Abstract
To investigate the evolution of Bergamasca sheep breed in the last two decades body measurements recently taken were compared with the breed standard (BMST) and with those from a previous study conducted in 1984 (BM84). Height at withers (HW), height at rump (HR), depth of body (DB), width at shoulders (WS), hearth girth (HG), anterior pelvic width (APW), middle pelvic width (MPW), body length (BL), distance from the front to the back margin (HOCK1) and from the lateral to the medial margin (HOCK2) of hock were measured on 495 Bergamasca sheep (466 ewes and 29 rams) from 14 flocks (seven sedentary and seven transhumance systems). Animals were grouped into 12–24 months and >24 months of age for the study. In general, a reduction of all body dimensions was observed compared to BMST and the largest decreases were for BL, APW and MPW. Compared to BM84, sheep older than 24 months were wider, with a slight increase in DB, HG and WS. Variations among these body measurements suggest that the breed standard need to be updated. Husbandry system (sedentary and transhumance) and age divided into 10 age classes of 6 months were also investigated as possible sources of variation for body measurements in females. Ewes raised in a transhumance system were taller, longer and showed a wider hock. On the contrary, ewes raised in a sedentary system were wider at chest and rump. Body measurements varied with increasing age: the smallest were for 12–18 months old ewes, whereas little variation was observed after 18 months of age. A factor analysis was used to study the interdependence among body measurements of young and adult sheep in each husbandry system. Two and four factors were retained in young and adult sheep in a sedentary system, whereas for both age groups of sheep in a transhumance system three factors were retained. In general, with the exception of young sheep in a sedentary system, the first and second factor showed largest positive association between variables and factors for measures concerning the width and height and the third was associated with body development. Since variation in body width was not associated with body height, body shape could possibly be improved to establish a tall animal with characteristic meat animal traits.
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