Published March 4, 2016
032 Effects of shoeing on the joints of the lower forelimb
and hoof morphology of mature horses.
D. K. Proske*1, K. J. Stutts2, J. L. Leatherwood2,
C. J. Hammer3, J. Coverdale4, M. J. Anderson2
Sam Houston State Universtiy, Huntsville, TX, 2Sam
Houston State University, Huntsville, TX, 3North
Dakota State University, Fargo, ND, 4Texas A&M
University, College Station, TX
033 Use of ultrasonography to evaluate the accuracy
of objective and subjective measures of body
composition in horses.
K. B. Pritchett*, J. L. Leatherwood, K. J. Stutts,
M. J. Anderson
Sam Houston State University, Huntsville, TX
1
Limited information is available regarding the utility of ultrasonic measurements of longissimus muscle area and fat thickness as non-invasive and objective means to evaluate body
composition in horses. Therefore, 20 stock-type horses (2 to
10 y; 362 to 482 kg BW) were utilized in an 84-d trial to determine the relationship between ultrasonic measurements of
lean and fat tissue with several common methods of evaluating body composition in horses. Feeding was divided into 2
phases: in phase 1 (d 0 to 56), horses were individually offered 2.5% BW coastal bermudagrass hay (Cynodon dactylon), and in phase 2 (d 57 to 84), horses received 0.75% BW
of a commercially available pelleted concentrate (Cargill Animal Nutrition, Elk River, MN) that was formulated to meet
100% NRC requirements with an additional 1.5% BW coastal
bermudagrass hay. All horses were maintained, housed, and
exercised in accordance with objectives of the SHSU equine
behavior and training course. Intake was adjusted every 7 d
according to BW. Biweekly morphometric measurements including height, body length, heart girth circumference (HGC),
body condition score (BCS), and topline evaluation score
(TES) were obtained. In addition, ultrasonic measurements
of rump fat (RF), back fat (BF), intramuscular fat (IMF) and
longissimus muscle area (LMA) were collected by a certified
technician. All images were evaluated by an independent laboratory (Designer Genes Technologies, Harrison, AR). Data
were analyzed using the PROC CORR procedure of SAS to
determine relationships between the subjective and objective
measures of lean tissue and body fat. A moderate positive correlation existed between LMA and both height (r=0.43) and
BCS (r=0.32); however, only weak positive correlations to
LMA were observed for the measures of TES (r=0.19), body
length (r=0.13), and HGC (r=0.21). Moderately positive correlations also existed between RF and both BCS (r=0.50) and
TES (r=0.28), but there was no relationship between BCS or
TES and BF. Ultrasonic measurements indicated that LMA
has a greater relationship to height and BCS than HGC, body
length, and TES. Relationships between ultrasonic measurements and other assessments of body fat were low to moderate with BCS having the strongest relationship. These results
indicate that many of the common methods currently used to
determine the body composition of horses are inaccurate and
a comprehensive investigation regarding the utility of each of
these conventional methods is necessary to justify their continued use in the equine industry. Keywords: horses, body composition, ultrasonography
doi: 10.2527/ssasas2015-033
Limited information is available pertaining to potential benefits of barefoot trimming techniques under standard management conditions. Therefore, twelve mature Quarter horses
(8-14 y; 450-572 kg) were utilized in a 91-d trial to determine effects of barefoot trimming and shoeing on joints of the
forelimb and digital cushion thickness. Prior to the start of the
trial, all horses were adapted to a standardized exercise protocol and lameness examinations were performed by a veterinarian; hooves were allowed to grow naturally with minimal
farrier interventions. Horses were group housed in adjacent
dry lots and provided a commercially available concentrate
formulated to meet or exceed 100% NRC requirements with
ad libitum access to coastal bermudagrass hay. This study was
divided into 2 phases: d 0-42 horses were barefoot trimmed
(BF) and d 49-91 horses were shod (SD) on the forehand with
standard St. Croix plain lite shoes. Horses were group exercised 3 times per wk on a 132 x 3.7 m linear dirt track. Pedometers were fitted to randomly selected horses to account for
steps traveled during exercise. Measurements were obtained
every 21 d following exercise and included thermography images (FLIR Systems; Boston, MA) of carpal and metacarpal
joints, superficial horn of the frog, and medial and lateral sole
of the front digits. Joint circumferences were obtained utilizing a soft tape measure level with the accessory carpal and
proximal sesamoid bones, respectively. Digital cushion thickness was also measured ultrasonically through the superficial
apex of the frog using a 5.0-MHz convex probe and stand-off
pad following previously described methods. Data were analyzed using the PROC MIXED procedure of SAS. Mean circumferences of the carpal and metacarpal joints were greater
(P ≤ 0.01) in SD compared to BF. In BF phase, greater (P ≤
0.01) surface temperatures of the frog, medial, and lateral sole
were observed. There was no main effect (P ≥ 0.52) of d or
treatment on digital cushion thickness. However, in BF phase
horses (1.41 ± 0.13) had greater (P ≤ 0.01) digital cushion
thickness at d 42 compared to the equivalent (d 91) in the SD
phase (1.26 ± 0.14). These data indicate that a shod fore digit
may fail to establish hoof to ground contact that could lead to
a limited vascular exchange. This alteration in lower limb and
hoof load dispersion may cause an increase in the incidence
of lameness over time.
Keywords: equine, hoof, barefoot
doi: 10.2527/ssasas2015-032
16