Study of potentials for utilization of waste biomass of Aspergillus niger in chicken fattening

This paper investigates the possibility of using the dry biomass of the Aspergillus niger mildew from the process of gluco-amylase production as a substitute for part of dried soybean oil meal and corn in the mixtures for fattening of chickens. Three experiments were performed upon the total of 980 day-old chickens of Hybro breed, originating from the Agricultural and food processing combine "Koka" in Varazdin. The chickens were kept in wire batteries. Each experiment lasted 50 days and was divided into the period of feeding with starter, up to 30 days and the period of feeding with finisher from 30 to 50 days. Two control starter and finisher mixtures were used in the experiment. The mixtures, although of varied composition, were made so as to meet the needs of fattening chickens in all basic nutritive matters. In the 1st experiment, incorporation of A, niger biomass as a substitute for equal parts of soybean oil meal and corn chop of 1,3 and 5% did not change notably the average weight gain of chickens fattened 50 days. According to the statistical processing of the data about feed conversion, the improvement of conversion on the level of 4.87%, obtained by incorporation of the sample A of A. niger biomass on the level of 1% was significant. Incorporation of this sample of A. niger biomass on the level of 1-5% did not have unfavourable effects on the health of the animals. Incorporation of sample B on the level of 1-3% did not change significantly the production results, while the level of 5% had an unfavourable effect. According to the statistical processing, differences in weight gain and conversion were not significant. With incorporation of biomass samples B and C on the level of 5%, the insignificant decrease in weight gain was followed by significantly higher feed consumption per unit of gain (6.76%).