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The equine industry contributes $74 billion and provides 1.3 million jobs annually to the United States economy. However, limited information is available on the current salaries and benefits of equine professionals. In 2022, an online survey was conducted to assess salaries, benefits, and education levels of equine professionals across several career types in the equine industry. The survey consisted of 38 questions with conditional branching and was distributed through social media and e-newsletters. Survey branching focused on grouping participants by career type into the following categories: farm management, government, industry, nonprofit, private practice, and university. The most prevalent career type represented was farm management (34%) followed by private practice (18%), academia (17%), industry (15%), nonprofit (12%), and government (4%). Associations between variables were examined with Chi-squared analysis. An association was observed between education level and salary (P = 0.001, X 2 = 103.17) with salaries greater than $50,000 being more prevalent with advanced degrees. Similarly, job type and salary were associated (P = 0.001, X 2 = 73.47), where salaries for academia and industry careers were often greater than $50,000 and nonprofit and farm management salaries were more often less or equal to $50,000. Compared to professionals in farm management or in private practice, those in academia and government received more benefits (P<0.05). Data collected from this survey creates a baseline for evaluating compensation across the equine industry and exposed opportunities for improvements in future surveys. Outside of industry salary comparisons, survey data can be used by educators to emphasize the benefit of further education to increase salary and benefits., Competing Interests: Declaration of competing interest None of the authors has any financial or personal relationships that could influence or bias the content of the paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

In recent years, the number of horses submitted for necropsy has been in decline. This study aimed to identify the perceptions and barriers of equine necropsy through an online survey of horse owners. The data were analyzed by multivariate models for associations and factors that influenced decision making regarding necropsy. The survey yielded 1,366 usable responses. Respondents had higher familiarity with the term "autopsy" compared to "necropsy" (P < 0.001) and showed a greater level of comfort using the terms "body" and "mortality" compared to "carcass" (P < 0.001). Most respondents (82 %) had experienced euthanizing a horse, but few (27 %) were offered a necropsy. Of those offered a necropsy, a majority (81 %) opted to perform one. When asked about their reasons for choosing to have a necropsy performed, recommendations from veterinarians (77.87 OR, 95 % CI: 49.3, 127.5) and already knowing the cause of death (1.85 OR, 95 % CI: 1.2, 30) were positively associated while a benefit to herd health was negatively associated (0.55 OR, 95 % CI: 0.3, 1.0). Owning horses for use as competition animals (1.44 OR, 95 % CI: 0.9, 2.2), the desire for personal closure (1.76 OR, 95 % CI: 1.1, 2.9), and the goals to protect human health (1.29 OR, 95 % CI: 1.0, 1.6) and to improve herd health (1.43 OR, 95 % CI: 1.1, 1.9) were positively associated with a likelihood of choosing to have a necropsy performed or recommending necropsies in the future. This research highlights the need for education of horse owners about the option and benefits of necropsy, and the use of more societally accepted language., Competing Interests: Declaration of competing interest None of the authors has any financial or personal relationships that could influence or bias the content of the paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Recent changes in rendering availability for chemically-euthanized animals have created a need to explore composting as an equine mortality management method. The objectives of this study were to evaluate equine mortality composting in the Upper Midwest during fall and spring, document sodium pentobarbital concentrations throughout the process, and determine nutrient content of finished compost. During each season, four horses were euthanized by intravenous administration of sodium pentobarbital. Carcasses were positioned at the center of a woodchip and shavings base and covered with a 2:1 mixture of horse stall waste and cattle feedlot waste. Data loggers were placed at 46- and 91cm depths to record pile temperatures every 8 hours. At turning (44-50 days) and trial conclusion (181-216 days), compost piles were sampled for sodium pentobarbital and nutrient composition. Piles contained large bones after 6 months of composting. Sodium pentobarbital remained detectable at trial conclusion (<0.002-1.49 mg kg 1 dry matter); however, composting reduced the estimated quantities of sodium pentobarbital by ≥94% (P ≤ .001). Compost from each season met ideal land application values for organic matter (45%-48%), pH (7.3-7.6), and electrical conductivity (3.3-3.4 mm hos cm -1 ). Low NPK and high C:N ratio (20-30) indicate compost could partially replace synthetic fertilizers when land applied. These findings suggest equine mortality composting is an effective management practice during fall and spring in the Upper Midwest. While remaining sodium pentobarbital residues were minimal, further research is needed to determine environmental implications of composting chemically-euthanized equines., (Copyright © 2022. Published by Elsevier Inc.)

