RUMINAL MUCOSA AS INDICATOR OF NUTRITIONAL STATUS IN WILD AND CAPTIVE MOOSE

Abstract

Ruminal mucosa samples were collected at four homologue sites from two subadult and 23 adult wild moose (both sexes) belonging to one Swedish and two Finnish populations, and compared with sampled from 7 moose kept in Zoos or Zoo Parks. Rumen papillary numbers were counted and measured and the absorptive mucosal surface enlargement factors (SEF) calculated. The four standardized sample sites (1-4) are reflective sites of intensive (2,3) and reduced (1,4) VFA concentration. Wild moose were shot between 6 June and 3 March. The overall average SEF was 10.31 (SD 3.44) and the winter average SEF 8.76 (SD 1.38); max. at 21.28, min. at 6.16. Surface reduction from summer to autumn was c. 50%! Average papillary number / 100 mm2 of all animals in all seasons was 40.7 (SD 9.2); summer: 50.4 (SD 7.4), autumn : 44.5 (SD 6.5), winter : 34.7 (SD 6.5); maximal number reduction was 31%. Average overall papillary length was 6.63 mm (SD 1.1); summer 8.01 mm (SD 0.9), autumn 6.19 (SD 0.9), winter 6.51 mm (SD 1.0); length reduction amounted to 25%. All differences were statistically highly significant, reduction / increase were cyclic. Moose have in summer c. 250% absorptive surface (enlarged 17 x) of grazing cattle (7 x).

In captive moose, overall average SEF was only 4.01, i.e. 31% of wild moose (49%) of winter average); average papillary number was 30.5 (regionally destroyed by acidosis), average papillary length was 4.14 mm. captive moose lack selectivity, diversity of forage plants and accordingly balanced VFA stimulation of mucosal blood flow. They usually suffer from acidosis, due to wrong feeding.