Six mature horses were offered both plain water and water with one of 4 different supplements. Additives included 2 electrolyte preparations (Farnam Apple Dex and Land O'Lakes Calf electrolyte), a vitamin/mineral (Farnam Red Cell) additive, and a joint additive (Finish Line Fluid Action). All additives were offered at a rate of 28 g per 5 gallons of water. Water intake from buckets was recorded via weight and replenished at 7:00 am and 6:00 pm each day. Horses were fed the same diets, had unlimited access salt, and were housed individually.
There was an effect of adding supplements and electrolytes to water as horses preferred plain water with a mean daily intake of 3 gallons versus 1 gallon for supplement or electrolyte water; horses drank over twice the amount of plain water compared to supplement or electrolyte water. There was no difference within the additive treatments for water intake. There was a trend for water intake to be affected by time of day, with the greatest volume consumed overnight. This trend may have been influenced by timing of water weighing and replenishment, and/or housing management conditions.
Adding supplements or electrolytes to water can decrease intake in horses. This may lead to dehydration, poor performance or other adverse health effects in horses. If planning to add supplements or electrolytes, acclimate the horse before traveling or placing the horse in a stressful condition.
Summarized by Krishona Martinson, PhD, University of Minnesota
]]>Eighteen mature Quarter Horse mares were assigned randomly to three treatment groups. The microchip group (n = 7) had microchips inserted using a sterile needle and syringe; the "sham" group (n = 7) had a needle inserted but no microchip; and the control group (n = 4) had no insertion. The insertion site was visually determined by a veterinarian to be within the nuchal ligament on the left side of the horse, with a transverse position halfway between withers and poll, and dorsal position several centimeters below the crest of the neck.
The inflammatory response was measured over a 2-week period by measuring dermal temperature, response to pressure and swelling at the insertion site, and plasma serum amyloid A (SAA). SAA is expressed in response to inflammatory stimuli.
For the migration component of the study, radiographs of the seven microchipped horses were taken over 6 months after insertion. These radiographs allowed measurement between a select vertebral point and the microchip.
The microchip and sham insertion did not cause a detectable increase in temperature. Algometer readings, used to quantify pressure necessary to induce a pain threshold response, indicated that microchip insertion area was more sensitive than sham insertion at 2 hours on day 1, and day 3 post insertion. Visible swelling began 2 hours post-insertion and resolved by day 3. SAA concentrations were affected by day following insertion, but not by treatment group. Increases in SAA concentration could not be matched with local insertion reactions. Migration was not detected in any of the horses during the 6 months.
Microchip identification is a viable alternative form of identification for equids. It does not cause excessive inflammation or continued tissue irritation after insertion. It also does not migrate if implanted within the nuchal ligament on the left side of the horse halfway between the withers and poll.
However, it may be important to continue to assess the microchips for migration in young growing animals. For some breed registries, identification has to be obtained on registration, so microchip insertion will have to be performed at less than 1 year of age. Although the microchip may not actually be moving, the development of the tissues around the microchip could put it in a different position than anticipated. Future studies should investigate ideal location as affected by age for microchip insertion.
Summarized by Krishona Martinson, PhD, University of Minnesota
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Four mature ponies were used for this study. Pasture intakes were measured on four, 3 hour occasions per pony when fitted with a muzzle or grazing without a muzzle. Pasture intake was determined by change in body weight after grazing.
Pasture intakes were significantly reduced when ponies were fitted with a grazing muzzle. Ponies averaged 1 pound of forage per 3 hours with grazing muzzles compared to 7 pounds of forage per 3 hours without a muzzle, representing a 83% reduction in pasture intake for ponies wearing grazing muzzles compared to those without. Pasture dry matter intake by ponies without grazing muzzles averaged 0.8% body weight during the 3 hours, which is equivalent to one half to two-thirds of the recommended daily energy requirement.
This evidence suggests that grazing muzzles are an effective means of restricting pasture intake by ponies.
