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FACTORS THAT CAN INCREASE PLANT NSC LEVELS INCLUDE :
• cool nights and the development of seed heads in spring may coincide , creating a situation where NSC peaks
• the more sunlight the more sugars plants produce by photosynthesis . Phalaris sugar levels are 31 % lower when days are cloudy but increase rapidly with 2- 4 hours of sunlight
• grass grown under trees is lower in NSC - planting a line of fast growing trees around the fence line or creating a paddock in the shade of a building can create safer grazing for at-risk horses
• sugar levels are highest at sunset and lowest at 3am – especially if the night is warm - pangola grass sugar levels were 75 % lower after a 14 hour night in warm conditions
• sunlight increases photosynthesis ( the sugar factory ) - in Canberra , sugar levels in phalaris can increase by 55 % between sunrise and mid-afternoon
• as a rule of thumb , sugar levels typically rise during daylight hours and decline overnight , so grazing should be permitted only between 3am and noon .
• how much light falls on the leaves - sparse , isolated plants that have all the leaves exposed to sunlight will function at full sugar manufacturing capacity
• if horses have unlimited pasture they over-eat – limiting intake with a grazing muzzle , strip grazing or restricting grazing time are useful
• mowing and slashing can increase the amount of sugar by exposing stem bases ( where starch levels are high ) and may also increase flat-leaved plants like clover , dandelion and plantain ( storksbill ) which can be very high in starch and sugar .
• grazing down to a plant height of 10-16cm is recommended ( about the height of a stubby bottle )
• stressed grass is higher in NSC because when plants cannot grow , sugars accumulate - some types of grass will be stressed more when conditions are hot , others in cool conditions
• NSC is higher in species from the Brome , Fescue , wheatgrass , Phalaris , timothy , bluegrass and cocksfoot families when grown in cool conditions .
• NSC is higher in tropical grasses ( Panic , Paspalum , Pennisetum and Sorghum families , the highest in sugars and starch
• drought stress causes water supplies to fail the enzymes involved in respiration ( uses up sugar ) are compromised before those involved in photosynthesis ( produces sugar )
• long-term gradual-onset drought can double the sugar and starch in Seteria and 45 days of drought can double the sugars in cocksfoot and ryegrass
• colour has no relationship to sugar content and dry , brown , stressed grass can have dangerously high sugar
• sugar in ryegrass is highest in July regardless of stage of growth
• stubble can be very high in sugar
WHAT TO FEED AND WHAT NOT TO FEED : 1 . no treats such as apples , carrots , bread , pasta , green grass or weeds 2 . limit ( or eliminate ) grass intake in high risk horses during periods when environmental conditions produce dangerously high NSC 3 . graze the paddock to no lower than 4-5cm 4 . a mix of legume / grass hay / non-molassed beet pulp / soyhulls plus a vitamin / mineral protein and biotin supplement is adequate
5 . soaking grass hay for 30 to 60 minutes in warm water will remove up to 50 per cent of NSC – it also removes minerals and a supplement is required
6 . the supplement needs to provide vitamins , minerals , amino acids and biotin and be low in starch and sugar . There are published levels for some feeds ( TABLE 2 ).
7 . Heat-processed ( extruded , micronized ) feeds produce rapid changes in sugar digestion . These and any feed containing grain or grain by-products should be avoided .
TABLE 2 . NSC LEVELS IN SOME COMMERCIAL FEEDS COMMERCIAL HORSE FEED *
NSC Jenquine all-4-feet ( laboratory analysis ) 6.3 Stance CoolStance 10.3 Omega Weight Gain 16.2 Stance GoStance 23.4 Barastoc Calm Performer 30.7 Mitavite Economix 31.5 Mitavite Xtra Cool 33 Mitavite Gumnuts 33 Horsepower Equestrian 33.4 Nutririce Show and Competition 35.4 Weightlifter Calm 40 Mitavite Formula 3 42.2 Pryde ’ s EasiResult 42.6 Barastoc Cool Command 43.4 Mi-Feed EasiRider Cool Mix 46
* Richards N ( 2008 ) Proc . Aust . Equine Sc . Symp ., Vol 2:25 THE NON-STRUCTURAL CARBOHYDRATE CONTENT OF SOME COMMERCIALLY AVAILABLE HORSE FEEDS IN AUSTRALIA .
Without research on your species of grass , climatic conditions and management , you will never know for certain what is happening to the NSC concentrations of your pasture . Identifying horses at high risk of laminitis is important because of the risk of recurrence and the difficulties in treating and managing chronic laminitis . Your veterinarian may advise blood tests to confirm the laminitis risk . Local government agronomists can be a valuable source of local information . A good outcome requires a dedicated team of vets , farriers and owners . In 1586 the recommended treatment for laminitis was the skin of a weasel cut into small pieces and mixed with butter , a rotten egg and vinegar ’ Fortunately today we have more scientific knowledge that can be applied in the feed bin . F
All content provided in this article is for general use and information only and does not constitute advice or a veterinary opinion . It is not intended as specific medical advice or opinion and should not be relied on in place of consultation with your equine veterinarian and farrier .
NOVEMBER / DECEMBER ISSUE 2020