Abstract
The discussion on the role of livestock in human food security is often controversial. Therefore, the aim of the present study was to assess the net contribution of different livestock to human food protein and energy supply. Furthermore, the proportions of feed protein and feed energy derived from different land categories were estimated. National data from 2011–2013 for the main Austrian livestock categories (cattle, dairy cows, growing-fattening bulls, swine, broiler chickens, laying hens, turkeys, sheep, and goats) were used in this case study. Cattle were the only species that were net contributors to both the human protein and energy supply. When accounting for the differences in protein quality between human-edible plant inputs and animal products, not only cattle, but also laying hens, sheep, and goats increased the value of protein available for human consumption. Except for growing-fattening bulls, about 50% of the feed protein and energy for ruminants was derived from permanent grassland, which could otherwise not be used for human food production. The results of this study showed that depending on the production system, the transformation process of feed into food of animal origin results in either an increase or decrease of the available food for human consumption, but it always increases protein quality.