Utilisation of urea-treated maize stalks by dairy cows in coffee and banana producing regions of Tanzania

Abstract

From 1988 to 1990 the authors tested ammonia treatment via ureolysis of maize stalks from the Masaï Plateau, Tanzania, either in pits (on the farm) or in large stacks (in the cooperative units). During the dry season, this feed is an essential dietary resource for the small farmers settled in the mountains. The procedures for pit and stack treatment are described in details in the paper. Increase in the crude protein content (N x 6.25) range from 37 to 48 and from 44 to 73 g/kg dry matter (DM) for pit and stack treatments, respectively. DM digestibility (expressed as % DM), mesured by the Rexen Cellulase technique, increased by 10.0-14.1 and 11.9-16.1 points, respectively for pit and stack treatments. Substitution of untreated for treated maize stalks in the daily diet of moderately yielding cows (5-6 kg milk milked a day in addition to that suckled by the calf) receiving the same feed supplements led to an average milk yield improvement of 0.8 kg/cow/day in 25 farms. This increase was less marked than that expected from the improvement of the feeding value and in comparison with observations made elsewhere in similar conditions. This improvement was, however, appreciated by most of the 276 farmers participating in a socio-economic inquiry launched in 1990. The advantage of treating maize stalks at the large scale remains to be more thoroughly analysed in keeping with the socio-economic context and the conditions of animal production. It mainly consists in simplifying the collection and transport of maize stalks from the Masaï Plateau to their site of utilisation (montain slopes).