The objective of the study was to assess the effect of addition of alfalfa extract to the diet of pigs on the colour of loin and its changes during 6 days of storage. The scope of this study comprised the quality assessment of loins in the control group derived from pigs fed traditionally (i.e. without the alfalfa extract added) and in the experimental group of pigs fed a diet enriched by an alfalfa extract. The study comprised 80 hybrid fatteners [(Polish Large White x Polish Landrace) x Duroc] of about 14 kg of initial body weight. Two feedings groups, 20 gilts and 20 boars each, were formed in the experiment. The control group received a feed containing no growth stimulants added whereas the experimental group was fed a diet enriched by the alfalfa extract (2 g per 1 kg diet). Upon the slaughter, meat samples were stored at the refrigerating conditions (4 ^oC) during a period of 6 days. The selected meat quality parameters were determined 2, 4, and 4 days after the slaughter. The scope of determined parameters comprised the acidity and the parameters of colour according to the CIE L*a*b system. The colour parameters were measured using a reflection method with a spherical colorimeter (X-Rite) 8200. The results obtained proved that the application of alfalfa extract to the diet of pigs impacted the values of meat colour parameters. It was found that during the entire storage period, the meat derived from pigs fed the alfalfa-enriched diet was characterized by the higher value of a* parameter, thus, by a higher content rate of red colour.