Summarized by Beth Allen, University of Minnesota
]]>Two alfalfa orchardgrass mixed hays were evaluated: a low and moderately moldy hay. Each day, one bale of each hay was steamed for 90 minutes using a commercial hay steamer (Happy Horse Products). Two flakes of steamed or un-steamed low or moderately moldy hay were offered simultaneously to six adult horses in individual hay nets (thee horses per treatment). Horses were fed for 5 days and then switched hay types for 5 additional days. Horses were allowed access to hay for 2 hours and dry matter intake was calculated. Flakes of un-steamed or steamed hay were also agitated in an electric cement mixer, and dust concentrations were recorded every min for 30 minutes using a tapered element oscillating microbalance (TEOM) sampler.
Steaming increased hay moisture and therefore reduced dry matter to 77 and 71% for low and moderately moldy hay, respectively. In both low and moderately moldy hay, steaming reduced phosphorus content. Steaming reduced water soluble and ethanol soluble carbohydrate content by 13% and 27%, respectively, for moderately moldy hay, but had no effect on low mold hay. Steaming reduced mold levels in both hays. Dust concentrations of moderately moldy hay were reduced by 55%; however, dust levels in low mold hay were not affected by steaming . Dry matter intake of low mold hay was increased by steaming; however, dry matter intake of moderately moldy hay was not affected by steaming.
For hay with low mold levels, steaming decreased mold levels, increased dry matter intake of the hay, but had no effect on dust level. In moderately moldy hay, steaming reduced mold and dust levels, but did not improve dry matter intake. Steaming represents a management strategy for reducing dust and mold levels and increasing dry matter intake in some hays. However, steaming should not replace the main goal of feeding good quality (i.e. low in dust and mold) hay.
Co-authors: J. Earing, PhD, M. Hathaway, PhD, C. Sheaffer, PhD, B. Hetchler, L. Jacobson, PhD, and J. Paulson, University of Minnesota and Tennessee Farmers Cooperative.
Continual temperature monitoring showed windrows maintained a minimum average temperature of 50°C between days 1 and 3, and the highest average maximum temperature was recorded on day 5 (57° C). The average viability of the eggs was significantly reduced after 2, 4, or 6 days in the compost windrow. The viability dropped to 0% after 8 days of composting.
Researchers concluded a well-maintained compost system is capable of rendering P. equorum eggs non-viable within 8 days, when eggs are located within the interior of the windrow.
Summarized by: Jennifer Earing, PhD, previously with the Univ. of Minn.
Nine Quarter Horse geldings were fed a 12% crude protein pellet diet at 0.75% body weight twice daily from one of the three feeders for 3 days, and then switched to the next feeder.
The horses spent more time eating from the Pre-Vent feeders (31 minutes) than from bucket (19 minutes) and tub (19 minutes) feeders. When fed from Pre-Vent feeder, horses dropped significantly less feed (3%) of their ration than when fed from the bucket (10%) and tub (7%)feeders. When the most wasteful horse was fed from the Pre-Vent feeder, he lost a average of 9% of his grain, compared with 33% when fed from the bucket, and 26% when fed from the tub feeders.
The Pre-Vent design is useful for increasing time spent eating and reducing grain wastage.
Summarized by Krishona Martinson, PhD, University of Minnesota
Summarized by: Krishona Martinson, PhD, Univ. of Minn.
]]>Cool-season grasses are the foundation of productive pastures throughout most of the U.S., however, many grasses have not been evaluated under horse grazing in the Midwest U.S. The objective of this study, conducted at the University of Minneosota, was to evaluate forage yield and persistence of cool-season grasses under horse grazing.
Four adult horses grazed tall fescue, meadow fescue, quackgrass, smooth bromegrass, meadow bromegrass, reed canarygrass, perennial ryegrass, timothy, Kentucky bluegrass, creeping foxtail, and orchardgrass. Horses grazed each month from May to October in 2010 and May to September in 2011.
