Fig 1: Representative pictures of immunohistochemical localization of IL1A in the endometrium of heifers inseminated with frozen–thawed semen from LF and HF bulls as well as a CTRL noninseminated treatment. Immunolocalization was performed on a subset of heifers (n = 3 per treatment). Tissue was imaged at 10x. Scale bar = 100 µm. IL1A is detectable by the presence of an insoluble brown precipitate in the tissue. Negative control (NC) was performed without primary antibody.