Effect of dietary restriction on body condition, composition and welfare of overweight and obese pony mares.
BACKGROUND
Increased prevalence of obesity among UK horses and ponies demands evidence-based advice to promote weight loss.


OBJECTIVE
Restriction of dry matter intake (DMI) to 1% of body mass (BM, 67% [corrected] of predicted maintenance digestible energy [DE] requirements) would promote weight loss without compromise to health.


METHODS
Five mature (mean ± s.e. 10 ± 2 years), overweight/obese pony mares (BM, 257 ± 20 kg: body condition score [BCS] 6.8/9 ± 0.5) were studied over 12 weeks. Animals were individually housed. Daily provision of a chaff-based, complete diet (measured DE, 8.5 MJ/kg DM) was restricted to 1% of actual BM as DMI daily. BCS, girth measurements and ultrasound-derived measures of subcutaneous fat depth overlying the gluteal region and 12th intercostal space (rib-eye) were recorded weekly. Body fat content was estimated at the beginning and end of the study by deuterium oxide dilution methods. Clinical biochemistry was monitored weekly. Behaviour was observed (24 h, 3/5 ponies) on 3 occasions.


RESULTS
BM decreased by 4.3 ± 1.1% during the first week and thereafter by 0.7 ± 0.1% of BM at end of Week 1 each week. BCS remained constant. Heart and belly girths, rump width and subcutaneous fat depth at rib-eye decreased significantly with time and BM. Fat comprised 45 ± 19% of BM loss. Fatter animals lost relatively more fat. With decreased feeding activity, time spent in 'play' and rest increased by 36 ± 11% and 438 ± 95%, respectively.


CONCLUSIONS
This plane of nutrition resulted in an overall rate of weight loss of 1% of outset BM weekly. BCS was not a useful index of early weight loss but heart and belly girths and subcutaneous rib-eye fat were identified as alternative markers.


CONCLUSIONS
This study provides an evidence-base for the management of weight loss in obese animals, especially those for which exercise may be contra-indicated.
Dugdale
A H A
AH
University of Liverpool, School of Veterinary Science, Leahurst, Neston, Cheshire CH64 7TE, UK.
Curtis
G C
GC
Cripps
P
P
Harris
P A
PA
Argo
C McG
CM
D000821:Animal Feed / Q000032:analysis*; D000824:Animal Nutritional Physiological Phenomena; D000827:Animal Welfare; D000818:Animals; D001823:Body Composition; D004032:Diet / Q000662:veterinary*; D005260:Female; D005508:Food Deprivation; D006734:Horse Diseases / Q000178:diet therapy*; D006736:Horses; D009765:Obesity / Q000178:diet therapy / Q000662:veterinary*