Analysis of the relationship between milk production, milk composition and morphological udder measurements in Wallachian sheep

Abstract

The aim of this study was to evaluate the potential of udder measurements for prediction of milk yield, milk components and somatic cell count in non-dairy Wallachian sheep. The study was performed on 38 ewes in the Beskids Mountains kept under extensive management on pasture. Milk production (MILK) as well as samples for milk component and somatic cell count determination were collected during two separate control days (42^nd day and 100^th day of lactation on average). Rear udder depth (RUD, cm), udder width (UW, cm), and teat length (TL, mm) were measured at each control day as well. Linear regressions of udder measurement characteristics showed a predictive character ability for MILK only. An increasing of 70 g MILK corresponded with a 1 cm increase of RUD (P < 0.01) or 1 cm increase of UW (P < 0.001). These positive linear relationships were supported by the positive partial correlation analysis between MILK and RUD (r = 0.503; P < 0.001) or MILK and UW (r = 0.627; P < 0.001). An increase of 1 mm TL was associated with a 10 g (P < 0.01) increase of MILK; however, correlations between these traits were not significant. Results of this study demonstrate an alternative way of MILK ability in non-dairy Wallachian sheep population in general. Correlation and regression analysis further estimated this expected potential in detail using udder measurement characteristics. Measurement of RUD and UW could serve as a tool for breeding and flock management in order to maintain and improve milk production; however, there was no obvious evidence for the prediction of milk composition characteristics and somatic cell count.