Blanketing is a highly debated practice utilized in the equine community as part of winter horse management. Despite this, little research is available on the prevalence, reasoning, and management decisions related to use of blankets for horses in North America. Therefore, the objective of this study was to develop an understanding of blanketing management practices and beliefs of North American horse owners. A 33-question, branched online survey was developed and available between December 1, 2020 and January 5, 2021 and advertised using social media and e-newsletters. The FREQ procedure for Chi-squared analysis in SAS was used when comparisons were made between participant-reported frequencies. There were 1,450 respondents from North America who completed the survey. Demographic information indicated the majority of respondents were from the Midwest region of the United States (68%); however, geographical region did not impact the frequency of blanket usage (P = .17, X 2  = 8.99). When respondents were asked to self-report discipline, recreational riding was the most prevalent (40%). Overall, 54% of respondents (n = 790) reported blanketing the majority of their horses during the winter. The most frequently selected reason respondents chose to blanket horses was exposure to precipitation (78%). Out of the respondents who did not blanket the majority of their horses (n = 660), the primary reason for not blanketing was access to shelter (50%). This survey provides valuable information on blanketing and winter management practices reported by horse caretakers in North America and will help direct future research and education efforts., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Cover crops are commonly used to provide environmental benefits and can extend the grazing season, but have not been explored in horse pastures. The objectives of this research were to evaluate forage mass, forage nutrient composition, and preference of annual ryegrass, winter rye, berseem clover, purple top turnip, and daikon radish under horse grazing. Cover crops were seeded in monoculture and mixtures in August 2018 and 2019 as a randomized complete block with four replicates and grazed by four adult horses. Prior to grazing, forages were sampled to determine herbage and root mass and nutrient composition. After grazing, forages were visually assessed for the percentage of removal on a scale of 0 to 100% to estimate preference. Data was analyzed using an analysis of variance and linear regression; significance was set at P ≤ .05. Berseem clover was the lowest producing forage (590 to 1,869 kg ha -1 dry matter; P ≤.001), while minimal differences in herbage mass were observed among the other cover crops. All forages met digestible energy (>2.17 Mcal kg -1 ) and crude protein (>19%) requirements for idle, adult horses. Berseem clover was most preferred (>73% removal) while turnip and radish were the least preferred (<19% removal; P ≤.001). Winter rye and annual ryegrass in monoculture and when seeded with berseem clover were moderately preferred (20%-68% removal). Placing a priority on preference, berseem clover, annual ryegrass, and winter rye appear to be suitable cover crops to extend the grazing season in horse pastures., (Copyright © 2021. Published by Elsevier Inc.)

