The domestication of cattle, pigs, poultry and other animals for their meat, milk, eggs and labor was revolutionary for human societies around the world. It even increased food security as it freed people from the need to hunt by providing them with available means to feed themselves.
However, not everything has gone well with animal husbandry, much less with the animals involved. The practice, especially when done on an industrial scale, has led to horrendous animal abuse.
But not only animals have suffered
We have inherited several deadly pathogens from livestock, including the influenza virus that likely jumped to humans from poultry, possibly in China, during ancient times and continues to sicken and kill millions of people around the world each year.
Domestic animals continue to be reservoirs for life-threatening pathogens that could infect people. That is especially concerning in this era of the Covid-19 pandemic. Worse still: the expansion of livestock has led to massive losses of biodiversity across much of the planet. An example of this is the continued destruction of the besieged forests of the Amazon in Brazil to make way for more grazing areas for livestock.
Epidemics on the rise
According to a team of researchers, between 1960 and last year, the number of epidemics affecting people increased along with the loss of local biodiversity. By analyzing the records, they discovered that as many 16,994 epidemics were caused by 254 infectious diseases inherited from livestock animals across the planet during those six decades.
"The emergence of epidemics is a worrying sign for the future of species conservation, since it could well indicate the march of biodiversity towards extinction", write the authors of anew study about how new emerging diseases, the expansion of livestock and the loss of biodiversity are intertwined globally.
"The relationship between the number of endangered species and the number of epidemics first increases, then reaches its peak, before finally decreasing," they explain. "However, the risk of an epidemic does not diminish with the disappearance of a species, but, on the contrary, it is transmitted even more by the increasing number of cattle."
Perhaps none of this should be news. Farm animals outnumber their wild counterparts and we live in close proximity to them. From domesticated cattle alone, there are about a billion at any one time. Meanwhile, the number of chickens in the world soared to nearly 24 billion in 2018 from around 14 billion in 2000 and the trend will increase in the coming years.
"The growing importance of livestock on the planet, while threatening biodiversity, increasingly puts human and animal health at risk," explain the scientists, adding that the expansion of livestock depends on several local variables, such as growth of human populations, changes in eating habits, agricultural industrialization and the cultural importance of livestock.
Eat less meat
The global solution lies in the transition to plant proteins in favor of animals, at least in part. The production of beef, for example, requires 28 times more land than the production of pork and chicken. It also requires 11 times more water and produces five times more climate-warming emissions.
"Compared to staples such as potatoes, wheat and rice, the impact of beef per calorie is even more extreme, requiring 160 times more land and producing 11 times more greenhouse gases," explains a study published inProceedings of the Natural Academy of Sciences last year.