Ovine ill-thrift in Nova Scotia:I. The possible regulation of the rumen flora in sheep by the fungal flora of permanent pasture

Abstract

SUMMARY The growth of ewe lambs of the Shropshire breed declined and in some cases ceased at the end of July, when they grazed permanent pastures at the Experimental Farm, Nappan, Nova Scotia. This decline in growth coincided with a decrease of about three orders of magnitude in the numbers of viable rumen bacteria. At the end of July an increase of one to two orders of magnitude was observed in the numbers of viable fungi collected from the pastures. Lambs grazing pastures developed from tidal marsh of the Bay of Fundy had a better growth performance than lambs grazing adjacent pastures developed from mixed conifer-deciduous forest. The forest soils supported a greater fungal population than the marshland soil, and several species were found predominantly on the forest soil.