Reduced lignin alfalfa (Medicago sativa L.) has the potential to provide a higher-quality forage source for livestock by improving forage digestibility. This study was conducted to evaluate apparent digestibility when feeding reduced lignin and nonreduced lignin alfalfa hay to adult horses, and to examine mean fecal particle size (MFPS) and mean retention time (MRT) between alfalfa forage types. In 2017, reduced lignin ("54HVX41") and nonreduced lignin ("WL355.RR") alfalfa hay was harvested in Minnesota at the late-bud stage. Alfalfa hays were similar in crude protein (CP; 199 g/kg), neutral detergent fiber (NDF; 433 g/kg), and digestible energy (2.4 Mcal/kg). Acid detergent lignin concentrations were lower for reduced lignin alfalfa hay (74 g/kg) compared to nonreduced lignin alfalfa hay (81 g/kg). Dietary treatments were fed to six adult, stock-type horses in a crossover study. Experimental periods consisted of a 9-d dietary adaptation phase followed by a 5-d total fecal collection phase, during which horses were housed in individual boxstalls and manure was removed on a continuous 24-h basis. At 12-h intervals, feces were thoroughly mixed, subsampled in duplicate, and used for apparent digestibility and MFPS analysis. On day 2 of the fecal collection phase, horses were fed two indigestible markers, cobalt (Co) and ytterbium (Yb), which were fed as Co-ethylenediaminetetraacetic acid and Yb-labeled NDF residue, respectively. Additional fecal samples were taken at 2-h intervals following marker dosing until 96-h post-dosing to evaluate digesta MRT. Data were analyzed using the MIXED procedure of SAS, with statistical significance set at P ≤0.05. Dietary treatment (i.e., alfalfa hay type) was included as a fixed effect, while experimental period and horse were considered random effects. Dietary treatments were similar in dry matter intake (1.6% bodyweight) and time to consumption (7.6 h). Apparent dry matter digestibility (DMD) was greater for reduced lignin alfalfa (64.4%) compared to nonreduced lignin alfalfa (61.7%). Apparent CP and NDF digestibility did not differ between dietary treatments, averaging 78% and 45%, respectively. Dietary treatments were similar in MFPS (0.89 mm) and MRT for both liquid (23.7 h) and solid (27.4 h) phase material. These results indicate an improvement in DMD for reduced lignin alfalfa hay when fed to adult horses, with no change in forage consumption, fecal particle size, or digesta retention time., (© The Author(s) 2021. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Challenges associated with burial, rendering, and cremation have forced horse owners to seek alternative mortality disposal methods. While equine mortality composting has been successfully demonstrated, industry-wide adoption has been limited. Therefore, evaluation of horse owners' and veterinarians' perceptions and experience with mortality composting is needed. Two surveys were developed to evaluate industry practices and decisive factors regarding equine euthanasia and mortality disposal methods. Each survey was designed for a separate audience: horse owners or veterinarians serving equines. The surveys were advertised as weblinks on relevant Facebook pages, e-newsletters, and email listservs. Data were analyzed using bivariate and multivariate models for associations and factors influencing decisions surrounding composting. The surveys yielded 1,225 and 244 usable responses from horse owners and veterinarians, respectively. Respondent demographics were consistent with previous survey reports for horse owners and veterinarians in the United States with a majority being female between 41 and 60 years of age with long-term industry involvement. Horse owners (86%) and veterinarians (84%) that preferred chemical euthanasia tended to prefer burial (58% and 42%, respectively) over other mortality disposal methods. Only 12% of horse owner respondents had ever tried composting and only 25% of veterinarian respondents had ever recommended composting. Horse owner (47%) and veterinarian (67%) respondents indicated they would be more open to trying and recommending mortality composting if more scientific research were available. Equine mortality composting shows potential as a primary disposal method for the equine industry. Research and educational programs are key to industry-wide acceptance of equine mortality composting., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Equine obesity is common, reducing quality of life and requiring dietary energy restriction. Equine obesity is identified using subjective body condition scoring. Considerations are given for life stage and health status when managing obese equines. Every effort should be made to maximize feeding duration, and minimize time spent without feed while meeting all