Comparison of In Vivo and In Vitro Digestibility in Rabbits

Abstract

The apparent dry matter digestibility of diets for rabbits was measured in vivo (ADMDvv) and in vitro with the Ankom DaisyII Incubator. Four diets were tested: low fiber (LF), LF + 5% of pregerminated fenugreek seeds (PGFS) (LF5), LF + 10% PGFS (LF10), and high fiber (HF). For the ADMDvv, feces samples were collected from 56 White New-Zealand × Californian rabbits fed the 4 diets; animals were randomly allocated into 4 groups and housed in individual cages. For the in vitro trial, 3 methods were tested: fecal inoculum (FA) with Kansans State buffer; fecal inoculum with artificial saliva (FB); and multienzyme (ENZ). Fecal inocula were collected at slaughtering from the distal colon of rabbits fed ad libitum the LF diet. For FA and FB methods, the digestibility was measured at 36 and 48 h. The in vitro methods ranked the apparent dry matter digestibility of diets in the same order as in vivo, but ENZ values were always higher than FA and FB at 36 and 48 h. The prediction equations of in vivo digestibility with the ENZ method showed higher coefficient of determination (R2 = 0.69) and lower SE (0.190) than FA and FB; also, reproducibility was higher with ENZ (CV = 3.1%). In conclusion, different methods can be applied to the Ankom DaisyII Incubator to study the digestibility in rabbits. In our trial, the better reproducibility was observed with the multienzyme method than FA and FB were probably related to the variability of inocula.

Estimation of In Vitro True Digestibility and Fiber Degradation from Feedstuff Fiber Composition When Incubated in Equine Fecal Inoculum

“…Because of the fiber-dense diet consumed by the horses in this study, the variations observed in the fiber degradation models may be attributed to the microbial population of the inoculum, thus donor diets containing higher soluble carbohydrates or lower NDF and ADF may produce different statistical models. Furthermore, in vivo and in vitro digestibility trials do not produce identical results [3,6,8]; thus, caution is warranted when translating the present in vitro models to an in vivo setting. Future investigation is warranted to determine if the models produced in this study are applicable using microbial inoculum from horses consuming diets of differing nutrient composition while also determining their relevance in vivo.…”

“…Previous research has established estimates of in vivo true digestibility for various nutrients (i.e., non-structural carbohydrates, crude protein, and neutral detergent fiber) within equine feedstuffs [2]. The application of in vitro methods within the Daisy II incubator (ANKOM Technology Corporation, Fairport, NY, USA) has been validated to estimate feedstuff digestibility in hindgut fermenters such as horses [3,4], donkeys [5], and rabbits [6] with a variety of applications for digestibility research [7]. Previous studies support using fresh feces as a microbial inoculum source to simulate hindgut digestion in the horse compared to in vivo trials [3,4,8].…”

Prediction of apparent total tract digestion of crude protein in adult dogs

“…For reasons related to their advantageous speed and cost, prediction models for in vivo digestibility using regression analysis are being widely investigated for economically important animals (cattle, poultry, pigs, and rabbits), companion animals, and humans [6,[40][41][42]. Prediction models for in vivo digestibility using regression analysis have not only identified nutrients in foods, including carbohydrates [24], CP [43], and phosphorus [44], but have also verified the potential feasibility of prediction models using regression analysis for energy [23] and the postprandial glycemic index [45].…”

Fortalecimiento de las capacidades productivas de la cunicultura en zonas rurales vulnerables en el oriente de Cuba

“…La digestibilidad in vitro y la estimación del valor nutritivo de las materias primas utilizadas en este proyecto se muestran en la Tabla 7, y los resultados son comparables a los obtenidos in vivo (Tassone et al, 2021) Estimaciones realizadas a partir de ecuaciones de predicción (Villamide et al, 2009) para estimar el valor nutritivo de piensos compuestos de conejos.…”