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

ABSTRACT

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) of 25 sheep grazed on grass, while the experimental group (EG) of 25 sheep 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 ˂ 0.0368). After one month of supplementation, 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 lower percentages of carboxylic acids associated with the pungent and rancid odour with respect to CG.