Energy and protein allowances in diets for athletic horses used in western riding Department of Animal Science University of Padova 10° Convegno Nuove acquisizioni in materia di Ippologia New findings in equine practice Druento (Torino), 31 ottobre -1 novembre 2008 A. Brigando, R. Mantovani, L. Bailoni

Western Riding  Growing interest for western disciplines in Italy, particularly for reining and cutting, i.e. the most popular in USA  Different nutritional management among studs in Italy  Use of empirical knowledge on horse-feeding in general and in particular for Western Riding horses

Background on Western horse feeding  Diets for the Western Riding horses are usually formulated on the basis of age and activity of horses (i.e., for groups of animals)  NRC 2007: new nutrient requirements equations, considering age, weight, growing rate and work intensity

 To verify Energy (DE) and Protein (CP) intakes in comparison with theoretical requirements of NRC (2007)  To analyze relationship between intakes and requirements on the basis of different ages and activities of horses Objectives

Materials and Methods  2 studs (A & B) located in northern Italy and specialized for reining and cutting, respectively.  62 athletic QH horses, aged between 2 and 8 yrs.  Trial lasted 5 months (from September to January), divided into 3 periods classified by intensity of work: 1. Medium work (from September to October) 2. Intense work (November) 3. Light work (from December to January)

Individual data recording  Use of specific forms to collect individually:  Animals’ age class (2,…..,8)  Daily activity (in arena, horse walking machine or in round yard )  Monthly estimated body weight (BW)  Monthly body condition score (BCS, French method, 5 classes)

Diets and Feeds recording  Daily amounts of single feeds administered to horses were recorded  Samples of each feed were collected periodically and subjected to chemical analyses  Contents of nutrients were calculated on the basis of chemical composition (NRC, 2007)  Dry matter (DM), energy (DE) and protein (CP) daily intakes were estimated from mean daily allowances  Intakes were compared with theoretical requirements calculated on physical activities and growth rates of each group and period

Statistical analysis  ANOVA using a split-plot model as follows: y ijkl =  +  i +  (  ) ij +  k +  ik +  ijkl  Simple regressions were calculated between intakes and requirements within period and age for both DE and CP where:  =overall mean;  i =effect of stud (i=A, B);  (  ) ij =effect of age class within stud:  k =effect of the period of activity (k=M, I, L);  ik =effect of the interaction stud x period;  ijkl =residual error ~N(0,  2 )

Main results  Both weight, BCS and time of exercise changed between age groups (mainly due to different age classed) and period of activity  A significant interaction Stud x Period for these variables was detected observed

Weight in different Period within Stud BCS in different Period within Stud

ANOVA for dry matter (DM), digestible energy (DE) and crude protein (CP) intakes (variance and P)

Relationship between intake and theoretical requirements of DE in different activity periods Relationship between intake and theoretical requirements of CP in different activity periods

Relationship between intake and theoretical requirements of DE in different age classes Relationship between intake and theoretical requirements of CP in different age classes

Conclusions  Results obtained in two big studs in northern Italy suggests that allowance of DE and CP calculated from intake are generally higher than suggested requirements (NRC, 2007)  However, energy and protein surplus are not linked to weight or BCS changes or to some pathology (e.g., lameness), particularly in STUD A, where allowances resulted much greater than requirement as compare with STUD B  Despite the need of more accurate studies involving higher no. of studs, animals and longer periods, the present results suggest a possible energy and (partial) protein underestimation of requirements in such category of athletic horses.

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