Litter management techniques in large-scale livestock farming Literature review

The explosion of population growth in the 20th century and the intensive development of large-scale, industrial livestock farming have gone hand in hand, bringing along a number of ecological and economic problems that have become increasingly apparent in the recent decades. The world population has more than doubled in the last 200 years. This intensive growth has also posed major challenges for agriculture, which has to supply the growing population with animal protein sources. As a result, continuous genetic selection and technological improvements have led to the modern large-scale livestock production. Animal production has developed at a rapid pace. The daily milk yield of dairy cows has doubled in the last 40 years. Whereas in 1957 the average weight of a 28-day-old broiler chicken was 316 g, this figure rose to 632 g in 1978 and 1396 g in 2005. Their feed conversion ratio fell by 50% between 1957 and 2005. This means that the bird needs half as much feed to gain 1 kg live weight. Apart from being a clear economic improvement, this also significantly reduces the environmental impact of poultry farming. However, genetic advances alone have not been sufficient to feed a rapidly growing population, so the number of farm animals has increased year by year at a staggering rate in the past decades, and with ii the emissions of pollutants from their keeping. The world population of domestic chickens increased by 448% between 1961 and 2014. The rise in atmospheric concentrations of various harmful gases is one of the most important environmental issues of our time, and large-scale livestock farming is an integral source of the problem, accounting for around 75% of European ammonia emissions. This fact has led to increasing attention being paid to research into livestock-related emissions and the solutions that could potentially mitigate them, both locally in the barn and globally. One of these options is the use of different litter management techniques, which can be divided into technological or physical, chemical or biological methods. In this current summary, we look at ways to reduce the greenhouse and other harmful gases, such as ammonia, emitted by different farming systems for different farm animal species. In addition, we also look at potential ways to reduce them through proper litter management.