”