essential nutrient requirements. Limiting total daily dry matter intake to 2% of current bodyweight per day of a low caloric, forage-based diet may result in adequate body weight loss. Weight loss and weight management plans should be monitored for success and potential gastrointestinal, metabolic, and/or behavioral complications., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Storing hay outdoors can result in detrimental changes in forage quality. Additionally, alfalfa ( Medicago sativa L.) cultivar may influence dry matter intake (DMI) and hay waste when feeding livestock. The objectives were to determine the effects of conventional or reduced-lignin alfalfa round bales stored outdoors and wrapped with plastic twine, net wrap, or B-Wrap on forage quality, beef cow preference, and hay waste. Round bales made from reduced-lignin ( n = 12) or conventional ( n = 12) alfalfa cultivars were baled and stored outdoors for 16 mo. Within each cultivar, four bale replicates were bound with plastic twine, net wrap, or B-Wrap. After storage, bales were fed in a switchback design with period confounded with alfalfa cultivar to 18 lactating Angus cows ( Bos Taurus L.). The pairs had ad libitum access to three round-bale feeders where bales of each wrap type were placed for eight 48 h periods. Position of round bale wrap type was rotated according to a Latin Square arrangement. Bales were weighed and waste surrounding each feeder was collected at 24 and 48 h to calculate DMI and hay waste. Statistical significance was set at P < 0.05. Alfalfa cultivar did not impact any of the response variables ( P > 0.05). At feeding, round bales wrapped in net wrap had greater ( P < 0.015) moisture content (16.4%) compared with those wrapped with B-Wrap (12.8%). Neutral detergent fiber was lower ( P = 0.03) in bales wrapped in B-Wrap (46%) compared with twine-tied bales (49%) while net wrapped bales were not different. Total digestible nutrients ( P = 0.02), and relative feed value ( P = 0.04) were lower in twine-tied bales compared with B-Wrap while net wrapped bales were not different. Twine (7.1 × 10 6 colony forming units [CFU]/g) and net wrap (4.7 × 10 6 CFU/g) bales had greater ( P < 0.0001) mold counts than B-Wrap bales (4.8 × 10 4 CFU/g), while concentrations of other forage components and yeast counts were not different among wrap types ( P > 0.05). Total DMI, and DMI during the first 24 h, were greater ( P ≤ 0.032) for B-Wrap bales compared to twine-tied bales indicating preference for hay wrapped in B-Wrap; net wrapped bales were not different. Dry matter intake in the first 24 h was negatively associated with the mold count ( r = -0.52; P = 0.02), and hay waste was not affected by wrap type ( P > 0.05). These results confirm that wrap type affected forage quality and mold counts, which in turn influenced beef cattle preference of round bales stored outdoors., (© The Author(s) 2020. Published by Oxford University Press on behalf of the American Society of Animal Science.)

Social media are an ever-present part of daily life and for researchers and may be a useful platform to increase potential participant pools for Web-based surveys. Although survey usage to evaluate practices in the equine community is not new, the use of social media to advertise and enhance the usage of Web-based surveys is novel. In 2018, the University of Minnesota (UMN) equine Extension program developed and administered two Web-based surveys through the UMN equine Extension Facebook page and monthly e-newsletter. Surveys focused on industry practices and motivating factors behind the usage of hay nets and methods to provide water in the winter to horses. Two thousand eighty-eight participants started the hay net survey with a completion rate of 96%, whereas the winter water survey had a completion rate of 94%, with 930 participants starting the survey. Participant demographics aligned with previous survey populations and represented all regions of the United States. Both surveys revealed information, which described current industry practices as well as future research needs. In addition, participants were asked if scientific research would impact future decision-making in regards to equine management. When exploring hay net practices, most participants responded "maybe" (48%, n = 527), whereas for the winter water survey, the majority responded "yes" (68%, n = 877). Web-based surveys administered through social media present multiple benefits, including savings of both cost and labor, compared with traditional mailed surveys. Despite the success observed with the present surveys, this methodology may not be suitable for organizations with limited social media followers., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Goldfish (Carassius auratus) have been