Yeast products as feed additives in weaning piglets

In a five week long trial with a total of 128 Large White piglets weighing 10 to 30 kg, the effect of the feed additive Diamond V XP Yeast Culture, a yeast-fermented cereal mixture, on growth rate, feed intake, feed conversion and medical treatment was examined. The 2-factorial design comprised two control treatments, a negative control without additives (CON) and a positive control with 50 mg of Carbadox (CARB), which were compared to two yeast containing diets, 1 % of yeast alone (YEA) and combined with Carbadox (CARB+YEA).<br>No animal losses and moderate medical treatment for diarrhoea went along with high daily gains: 521 g CON, 587 g CARB, 553 g CAR+YEA, 519 g YEA. Diamond V XP Yeast Culture did not improve growth. In the combined treatment CARB+YEA, growth rates were increasingly depressed in a time dependent manner with a concomitant inhibited feed intake for both yeast treatments from the 3rd to 5th week on trial. This intake reduction has a probability of error of p = 0.099. Taken the 5 weeks on trial together, the following daily feed intakes were measured: 831 g CON, 922 g CARB, 858 g CARB+YEA, 821 g YEA. The treatment CARB and CARB+YEA required the least feed per kg of weight gain during the two first weeks. On the other hand, piglets fed yeast alone converted the feed the least efficient. Differences in feed conversion ratio from week 3 to 5 were not significant but a changed ranking order was observed. Considering the whole experimental period, feed conversion ratio manifested no significant diet effect.<br>Based on the fact that several yeast products tended to decrease voluntary feed intake, one may draw the conclusion of a reduced feed palatability or gastrointestinal effects underlining the need for further investigations.