Scientists in Brazil are working on a lab-grown donkey collagen that might save the animals from being wiped out worldwide.Their goal is to meet the Chinese middle class’ insatiable demand for ejiao – a traditional Chinese medicine with purported anti-ageing benefits that is derived from donkey skins – while also offering a purer product that poses less risk of contamination.Carla Molento, a professor of animal welfare at the Federal University of Parana and head of its Cellular Animal Science...