Undernutrition of the Merino sheep and its sequelae. I. The growth and development of lambs following prolonged periods of nutritional stress

Abstract

The growth of Merino lambs was arrested for periods of up to 400 days at different stages of early post-natal life, and long after the restoration of a normal diet the sequelae to these treatments were measured in terms of growth, form, feed intake, feed utilization for weight gain, and the eruption of the permanent incisors. None of the restrictions impaired the capacity of the sheep to resume normal growth, and although the most severe handicap (growth arrested at 15 kg weight for 400 days) had as its sequel a smaller sheep at 3 years of age this effect was not statistically significant. The impetus to grow was more closely related to somatic development than to chronological age. However, the eruption of the permanent incisors was associated more with age than with size, although the relationship was not a close one. In other respects the normal pattern of allometric growth was undisturbed. Feed consumption and feed utilization for weight gain were in the long term unaffected by the treatments imposed, although minor deviations from the general pattern were observed during the early part of the recovery period.