Bedding and within-pen location effects on feedlot pen runoff quality using a rainfall simulator

Area of Science:

• Environmental Science
• Animal Science
• Agricultural Engineering

Background:

• Feedlot runoff poses environmental risks due to soluble salts, nutrients, and bacteria.
• Managing runoff is crucial for preventing water pollution from livestock operations.

Purpose of the Study:

• To assess the impact of bedding material (barley straw vs. wood chips) and pen location on feedlot runoff.
• To analyze chemical and bacterial properties of runoff under different management scenarios.

Main Methods:

• A two-year study using a portable rainfall simulator to generate runoff from beef cattle feedlots.
• Analysis of runoff for chemical constituents (N, P, salts, EC, SAR, DO, pH) and bacterial populations (E. coli, total coliforms, total aerobic heterotrophs).

Main Results:

• Barley straw bedding resulted in lower concentrations and loads of ammonium-nitrogen (NH4-N) and sulfate (SO4) compared to wood chips.
• Pen location significantly affected electrical conductivity (EC) and concentrations of total Kjeldahl nitrogen (TKN), sodium (Na), potassium (K), sulfate (SO4), and chloride (Cl), with higher levels at bedding packs.
• Wood chip bedding in conjunction with bedding pack location showed the highest nutrient and bacterial runoff, particularly in 1998.

Conclusions:

• Bedding material and pen location are significant factors influencing the quality of feedlot runoff.
• Barley straw bedding and strategic pen management can mitigate the environmental impact of feedlot operations by reducing nutrient, salt, and bacterial loads in runoff.
• The interaction between bedding type and location offers a potential management strategy for feedlot runoff quality.