Methods for treating an animal for low milk production

A method for treating an animal having low milk production, the method comprising administering to a milk producing animal having or at risk of having a low milk production an effective amount of a first composition comprising:

• at least two siderophore receptor polypeptides isolated from a gram negative microbe;
• at least two porins isolated from the gram negative microbe;
• lipopolysaccharide;
• and
• a pharmaceutically acceptable carrier, wherein the concentration of lipopolysaccharide present in the first composition is no greater than the concentration of lipopolysaccharide in a second composition comprising:
• the at least two siderophore receptor polypeptides isolated from the gram negative microbe;
• the at least two porins isolated from the gram negative microbe;
• lipopolysaccharide;
• wherein the second composition is produced by a process comprising:
• providing the gram negative microbe;
• disrupting the gram negative microbe in a buffer;
• solubilizing the disrupted gram negative microbe for greater than about 24 hours in a solution comprising sarcosine to result in solubilized and insoluble cellular material, wherein a ratio of the sarcosine to gram weight of disrupted gram negative microbe is between about 0.8 gram sarcosine per about 4.5 grams of disrupted gram negative microbe and about 1.2 grams sarcosine per about 4.5 grams of disrupted gram negative microbe;
• and
• isolating molecules of the gram negative microbe, wherein the isolated molecules comprise the at least two siderophore receptor polypeptides, the at least two porins , and lipopolysaccharide.