Strip-grazing: Reduces pony dry matter intakes and changes in bodyweight and morphometrics.

Abstract

Obesity can negatively impact upon equine welfare and bodyweight (BW) of pastured equines is often difficult to manage. To compare the effects of three restricted grazing regimens on changes in pony BW and morphometric measurements. Randomised study. Twelve mature ponies were individually grazed in 10m wide, rectangular, electric fenced paddocks. The dry matter (DM) herbage yield of each paddock was determined, and paddock length adjusted on Day 1 to provide 1.5% of individual pony BW as herbage DM daily, for 28days. There were four ponies per treatment. Treatments were: total paddock area (TA) and strip grazing treatments, SG1 and SG2. SG1 had a 'lead' fence spanning the paddock width being moved a set distance along the paddock length daily to provide 1.5% of pony BW as fresh pasture DM (as determined on Day -1). SG2 also had a 'back fence' 7-12m behind the 'lead' fence which was moved the same distance as the lead fence daily. Calculated dry matter intakes, changes in cresty neck score (CNS), body condition score (BCS) and percentage changes in BW, heart girth (HG), belly girth (BG) and rump width (RW) were compared between treatments. Mean (±SD) calculated pasture DM intakes (as % BW/d) by TA ponies were 2.33±0.50, being significantly higher (P< 0.05) than 1.82±0.43 (SG1) and 1.59±0.42 (SG2). Mean percentage BW changes were higher (P<0.05) for TA ponies at 4.82±1.36 vs. 1.16±0.39 (SG1) and 1.54±1.35 (SG2). SG1 and SG2 pony BW changes were not significantly different. TA, but not SG1 or SG2 animals showed significant (P<0.05) increases in BCS1/9 (+0.94±0.32), CNS1/5 (+0.5±0), RW (+2.11±3.6) and BG (+4.15±2.29). SG1 and SG2 ponies showed significant (P<0.05) decreases in HG (-0.05±2.12) and BG (-5.53±4.89) respectively. Small sample size. Strip grazing limited pony bodyweight gains and upward changes in morphometric parameters.