This study evaluated the effect of supplemental vitamin E to ewes in late pregnancy on the
rate of stillborn lambs. Ewes in 19 flocks in 5 regions of Norway were daily supplemented
the 6–7 weeks before average expected lambing date with either (1) 360 IU of vitamin E
(supplemented), or (2) placebo (control). The daily supplement was given in addition to the
daily basal diet of forage, concentrate and mixture of minerals and vitamins in each flock,
assuming that forage contained on average 40 mg -tocopherol/kg DM. Information about
the basal diets was collected via analyses of forage samples and questionnaires. Blood was
collected from a sample of ewes in each flock 1 week pre-treatment (7–8 weeks before
lambing), and from some flocks 1–2 weeks after initiation of supplementation (5–6 weeks
before lambing) and 1–2 weeks after lambing. The body condition score (BCS) of the ewes
was assessed 4–6 weeks before lambing. Mean content (±SD) of -tocopherol in the forage
of the 19 flocks was 25 ± 17 mg/kg DM. Mean daily intake of vitamin E of the ewes from
the basal diet was 153 ± 44 IU. Vitamin E supplementation increased serum concentration
of -tocopherol (P = 0.0002) 5–6 weeks before lambing. After lambing there was a higher
ratio of -tocopherol to cholesterol in serum of supplemented ewes compared with control
ewes (P = 0.02). Ewes with one or more stillborn lambs had lower serum -tocopherol
concentrations than ewes without stillborn lambs in litters with ≥3 lambs (P = 0.01). For
ewes with ≥3 lambs there was a significantlower stillbirth rate for vitamin E supplemented
than for control ewes (P = 0.0004), while there was no effect on the stillbirth rate for ewes
having ≤2 lambs. Ewes with low BCS had a higher stillbirth rate than ewes with medium or
high BCS (P = 0.001). The results ofthis study indicate that daily supplementation of vitamin
E during the last 6–7 weeks before lambing decreases the stillbirth rate of ewes having ≥3
lambs.
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