Semiextensively reared lactating ewes: Effect of season and space allowance reduction on behavioral, productive, and hematologic parameters

Thirty lactating Comisana breed ewes were used for the trial, and were subdivided in two experimental groups. Both experimental groups were placed on pasture during daylight hours and reared in two equal indoor pens during nighttime. The indoor pen was provided with an outdoor area allowing 2.5 m2/head, and was always available during nighttime housing. During the experiment, the density of indoor pens varied weekly, while the outdoor area did not change. The indoor stocking densities tested were: low stocking density (LD) (1.5 m2/ewe), medium stocking density (MD) (1.0 m2/ewe) and high stocking density (HD) (0.5 m2/ewe). Throughout the trial period, indoor experimental pens were provided with unlimited access to water anda consistent number of feeding places at troughs equal to the number of ewes in the penEach density test was lasted seven days. The first five days were used to allow adaptation to experimental conditions. During the last two nights (sixth and seventh day) we recorded behavioral patterns. Jugular vein blood samples were taken to determine the hematological and biochemical profile. Ewe milk yield was recorded on the seventh day and individual milk samples were analyzed for milk composition, renneting properties and somatic cell count (SCC). All the experimental activities were performed during winter and summer seasons to evaluate the effect of both season and space allowance on all parameters considered. No effect of space allowance and season was observed on hematological and biochemical parameters (P > 0.05). During summer, animals spent more time in external areas, and this time increased with the reduction of space allowance. Ewes spent more time standing (P < 0.001) and less time in lying down (P < 0.001) during the summer. During winter, in contrast, ewes did not use external area, but they spent more time standing and less time lying down in the indoor pens (P < 0.001). Milk production was poorly affected by stocking density. However, these results suggested that behavioral measurements seem to be more sensitive for the detection of stressful conditions as compared to other commonly used measures like endocrine, biochemical or productive indicators of welfare in short term stocking increasing.