Nutritional Value of Biofuel Residues from Beet
DENMARK - Scientists from the Department of Animal Health and Bioscience at Aarhus University and the Risoe National Laboratory for Sustainable Energy in Denmark found that the root pulp of beet, a by-product of biofuel production, could be a good source of energy for both sows and ruminants.The scientists, J.V. Nørgaarda, T. Hvelplunda, J.A. Fernándeza, M.H. Thomsenb, H.D. Poulsena, set out to evaluate the fresh pulp of top and root from sugar (Angus) and fodder (Colosse) beets as feed for pigs and ruminants.
Their hypothesis was that an alternative substrate in the biogas or bioethanol production may be the sugar containing juice obtained after fractionation of beets into a juice used for fermentation and into a pulp used for feeding.
The pulp was prepared by a cold mechanical pressing.
Two digestibility experiments were carried out according to the difference method.
In the first experiment, 30 sows were housed individually in metabolic cages for 12 days and urine and faeces were collected during the last 7 days. The daily ration consisted of either root or top pulp combined with a basal diet.
In a second experiment, 25 wethers were housed individually, and faeces were collected during the last 7 days of the experiment. The daily ration was either root or top pulp combined with hay.
The chemical composition of the pulp of the two beet varieties varied only little.
However, the top fraction contained more ash (150 vs. 34g/kg DM), crude protein (175 vs. 53g/kg DM) and total dietary fibre (460 vs. 206g/kg DM) compared to the root fractions.
The in vitro and the apparent digestibility of sows and wethers were higher for root pulp than for top pulp, whereas there were no differences between the two beet varieties.
The scientists found that the fresh root pulp may be considered a good energy source for both sows and ruminants, whereas the fresh top pulp may serve as a satiety-enhancing feedstuff for sows. The protein value of both root and top pulp is considered to be low.
The report is to be published in Animal Feed Science and Technology apprearing next month.