261 Effect of Alga 1.0 on Reducing Enteric Methane Emissions from Cattle

Abstract

Abstract Alga 1.0, an algae-derived product was used to evaluate the effect of inclusion on methane (CH4) and carbon dioxide (CO2) emissions from cattle along with diet digestibility. Twelve non-lactating, non-pregnant Jersey cows were used in 4 replicated 3x3 Latin squares. Cows were blocked by intake and assigned randomly to three treatments. Three periods were utilized with each period being 21 days long. Three treatments were evaluated with 0, 69, and 103 grams per day Alga 1.0, fed as a top dress with modified distillers grains plus solubles (MDGS) as a carrier in a corn-based diet. Diet consisted of 60% dry-rolled corn, 20% corn silage, 15% MDGS, and 5% supplement. Headbox-style indirect calorimeters were utilized to evaluate gas production from individual cows with 2 non-consecutive 23-h collections in each period. Diet digestibility was measured using complete fecal collection the last 4 days of each period. Data were analyzed with GLIMMIX procedure of SAS with cow within period as experimental unit, cow and period as random effects, and treatment as fixed effect. Alga 1.0 inclusion decreased CH4 production measured as g/d (P < 0.01) and g/kg DMI (P < 0.01). A 39% percent reduction in CH4 was expressed as g/kg of DMI with 69 g inclusion; and a 63% reduction (g/kg DMI) with 103 g inclusion of Alga 1.0. Average eructated CH4 was 17.5 g/kg of DMI, 10.7 g/kg of DMI, and 6.4 g/kg of DMI, for the control, 69 g, and 103 g treatments, respectively. Emissions of CH4 reported as g/d were 164.9 for the control diet and decreased to 88.2 g/d for 69 g inclusion and 44.4 g/d for 103 g inclusion. Emissions of CO2 as g/d tended (P = 0.08) to be less for cattle receiving 103 g of Alga 1.0; but did not differ when calculated as g/kg of DMI (P = 0.39). Oxygen consumption (O2) amounts did not differ between treatments for g/day (P = 0.26) and g/kg DMI (P = 0.39). Respiratory quotient (RQ) was not significantly impacted (P = 0.32) by treatments. Alga 1.0 inclusion did influence organic matter (OM) intake (P = 0.01) with a 0.98 kg/d decrease with 69 g inclusion and a 1.27 kg/d decrease with 103 g inclusion compared with the control. Digestibility of OM was not influenced (P = 0.89) by the inclusion of Alga 1.0 and averaged 74.9%. Digestible Energy expressed as Mcal/kg did not differ (P = 0.67) between treatments. Feeding Alga 1.0 decreased OMI but did not affect digestibility. Alga 1.0 inclusion reduced CH4 emissions from cattle compared with a dry rolled corn control diet with no significant impact on CO2 emissions.