ARS | Publication request: Dietary CP and Tannin Extracts Impact Ammonia Emissions From Manure Deposited On Dairy Barn Floors

Submitted to: Joint Meeting of the ADSA, AMSA, ASAS and PSA
Publication Type: Abstract Only
Publication Acceptance Date: March 15, 2010
Publication Date: June 15, 2010
Citation: Powell, J.M., Aguerre, M.J., Wattiaux, M.A. 2010. Dietary CP and Tannin Extracts Impact Ammonia Emissions From Manure Deposited On Dairy Barn Floors. Joint Meeting of the ADSA, AMSA, ASAS and PSA. Abstract W331. 693 J. Anim. Sci. Vol. 88, E-Suppl. 2/J. Dairy Sci. Vol. 93, E-Suppl. 1/Poult. Sci. Vol. 89, E-Suppl. 1. 2010

Technical Abstract: The impact of dietary CP and Quebracho-Chestnut tannin extracts on dairy cow performance and N partitioning are reported elsewhere at this meeting. Mixtures of feces/urine from these studies were applied to lab-scale ventilated chambers to measure ammonia-N emissions (ANE) from simulated concrete barn floors. Feces and urine were collected separately from lactating Holstein cows fed 2 levels of dietary CP (%DM): low protein, LP=15.5 and high protein, HP=16.8; each at 4 levels (%DM) of dietary tannin: T1=0, T2=0.45, T3=0.90 and T4=1.80. Feces and urine having a total weight of 16g were mixed in their excreted mass ratios (g/g) and applied to chambers. ANE were measured 1, 3, 6, 12, 24, 36 and 48h after application. Although patterns of ANE were similar over time, the 48h cumulative ANE (CANE, mg) was lower (P<0.05) for manure from the LP diets (12.1) than from the HP diets (24.7). As a percent of total N (%TN) and urinary N (%UN) applied, losses from the LP diets (16.9 and 46.2) were lower than from the HP diets (27.7 and 56.3). Tannins impacted CANE, %TN and %UN for both the LP and HP diets. For the LP diets, the non-tannin ration (T1) had CANE, %TN and %UN of 14.6, 19.6 and 48.0, respectively vs. 11.2, 16.1 and 45.7, respectively for the tannin-containing rations (average of T2, T3 and T4). Results were similar for the HP diets, except for %UN. Average CANE and %TN for manure from the HP non-tannin ration were 27.5 and 29.1, respectively vs. 23.7 and 27.2 for the HP tannin-containing rations. %UN was lower however for manure from the HP non-tannin ration (52.4) compared to the HP tannin-containing rations (57.5). These differences were likely due to overall higher excretions of urinary N by cows fed HP diets, and therefore higher amounts of urine N applied. For the LP diets, lowest CANE, %TN and %UN occurred at T2 and T4. For the HP diets, lowest CANE, %TN also occurred at T2 and T4, but %UN was lowest at T1 and T2 due to reasons mentioned above. The addition of tannin extracts to dairy rations can reduce ammonia emissions from dairy barns, but relative reductions depend on the amount of CP fed and therefore urinary N excretion.