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Table 2: Average test day milk production and milk composition of stage of lactation and
supplementation treatments.
Stage of lactation a Supplement level b
Late Early No supplement Supplement
n mean ± se n mean ± se P < n mean ± se n mean ± se P <
Milk, kg 130 1.21 ± 0.05 598 1.74 ± 0.02 0.0001 364 1.36 ± 0.04 364 1.59 ± 0.04 0.0001
Fat, % 60 5.80 ± 0.11 276 5.95 ± 0.05 0.2526 168 6.00 ± 0.09 168 5.75 ± 0.09 0.0539
Protein, % 60 5.02 ± 0.05 276 4.86 ± 0.02 0.0057 168 5.04 ± 0.04 168 4.84 ± 0.04 0.0007
FCM, kg 60 0.86 ± 0.05 276 1.22 ± 0.02 0.0001 168 0.96 ± 0.04 168 1.12 ± 0.04 0.0071
FPCM, kg 60 0.85 ± 0.05 276 1.19 ± 0.02 0.0001 168 0.95 ± 0.04 168 1.09 ± 0.04 0.0073
a Late lactation ewes are 136 ± 9 DIM, early lactation ewes 21 ± 10 DIM.
b Supplement received 0.80 kg DM/d.
Figure 2: Average test day milk production for stage of lactation and supplementation
treatments.
Milk (kg/d)
Milk (kg/d)
3
2.5
2
1.5
1
0.5
0
3
2.5
2
1.5
1
0.5
0
-2 5 12 19 26 33 40 47 54 61 68 75 82
61
Early lactation
Late lactation
-2 5 12 19 26 33 40 47 54 61 68 75 82
Day of trial
Supplemented
Unsupplemented
Late lactation ewes had a significantly higher milk fat percentage than early lactation ewes
before the start of the trial, but the differences between stage of lactation treatments were not
significant for any of the test days during the trial (Figure 3) or averaged over all test days (Table
2). This contradicts previous work, in which milk fat percentage tends to increase throughout
lactation as milk production decreases (Pulina, 2002).