Degree Type

Thesis

Date of Award

2020

Degree Name

Doctor of Philosophy

Department

Agricultural and Biosystems Engineering

Major

Agricultural and Biosystems Engineering

First Advisor

Brett C Ramirez

Abstract

The United States (US) swine industry plays an important role in providing a safe and reliable source of animal proteins for a growing world population. As the industry evolves and society advances, producers face new and complex challenges such as optimizing animal production, welfare, and health. This dissertation contributes novel evidence-based knowledge to address current swine housing and management challenges in several key areas that formed the objectives of this dissertation, which were to: develop a computer vision system to monitor sow behavior in farrowing stalls (Chapter 2), evaluate the impacts of farrowing stall layout and number of heat lamps on sow and piglet productivity (Chapter 3) and behavior (Chapter 4), quantify the static and dynamic space usage of late gestation sows (Chapter 5), and determine supplemental heat requirements to implement ventilation shut down plus and virus inactivation (Chapter 6).

The research presented in this dissertation contains the following discoveries. In Chapter 2, a large-scale computer vision system was established and implemented to simultaneously and continually monitor 60 farrowing stalls. The semi-automatic image processing algorithm achieved sow posture classification accuracies of >99.2% (sitting: 99.4%, standing: 99.2%, kneeling: 99.7%, lying: 99.9%) and >97% accuracy for sow behaviors (feeding: 97.0%, drinking: 96.8%, other: 95.5%). The computer vision system provided the foundation for carrying out the subsequent study concerning the impact of farrowing stall layout and management strategies.

It was revealed in Chapter 3 that farrowing stall physical dimensions and number of heat lamps for localized heating did not significantly impact the percentage of pre-weaning mortality, overlay, number of piglets born alive, number weaned, average daily weight gain, or litter uniformity. Stall layout did significantly influence percent stillborn; however, the difference was not of practical significance.

While experimental treatment did not significantly impact production outcomes, there were significant sow and piglet behavioral differences which are reported in Chapter 4. It was found that sows in wider stalls spend more time lying down and less time sitting. Piglets in stall layouts with expanded creep areas spent more time in the creep and less time near the sow compared to traditional stall layouts. Further, when two heat lamps were used sows spent significantly more time lying and piglets spent a greater proportion of time in the heated areas.

Static and dynamic space usage of individually housed gestating sows was quantified and reported in Chapter 5. An average 228 kg sow requires stall dimensions of 196 × 115 × 93 cm (L × W × H) to provide uninhibited space. To accommodate average to 95th percentile (267 kg) sows, minimum stall dimensions need to be 204 × 112 × 95 cm. The 95th percentile sow space usage had a 4% decrease in length, 84% increase in width, and 5% decrease in height compared to typical gestation stall dimensions.

Chapter 6 describes the development of a model to predict minimum supplemental heat requirements for ventilation shut down plus and virus inactivation (VSD+). Tables are presented with heating values needed to achieve greater than 95% mortality within 1 h of VSD onset, as well as for virus inactivation for African Swine Fever (ASF). Requirements of supplemental heat for various pig body weights, ambient conditions, facility air tightness, and stages of production are estimated.

Overall, this dissertation provides information to fill knowledge gaps regarding current challenges in the US swine industry. Results can be used to guide producers as they strive to provide safe and reliable pork for the growing world population while safeguarding wellbeing of the animals.

DOI

https://doi.org/10.31274/etd-20200624-159

Copyright Owner

Suzanne M Leonard

Language

en

File Format

application/pdf

File Size

171 pages

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