The effects of feeding supplementation on the nutritional quality of milk and cheese from sheep grazing on dry pasture

The effect of feeding supplementation on the nutritional characteristics of milk and cheese was studied in dairy sheep grazing on low mountain dry-grasslands during summer in typical sub-Mediterranean conditions of aridity. The control group (CG) sheep grazed on grass in these pastures, while the experimental group (EG) grazed on grass and received 600 g a day of a barley and corn mixture. Daily milk production showed a less pronounced decrease in EG than in CG (p two-tail test 0.0368). At the end of the study, the concentrations of retinol and α-tocopherol in milk and cheese from EG were higher than CG (p<0.05). Supplementary feeding had a positive effect on the fatty acid composition of the sheep milk. For the first time, positive effects on the volatile composition were found in EG cheese, displaying a lower percentages of carboxylic acids associated with the pungent and rancid odor with respect to CG.