Effects of dietary inclusion of sunflower soap stocks on colour, oxidation and microbiological growth of meat from light fattening lambs

Summary Thirty‐two lambs were finished on a total mixed ration ( TMR ) pelleted alone (00 SS ) or including sunflower soap stock ( SS ): 15 SS (15 g SS per kg TMR ), 30 SS (30 g SS per kg TMR ) and 60 SS (60 g SS per kg TMR ). Lambs (8 per group) were slaughtered at 27 kg live weight. Colour evolution, lipid oxidation, microbial growth and detection of diarrhoeagenic Escherichia coli were studied in meat samples. SS in the diet reduced meat lipid oxidation ( P < 0.05), but had no significant effect (P > 0.05) on the cholesterol oxidation products. Meat from 60 SS and control animals (00 SS ) revealed greater discoloration ( P < 0.05) than 15 SS . SS supplementation did not affect the microbiological populations, whereas high doses of SS seemed to increase the proliferation of diarrhoeagenic E. coli on day 14 ( P < 0.10). These results suggest that the rate of SS inclusion in the diet of fattening lambs should not be above 15 g SS per kg TMR .