PG . 49
REACTIVITY AND RESTLESSNESS ARE COMMON BEHAVIOURAL PROBLEMS IN
HORSES . even more , to 3.1m / sec – i . e ., they were less reactive than the ACE-sedated horses ! This is the first time an objective measurement of behavioural change due to oral Mg supplementation has been reported in the horse .
Another study from the University of Guelph and published in 2017 , looked at the amount of stress horses experienced ( in terms of heart rates and cortisol levels ) performing a set task . They received either ACE or a Mg-thiamine supplement . The horses were loaded onto a weighbridge for 3 seconds . Heart rate was significantly lower when the horses received ACE or Mg , compared to when they were unsupplemented . When given 30 minutes before the onset of a stress , Mg-thiamine is as effective as ACE in blunting stress-induced increases in heart rate . Mg is also thought to help soothe nervous horses by working in concert with calcium on muscle contractions . Calcium stimulates contraction , Mg facilitates relaxation . If Mg levels are low , muscles can spasm due to an inability to achieve full relaxation . Some forms of chronic tying-up and PSSM also respond to Mg supplementation .
International Olympic veterinarians found Mg reduced muscle tiredness and increased work tolerance in show jumping , 3-day event , dressage and 4-in-hand horses . They also reported a decrease in skin sensitivity , ‘ hot ’ behaviour , unexplained hindleg lameness ( muscular in origin ), irritability , muscular cramping , weakness and stiffness , particularly of the hindlimbs .
More recent studies examined the effect of daily Mg on muscle function in horses – specifically tying up ( PSSM , exertional rhabdomyolysis ). Enzymes released during exercise indicate the amount of muscle damage . These are measured by your veterinarian when they test for AST , LDH , CK and ALP . Horses on a daily Mg supplement had lower enzyme levels after exercise , and also lower heart rates . In addition to allowing the proper relaxation of muscle fibres , Mg is a catalyst for generating energy ( ATP – the basic currency of energy ), and it facilitates oxygen delivery and uptake in working muscles .
www . jenquine . com
2021 AQHA YEARBOOK ~ MAY / JUNE ISSUE