Prediction of ammonium emission from dairy cattle based on milk urea nitrogen using the precision farming methodology

Currently the livestock production sector causes the production of huge amounts of manure, which is a source of ammonia. Ammonia is dangerous to human, animal and environmental health. According to some studies, livestock is responsible for 76% of global nitrogen emissions, with cattle production accounting for 36% of ammonia emissions in Europe. An important challenge during the increase and strengthening of the livestock production sector is the impact of livestock on the environment - especially on the climate and ecosystems. Reducing greenhouse gas emissions and ammonia emissions from dairy farms is one of the main goals in achieving environmentally sustainable milk production. A prerequisite for the reduction is a quick, simple and accurate assessment based on already available data, which in the case of dairy farms means the use of milk control data (control day data). By feeding lactating cows balanced meals in terms of protein and energy content, the urea content in milk (MUN) ranges from 15 to 30 mg/dl, which is a general recommendation. When the urea content in milk increases by 20 and 30 mg/dl, the ammonia emission increases by 2.5%, ie. 3.5%. The urea content in milk is highly correlated with daily milk yield, the increase in production also increases the urea content in milk. The low content of urea in milk indicates a lack of ammonia in the rumen, ie. to the insufficient amount of proteins degradable and unfavorable conditions for the growth of microorganisms in the rumen. High values of MUN content are an indicator of excessive formation of ammonia in rumen, as a consequence of high content of proteins degradable in rumen and small amounts of carbohydrates. The high concentration of ammonia in the rumen burdens the liver, which synthesizes urea. The amount of ammonia in the barn increases, which negatively affects the welfare of animals and humans. Many researchers have proven that the properties of milk content can be used not only to assess animal productivity, but also to characterize metabolic processes in the animal body, and thus to predict possible diseases in time (ketosis, acidosis) and control production efficiency. Determination of urea content in milk using IR spectrophotometry in milk analysis during regular monthly control of milk yield of cows provided new opportunities in monitoring milk quality, through which it is possible to assess the quality of nutrition on dairy farms, especially in terms of feed balance in terms of crude protein content and energy in the meal. This indicates the possibility of applying the urea content in milk in practice, in order to determine the efficiency of protein utilization from meals. A precise system of protein nutrition in lactating cows must provide a meal in accordance with the level of milk production, but also avoid consuming too much protein, which results in their inefficient use, adverse effects on energy balance of animals, and increased nitrogen excretion into the environment, but also unnecessary increases meal price.