Methods of forming proteinaceous products such as cell culture supplement capable of supporting the growth and culturing of cells, tissue, and organs, are generally disclosed. One method generally provides for the collection of the internal tissue of an animal, such as a bovine, and the processing of the internal tissue to degrade and/or lyse the tissue components. A cell culture supplement or other proteinaceous product can be prepared from the processed tissue. A proteinaceous product can include, for example, a complete protein profile of the tissue or only certain biological factors extracted from the tissue. Collected internal tissue can be lymphatic tissue such as the supramammary glands of a dairy or beef cow or the thymus gland of a veal calf.