Orchardgrass, meadow fescue, Kentucky bluegrass and tall fescue were the most persistent grasses with ≥78% ground cover, while timothy, reed canarygrass, smooth bromegrass, and creeping foxtail were less persistent, with ≤ 24% ground cover.
Orchardgrass produced the highest yields while creeping foxtail, smooth bromegrass, and timothy produced the lowest yield. The majority of yield for most grasses occurred during summer, with summer months contributing 32 to 74% of the total yield.
Kentucky bluegrass, timothy, and meadow fescue were the most preferred grasses with most post-grazing forage removals greater than 60%, while meadow bromegrass, creeping foxtail, reed canarygrass, and orchardgrass were less preferred with most post-grazing forage removals less than 50%.
To maximize forage use, grasses with similar preferences that persist well under horse grazing should be planted in horse pastures. A mixture that results in uniform grazing should maximize forage use and minimize pasture maintenance and associated expenses. To accomplish this, planting mixtures of Kentucky bluegrass, orchardgrass, and tall and meadow fescue in well-grained soils should achieve a balance of forage persistence, horse preference, and maximum yield in Midwest U.S. horse pastures.
]]>The population of horses 20 years of age and older is rising, and little research exists exploring the differences in nutrient digestibility in aged horses versus adult horses. It is widely accepted that aged horses have a decreased ability to absorb nutrients from the diet. The objective of the experiment, conducted at Michigan State University, was to compare the digestibility of various feedstuffs in healthy adult horses in contrast to healthy, aged horses.
Eight adult (5 to 12 years) and 9 aged (19 to 28 years) stock-type mares were fed. Horses were rotated through three diets: hay only, hay plus a cereal-based feed, or hay plus a fat and fiber-rich feed. Horses were housed and fed one of the three diets outdoors in a group for 3 weeks, and then indoors in individual stalls for 3 weeks to record feed refusals. During week 6 of each period, a 72 hour digestibility trial was conducted in which feed intake and feces and urine were collected. The same protocol was followed for each diet.
No age by diet interaction, or differences in daily feed and hay intake were detected. No differences in fecal or urine output were noted between the horse groups. There was no effect of age on fiber, crude protein, energy and digestibility, or mineral retention.
These results indicate that under most practical feeding scenarios, it is unlikely that differences in digestive capacity are present between adult and aged horses. However, all horses utilized in this trial were healthy, and it's possible that there are differences in compromised (i.e., diseased) older horses, or those with dental disorders.
]]>Hay types included bud and flowering alfalfa, and vegetative and flowering orchardgrass. Flakes were submerged for 15, 30 and 60 minutes in 7 gallons of cold (72°F) and warm (102°F) water and for 12 hours in cold water.
Prior to soaking, both alfalfa hays were below the 10 and 12% NSC recommended for horses diagnosed with PSSM and laminitis, respectively, and would not have required soaking. This is common for alfalfa, since legumes store their carbohydrates as starch, compared to grasses that store their carbohydrates as fructans (a sugar). The orchardgrass hays were above these recommendations (approximately 14% NSC pre-soaking), however, after soaking for 15 to 30 minutes, were at or below 10 to 12% NSC.
Dry matter losses were similar among all hays after soaking for 15, 30 and 60 minutes in either warm or cold water. Dry matter losses after soaking for 12 hours were greater than other treatments.
Owners should rely on forage analysis, both before and after soaking, as the primary method of determining the appropriate hay for horses, especially when feeding horses diagnosed with laminitis and PSSM. Soaking hay for short durations (15 to 60 minutes) is an acceptable management method, but should only be used if preferred hay is not available. Soaked hay should be fed immediately to reduce the chance of mold.
]]>Minnesota has an active equine industry with an estimated 90,140 horses and 13,048 farms, ranking Minnesota 13th in the nation with a $1 billion impact on the state annually. In Minnesota, more than 1,000 miles of horseback riding trails are managed by the Department of Natural Resources, with more than 200 miles of additional trails on other lands. Minnesota is home to over five million people, of whom 4.5% participate in horseback riding. The objectives of this research were to document the profile of recreational horse trail users, their motivations, expenditures, and their economic impact on the state.
