Effect of cultivated or semi-natural pasture on changes in live weight, body condition score, body measurements and fat thickness in grazing Finnhorse mares

Abstract

Two groups of Finnhorse mares, 11 horses in each group, were grazed on cultivated pasture (CG) or semi-natural grassland (NG) from the end of May to the beginning of September 2011 and the effect on possible development of obesity was followed. The observations of live weight, body condition score (BCS), cresty neck score (CNS), body measurements and fat thickness were made during the grazing season. At the end of the grazing season, the horses grazing CG were significantly heavier (P<0.05) compared to the horses grazing NG. On average, the live weight change was +71 kg in CG and +31 kg in NG pastures. The waist (abdominal) circumference started to grow rapidly at the beginning of the grazing season in CG group and it ended up being different (P<0.05) from NG group at the end of grazing season. The BCS at the end of the grazing season averaged 1.35 points higher for the CG group compared to the beginning of the trial. The neck circumference was 4.1 cm more in CG group compared to NG at the end of grazing season. Results showed fat deposition in both experimental groups and in all measured spots during the grazing season. The most significant difference between groups in fat deposition was in the shoulder and tailhead areas (P<0.05). These preliminary results show, that fat accretion was greater in animals grazing the cultivated, high yielding pastures compared to those grazing semi-natural grasslands. Several parameters can be used to measure the development of obesity, but some seem to be more reliable than others.