Influence of maternal undernutrition on the behaviour of juvenile lambs

The objective of the present experiment was to determine the implications of prenatal undernutrition on the behaviour of juvenile lambs. Dams of one group (C) were fed 100% of the recommended requirements throughout pregnancy, while those of two other groups were fed 50% of the control nutrient allowance during the first 30 days of pregnancy (R1) or 50% of the control nutrient allowance from days 31–100 of pregnancy (R2). Between 2 and 5 months old, behaviour of lambs was tested by the implementation of 2 types of test: isolation and novelty. There were no statistical differences between lamb treatments in escape behaviour and heart rates during isolation test, or the latency to approach a novel or a familiar object in the novelty test in tests conducted at 2, 3, 4 and 5 months of age. Male lambs showed a tendency of turning to the right-hand side of the test pen, irrespective of treatment group, between the age of 2 and 5 months old. A greater proportion of C compared to R1 males turned right at the age of 2 and 5 months old ( P < 0.05). Significant differences concerning laterality were found also between C and R1 female lambs at the age of 2 and 4 months old ( P < 0.001), between C and R2 male lambs at the age of 2 months old ( P < 0.05), between C and R2 female lambs at the age of 4 and 5 months old ( P < 0.01), between R1 and R2 male lambs at the age of 2 and 5 months old ( P < 0.05) and between R1 and R2 female lambs at the age of 2 months old ( P < 0.001). It is concluded that prenatal undernutrition during different periods of pregnancy had no effect on fear-related behaviour, but effect on laterality at the early stages of lamb age between 2 and 5 months old.