EQUIPMENT-DEPENDENT NITROGEN LOSS DURING CATTLE MANURE REMOVAL FROM LIVESTOCK HOUSE.

The study objective was to establish the patterns of nitrogen loss from manure, when it was removed from the cow houses by different equipment most common in the animal husbandry of North-West Russia. The excrement total nitrogen was calculated by the mass balance method using the actual diet and milk yield data for cows of different lactation phases in a selected cattle-rearing complex. The calculated data were compared with the data obtained experimentally by sampling and analysis in the analytical laboratory. The difference was found to be below 9 %. The calculation of manure total nitrogen (ex-housing) included the mass of the added bedding material. In the study, different manure removal equipment was tested under the similar livestock house dimensions, climate control systems, and cow feeding diets -- a screw conveyor in Building 1 with the tied animal housing, a scraper system in Building 2 with the loose animal housing, and a TSN-160 scraper chain conveyor in Building 3 with the loose animal housing. According to the study findings, the screw conveyor demonstrated the minimum total nitrogen loss of 7.31 % during the manure removal from the premises. The maximum total nitrogen loss of 32.26 % was recorded for the TSN-160 scraper chain conveyor. The use of the scraper system featured 16.81 % total nitrogen loss. The output of the experimental study was the graphical dependencies of the total nitrogen loss on the distance the manure was moved inside the premises by various manure removal equipment. [ABSTRACT FROM AUTHOR]