Effects of Crate Size on Mortality and Postural Behavior in Post-farrowing Sows

Authors

Md Towfiqur Rahman, University of Nebraska-LincolnFollow
Tami M. Brown-Brandl, University of Nebraska-LincolnFollow
Gary A. Rohrer, United States Department of Agriculture, Agricultural Research Service, Meat Animal Research CenterFollow
Sudhendu R. Sharma, University of Nebraska-Lincoln
Yeyin Shi, University of Nebraska-LincolnFollow

Document Type

Abstract

Date of this Version

2024

Citation

Abstract

Proceedings of the São Paulo School of Advanced Science on Precision Livestock Farming (October 15-24, 2024 : Jaboticabal, Brazil)

Comments

United States government work

Abstract

Preweaning mortality (PWM) is a economic and animal well-being issue for swine producers in the US. On average, producers face about a 16% pre-weaning mortality. A significant portion of this, around 6%, is because sows accidentally overlay their piglets in farrowing crates. The posture behavior of sow plays a vital role in overlaying piglets and this behavior has a significant effect on farrowing crate dimensions. This study aims to explore the interplay between farrowing crate size, mortality rates, and postural behavior in post-farrowing sows. This study employed three farrowing stalls: Traditional (T), Expanded creep area (C), and Expanded sow area (S). Expanded creep area extended the piglet area (2.44 m × 1.83 m) while retaining the sow area identical to Traditional, while Expanded sow area included an extended piglet area (2.44 m × 1.83 m) with a sow area of 2.13 m × 0.71 m. Postural data were collected from 18 post-farrowing sows over three consecutive days, each comprising a 24-hour period. A computer vision system employing top-down Kinect V2 depth sensors captured images at a rate of 10 frames per minute throughout the duration of the study. Depth images were utilized exclusively due to their ability to convey relative height differences of the animals, while RGB images were disregarded due to variations in light intensity. A pre trained YOLO v8_cls model that trained with six different postural categories (standing (STAND), kneeling (KNEEL), sitting (SIT), sternal lying (LOB), lying on the right side (LOR), and lying on the left side (LOL)) was utilized for inferencing all the depth images to posture database. The mortality class high and low was determined from the piglet survival rate. The results showed that the SIT posture has a significant effect on the mortality rate (p-value = 0.004) and the sows from expanded sow area crates (S type) shown more time spent in SIT (average 38 min/day) in this posture compared to traditional one (average 29.89 min/day). This study provides valuable insights for farmers to make decisions about crate size.