|Baldwin, Ransom - Randy|
|Fultz, Stanley - University Of Maryland|
|Harris, Christina - Virginia Polytechnic Institution & State University|
|Van Hekken, Diane|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 3/1/2013
Publication Date: 7/19/2013
Citation: Baldwin, R.L., Zhang, A., Fultz, S., Abubeker, S.U., Harris, C., Connor, E.E., Van Hekken, D.L. 2013. Brown marmorated stink bug odor compounds do not transfer into milk in lactating dairy cattle by feeding bug contaminated corn silage. In: J. Anim. Sci Vol. 91, E-Suppl. 2/J. Dairy Sci. Vol. 96, E-Suppl. 1, pp. 263.
Technical Abstract: In the northeastern United States, the brown marmorated stink bug (BMSB), Halyomorpha halys, is an emerging invasive species of grave concern to agriculture. BMSB is a highly polyphagous plant pest but also has potentially negative impact to dairy industry through contamination of silage and potential transfer of off flavors to fluid milk. Using three approaches we sought to determine the risk of including BMSB contaminated silage in lactating dairy cow rations. First, six dairies were identified as highly infested (n=3; 30 to 100 bugs per corn plant at harvest) or not infested (n=3) and samples of silage and milk were collected while the contaminated and uncontaminated silage were being used in the total mixed ration (TMR) to assess prevalence of the bug secretion compounds, including principle components (tridecane) and primary odor producing component (E-2-decenal). Second, using wild BMSB collected from the field, a mini-silo dose response experiment (adding 100, 50, 25, 10, and 1 fresh crushed bugs/0.5 Kg chopped corn) was conducted to assess the impact of ensiling on BMSB odor compounds. Finally, synthetic BMSB secretion compounds (10g tridecane and 5g E-2-decenal; equivalent to eating 10,000 bugs/d) were directly infused into rumen of four lactating cows 2 times daily over 3 d and samples of milk, urine, and rumen fluid were collected to evaluate disposition of these BMSB secretion compounds in cow body fluids. Samples were analyzed by solid phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS) techniques. Our results demonstrated that milk and silage from the farm-wide survey determined no detectable changes in feed intake nor milk production when bug contaminated silage was being fed. Moreover, no E-2-decenal was detected in silage nor milk (detection threshold = 0.00125 ppm). Dose response of tridecane in well preserved samples exhibited a linear relationship (R2= 0.78) with BMSB added; however, E-2-decenal was completely decomposed and undetectable in spiked mini-silos after ensiling. In addition, contents of both synthetic secretion compounds infused into rumen were undetectable in all milk and urine samples. Content of E-2-decenal was also not detectable in all rumen fluids; however, tridecane was detected in significant amount after 15 minutes infusion and decreasing quickly thereafter. Overall, feed intake was unaffected by treatment and bug secretion compounds in milk production were not observed. The secretion compounds from the metathoracic gland of BMSB are not able to contaminate milk due to either the ensiling process or metabolism within the rumen. Concern over BMSB stink odor compounds contaminating the fluid milk supply even on highly infested farms is not warranted.