Dairy Sheep Symposium - the Department of Animal Sciences ...

Teat size is determined by length. Extreme sizes impede adaptation to standard teat cups,
manual milking and suckling. In the Churra breed, the average teat length is 3.83 cm (Fernández
et al., 1995), corresponding to 5 points on the scale.
Udder shape (US) measures the morphology of the udder relative to the optimum for machine
milking (9 points) and corresponds to the “udder machine” described by Mikus (1978).
Udder shape is scored by its symmetry, depth, attachment, teat position and size. Although udder
shape includes several udder traits, it is also considered in the method in order to have a general
parameter of the udder, similar to the “dairy form” in cattle.
Figure 2. Punctuation scale for the udder traits
Evaluation
Variable 1 point 5 points 9 points
Udder depth
Udder
attachment
Udder shape
Teat placement
Teat size
The method was developed on the selection nucleus of the Spanish Churra sheep and experimental
procedures carried out in order to evaluate the method were as follows. Udder morphology
was determined on 113 Churra breed ewes from three different flocks using the methodology
of Labussière et al. (1981) modified according to Mavrogenis et al. (1988) by replacing the
measurements of mammary volume and rear surface by those of width and mammary circumference
because the latter are easier to measure and define the udder volume. From these data,
environmental factors significantly affecting udder traits appeared to be: lactation month, flock,
parity and milk yield (Fernández et al., 1995). Phenotypic correlations between traits were
estimated as well as the optimum time to perform udder evaluation (between the 30 th and 120 th
day of lactation) all these results allowing for a design of a linear evaluation system orientated
towards sheep mechanical milking (de la Fuente et al., 1996). In a second trial 2015 Churra ewes
from seven flocks were scored using the proposed method in order to evaluate its objectivity,
obtaining a total of 5265 scores. Phenotypic correlations among scores from three different
qualifiers are shown in Table 5.