| Sumario: | Diet is an important factor to contribute the final quality of dairy products in ruminants, in which the supplementation with concentrate is used to increase and to equilibrate the intake of nutrients, expecting to produce a higher milk yield or to modify its composition. Nevertheless, the effects of forage:concentrate ratio on milk composition and cheese-yielding performances are scarcely known in the case of dairy sheep. With this aim, an experiment was conducted using a total of 72 dairy ewes at early lactation and lasting 3 mo. Ewes of 2 breeds (Manchega, n = 36; Lacaune, n = 36) at d 60 of lactation were allocated in balanced groups of 6 ewes by breed. Experimental treatments consisted of different levels of concentrate (%, dry matter basis) added to a total mixed ration made of a similar forage and fed ad libitum; they were: Control (C, 30%), Medium (T1, 45%) and High (T2, 60%). Ewes were machine milked twice daily and milk yield automatically collected at each milking by using electronic identification and direct flow milk meters. Individual milk samples were collected on d 90 and 120 of lactation for composition and to evaluate the coagulation and cheese-yielding features of the milk according to treatments. Despite clear differences observed by ewe breed and stage of lactation, no differences were detected by the forage:concentrate ratio for all the milk yield and composition traits studied as well as on the cheese-yielding performances. In conclusion, under the feeding and management conditions used, the high- (Lacaune) and medium-yielding (Manchega) dairy ewes used may be fed with a wide range of concentrate (30 to 60%, on dry matter basis) without deleterious effects on milk and cheese-yielding traits. The optimal diet to be used in dairy ewes should depend on the forages and concentrate market prices and not on dairy performances.
|
|---|
