The volatile compounds in lamb fat are affected by the time of grazing

This study was designed to assess whether different grazing managements affect the appearance of organic volatile compounds (VOC) in lamb fat. Forty-two lambs were divided into four groups: 9 lambs were restricted in stall and fed concentrate (S group); 12 lambs grazed from 9 am to 5 pm (8 h group); 10 lambs grazed from 9 am to 1 pm (4hAM group) and 11 lambs grazed from 1 pm to 5 pm (4hPM group). After 72 days on feed the animals were slaughtered and the perirenal fat subjected to SPME-GC/MS analysis of VOC; the data were analyzed by stepwise discriminant analysis. The 6-methyl-2-heptanone and furanone, 2,5-dimethyl, 4-hydroxy-3(2H) allowed discrimination between the 4hAM and the 4hPM animals. These are the first results indicating that the time of the day in which the animals are allowed to graze affects the appearance of VOC in lamb fat.

► 3 groups of lambs grazed 8 h, 4 h in the morning (4hAM) or 4h in the afternoon (4hPM).
► The fat volatile organic compounds (VOC) profile was determined.
► Two VOCs discriminated between the 4hAM and 4hPM lambs.
► Fat VOCs differ in lambs grazing for 8h, or 4h in the morning or in the afternoon.