Postnatal Stomach Development of White-Tailed Deer

Abstract

Fifteen white-tailed deer (Odocoileus virginianus), newborn, 1/2, 1, 2, 3, and 4 months of age, and adult, were studied. The anatomy of the ruminant stomach is reviewed. Measurements re- corded in this study were selected anatomical indices, stomach tissue weights, analysis of stomach contents, and volume measurements of stomach compartments. At birth, the deer rumen is diminutive and the abomasum large and functional. The rumen and reticulum at 2 months of age have greater volume and weight dimensions than do the omasum and abomasum, and by 4 months of age stomach proportions are similar to those of adult deer. The stomach of deer is relatively smaller than is that of domestic cows or sheep, suggesting differences in food habits and inequalities in the digestion of fibrous vegetation. Differences also exist between deer and sheep in the relative sizes of the four stomach compartments. White-tailed deer are functional ruminants by ? month, essentially depen- dent on ruminant digestive processes by 5 weeks, and nutritionally self-sufficient by 4 months. This paper describes several aspects of the postnatal development of the com- pound stomach of white-tailed deer. Gross changes in the appearance of the deer's stomach were recorded. This study also (1) allowed some insight into questions of the age at weaning and self-sufficiency of fawns and (2) pointed out some anatom- ical relationships which reflect on food habits and metabolism of deer. Since sim- ilar studies have been conducted with do- mestic ruminants, I made limited compari- sons of those animals with deer. This research was done while I was a