THE CONTROVERSY ABOUT CATTLE’S ROLE IN THE GLOBAL ENVIRONMENT.

Cattle have been the focus of an intense debate between those concerned about, among other things, the possible negative effects on global warming, land degradation, food competition and human health, and those who are positive toward the possible role of cattle in maintaining global socio-economic and environmental sustainability. The purpose of the investigation by the authors cited, was to evaluate the risk to the global socio-economy and the environment if cattle production increases towards 2050, according to projected needs and demands of the global economy. The most important findings from the review are provided:

• Estimations of global and country cattle numbers vary considerably between literature sources. Also, expectations of numbers towards 2050 are unrealistic, which are of concern as projections of needs, future production and trade will not realise. Projections indicate stagnation and possibly a decrease in cattle foods, at least per capita. For the developing world an increase in cattle foods is beneficial. However, cattle number and production trends do not predict an increase, which points to further increases in pork and chicken to meet future demands for animal-based foods.

• Livestock provide over half of the global agricultural output and current world trade is healthy. Cattle, in addition to being a source of food, provide several essential socio-economic services in the developing world which cannot be replaced.
• Consumption of animal-based foods is rapidly increasing in developing and transition countries, yet still way below consumption in developed countries. The low consumption in poor countries is a major reason for nutritive imbalances, stunting and low cognitive development as animal-based foods are nutrient dense, in contrast to plant-based foods, which alone can rarely meet nutrient requirements.
• Although the literature is contradictory, there are very little meta-analysed studies which show negative relationships between animal-based foods and cardiovascular diseases and cancer. It is rather a case of quantity resulting in obesity and insulin resistance.
• Methane emissions by cattle are much lower than previously accepted because global cattle numbers are much lower than estimated, the global warming potential of CH₄ has apparently been over-estimated, the relationship with the biogenic carbon pathway has not been understood, as well as how it is affected by the physiological function of the animal. Furthermore, the effect of additional soil carbon resulting from the manure is generally ignored. 
• Nitrous oxide is a dangerous polluter in the atmosphere. In agriculture, it is primarily derived from chemical fertilisation during crop and pasture cultivation, which in addition is damaging to soil health. These practices should be limited and organic sources such as animal (cattle) manure and compost used.
• Grasslands constitute 46% of rangeland surface, have co-evolved with herbivores and is the largest source of photosynthesis and carbon sink into soil, even larger than forests. The implication is that this resource and its herbivore grazers (cattle being the prime example) need to be protected against degradation at all costs through well-adapted livestock grazing systems in different contexts.
• Photosynthesis, carbon sequestration and soil health should be emphasised in rangeland management using quick rotation and comparatively high-density grazing practices with cattle where feasible, and in integrated crop-livestock systems, by introducing multi-species cover crops and livestock grazing, and/or employing feedlot feeding as alternative. This will allow more animals per area of land to the benefit of healthy ecosystems, productivity and economic returns.
• Livestock forms an integral part of regenerative agriculture systems leading to multiple environmental, social and economic benefits, with soil health at the centre. The research and development of well-adapted and adopted livestock and grazing management practices using CA principles in different local contexts are key.
• Finally, there is very little evidence of socio-economic and environmental risk if cattle production is to be increased towards 2050. In fact, a reduction in cattle numbers could limit the advantage of livestock related carbon sequestration and therefore largely defeat the objective of limiting global warming. However, a number of influencing factors need to be addressed, such as resource degradation and the implementation and scaling of sound grazing management practices.

Final comments: This review supplements and supports the papers in the April 2023 issue of Animal Frontiers (Volume 13, Issue 2), which was compiled from a dedicated symposium at Dublin, further resulting in ‘’The Dublin Declaration of Scientists on the Societal Role of Livestock’’. The Declaration highlights the following:

• Livestock systems must progress on the basis of the highest scientific standards. They are too precious to society to become the victim of simplification, reductionism or zealotry.
• Today’s food systems face an unprecedented double challenge. There is a call to increase the availability of livestock-derived foods to satisfy the unmet nutritional needs of many who experience stunting, wasting, anaemia, and other forms of malnutrition, which often cannot be provided by plant-based foods.  At the same time, some methods and scale of animal production systems present challenges with regards to biodiversity, climate change and nutrient flows, as well as animal health and welfare within a broad One Health approach.
• Farmed and herded animals are irreplaceable for maintaining a circular flow of materials in agriculture, by recycling in various ways the large amounts of inedible biomass that are generated as by-products during the production of foods for the human diet.
• For millennia, livestock farming has provided humankind with food, clothing, power, manure, employment and income as well as assets, collateral, insurance and social status.
• A summarized (philosophical) outlook: Human civilisation has been built on livestock from initiating the bronze-age more than 5000 years ago towards being the bedrock of food security for modern societies today. Livestock is the millennial-long-proven method to create healthy nutrition and secure livelihoods, a wisdom deeply embedded in cultural values everywhere. Sustainable livestock will also provide solutions for the additional challenge of today, to stay within the safe operating zone of planet Earth’s boundaries, the only Earth we have.