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The present research has the objective of better understanding the environmental factors that influence the time in Quarter Horse races, in the principal national hippodromes of this breed
Se estudia el papel de los factores ambientales en la velocidad en las carerras de caballos Cuarto de Milla, en los principales hipodromos en los que tienen lugar.



Publié par
Publié le 01 janvier 2004
Nombre de lectures 18
Langue English


Mota, M.D.S. and A.R. Abrahão
Dep. Melhoramento e Nutrição Animal. FMVZ. Unesp. Botucatu/SP. CP 560. CEP 18618-000. Brasil.
E-mail: mdsmota@fca.unesp.br
The time is a trait normally regis- the present research has the objective
tered in every kind of race. With horses, of better understanding the environ-
specially, the study of environmental mental factors that influence the time
factors that influence in race time of in Quarter Horse races, in the principal
the animals have been described by national hippodromes of this breed.
various authors (Buttran et al., 1988;
Wilson, 1990; Leroy et al., 1991; Mota
MATERIALS AND METHODSet al., 1998), most of them with animals
Thoroughbred and trotters.
The original file of data providedIn Brazil some studies of this nature
by the Sorocaba Jockey Club waswere made with animals of the breeds
compound of 17,479 registers aboutThoroughbred (Mota et al., 1998;
3,518 races runned by 4,068 animals.Taveira e Mota, 2002) and Quarter
Since the concern was to study theHorses (Mota et al., 1999 e Villella et
time, were excluded initially 2,302al., 2002). With Thoroughbred,
registers in which there wasn't notesalthough the number of races is very
about that trait. Following were thegreat and the number of competitors in
only separated observations of raceseach one is high, normally only the
runned in the towns of Sorocaba,time of the winners is registered,
Ribeirão Preto and Jaú, which compo-limiting the interpretation of these
studies in the population as a whole. In unded 91 percent of the total of races.
Quarter Horses races, on the other side, From this file, were being excluded
even though all the competitors of one what was considered as mistakes of
race do have the time registered, the annotation and types of fixed effects
yearly total of races is low and the with low number of observations,
number of horses by race small . In this summarizing one file with 13,477
breed, lonely the works, considering registers of time submitted to analyses.
only races in the Paulistian Hipodrome Preliminary analyses were made as
of Sorocaba, were done in Brazil. Thus, to verify which fixed effects were
Arch. Zootec. 53: 95-98. 2004.MOTA AND ABRAHÃO
included in the analyses and their races was 21.35 s, with coefficient of
interactions. The linear model used for variation of 2.56 percent, and the
evaluation of the information was: effects included in the model formed a
2R of 96.02 percent. A summary of the
γ = µ + C + I + S + + A +M analysis of variance is showed in the
ijklmno i j k l m n
+ b (X + X) + b (P - P) + following table I.
1 ijklmno 2 ijklmno
e Various authors have reported
significant differences of time in races,
Where: depending on the animal sex (Mota et
γ = race time (s) observed for al., 1998: Taveira e Mota, 2002; Villela
-theach animal; C = fixed effect of i city et al., 2002), normally with superiority
(Sorocaba, Ribeirão Preto and Jaú); of the males, as it happened with the
-thI = fixed effect of j age (2, 3 e >4 present work (males 2 hundredth
-thyear); S = fixed effect of k sex (male seconds more fast). This result is simi-
-thand female); O= fixed effect of l lar to the described by Villela et al.
origin (national e imported); A = fixed (2000), also with Quartes Horses, that
-theffect of m year of the race (1983, ..., reported average superiority of 0.025
-th2002); M = fixed effect of n month of seconds of the males, and slightly in-
the race (1,...,12); b e b = linear ferior to the related by Mota et al.
1 2
regression coefficients of the γ (1998) 0.13 s with Thoroughbred.
variable in relation to distance (meters) The significant effect of the local of
and jockey weight (kg), respectively; the race agree with the ones observed
b = quadratic regression coefficient of by Leroy et al. (1991) Buttran et al.
the γ variable in relation to jockey (1988), Mota et al. (1998), Taveira e
weight (kg), (X + X)= difference Mota (2002), and normally is due to
between the distance when the time the different constructions, different
was observed and the overall mean maintenance programs, surface of the
racing distance; (P - P)= difference ground, climate, etc. The hippodrome
between the jockey weight when the of Sorocaba was the local where the
time was observed and the overall mean times were significantly (p<0.05) more
jockey weight; and e = random rapid (20.83 s versus 21.73 s and 21.56
error associated with each observation. s of Ribeirão Preto e Jaú, respectively).
The data were analysed based on In part, this may be explained by the
the statistical program SAS (1996), fact that, since middle the years 90,
using the procedure GLM (general li- Sorocaba was transformed in the prin-
near model). Contrast test were done, cipal center of races of Quarter Horse
in Brazil, attracting a higher number ofat the level of 5 percent of significance,
animals with superior performance, andfor certain classes of fixed effects
making greater, consequently, theconsidered relevant.
possibility of differences between
hippodromes to happen.
RESULTS AND DISCUSSION The significant influence of the
origin of the animal on the time, with
The average observed for time in superiority of the imported ones, was
Archivos de zootecnia vol. 53, núm. 201, p. 96.ENVIRONMENT FACTORS AFFECTING TIME IN QUARTER HORSES RACES
The average distance in races wasTable I. Analyses of variance for race time.
