Theses and Dissertations

Issuing Body

Mississippi State University


Davis, Jeremiah D.

Committee Member

Purswell, Joseph L.

Committee Member

Kiess, Aaron S.

Committee Member

Hoff, Steven J.

Date of Degree


Document Type

Dissertation - Open Access


Biological Engineering

Degree Name

Doctor of Philosophy


James Worth Bagley College of Engineering


Department of Agricultural and Biological Engineering


Tunnel ventilation is the design practice of placing exhaust fans and air inlets on opposite ends of animal production facilities and moving air through the building via negative pressure. Increasing air velocity within tunnel ventilated broiler production facilities increases sensible cooling and reduces the need for latent cooling (panting), which improves production efficiency. An air velocity measurement system was developed and measurement density analysis for quantifying air velocity distribution was performed in a 12.19 x 121.9 m commercial broiler production facility. Results showed that axial measurement distances of 3.05 m and 40 measurement points per cross-section produced the most descriptive air velocity distribution maps. Air velocity distribution, mean cross-sectional air velocity, and total facility air flow was assessed in three tunnel ventilated commercial broiler production facilities. These facilities differed in size, design, and equipment configurations (test facility 1 was 18.3 × 170.7 m, test facility 2 was 15.24 × 144.8 m, and test facility 3 was 12.19 × 121.9 m). Air velocity distribution varied within all three facilities. Normalized cross-sectional air velocity was plotted against proportion of total house length to compare the cross-sectional air velocity of the three facilities. House width and physical arrangement of the feed hoppers, heating systems, and tunnel fans are impacting air velocity uniformity and mean cross-sectional air velocity in the three broiler houses. Precision Livestock Farming (PLF) seeks to improve production efficiency and animal well-being by model based control of animal production facilities. Four broiler production facilities were assessed for spatial bird body weight (BW) variability. The facilities were 15.24 × 144.8 m solid side-wall tunnel ventilated broiler houses containing birds at 58 and 59 d of age. Significant differences in BW were found between birds residing at center house (3.47 kg average) and at the side-walls (3.38 kg average) (P = 0.025). This variability in BW could be attributed to any number of environmental, nutrient, or behavioral causes. A discussion of input/control parameters for PLF management of broiler production is presented. Quantification of performance variability within these facilities and defining models for control of input parameters is essential to making PLF management feasible.



anemometer||Kriging||broiler||air velocity