@article{siciliano_gill_bowman_2017, title={Effect of Sward Height on Pasture Nonstructural Carbohydrate Concentrations and Blood Glucose/Insulin Profiles in Grazing Horses}, volume={57}, ISSN={["1542-7412"]}, DOI={10.1016/j.jevs.2017.06.004}, abstractNote={Six mature stock-type geldings with maintenance only requirements were used in a randomized cross-over design to determine the effect of sward height on pasture plant nonstructural carbohydrate (NSC) concentrations and blood glucose and insulin concentrations. Horses were randomly assigned to one of two tall fescue (Lolium arundinaceum Schreb cv Max-Q, Pennington Seed, Madison, GA) grazing cells (0.37 ha) having two different sward heights for a period of 7 days: (1) short (approximately 15 cm; n = 3) or tall (between 30 and 40 cm; n = 3). After the first 7-day period, treatment groups were reversed by moving horses to ungrazed cells having similar characteristics to those used in the first 7 days, so that all horses receive all treatments resulting in six observations per treatment. Both short and tall grazing cells were mowed to a height of approximately 15 cm 32 days before the experiment starts. The short grazing cells were removed to approximately 15 cm at 11 days before the start of the first 7-day period and again 1 day before the start of each 7-day period. All horses had access to pasture for 10 h/d beginning at 8 AM and ending at 6 PM. Although not at pasture, all horses were individually housed in 3.7 × 12.2 m partially covered pens containing automatic water troughs and a crushed stone surface. Herbage mass (kg DM/ha) was determined by use of a falling plate meter for each pasture to ensure that both groups of horses had adequate dry matter to provide grazing for at least 7 days. On day 7 of each period, jugular venous blood samples were collected from each horse before being turned out to pasture, and then at 2, 4, 6, and 8 hours after turn-out. Pasture samples were also collected from each grazing cell at the same time blood samples were taken. Serum and plasma from blood samples were harvested and analyzed for insulin and glucose concentrations, respectively. Pasture samples were analyzed for water soluble carbohydrate (WSC), ethanol soluble carbohydrate (ESC), and starch. The sum of WSC and starch were used as an estimate of NSC. Area under the curve (AUC) and peak concentration were calculated for both plasma glucose (PPG) and serum insulin (PSI) concentration and were analyzed using analysis of variance for randomized cross-over designs. Pasture WSC, ESC, starch, and NSC concentrations were analyzed using analysis of variance for randomized complete block design. A P value of < .05 was considered significant. Mean pasture plant NSC, WSC, and ESC concentrations were lower (P < .001) in short as compared with tall. Pasture plant starch concentration was not different between treatments. Mean pregrazing plasma glucose concentrations, PPG concentrations, and plasma glucose AUC were not affected by treatment. Mean pregrazing serum insulin concentrations were not affected by treatment. Mean PSI and insulin AUC were greater (P < .01) when horses grazed tall, as compared with short. In conclusion, decreasing the sward height by mowing pasture decreased NSC, WSC, and ESC concentrations and subsequently decreased the postprandial insulin response of horses grazing the pasture. These findings may be important in developing strategies aimed at preventing insulin resistance in grazing horses.}, journal={JOURNAL OF EQUINE VETERINARY SCIENCE}, author={Siciliano, Paul D. and Gill, Jennifer C. and Bowman, Morghan A.}, year={2017}, month={Oct}, pages={29–34} }
 @article{gill_lloyd_bowman_siciliano_pratt-phillips_2017, title={Relationships Among Digestible Energy Intake, Body Weight, and Body Condition in Mature Idle Horses}, volume={54}, ISSN={["1542-7412"]}, DOI={10.1016/j.jevs.2017.02.017}, abstractNote={The objective of this study was to evaluate the relationships among digestible energy (DE) intake, body weight (BW), and body condition score (BCS) in lean/moderate condition horses. The feed intake of 35 Quarter Horses (age 5.3 ± 1.2 years; BW 462 ± 39 kg; BCS 4.5 ± 0.5) was recorded daily over three, 42-day feeding trials. Horses were offered 1.75–2.00 kg DM/100 kg BW in Orchard grass hay and 0.2 kg/100 kg BW in whole oats. Body weight and BCS were recorded biweekly. Daily DE intake was calculated according to Pagan and recorded as the amount fed minus any refusal. The daily kilogram intake was multiplied by the DE (Mcal/kg) content of the feed to equal the total calories per day. The mean within-horse ΔBW and ΔBCS from 0 to 42 days of each trial were evaluated using paired t tests. Trial 1 horses consumed 24.5 Mcal/d and BW increased (P < .001) by 24 ± 3 kg; however, there was no significant change in BCS (0.0 ± 0.5). Trial 2 horses consumed 22.8 Mcal/d and BW increased (P = .009) by 8 ± 3 kg and BCS tended to increase (P = .06) by 0.5 ± 0.5. Trial 3 horses consumed 25.7 Mcal/d and BW and BCS increased (P < .001) by 22 ± 2 kg and 1.0 ± 0.5, respectively. According to trial, horses required approximately 19, 34, and 18 Mcal/kg of weight gain, respectively. Additional factors affecting weight gain are related to the individual.}, journal={JOURNAL OF EQUINE VETERINARY SCIENCE}, author={Gill, Jennifer Christine and Lloyd, Karen Elizabeth and Bowman, Morghan and Siciliano, Paul David and Pratt-Phillips, Shannon Elizabeth}, year={2017}, month={Jul}, pages={32–36} }