364.47 meters, with coefficient of
(Análise de variância para tempo em corrida).
variation equal to 12.86 percent. The
behavior of time (s) in relation to theSource of variation D.F. M.S. Pr > F
distance (m) of the race showed that
Distance 1 65408.6146 0.0001 the times grow nearly 0.55 s each 10
Age 2 33.8096 0.0001 meters of the race, value greater than
City 2 20.9831
related by Mota et al. (1998) with
Origin 1 28.0634 0.0001
Thoroughbred (0.022 s).Sex 1 1.7878 0.0134
The weight of the jockey presentedMonth 11 3.4964 0.0001
average equal to 52.98 kg, withWeight of
coefficient of variation of 3.04 percent.the Jockey 1 21.0306 0.0001
Year 19 58.5053 The evaluation of this covariable
showed an increase in race times as
jockey's weight becomes higher, up to
already verified by Villela et al. (2002) 53 kg (mode), an occasion in which
in the Sorocaba hippodrome. These
they begin to improve with a weight
authors found differences of 0.14 s
increase. At first, that may look odd,
between both, value lightly inferior to
once one would expect a worsening in
the reported in this research (0.17 s).
time as jockey's weight increases.Animals with 4 years of age or
However, such behavior may, in part,more were significantly faster than the
be related to the way Quarter-Horseones 2 and 3 years old (0.3 s and 0.11
races are organized in Brazil. Animalss respectively). It is interesting notice
with a better race history, morethat, although this happens, animals
victories, more prizes, better times)with 4 years of age are considered old
may encounter difficulty in partici-inside the national breeding of the
pating in races, once most breeders doQuarter Horse runners. Only the
not want their animals to race withoutstanding animals reach this age in
better specimens, owing to the factactivity. The breeders concentrate in
that winning chances are slim. Conse-animals 2 years old, mostly, due to the
quently, in order to make the samemore important races and awards being
chance of winning possible for alloffered to animals of this age.
animals in a race, horses consideredThe effects of the year on the time
superior by the Race Commission mustin races are very variable, and normally
compete showing a minimum weightare accredited to the different climate
of 53 kg. That means that weightsconditions, timing and training system,
higher than 53 kg normally refer tobesides the gain due to the selection.
animals with a better performance, andThe years of 1998 and 2001 show
that the strategy used by Quarter-Horseaverages of time significantly smaller
than others. The months from February race organizers in Brazil to offset this
and November were the ones in which superiority has not proved very
the time was significantly better than efficient, once animals carrying more
others, although no particular reason than 53 kg show higher chances of
has been proposed to explain that fact. winning (lower race times).
Archivos de zootecnia vol. 53, núm. 201, p. 97.MOTA AND ABRAHÃO
Associação Brasileira de Criadores de Cavalos Ojala, M. 1987. Heritabilities of annually
summarized race records in trotters. J. Anim.Quarto de Milha. 1995. Regulamento geral
de concursos e competições Quarto de Milha. Sci., 64: 117-125.
S.A.S. 1996. Systems Analyses Statistical. User'sSão Paulo, 140 p.
Buttram, S.T., D.E. Wilson and R.L. Willham. guide: basics and statistics. SAS Inst. Inc.
Cary, NC, 956 p.1988. Genetics of racing performance in the
American Quarter horse. III. Estimation of Taveira, R.Z. and M.D.S. Mota. 2002. Comparasion
of thoroughbred race performance in Brazilianvariance components. J. Anim. Sci., 66: 2808-
2816. hippodromes. Arch. Zootec., 51: 385-388.
Villela, L.C.V., M.D.S. Mota y H.N. Oliveira. 2000.Leroy, P.L., N. Kafidi and E. Bassleer. 1991.
Estimation of breeding value of belgian trotters Estimativas de herdabilidade e repetibilidade
para tempo final em corridas de cavalos dausing an animal model. Faculté de Médecine
Vétérinaire-Universite de Liège (internal raça Quarto de Milha. In. III Simpósio Nacio-
nal de Melhoramento Animal. Belo Horizonte.report).
Mota , M.D.S., H.N. Oliveira and R.G. Silva. 1998. Anais..., 484-485.
Villela, L.C.V., M.D.S. Mota and H.N. Oliveira.Genetic and environmental factors that affect
the best time of Thoroughbred horses in Brazil. 2002. Genetic parameters of racing perfor-
mance traits of Quarter horses in Brasil. J.J. Anim. Breed. Genet., 115: 123-129.
Mota, M.D.S., L.C.D. Villela, H.N. Oliveira, L.S.L.S. Anim. Breed. Genet., 119: 229-234.
Wilson, D.E. 1990. Genetics of racing performan-Mota and Y. Eid. 1999. Estimativas de
herdabilidade e repetibilidade para colocação ce in the American Quarter horse: Adjustments
for jockey weight. Proc. 4th World Congressfinal em corridas de cavalos da raça Quarto
de Milha. Genetics and Molecular Biology, on Genetics Applied to Animal Production,
XVI, Edinburgh, Scotland. 198-201.22: 142.
Recibido: 17-9-03. Aceptado: 11-7-03.
Archivos de zootecnia vol. 53, núm. 201, p. 98.