Milk characteristics of grazing sheep fed with different hay/concentrate ratio

Seasonal production of pasture forces in the period of grass shortage to supply the animal feeding with hay and concentrates. The supplies satisfy the animal nutritive needs, but reduce the advantages coming from the grazing on milk quality. The present trial was carried out on Massese breed on a low productive pasture, testing four kinds of feeding supplies with different hay/concentrate ratio. The individual milk productions, the chemical composition so as the acidic milk composition have been controlled for six weeks. Although the four feeding supplies given to the animals had different chemical-nutritional values (diet A 0.84 MFU/kgDM with forage/concentrate ratio 1:1.7; B 0.78 with 1:1; C 0.72 with 1: 0.7; D 0.68 with 2:1), they did not influence the milk production which resulted quite low and without significant differences. Results did not show differences in relation to the nutritional characteristics and the acidic milk composition. In the four groups Vaccenic acid and Conjugated linoleic acid (CLA) of milk showed similar and decreasing trends during the trial. These trends were probably due to the progressive grass reduction on the grazing: the effects on the dietetic characteristics of the milk did not depend on the supply but on the quantity of grass intaken during the grazing.