Effects of feeding lubabegron on gas emissions, growth performance, and carcass characteristics of beef cattle housed in small-pen environmentally monitored enclosures during the last 3 months of the finishing period

The development of technologies that promote environmental stewardship while maintaining or improving the efficiency of food animal production is essential to the sustainability of producing a food supply to meet the demands of a growing population. As such, Elanco (Greenfield, IN) pursued an environmental indication for a selective β-modulator (lubabegron; LUB). LUB was recently approved by the United States Food and Drug Administration (FDA) to be fed to feedlot cattle during the last 14 to 91 d of the feeding period for reductions in gas emissions/kg of unshrunk final BW and HCW. A 4 × 2 factorial arrangement of treatments was used with the factors of dose (0.0, 1.38, 5.5 or 22.0 mg·kg-1 DM basis) and sex (steers or heifers). Three 91-d cycles were conducted (112 cattle/cycle) with each dose × sex combination being represented by a single cattle pen enclosure (CPE; 14 cattle/CPE) resulting in a total of 168 steers and 168 heifers (n = 6 replicates/dose). There were no interactions observed between dose and sex for any variable measured in the study (P ≥ 0.063). Five gases were evaluated for all pens based on CPE concentrations relative to ambient air: NH3, CH4, N2O, H2S, and CO2. Cumulative NH3 gas emissions were reduced by feeding cattle 5.5 and 22.0 mg·kg-1 LUB (P ≤ 0.023) and tended (P = 0.076) to be lower for the cattle fed 1.38 mg·kg-1 LUB compared to the negative controls (CON). The cumulative NH3 gas emission reductions of 960 to 1032 g, coupled with HCW increases (P ≤ 0.019) of 15 kg to 16 kg for all LUB doses vs. CON, led to reductions in NH3 gas emissions/kg HCW for all 3 LUB treatments (P ≤ 0.004). Similar to HCW, reductions in NH3 gas emissions/kg of unshrunk final BW were observed for all LUB doses (P ≤ 0.009) and were attributable to both decreases in NH3 gas emissions and numerical increases in BW. Dose had no effect on cumulative emissions or emissions standardized by BW or HCW for the other 4 gases (P ≥ 0.268). Lubabegron is a novel tool to reduce emissions of NH3 gas per kg of unshrunk live BW and hot carcass weight.

Phytoplankton Community Characteristic and it's Environmental Indication in the Luanhe–Beidaihe Estuary

The work showed that there were 44 species belonging to 23 genera, 3 phylum of phytoplankton in the research area. Among them, 31 species of 16 genera were Bacillariophyta, which accounted for 70.5 % of all species, 12 species of 6 genera were Pyrrophyta, which accounted for 36.4 % of all species, as well as one sepecies of genera was Chrysophta, which accounted for 2.3 % only. And 16 species, as the indicator of ‘red tide’ usually, were identified. Among them, 10 species belong to Pyrrophyta, 5 species were belong to Bacillariophyta, and one species of Chrysophta identified was also the dominant alga of ‘red tide’. The Shannon-Wiener biodiversity index showed that the water qualities in all sections were in the level of moderate polluted.