Abstract

GONZALEZ-PECH, P.  and  AGREIL, C.. Characterization of intake by direct observation in ewes flocks of southeastern France. Arch. zootec. [online]. 2012, vol.61, n.235, pp.343-354. ISSN 1885-4494.  https://dx.doi.org/10.4321/S0004-05922012000300003.

When ruminants graze on heterogeneous vegetation, direct observation of bites is one of the most fitted method to estimate intake. Nevertheless its implementation in herds of more than 500 individuals has been scarce. In our study, this method was implemented to characterize the intake and know the feeding value offered by steppe vegetation. We observed two ovine flocks of 1100 and 1200 animals guided by shepherds in farm conditions. The animals used were Merinos d'Arles a breed with marked gregariousness. They constitute transhumant flocks that every spring graze the steppe vegetation of the Nature Reserve Coussouls de Crau located in Southeast France. The period of adaptation was brief lasting from 7 to 22 days. In this environment composed of a unique herbaceous layer, the intake rate was 5.9 ± 2.4 g DM/min, which is similar to levels reported in woody or shrubby rangelands. We found that in this steppe vegetation sheep are capable of flows up to 13 g DM/min. In previous studies the Brachypodium retusum has been considered of low nutritional value and little appreciated by the sheep. In our case it was found that the sheep eat a wide variety of plants. But when Brachypodium retusum contributes to the majority of dry matter intake, intake rate is significantly greater (6.8 g DM/ min) than when this is contributed by forbs (4.4 g DM/min) or by the other grasses (5.8 g DM/min). This plant is revalued, our results showed that it allows sheep to make bites of mass higher than forbs and other grasses which explains its improved efficiency of collection. Direct observation allowed us to characterize the intake of sheep in Crau steppe and we consider this type of vegetation as a food source similar to woody or shrubby rangelands.

Keywords : Biodiversity; Bite mass; Intake rate; Range.

        · abstract in Spanish     · text in Spanish     · Spanish ( pdf )