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New method of preparation of bovine colostral immunoglobulins for parenteral application in calves

SEMOTAN K, KALAB D
Veterinarni Medicina 42, 1997, 249-252

A new simple method of preparation of bovine colostral immunoglobulins was described using a single step precipitation of skimmed bovine colostrum with dimethyllaurylbenzylammonium bromide (DMLBAB). This quaternary ammonium compound precipitated simultaneously nearly all colostral proteins lacking antibody activity. Bovine colostrum was collected mostly during of the first 24 hours after calving, at the latest however until 48 hours. isolation of bovine colostral immunoglobulins proceeded as follows: one volume of skimmed colostrum containing 3-6% of immunoglobulins was slowly precipitated with the same volume of 2% water solution of DMLBAB at pH 7.9-8.1 along with continuous stirring. Turbid mixture was then heated to 43-45 degrees C and subsequently cooled to a room temperature standing overnight. Heavy precipitate sedimented down and supernatant fluid containing purified immunoglobulins was decanted and clarified by filtration. Residual DMLBAB occurring in the filtrate was removed by passage through a column of strongly acid cater, prepared in Na+ form. Purified colostral immunoglobulins were thickened to the required protein concentration by ultrafiltration. Dense retentate was clear and became an amber colour. Average yield of purified colostral immunoglobulins reached 18.8 g/litre of skimmed bovine colostrum (Tab. I). Electrophoretic purity of immunoglobulins fraction amounted to 90-95% (Fig. 1). For parenteral application in calves the above solution of immunoglobulins was subsequently adjusted to 9-11% content of protein, 0.9% of sodium chloride, pH 7.2, stabilized with 2% of aminoacetic acid and conserved with 0.015% of thiomersal. Finally, the preparation was sterilized by filtration, kept its content of immunoglobulins minimally 2 years at the temperature of storage between 2-8 degrees C and remained biologically harmless. Using the method described it was not necessary to remove casein from skimmed bovine colostrum prior to the purification of immunoglobulins. Hence the method provided a significant short cut especially in laboratory as well as pilot scale production of bovine colostral immunoglobulins bringing about a marked economic benefit


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