Great Lakes Dairy Sheep Symposium - the Department of Animal ...

significantly increase milk production when compared to grazing alone, but it does increase the
variability of the means (a sort of standard error). Indeed, the upper 2.5% of means of grazing
groups falls over 1,263 g/d, whereas the same datum is 1,473 g/d for supplemented groups.
Higher milk yield generally leads to significantly lower fat and protein concentrations in dairy
sheep (Pulina et al., 2005), so that the differences in daily yield of Total Utilisable Substances
(TUS = the quantity of fat + protein daily produced by a single animal) are lower. However, C
groups maintain their advantage over grazing ones: 4.52 vs. 3.30 and 2.91 g TUS/kg BW,
respectively for C, P+C and P groups (P< 0.001).
0 500 1000 1500 2000 2500 3000
Milk (g/d)
Figure 1 – Distribution of means in daily milk yield of 43 experimental Sarda dairy sheep groups
under three different feeding conditions (C = complete pelleted diet; P = pasture; P+C = pasture
+0.47 kg DM head -1 of concentrates).
Table 3 – Productive performances of Sarda dairy ewes under three different feeding regimes.
Trials-
Feeding
animals (n.) Milk yield (g/d) Milk fat (%) Milk protein (%)
Complete pelleted diet 12-86 1791 a 5.57 b
5.38 b
Pasture + concentrates 12-744 1251 b 6.48 a
5.84 b
Pasture 19-1078 1087 b 6.56 a
5.88 a
P-value