- Invited Review - Precision livestock farming: from where we came and where we go

This paper describes how animal management was done in the past and how we evolved to continuous animal monitoring by using technology. Based upon peer-reviewed literature, we show several technologies (cameras, microphones, sensors) developed and used for monitoring and managing indoor farm animals applied to different animal species: broilers, pigs, dairy cows, and horses. The main idea in developing precision livestock farming (PLF) technology is continuous 24/7 monitoring to generate objective data for farmers, veterinarians, and other stakeholders (pharma, feed company, equipment, climate control, etc.). Development started in laboratory settings and evolved to data collection in commercial farms. This paper shows that PLF monitoring allows us to measure objective data in each term of the fundamental process equation in producing animal products: the transfer from feed energy into animal product (meat, milk, eggs, fiber, and reproduction). The accuracies obtained are impressive in several examples. Regarding where to go with PLF, we show the great importance of animal welfare in the efficiency of the production process. Improving process efficiency is key in avoiding the need for even more farm animals to be slaughtered every year to fulfill the increasing worldwide demand for animal products. Field implementation of PLF technology for continuous objective measurements on indoor farm animals, to improve the efficiency of the production process, is an important contribution to feeding the worldwide increasing demand for animal products without a high increase of the number of farm animals.