Faecal output and N balance in pigs fed with diets of sugar cane molasses based on soybean meal or proteic-molasses as protein sources

In order to study faecal output and N balance a design of sequence of treatments with double change in blocks and three treatments was carried out in six pigs of 35 kg live weight. The diets of the experimental treatments were: I, sugar cane molasses type B (MB) and soybean meal in proportion 60.9:35.3 dry basis (BS), II and III, MB (44.0 in BS) or MB plus Cuban Zeolite (40.0:4.0 BS), respectively, and proteic-molasses (molasses plus Saccharomyces spp yeast) plus soybean meal (33.6:18.6 in BS). The diets were isonitrogenous (2.99 ± 0.06% in dry basis) and daily feed intake was 0.08 kg DM/kg^0.75. There was no treatment effect on rectal digestibility of organic matter, but zeolite decreased (P<0.01) rectal digestibility of DM. The diets containing proteic-molasses signifi cantly (P<0.01) increased faecal output of fresh material and water. The digested N was high and greater (P<0.05) in the control diet (I, 88.3%) than in that of proteic-molasses (II, 83.5%), but both did not differ from that formulated with zeolite (III, 85.1%). There was not effect of treatment on retained N, neither related to that consumed (average, 52.5%) nor to that digested (average, 61.5%) although the diet containing zeolite tended (P<0.10) to be better than the other two. The present study suggests there will be no signifi cant changes in the N balance if the dietary soybean meal is partially substituted by proteic-molasses in diets for growing pigs, but zeolite might contribute to a greater N retention.