Objective: study the effects of different sources of artificial light on the growth of alfalfa plants (Medicago sativa L.).
 Design/Methodology/Approximation: The experiment was established on four shelves with a height of 2.50 m with three divisions each, each division 80 x 60 cm long and wide, respectively. In three of the upper divisions the sun's rays were allowed to penetrate, in the remaining nine divisions three different sources of artificial light (LED, incandescent and fluorescent) were placed, three divisions for each light source, at a density of four lamps per division. The energy expenditure per lamp, the intensity of photons and the production of dry matter were quantified.
 Results: The data indicated that the incandescent lamp had an energy expenditure 8 times higher than the LED lamp and 3.5 times higher than the fluorescent, however, the intensity of light emitted is 3 and 2 times higher in the LED lamp vs. incandescent and fluorescent. respectively, the highest production of dry matter was found with sunlight, obtaining values of 391 g m-2 and the lowest production with the incandescent lamp with 17 g m-2.
 Study limitations/Implications: It is necessary to continue carrying out research work on forage production with artificial light, to increase biomass yields.
 Findings/Conclusions: With the data obtained, it is concluded that LED light can be a viable alternative in the future to produce food for animal consumption.