Effects of pen bedding and feeding high crude protein diets on manure composition and greenhouse gas emissions from a feedlot pen surface

Abstract

Greenhouse gas (GHG) emissions from concentrated animal feeding operations vary by stage of production and management practices. The objective of this research was to study the effect of two dietary crude protein levels (12 and 16%) fed to beef steers in pens with or without corn stover bedding. Manure characteristics and GHG emissions were measured from feedlot pen surfaces. Sixteen equal-sized feedlot pens (19 Â 23 m) were used. Eight were bedded approximately twice a week with corn stover and the remaining eight feedlot pens were not bedded. Angus steers (n ¼ 138) were blocked by live weights (lighter and heavier) with 7 to 10 animals per pen. The trial was a 2 Â 2 factorial design with factors of two protein levels and two bedding types (bedding vs. non bedding), with four replicates. The study was conducted from June through September and consisted of four~28-day periods. Manure from each pen was scrapped once every 28 days and composite manure samples from each pen were collected. Air samples from pen surfaces were sampled in Tedlar bags using a Vac-U-Chamber coupled with a portable wind tunnel and analyzed with a greenhouse gas gas chromatograph within 24 hr of sampling. The manure samples were analyzed for crude protein (CP), total nitrogen (TN), ammonia (NH 3 ), total volatile fatty acid (TVFA), total carbon (TC), total phosphorus (TP), and potassium (K). The air samples were analyzed for methane (CH 4 ), carbon dioxide (CO 2 ), and nitrous oxide (N 2 O) concentrations. The concentration of TN was significantly higher (p < 0.05) in manure from pens with cattle fed the high protein diets. The volatile fatty acids (VFAs) such as acetic, propionic, isobutyric, butyric, isovaleric, and valeric acids concentrations were similar across both treatments. There were no significant differences in pen surface GHG emissions across manure management and dietary crude protein levels.Implications: Livestock manure produces odor and emits GHGs (CO 2 , CH 4 , and N 2 O) at different stages of production and management practices that have significant environmental concerns. Thus, it is important to measure GHG contributions from different sources and develop appropriate mitigation strategies for minimizing GHG contribution from livestock production facilities. Two dietary protein levels (12 and 16%) fed to beef steers in pens with or without corn stover bedding were studied. The results indicated that dietary protein levels and bedding vs. no bedding had very little effect on GHG emissions and manure composition under open feedlot conditions in North Dakota climatic conditions and management practices. IntroductionThe overall gaseous emissions from concentrated livestock operations vary by animal type and growth stage due to different diets, daily feed intake, quality of diet, and feed conversion mechanism. In the U.S., total greenhouse gases (GHG) including methane emissions from agricultural sources (livestock production, agricultural soils, and rice production) were estimated to be approximately 500 metric tons CO 2 e...

The effect of feeding high fat diet to beef cattle on manure composition and gaseous emission from a feedlot pen surface

“…Total carbon (TC) in manure was significantly lower in August as compared to other months. In 2012 summer, Borhan et al [ 45 ] had also measured the nutrient composition of the manure in the same feed lot under similar condition and the values of nutrient parameter were almost comparable with this study.…”

“…In comparing the results with the previous study; in 2011, Rahman et al [ 40 ] simply measured GHG emission from the same feedlot pen surface and they found that CH 4 , CO 2 and N 2 O emission were 38, 26, and 17 g hd -1 d -1 , respectively, during the 2011 summer period. Similarly, in 2012, Borhan et al [ 45 ] studied the effects of two dietary crude protein levels (12 and 16 %) in the GHG emission on the similar conditions. They found that CH 4 , CO 2 and N 2 O emission ranged from 40–61, 31–43, and 50–116 gAU -1 d -1 (0.8–1.1, 593–431, and 1–1.9 g m -2 d -1 ), respectively, during the summer months.…”