Abstract :
Objective of the study was to assess udder morphology and milking characteristics of Chiosbreed
dairy ewes. Moreover, by using Principal Component Analysis, the probability of any
correlations between various udder traits was studied. Thirty pure-bred Chios-breed dairy
ewes in a commercial flock were assessed for 10 udder traits (6 direct and 4 indirect measurements)
during three consecutive lactations. Milk yield (MY) and milking time (MT) were
electronically recorded for each ewe on a daily basis. Direct measurements included udder
length (UL), udder width (UW), udder height (UH), gland cistern height (CH), teat length
(TL) and teat diameter (TD). Indirect measurements included teat placement (TP), udder
depth (UD), udder cleft (UC) and degree of suspension of the udder (SU). Data analysis was
performed using SPSS 16©. The results showed that mean values for UL, UH and TP increased
from first to third lactation; TL and TD did not change, whilst UD and UC decreased. The UH
and CH were all negatively correlated with UD and SU (P < 0.01) and positively correlated
with TP (P < 0.01). UW had a significantly negative and positive relationship with UD and
UC (P < 0.01), respectively. Significant negative correlations were also revealed between TL
and TP (P < 0.01). Four PCs (‘udder dimensions’, ‘teat’, ‘udder morphology’ and ‘teat and
suspension’) were recognized explaining about 76% of the total variance. Effect of lactation
number was significant for UL, UH, CH, TP, UD, UC, ‘udder dimensions’ and ‘udder morphology’
variables (P < 0.05 to P < 0.001). ‘Udder dimension’, ‘teat’ and ‘udder morphology’
were significantly related to MY (P < 0.05 to P < 0.001). In conclusion, the results provide
significant information for udder characteristics of the Chios breed, which is the most popular
indigenous Greek breed of sheep. Such information could be used as a basis for genetic
improvement of the breed.
