Effects of rumen undegradable protein sources on nitrous oxide, methane and ammonia emission from the manure of feedlot-finished cattle

Abstract

Here, the effects of sources of rumen undegradable protein (RUP) in diets on methane (CH4), nitrous oxide (N2O) and ammonia (NH3) emissions from the manure of feedlot-finished cattle were evaluated. We hypothesized that the use of different RUP sources in diets would reduce N loss via urine and contribute to reduced N2O, CH4 and NH3 emissions to the environment. Nellore cattle received different diets (18 animals/treatment), including soybean meal (SM, RDP source), by-pass soybean meal (BSM, RUP source) and corn gluten meal (CGM, RUP source). The protein source did not affect the N and C concentration in urine, C concentration in feces, and N balance (P > 0.05). The RUP sources resulted in a higher N2O emission than the RDP source (P = 0.030), while BSM resulted in a higher N2O emission than CGM (P = 0.038) (SM = 633, BSM = 2521, and CGM = 1153 g ha− 2 N-N2O); however, there were no differences in CH4 and NH3 emission (P > 0.05). In conclusion, the use of RUP in diets did not affect N excretion of beef cattle or CH4 and NH3 emission from manure, but increased N2O emission from the manure.

Emission of Greenhouse Gases and Ammonia from the Excreta of Nellore Bulls Submitted to Energy and Tannin Supplementation

“…On average, one head emitted 0.31 g N-N2O/day, which was within the range of 0.0 to 1.1 g N-N2O/day observed before [30]. Additionally, this represents approximately 0.043% of the N excreted by the animals being emitted as N2O, a similar proportion to that observed in grazing experiments in the same climate area [9,14,30]. After the applications Climatic variables play the most important role in the magnitude of the N 2 O, CH 4 fluxes, and NH 3 volatilized [30,47,48].…”

“…The amount of N 2 O produced is regulated by the N availability, while the soil moisture and temperature drive the microorganism activity [12,13]. The lack of synchronism between N and energy in the ruminant diet may lead to increases in N-ammoniacal production and its excretion via urine, which increases N availability in the soil pasture to be lost as N 2 O [7,10,14].…”

“…Supplements that are a source of energy (e.g., corn) increase the energy in the rumen for the growth of the microbial population, leading to an increase in the use of ammoniacal nitrogen and thus decreasing the concentration of nitrogen in the blood, consequently reducing N excretions in urine and the emissions of N 2 O and CH 4 [3,14]. Furthermore, the efficiency of microbial protein synthesis increases.…”

“…Ammonia volatilization occurs from nitrogen fertilization and the excretion of dung and urine in the soil. N volatilization is the primary source of N loss to the environment when not used by the ecosystem (soil, plant, and animal) [14]. The type of nitrogen fertilizer; animal excreta; and variables such as the temperature, precipitation, soil temperature, moisture, nitrification, and pH influence the volatilization [13].…”

“…Energy supplementation can increase the metabolizable energy in the rumen and substrate for the consumption of microorganisms that promote microbiota growth associated with condensed tannins and increase the flux of metabolizable protein from feed, improving the nutritional profile, energy balance, and animal performance [14]. Tannins form complexes with proteins through hydrogen bonds in the rumen.…”