reported as a method to keep water tanks clean; however, little information exists on this approach. The objectives were to evaluate the efficacy of goldfish on maintaining water quality in tanks and to evaluate the frequency that this method is used. The first objective was completed during June through October 2017 in St. Paul, MN, using plastic and metal 379 L stock tanks, each with and without goldfish in a drylot that housed six adult horses. The stocking rate was 5 goldfish per tank. Daily readings of total dissolved solids (TDS) and water turbidity (NTU), and weekly samples to measure chlorophyll a were taken. At the end of each 28-day period, tanks were cleaned and rotated. Plastic tanks had lower TDS than metal tanks (P < .001); however, metal tanks had lower NTU and chlorophyll a (P ≤ .008). Adding goldfish resulted in lower TDS (P < .001); however, there was no effect on NTU or chlorophyll a (P ≥ .097). No parameters had an impact on horse preference (P ≥ .108). The second objective was completed using an online survey that was open from October 31 until December 15, 2018. Of the 672 completed surveys, 56% had not tried using goldfish in water tanks, 26% had utilized goldfish in the past, and 18% currently used goldfish. The inclusion of goldfish in water tanks did not affect all water quality parameters; however, 44% of survey respondents had tried, or were currently using, this management method., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Adding breed type, height, and neck circumference to body length and girth circumference improves bodyweight (BW) estimation in different breeds of horses; however, equations have not been developed for all breed types. The objectives were to develop BW estimation equations for Miniature, saddle-type, and Thoroughbred horses using morphometric measurements. Measurements were collected on adult (≥3 years, nonpregnant) saddle-type (n = 209), adult (n = 249) and juvenile (<3 years, n = 61) Miniatures, and adult Thoroughbreds (n = 100). Personnel determined body condition score (BCS), measured withers height and girth circumference at the third thoracic vertebra, body length from the point of the shoulder to the point of the buttock and to a line perpendicular to the point of the buttock, and neck circumference at the midway point between the poll and withers. Each horse was weighed using a livestock scale. Bodyweight estimations equations were developed using linear regression modeling and log transformation. Mean (±standard deviation) BCS was 6.1 (±0.8), 5.4 (±0.6), 6.0 (±1.0), and 5.0 (±0.6) for adult and juvenile Miniatures, saddle-type, and Thoroughbreds, respectively. Bodyweight estimation equations developed through the current research were within 4% of the scale BW and offered improvements over previous BW estimation equations and weight tapes, which were off by 5%-25%. Owner-estimated BW was within 8%-15% of scale BW. Morphometric measurements were successfully used to develop BW equations for Miniature, saddle-type, and Thoroughbred horses. The equations will assist owners and professionals with managing horse BW and will be added to the Healthy Horse application., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Spring and late fall grazing can lead to metabolic problems in horses (Equus caballus L.) as a result of elevated nonstructural carbohydrates (NSC) in pastures. Therefore, the objectives were to determine the impact of different forage species on blood glucose and insulin concentrations of horses during the spring and late fall. Research was conducted in May (spring) and October (late fall) in St. Paul, MN. Alfalfa (Medicago sativa L.) and mixed perennial cool-season grasses (CSG) were grazed in spring, and CSG and teff (Eragrostis tef [Zucc.] Trotter) were grazed in late fall by six adult horses randomly assigned to a forage in a cross-over design. Jugular catheters were inserted 1 hour before the start of grazing, and horses had access to pasture from 8 AM to 4 PM in the spring and 8 AM to 12 PM in the late fall. Jugular venous blood samples were collected from each horse before being turned out (0 hours) and then at 2 hours intervals after turnout. Plasma and serum samples were collected and analyzed for glucose and insulin, respectively. Corresponding forage samples were taken by hand harvest. Seasons were analyzed separately, and data were analyzed using the MIXED procedure in SAS with P ≤ .05. Teff had lower NSC compared with CSG in the late fall (P ≤ .05) with subsequently lower average glucose, average insulin, and peak insulin in horses grazing teff compared with CSG (P ≤ .05). These results suggest grazing teff could lower the glucose and insulin response of horses during late fall., (Copyright © 2018 Elsevier Inc. All rights reserved.)

