Feed supplement for animals and production thereof

An animal feed supplement is prepared by cultivating a micro-organism of the species Bacillus subtilis or Bacillus natto, stopping the cultivation between the beginning and middle of the logarithmic growth phase of the micro-organism, and heating the resulting culture at a pH of 4.0 to 8.0 and at a temperature of 50 DEG to 80 DEG C. for 1 to 3 hours. The cultivation may be conducted as a solid culture process or as a submerged cultivation under agitation and aeration with a starting pH of 6.0 to 8.0 and at a temperature of 30 DEG to 40 DEG C. Constituents for the culture medium are mentioned. The growth promoting factor is found in both the liquid and solid portions of the broth. The heat-treated culture, as such or after concentration, may be absorbed in an animal feed such as bran. Alternatively, the heat treated culture may be roller dried or spray dried to a powder. Examples directed to the feeding of poultry, rats, pigs and cows with specified feed ingredients including furazolidone, rice grass and McCollam's salt mixture (specified), demonstrate that (i) the growth promoting factor is produced in the early stages of the logarithmic growth phase whereas a growth inhibiting factor appears in the latter stages and (ii) the effectiveness of the growth promoting factor is increased by the heating under the specified conditions. The heat treated culture can be used in proportions generally in the range 0.02-1% solids by weight of the basal feed to produce an increase in the percentages of weight gain, feed conversion and egg production of poultry, to produce an increase in the percentages of weight gain of cows and pigs and in milk production, and for ta. &c.ALSO:An animal feed supplement is prepared by cultivating a micro-organism of the species Bacillus subtilis or Bacillus natto, stopping the cultivation between the beginning and middle of the logarithmic growth phase of the micro-organism, and heating the resulting culture at a pH of 4.0 to 8.0 and at a temperature of 50 DEG to 80 DEG C. for 1 to 3 hours. The cultivation may be conducted as a solid culture process or as a submerged cultivation under agitation and aeration with a starting pH of 6.0 to 8.0 and at a temperature of 30 DEG to 40 DEG C. Constituents for the culture medium are mentioned. The growth promoting factor is found in both the liquid and solid portions of the broth. The heat-treated culture, as such or after concentration, may be absorbed in an animal feed such as bran. Alternatively