Utilization of by-products of the food and pharmaceutical industry in producing supplementary forage concentrate

Probiotics (namely bacterial concentrates of various strains of microorganisms) strengthen the immune system, supress undesirable intestinal microflora and improve the conversion of forages. The objective of the presented work was to develop a supplementary concentrate for polygastric animals utilising by-products of the dairy and pharmaceutical industry - whey and mycelium of industrial fungus. In the first part of the work, appropriate microorganisms and a suitable pharmaceutiacal medium for preparation of bacterial concentrate were selected, focusing on viability after drying of over 10E6 microorganisms. For experiments Lactobacillus lactis and a mixed bifidobacterial culture composed of the four Bifidobacterium strains (B.lipidum, B.longum, B.infantis and Bacterium species) were selected. As a fermentation medium skimed milk and sweet whey were used in three ratios (50:50, 25:75 and 75:25) by inoculating L. Lactis and mixed bifidobacterial culture in ratio 1:1. The process of fermentation (at 37 degree C) was observed at intervals of 2-4-16 hours. pH and SH values were measured as well as the content of microorganisms. At the same time the effect of Corn Steep (5 g in liter of fermented mixture) was observed, acting as the growth stimulator of microorganisms. In the second part of the experiments, microorganism strains and medium combinations suitable for preparation of basic forage concentrate were chosen in terms of acquiring the maximum concentration of nutrients and maximum fermentation of lactose and lactic acid formation. With regard to the stated requirements Streptococcus thermophilus and Lactobacillus casei were found to be suitable. Fermentation medium (the whey and mycelium of industrial fungus) in ratio of 50:50, 60:40 and 40:60 were fermented for 24 hours at 42û45 degree C. Fermentation time, pH-value and microorganism content was the selected criterion for suitable combination. The fermented basis was three times neutralised with ammonia water during fermentation in order to increase the nitrogen content in concentrate). After drying the concentrate was submitted to principal chemical and organic analyses on the basis of which the nutritional value was calculated. The results of the first part of experiments demonstrate that the most suitable combination of skimed milk and whey was shown to be a ratio of 50:50 with addition of maize extract. In the second part of experiments, the combination of mycelium and whey apeared to be the most suitable at a ratio of 60:40. From results of analyses it follows that this concentrate: - contains a lot of N-substances (421.16 g/kg of original matter) with high digestibility in vitro, - involves a high ration of soluble nitrogen (90.1% of total nitrogen), - the ratio of protein nitrogen is rather low (only 29.1% of total nitrogen), - shows high content of total sugar (120.13 g/kg of the original matter), - the ash content (60.21 g/kg of original matter) is comparable with prevailing forages and feed mixtures. The selected concentrate represents a balanced source of energy and nitrogen and so is suitable as supplement of forage mixtures for polygastric animals (at amounts of 5% of the weight).