Development of the Neonatal Lamb and Piglet

In some ways, the neonatal period may be regarded as an extension of the intrauterine period. As then, the young are nutritionally dependent on what the mother may provide in that growth rate may be still limited by maternal nutrition. It is true that there is an additional constraint, the capacity of the neonate to take what is offered. Nevertheless, growth may be very similar in late pregnancy and in the early post-natal period. This may be seen if we compare typical growth in the piglet and the lamb, from about 50 d of pregnancy over the next 100 or 80 days (Fig. I). The two rates are quite similar if we ignore the fact that term for the pig is about I 15 d and for the sheep 147 d. The comparison may be extended from the findings of Hodge (1974). He compared piglets and lambs given milk artificially, from 5-50 d after birth. The most striking difference was that the voluntary feed intake (per unit metabolic