title: An approach to assessment of the efficiency of dietary energy utilization by horses and ponies kept at riding schools.
abstract: The ratio of calculated net energy intake (NEi) to calculate net energy requirement (NEr) might serve as an indicator of the efficiency of dietary energy utilization. The ratio was determined for 93 horses and ponies from 10 riding schools. For each animal with an assumed constant body weight, energy intake and energy requirements were assessed. On average, the estimated NEi was 14% greater than NEr. There was a significant, negative association between crude fibre intake and the NEi: NEr ratio. Earlier work indicated that extra fat intake may lead to over estimation of the calculated energy value of the ration due to changes in macronutrient digestibility. Dietary fat concentration was found to range from 32 to 52 g/kg dry matter (5 to 6 g/MJ net energy), but on the basis of digestibility trials this range in fat concentration is too small to significantly influence the NEi: NEr ratio. This study shows that assessment of the efficiency of dietary energy utilization under normal conditions, on the basis of the NEi: NEr ratio is fraught with uncertainty.
authors.affiliation: Department of Nutrition, Faculty of Veterinary, Medicine, Utrecht University, The Netherlands.
authors.forename: W L
authors.initials: WL
authors.lastname: Jansen
authors.forename: M
authors.initials: M
authors.lastname: van Alphen
authors.forename: M
authors.initials: M
authors.lastname: Berghout
authors.forename: H
authors.initials: H
authors.lastname: Everts
authors.forename: A C
authors.initials: AC
authors.lastname: Beynen
mesh_terms: D000821:Animal Feed; D000822:Animal Husbandry; D000818:Animals; D001835:Body Weight; D004041:Dietary Fats; D004043:Dietary Fiber; D002149:Energy Intake; D004734:Energy Metabolism; D005260:Female; D006736:Horses / Q000502:physiology*; D008297:Male
chemical_list: D004041:Dietary Fats; D004043:Dietary Fiber