In vitro, in situ, and in vivo evaluation of a sesame paste supplement for grazing calves

Abstract

Objective: To carry out an in vitro, in situ, and in vivo evaluation of soybean paste (T1) and sesame paste (T2) supplements for calves under grazing conditions. Methodology: Partial (24, 48, and 72 h) and accumulated biogas and methane production, as well as dry matter degradation (DMD), were measured in the in vitro analysis. The digestibility kinetics parameters (a, b, a+b, c, k, ED) were estimated in the in situ test. Feed supplement consumption (SC), daily weight gain (DWG), bacterial and protozoan populations, acetate, propionate, and butyrate were evaluated in the in vivo test. A completely randomized experimental design was used. Results: T1 produced a higher amount of partial and accumulated biogas and methane at 24 h, as well as the highest values in the b, a+b, k, and ED (p ≤ 0.05) parameters. Meanwhile the rest of the in vitro, in situ, and in vivo variables did not record any differences between treatments (p > 0.05). Study Limitations/Implications: The production of sesame paste is seasonal; consequently, its harvest limits its year-round availability. Conclusions: Based on the in vitro, in situ, and in vivo evaluations, sesame paste is a feasible option to replace soybean paste as a source of protein, in the supplementation of calves in the tropics.