The impact of forage species on plasma amino acid (AA) concentrations of grazing horses (Equus caballus L.) is unknown. The objectives of this study were to determine the impact of different forage species on plasma AA concentrations and protein synthesis. Research was conducted in July in St. Paul, MN, USA. Alfalfa (Medicago sativa L.), mixed perennial cool-season grasses (CSGs), and teff (Eragrostis tef [Zucc.] Trotter) pastures were grazed by six horses randomly assigned to one of three forage types in a replicated Latin-square design. Horses had access to pasture each day. Jugular venous blood samples were collected from each horse before being turned out (0 hours) and then at 2 and 4 hours after turnout. Corresponding forage samples were taken by hand harvest and analyzed for AA concentrations. Equine muscle satellite cell cultures were treated with sera from grazing horses to assess de novo protein synthesis. Data were analyzed using PROC MIXED in SAS. When evaluating forage, AA concentrations were generally lowest in teff and highest in CSG (P ≤ .05). Significant differences in threonine concentration in the plasma were observed; there was no effect on de novo protein synthesis of cultured equine myotubes treated with plasma obtained from the grazing horses (P ≥ .20). As a result, although there were significant differences in forage AA content, only plasma threonine concentration was different at 4 hours with no effect on protein synthesis of cultured equine satellite cells., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Elevated nonstructural carbohydrate (NSC) values in pasture forages can cause adverse health effects in some horses (Equus caballus L.). The objectives of this study were to determine the impact of different forage species on blood glucose and insulin concentrations of horses throughout the grazing season. Research was conducted in July (summer) and September (fall) in St. Paul, MN. Alfalfa (Medicago sativa L.), mixed perennial cool-season grasses (CSG), and teff (Eragrostis tef [Zucc.] Trotter) pastures were grazed by six horses (24 ± 2 years) that were randomly assigned to one of three forage types in a replicated Latin-square design. Jugular catheters were inserted 1 hour before the start of grazing and horses had access to pasture each day from 08:00 to 16:00 hours. Jugular venous blood samples were collected from each horse before being turned out (0 hours) and then at 2-hour intervals following turnout. Plasma and serum samples were collected and analyzed for glucose and insulin, respectively. Corresponding forage samples were taken by hand harvest. Seasons were analyzed separately and data were analyzed using the MIXED procedure in SAS with P ≤ .05. Teff generally had lower (P ≤ .05) equine digestible energy, crude protein, and NSC compared to the other forages. Differences in peak insulin were observed between horses grazing CSG and teff during the fall grazing (P ≤ .05). These results suggest grazing teff could lower the glucose and insulin response of some horses., (Copyright © 2018 Elsevier Inc. All rights reserved.)

