Suzanne Leonard

Dr. Suzanne Leonard

North Carolina State University, Raleigh, North Carolina, USA

Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
1 August 2019 in Computers and Electronics in Agriculture
Verified
Journal Article
Closed access
Suzanne LeonardSuzanne Leonard
Suzanne Leonard
HXH. Xin
H. Xin
TBT.M. Brown-Brandl
T.M. Brown-Brandl
Brett RamirezBrett Ramirez
Brett Ramirez

22 February 2020 in Animals
Verified
Journal Article
Open access
PDF file
Suzanne LeonardSuzanne Leonard
Suzanne Leonard
HXHongwei Xin
Hongwei Xin
TBTami Brown-Brandl
Tami Brown-Brandl
Brett RamirezBrett Ramirez
Brett Ramirez
SDSomak Dutta
Somak Dutta
GRGary A. Rohrer
Gary A. Rohrer
Most farrowing facilities in the United States use stalls and heat lamps to improve sow and piglet productivity. This study investigated these factors by comparing production outcomes for three different farrowing stall layouts (traditional, expanded creep area, expanded sow area) and use of one or two heat lamps. Data were collected on 427 sows and their litters over one year. Results showed no statistical differences due to experimental treatment for any of the production metrics recorded, excluding percent stillborn. Parity one sows had fewer piglets born alive (p < 0.001), lower percent mortality (p = 0.001) and over-lay (p = 0.003), and a greater number of piglets weaned (p < 0.001) with lower average daily weight gain (ADG) (p < 0.001) and more uniform litters (p = 0.001) as compared to higher parity sows. Farrowing turn, associated with group/seasonal changes, had a significant impact on most of the production metrics measured. Number of piglets born influenced the percent stillborn (p < 0.001). Adjusted litter size had a significant impact on percent mortality (p < 0.001), percent over-lay (p < 0.001), and number of piglets weaned (p < 0.001). As the number of piglets weaned per litter increased, both piglet ADG and litter uniformity decreased (p < 0.001). This information can be used to guide producers in farrowing facility design.

1 June 2021 in Applied Animal Behaviour Science
Verified
Journal Article
Closed access
Suzanne LeonardSuzanne Leonard
Suzanne Leonard
HXHongwei Xin
Hongwei Xin
TBTami Brown-Brandl
Tami Brown-Brandl
BRBrett C. Ramirez
Brett C. Ramirez
AJAnna K. Johnson
Anna K. Johnson
GRGary A. Rohrer
Gary A. Rohrer

29 August 2023 in Animal
Verified
Journal Article
Open access
ZPZ.C. Peppmeier
Z.C. Peppmeier
Jeffrey HowardJeffrey Howard
Jeffrey Howard
MKMark T. Knauer
Mark T. Knauer
Suzanne LeonardSuzanne Leonard
Suzanne Leonard
Fast, accurate, and reliable estimates of backfat depth, loin depth, and intramuscular fat percentage in swine breeding stock are used to increase genetic improvement and farm profitability. The objective of this study was to develop an equation-based model for the estimation of swine backfat depth, loin depth, and intramuscular fat percentage estimates obtained from longitudinal ultrasound images. Images were collected from purebred Duroc (n = 230), purebred Large White (n = 154), and commercial (n = 190) pigs born in January 2021 at three farms located in North Carolina. An Exapad ultrasound machine captured longitudinal images across the 10th to 13th ribs at 182 (±12.8 SD) days of pig age. The total number of images processed for Duroc, Large White, and commercial pigs was 1 385, 928, and 1 168 images, respectively. To establish a standard measurement for model comparison, trained personnel following standard company procedures using the BioSoft Toolbox (v4.0.1.2; Biotronics Inc., Ames, IA) obtained backfat and loin depth measurements from the images. Longissimus muscle intramuscular fat percentage was predicted using near-infrared spectroscopy at approximately 22 h postmortem. Backfat and loin depth estimation were conducted only for commercial pigs (n = 190) while intramuscular fat estimation was conducted on all pigs (n = 574). Average backfat depth, loin depth, and intramuscular fat percentage were 14.6 (±2.6 SD) mm, 63.7 (±5.5 SD) mm, and 2.21 (±0.82 SD) %. Image analysis and estimation model development were conducted in MATLAB R2021a. Edge detection via the image gradient was applied to segment ultrasound images into backfat, loin, and rib regions. Segmented images were used to estimate backfat depth, loin depth, and loin intramuscular fat percentage. After image quality control and filtering, the image inclusion rate for each breed-trait combination ranged from 76 to 97%. All Duroc and commercial pigs and 97% of Large White pigs were represented by at least one image for trait estimation. Coefficient of determination of models for the estimation of backfat depth, loin depth, and intramuscular fat percentage were 0.58, 0.57, and 0.56, respectively. Root mean square error of backfat depth, loin depth, and intramuscular fat estimation were 1.65 mm, 3.58 mm, and 0.54%, respectively. Results demonstrate the feasibility of using ultrasound image gradient and an equation-based approach to estimate swine backfat and loin depth, and intramuscular fat percentage. This equation-based approach to estimate carcass traits in live swine can enhance genetic improvement.

14 September 2022 in Animals
Verified
Journal Article
Open access
PDF file
TBTimothy E Boston
Timothy E Boston
FWFeng Wang
Feng Wang
XLXi Lin
Xi Lin
Suzanne LeonardSuzanne Leonard
Suzanne Leonard
Sung Woo KimSung Woo Kim
Sung Woo Kim
JOJack Odle
Jack Odle
To combat the stress of weaning, we utilized novel gruel creep feeders to supplement suckling pigs with divergent soluble (n = 6 litters) versus insoluble (n = 6) diets compared with un-supplemented controls (n = 6). Post-weaning, pigs were fed a common phase 1 diet. Average daily weight gains of pigs fed soluble and insoluble creep diets were 53% and 17% greater than control pigs, respectively (p < 0.01). Creep intake was higher (82%) for pigs fed the soluble diet, and the accompanying weight increase was sustained post-weaning (p < 0.02). Villus measures were prematurely altered in soluble-creep-fed pigs (p < 0.01), with decreases in villi length, crypt depth, and villus area pre-weaning. No effects of treatment were detected for VFA concentrations and pH in the cecum. There was an interaction between treatment and age for several pro- and anti-inflammatory cytokines (p < 0.01), where soluble-creep-fed pigs had increased cytokine levels with age, whereas cytokine levels in the insoluble and control groups decreased over time. We conclude that a soluble creep diet fed in a gruel state during the pre-weaning period has a positive impact on weaning weight that is sustained post-weaning, and is accompanied by alterations in the intestinal health of young pigs.

27 December 2024 in Computers and Electronics in Agriculture
Verified
Journal Article
Closed access
RHR. Hodges
R. Hodges
Suzanne LeonardSuzanne Leonard
Suzanne Leonard