Both statements are correct: cutaneous fibropapillomas / warts in cattle are caused by Bovine Papillomaviruses (BPV-1 through BPV-14, family Papillomaviridae). Ringworm (dermatophytosis) in cattle is an infectious superficial mycosis predominantly caused by the zoophilic fungus Trichophyton verrucosum (and occasionally T. mentagrophytes).

Radiation measurement units and quantities:

• Roentgen equivalent man (rem) is the conventional (non-SI) unit for equivalent dose ($1\text{ Sv} = 100\text{ rem}$).
• Gray (Gy) is the SI unit of Absorbed Dose ($1\text{ Gy} = 1\text{ J/kg} = 100\text{ rad}$).
• Roentgen (R) is the traditional unit of Radiation Exposure in air.
• Sievert (Sv) is the International System of Units (SI) unit for Equivalent Dose and Effective Dose, taking into account the biological effectiveness of different radiation types ($H = D \times W_R$).

Physics of X-ray interactions with matter:

• Low-energy photons interacting with tightly bound inner shell electrons produce the Photoelectric effect, where the photon is completely absorbed.
• Low-energy photons interacting with whole atoms without ionization cause Coherent (classical/Rayleigh) scattering.
• Inner-shell electrons have high binding energies and undergo photoelectric absorption when energy matches the K-edge.
• Compton scattering (Compton effect) predominates at higher diagnostic photon energies (moderate to high energy X-rays) interacting with loosely bound outer-shell valence electrons, ejecting a recoil electron and scattering the photon with reduced energy.