Modern horse management systems tend to limit a horse's opportunity to forage, rely on meal feeding, and may contribute to the increase in equine obesity. The use of slow-feed hay nets represents an opportunity to extend foraging time while feeding a restricted diet. The objectives of this study were to determine if limit feeding combined with a slow-feed hay net would affect morphometric measurements and postprandial metabolite and hormone patterns in overweight adult horses. Eight adult Quarter horses (BW 563 kg ± 4.6 kg; BCS 7.2 ± 0.3) were used in a randomized complete block design, with 4 horses assigned to feeding hay off the stall floor (FLOOR) and 4 horses assigned to feeding from a slow-feed hay net (NET). Horses were fed in individual stalls at 1% BW each day, split evenly between 2 meals at 0700 and 1600 h. Body weight, BCS, neck and girth circumference, cresty neck score, and ultrasound measurements of average rump fat, longissimus dorsi (LD) depth, and LD thickness were taken on d 0, 14, and 28. Three 24-h blood samplings were conducted on d 0, 14, and 28 and were analyzed for glucose, insulin, cortisol, and leptin concentrations. Samplings occurred every 30 min for 3 h postfeeding, with hourly samples occurring between feedings. Horses feeding from the FLOOR took less time to consume their hay meal compared with horses feeding from the NET ( < 0.001). All horses lost weight over the 28-d period ( < 0.0001); however, no difference was observed between treatments. There was no difference in BCS, neck and girth circumference, cresty neck score, rump fat, or LD depth between days or treatments ( ≥ 0.25). There was an effect of day on LD thickness in horses feeding from the NET. Longissimus dorsi thickness was lower on d 28 compared with that on d 0 ( = 0.0257). Only time to peak insulin and peak cortisol were affected by treatment ( ≤ 0.037), with horses feeding from the NET having lower values than horses feeding from the FLOOR. Average glucose, insulin, cortisol, and leptin were affected by day ( ≤ 0.0102). Glucose and insulin values increased, whereas cortisol and leptin levels decreased throughout the 28-d study. The use of a slow-feed hay net coupled with a limit-fed diet appears to be an effective method for decreasing BW and maintaining more homeostatic levels of postprandial metabolites and hormones when feeding overweight adult horses.

Excessive BW has become a major health issue in the equine (Equus caballus) industry. The objectives were to determine if the addition of neck circumference and height improved existing BW estimation equations, to develop an equation for estimation of ideal BW, and to develop a method for assessing the likelihood of being overweight in adult equids. Six hundred and twenty-nine adult horses and ponies who met the following criteria were measured and weighed at 2 horse shows in September 2011 in Minnesota: age ≥ 3 yr, height ≥ 112 cm, and nonpregnant. Personnel assessed BCS on a scale of 1 to 9 and measured wither height at the third thoracic vertebra, body length from the point of shoulder to the point of the buttock, neck and girth circumference, and weight using a portable livestock scale. Individuals were grouped into breed types on the basis of existing knowledge and were confirmed with multivariate ANOVA analysis of morphometric measurements. Equations for estimated and ideal BW were developed using linear regression modeling. For estimated BW, the model was fit using all individuals and all morphometric measurements. For ideal BW, the model was fit using individuals with a BCS of 5; breed type, height, and body length were considered as these measurements are not affected by adiposity. A BW score to assess the likelihood of being overweight was developed by fitting a proportional odds logistic regression model on BCS using the difference between ideal and estimated BW, the neck to height ratio, and the girth to height ratio as predictors; this score was then standardized using the data from individuals with a BCS of 5. Breed types included Arabian, stock, and pony. Mean (± SD) BCS was 5.6 ± 0.9. BW (kg) was estimated by taking [girth (cm)(1.48)6 × length (cm)(0.554) × height (cm)(0.599) × neck (cm)(0.173)]/3,596, 3,606, and 3,441 for Arabians, ponies, and stock horses, respectively (R(2) = 0.92; mean-squared error (MSE) = 22 kg). Ideal BW (kg) was estimated by taking [length (cm) × 2.8] + [height (cm) × 4.2] - 611, 606, and 577 for Arabians, ponies, and stock horses, respectively (R(2) = 0.86; MSE = 24). Equids with a BCS of ≥ 7 had a greater likelihood of being overweight, and the model suggested cutoffs at the 48th and 83rd percentiles for underweight and overweight individuals, respectively. Morphometric measurements were successfully used to develop equid BW-related equations.