Minnesota residents who purchased a state horse trail pass were used to develop the survey database. From this database, a random sample of 804 Minnesota residents was selected. An eight page mail questionnaire was developed, pre-tested and implemented in fall 2008. The questionnaire included sections on experiences, trips and expenditures, and demographics. There was a 60% response rate. Spending and economic impacts were estimated at the destination regions. Estimates from an exit-survey of Minnesota state park visitors were used to determine trip spending for major consumer items. Park attendance data was applied to the average spending to project visitor spending.
Eighty percent of respondents were female, between the ages of 41-50 (55%), and were White, non-Hispanic (90%). Respondents reported an average of 27 years of horseback riding experience. Of the 20 possible motivations for horseback riding, seven were important or very important to more than 75% of respondents, including to view the scenery (96%), be close to nature (94%), get away from the usual demands of life (94%), experience nature (93.1%), explore and discover new things (90%), relax physically (90%), and be physically active (88%).
Respondents spent an average of 23.5 days trail riding within 30 minutes of their home. Trips to nearby trails by residents accounted for 72% of total days spent on horseback trails in the state. Resident horseback riders spent an average of $26.88 per person-day at nearby trails. Horseback riding by residents resulted in almost $43 million in consumer spending. Out-of-state visitors added $6.9 million which increased total spending on Minnesota horse trails to almost $50 million.
It is estimated that total horseback trail riding expenditures produced $34.7 million in output of directly affected businesses, and the gross state product amounted to $29.4 million. Three hundred and fifty-nine jobs were supported by the direct spending, plus an additional 163 jobs from indirect impacts on related businesses and local suppliers. Total labor compensation was estimated at $16.9 million, and state and local tax revenues at $3.7 million.
Average annual per person equipment expenditures for horseback riding included $536.55 in horse feed, $521.91 in truck/trailer maintenance, $243.20 in veterinarian costs, $201.25 in farrier costs, $189.15 in new equipment, and $101.62 in the purchase of used equipment. Total spending reached $530.2 million. This resulted in, $390.9 million in gross state product, and $49.4 million in state and local taxes.
This study demonstrates the importance of the horse industry to the Minnesota economy. Maintenance of existing horse trails and consideration for trail expansion in Minnesota is recommended.
]]>The experiment measured equine forage intake during morning (AM) and afternoon (PM) grazing periods. Six light horse breed geldings were used and randomly allocated into one of two groups: an AM or a PM grazing treatment for 14 days. After the first 14 days, horses were switched to the opposite treatment for an additional 14 days. Morning treatment groups were grazed from 7:00 am to 1:00 pm and PM groups were fed from 12:30 pm to 8:30 pm. Horses were grazed on tall fescue pastures.
Horses had higher intake rates in the PM grazing sessions compared to the AM sessions. These results confirm pervious beliefs that horses increase their DMI throughout the day, likely in response to increases in NSC. However, caution should be taken when grazing horses, especially horses prone to laminitis, on grasses high in NSC in the afternoon hours.
]]>Have you ever wondered if your horse's diet affects their need for dental work? Previous studies have suggested that temporomandibular or jaw joint (TMJ) kinematics (chewing motion) depended on the type of food being chewed or masticated, but accurate measurements of TMJ motion in horses chewing different feeds has not been published. A group of researchers in the College of Veterinary Medicine at Michigan State University set out to determine if the TMJ has a larger range of motion when horses chew hay compared to pellets (grain).
An optical motion capture system was used to track skin markers on the skull and mandible (lower jaw) of seven horses as they chewed hay and pellets. A virtual marker was created on the midline between the mandibles at the level of the 4th premolar teeth to represent the overall motion of the mandible relative to the skull during the chewing cycle.
Frequency of the chewing cycles was lower for hay than for pellets. Excursions (chewing motion of mandible) of the virtual mandibular marker were significantly larger in all three directions when chewing hay compared to pellets. The mean velocity of the virtual mandibular marker during the chewing cycle was the same when chewing the two feeds.
