Abstract :
Lamb survival is affected by maternal temperament and the quality and availability of
colostrum available soon after birth. In this study we tested whether nutritional supplementation
of calm ewes would increase the volume and reduce the viscosity of colostrum
compared to ewes selected for nervous temperament. Twin-bearing Merino ewes of calm
or nervous temperament were either fed at maintenance or supplemented with barley during
the last week of gestation. The weight of colostrum was measured at 1, 3, 6 and 12 h
after birth and analysed for viscosity, fat, lactose, protein and immunoglobulins. During
the first hour after birth, calm ewes produced more colostrum than nervous ewes fed at
maintenance (P < 0.05). Supplementation increased the volume and reduced the viscosity
of colostrum produced by nervous ewes to a level comparable to that produced by calm
ewes (P > 0.1). Supplementation increased the concentration of lactose and decreased the
concentration of protein in all ewes (P < 0.05). Neither nutritional supplementation nor
temperament affected the concentration of fat or total solids in the colostrum (P > 0.1).
In conclusion, nervous temperament predisposes twin-bearing Merino ewes to produce
a lower volume of higher viscosity colostrum than ewes selected for calm temperament.
Nutritional supplementation appears to correct this disparity, potentially by increasing the
biological resources available for colostrum production in nervous ewes.