Management strategies for horses with respiratory disease include soaking hay before feeding. Hay steaming is an alternative to this practice; however, little is known about its impact on forage nutritive values or intake. The objective was to determine the effect of steaming on forage nutritive value and intake by horses. Two alfalfa (Medicago sativa L.)-orchardgrass (Dactylis glomerata L.) mixed hays were evaluated: a low moldy (NM) and moderately moldy (MM) hay. Six mature horses were used in a 10 d crossover design. Three horses were assigned to each hay type and treatments were switched on d 6. Each day, one bale of each hay was sampled (pre- and poststeaming) and steamed for 90 min using a commercial hay steamer. Two flakes of steamed or unsteamed NM or MM hay were weighed and offered simultaneously to each horse in individual hay nets. Horses were allowed access to hay for 2 h, orts were collected, and 2 h DMI was calculated. Six additional bales of NM and MM were used to evaluate the effect of steaming on total suspended particulate (TSP). Flakes of unsteamed or steamed hay were agitated in an electric cement mixer, and TSP were recorded every min for 30 min using a tapered element oscillating microbalance sampler. Paired t tests and PROC MIXED of SAS (SAS Inst. Inc., Cary, NC) were used to compare steamed and unsteamed hay nutritive values, mold concentration, TSP, and 2 h DMI. Steaming increased hay moisture and therefore reduced DM to 77 and 81% for NM and MM, respectively (P < 0.001). In NM and MM hay, steaming reduced P content by 16 and 17%, respectively (P ≤ 0.007). Steaming reduced water-soluble carbohydrates (WSC) and ethanol-soluble carbohydrates (ESC) by 13% (P = 0.001) and 27% (P = 0.003), respectively, for MM but had no effect on NM (P > 0.05). Steaming reduced mold concentrations in both hays by ≥ 91% (P < 0.001). Total suspended particulate of MM hay was reduced by 55% (P = 0.043), but TSP in NM hay was not affected by steaming (P = 0.445). Dry matter intake of NM was increased by steaming; horses ingested 0.64 kg of unsteamed and 2.02 kg of steamed hay (P < 0.001). Dry matter intake of MM was not affected by steaming (P > 0.05). For NM hay, steaming decreased P and mold concentrations and increased DMI of the hay but had no effect on TSP. In MM hay, steaming reduced P, WSC, ESC, mold concentrations, and TSP but did not affect DMI. Steaming represents a strategy for reducing TSP and mold concentrations and increasing DMI in some hays but can result in leaching of essential nutrients.

Reasons for Performing Study: We hypothesised that seasonal pasture myopathy (SPM), which closely resembles atypical myopathy (AM), was caused by ingestion of a seed-bearing plant abundant in autumn pastures., Objectives: To identify a common seed-bearing plant among autumn pastures of horses with SPM, and to determine whether the toxic amino acid hypoglycin A was present in the seeds and whether hypoglycin metabolites were present in SPM horse serum or urine., Methods: Twelve SPM cases, 11 SPM pastures and 23 control farms were visited to identify a plant common to all SPM farms in autumn. A common seed was analysed for amino acid composition (n = 7/7) by GC-MS and its toxic metabolite (n = 4/4) identified in conjugated form in serum [tandem mass spectrometry (MS/MS)] and urine [gas chromatography (GC) MS]. Serum acylcarnitines and urine organic acid profiles (n = 7) were determined for SPM horses., Results: Seeds from box elder trees (Acer negundo) were present on all SPM and 61% of control pastures. Hypoglycin A, known to cause acquired multiple acyl-CoA dehydrogenase deficiency (MADD), was found in box elder seeds. Serum acylcarnitines and urine organic acid profiles in SPM horses were typical for MADD. The hypoglycin A metabolite methylenecyclopropylacetic acid (MCPA), known to be toxic in other species, was found in conjugated form in SPM horse serum and urine. Horses with SPM had longer turn-out, more overgrazed pastures, and less supplemental feeding than control horses., Potential Relevance: For the first time, SPM has been linked to a toxin in seeds abundant on autumn pastures whose identified metabolite, MCPA, is known to cause acquired MADD, the pathological mechanism behind SPM and AM. Further research is required to determine the lethal dose of hypoglycin A in horses, as well as factors that affect annual seed burden and hypoglycin A content in Acer species in North America and Europe., (© 2012 EVJ Ltd.)