The range of mediolateral displacement of the mandible was sufficient to give full occlusal contact of the upper and lower dental arcades when chewing hay but not when chewing pellets. These findings support the suggestion that horses receiving a diet high in concentrate feeds (grains) may require more frequent dental prophylactic examinations and treatments to avoid the development of dental irregularities associated with smaller mandibular excursions during chewing compared to horses fed a diet high in forages.
In a separate study conducted at Virginia Tech, chewing direction both before and after dental treatments was investigated. Seventeen horses were observed while consuming small portions of mixed grass-alfalfa hay. Chewing direction was determined by the horse's jaw motion as either counter-clockwise or clockwise.
Horses chewed counter-clockwise 60% of the time before dental work and 37% of the time after dental work. While chewing direction varied between the horses, there was a significant effect of lateral excursion on chewing direction with counter-clockwise chewers having a greater left lateral excursion. There was also a trend for clockwise chewers to have greater right lateral excursion. Dental treatment did not appear to have an impact on chewing direction.
The take home message: horses should have a yearly dental evaluation, especially if the horse if consuming a diet low in forage or high in grains (pellets).
]]>Cool season pastures can contain substantial amounts of non-structural carbohydrates (NSC). Research links over consumption of NSC by grazing horses to laminitis, especially when horses have an existing health condition (i.e. previous history of laminitis). Restricted grazing is a common solution to managing laminitic horses, however, little research has measured pasture intake during periods of restricted grazing. The goal of this project, conducted by researchers in England, was to determine the relative dry matter intake (DMI) of pasture by ponies allowed three hours of grazing time per day and un-restricted access to hay for the remainder of the day over a six week period.
Four ponies were used for the study and were turned out daily in the afternoon into a mixed grass clover pasture. When not grazing, ponies were housed in individual stalls with un-restricted access to water and mixed grass hay. Pasture samples were taken to determine quality and pasture dry matter intake were determined from change in pony body weight over the three hour grazing period. Intake of hay was determined daily for each pony.
Ponies gained an average of 0.7 pounds per day and total daily dry matter intake over the six week period remained constant averaging 2% body weight per day. The proportion of total daily dry matter intake accounted for by grazing rose from 22% to 49% by week 6 representing 0.49 and 0.91% of body weight in weeks one and six, respectively. In conclusion, the increase of 0.49% to 0.91% body weight suggests that as the trial progressed, restricting grazing time for ponies became increasingly less effective in reducing pasture intakes.
In other words, the ponies anticipated the restricted grazing time period and as a result, ate more quickly as the trial progressed.
]]>Preferred flavors added to food, water, or medications my possibly increase palatability and intake. Although there is some research on certain flavors such as sour, peppermint, and banana, little evidence exists measuring the taste preferences of horses. Researchers at the University of Guelph set out to determine the horse preference or aversion to sourness through alteration of water pH.
Twelve horses were used for the study. All horses received daily turnout with free access to forage and water. Each horse was given a treatment for four consecutive days. Treatments were fed in identical black buckets and consisted of control water (pH 7.5) and control water plus citric acid with either a pH of 5.0, 3.6, or 2.9 (the lower the pH, the more acidic the water). Citric acid is sometimes used to flavor water for horses. Water buckets were refilled and weighed as necessary to determine total amount of water consumed from each bucket. Treatment intake was calculated as the percentage of total daily fluid intake, and these values were used to determine preference.
Preference and aversion were established as percent intake above 60% and below 40%, respectively. Differences of intake were noted in the buckets with a pH of 3.6 and 2.9 (these groups did not differ from each) whereas a pH of 5.0 was moderately aversive and tended to differ from the control bucket, which the horses most preferred. Although acidic treatments were found to be aversive, no treatment was completely rejected by the horses. However, the buckets with a pH of 2.9 were the least preferred.
In conclusion, the lower the pH of the water the less the horses will consume.