REDUCTION OF ENVIRONMENTAL POLLUTION THROUGH DECREASE OF NITROGEN CONTENT OF PIG FEEDS | Намаляването замърсяването на околната среда чрез понижаване съдържанието на азот в дажбите на свине
2011
Ilchev, A., Thracian University, Stara Zagora (Bulgaria) | Ganchev, G., Thracian University, Stara Zagora (Bulgaria) | Bivolarski, B., Thracian University, Stara Zagora (Bulgaria) | Ilcheva, D., Thracian University, Stara Zagora (Bulgaria)
Serial balance trials were performed with three groups of castrated male Danbred and Topigs hybrid pigs, with three dietary levels of digestible amino acids – 85%, 100 % and 115%. The control group was fed in compliance with recommendations for feeding the respective hybrid - 100%. The other two groups received rations whose nitrogen content was by 15% lower or higher vs controls. The high dietary protein content increased water intake and the amount excreted urine. On the average, 20% of dietary nitrogen during the starter period, 17% during the grower and 16% during the finisher period were excreted with faeces. The main amount of nitrogen was excreted with urine. The increased content of crude protein in rations increased statistically significantly the urine nitrogen output. The feeding standards for digestible amino acids of Danbred and Topigs hybrids during the grower and finisher periods exceeded the potential of animals to utilize them. The reduction of norms by 10-15% in these two periods reduced the total nitrogen output by 16% without significant change in nitrogen retention. Dietary nitrogen levels over the standards did not improve nitrogen retention but increased nitrogen output in faeces and urine, but contributed to environmental pollution.
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