Study of Some Factors of Variation of intake on Course by Dairy Ewes

The quantity of herbage intake by sicilo-sarde dairy ewes, under a rotational grazing system, was determined by the method of count bite. Measurements were taken on a mountainous area of Beja (northern west of Tunisia) being the pasture mainly constituted by herbaceous species, especially of the graminaceous ones, its composition as well as bite weight and rate were estimated. Grazing time was around 7 h per day. Average ewes dairy production was around 0.8 kg per day (0.4–1.3 kg). All ewes were supplemented by avena hay ad labitum, and 0.35–0.70 kg of concentrate. Concentrate feed consisted of a mixture of barley, wheat bran, and soybean meal. The results obtained show that biting rate varies between dairy ewes according to their milk production, and pasture availability. The average pasture consumption varied between 420 and 640 g/day. Pasture consumption increases with the level of production and concentrate in the diet. Individual intake variability was also observed, and can be related to other zootechnical factors such as age and weight of the animals.