Archivos Latinoamericanos de Producción Animal. 2024. 32 (1)
Hematological and biochemical reference values for
the Brazilian Pony breed
Recibido: 20220225. Revisado: 20220509. Aceptado: 20231226
1Corresponding author:
Miguel Alejandro Silva Rua
Abstract: The aim of this study was to characterize the hematological profile of the equine Brazilian Pony breed herds
in northern of Rio de Janeiro state, Brazil. Blood samples were separated in categories: adult stallions, pregnant mares
and nonpregnant mares. The red blood cells (RBC), packed cell volume (PCV), hemoglobin (Hgb), main corpuscular
volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), white
blood cells (WBC) and differential count of basophils (Baso), eosinophils (Eos), band cells (Bands), segmented
neutrophils (Neut), lymphocytes (Lym), monocytes (Mono), and platelets (Plat) were evaluated. The biochemical
parameters of urea (Urea), alanine aminotransferase (ALT), aspartate aminotransferase (AST), gamma glutamyl
transpeptidase (GGT), and creatinine were measured in pregnant and nonpregnant mares. Analysis of variance was
carried out with difference of hematological parameters between males and females. Also, analysis of variance was
used to verify the effect of pregnancy on biochemical parameters. There was effect of sex on RBC, hemoglobin, VCM
and MHCH, but PVC and MHC were not affected by sex. Higher means were observed in females. There was an
effect of sex on WBC, eosinophils and neutrophils. There was effect of pregnancy on AST, but no effect on urea, GGT
and Creatinine. According to the results obtained in this study, it can be concluded that the analysis of the blood count
and the biochemical of the Brazilian Pony reveals specificities compared to other equine breeds. Thus, these results
could be used as biomarkers for the evaluation of the Brazilian Pony breed in Rio de Janeiro.
Keywords: blood, horse, leukogram, pony.
Laboratory of Animal Reproduction and Genetic Improvement, Northern Rio de Janeiro State University
(Universidade Estadual do Norte Fluminense/UENF). Brazil.
Wilder Hernando Ortiz Vega
Valores de referencia hematológicos y bioquímicos para la raza Pony Brasileño
Hematología y bioquímica en Pony brasileño
Resumen. El objetivo de este estudio fue caracterizar el perfil hematológico de un plantel de equinos de la raza
Pony Brasilera en el norte del estado de Rio de Janeiro, Brasil. Muestras de sangre fueron separadas en categorías:
sementales adultos, yeguas preñadas y yeguas no preñadas. Fueron evaluados los glóbulos rojos (RBC), el volumen
globular (PCV), la hemoglobina (Hgb), el volumen corpuscular principal (MCV), la hemoglobina corpuscular media
(MCH), la concentración de hemoglobina corpuscular media (MCHC), los glóbulos blancos (WBC) y el contaje
diferencial de basófilos (Baso), eosinófilos (Eos), células en banda (Bands), neutrófilos segmentados (Neut),
linfocitos (Lym), monocitos (Mono) y plaquetas (Plat). Los parámetros bioquímicos de Urea (Urea), alanina
aminotransferase (ALT), aspartato aminotransferase (AST), gama glutamil transpeptidase (GGT) y creatinina fueron
medidos en yeguas gestantes y no gestantes. Fue realizado análisis de varianza para verificar diferencias entre
machos y hembras en los parámetros hematológicos y bioquímicos. Fue verificado efecto del sexo sobre RBC,
hemoglobina, VCM y MHCH, pero PVC y MHC no fueron afectados por el sexo. Medias mayores fueron
observadas en el sexo femenino. Hubo efecto del sexo sobre leucocitos, eosinófilos y neutrófilos. Hubo efecto de la
preñez en AST, pero ningún efecto en la Urea, GGT ni Creatinina. De acuerdo con los resultados obtenidos en este
estudio, se puede concluir que el análisis del hemograma y la bioquímica del Pony Brasileño revelan especificidades
en comparación con otras razas de equinos. Por lo tanto, estos resultados podrían ser utilizados como puntos de
referencia para la evaluación de la raza Pony Brasileño.
Palabras clave: equinos, leucograma, bioquímica, poni.
Aylton Bartholazzi Junior
Luís Fonseca Matos Celia Raquel Quirino1
Silva Rua et al.
The Brazilian Pony breed is a recently created breed,
records began in 1970, with the founding of the
Brazilian Association of Piquira and Pony Horses
(ABCCPONEI, 2022). These horses have been selected
since then, and due to their characteristics it is
necessary to conservation of the breed, as well as an
exhaustive control of mating in order to avoid
problems related to inbreeding. The control of animals
from the point of view of health is fundamental in any
program of genetic improvement and conservation. In
association with this, demand is increasing for
information about these horses’ physiology to support
diagnosis of health based on hematological parameters.
The literature contains a large amount of information
about the hematological and biochemical profile of
horses (Zobba et al., 2011; Adamu et al., 2013; Rukavina
et al., 2017; Ono et al., 2019; Ata et al., 2020;), but none is
available regarding the Brazilian Pony breed.
Horse breed is the result of natural and artificial
selection, and animals of the same breed in different
regions can present peculiarities regarding their
physiological characteristics (Fonteque et al., 2016). The
population of the modern horse have particularity
comparing to locally adapted breeds of horses
subjected to periods of natural selection (Petersen et al.,
2013). The correct interpretation of hematological and
biochemical test results requires specific reference
values for studied populations, due to important
variations observed in the local environment.
The horse hematological profile reported in the
literature (Chiba et al., 201 Kupczynski & Spitalniak,
201Wanderley et al., 2015) may not be fully applicable
under all conditions because it is influenced by multiple
factors, including breed, environment and differences in
management (Adamu et al., 2013; Paden et al., 2014).
The evaluation of blood cells and biochemical
hematological profile is part of the clinical assessment
routine of horses. Hematological and biochemical
blood parameters are important to identifying the
breed’s physiological variations and are used for
clinical diagnosis of infectious and parasitic diseases.
They are also used to provide information about the
metabolic situation of animals and to monitor recovery
in the case of health problems (Adamu et al., 2013).
Information about the physiological characteristics
of the Brazilian Pony horse breed is limited in the
literature. Thus, the aim of this study was to evaluate
hematological and biochemical characteristics in
clinically healthy stallions and mares of the Brazilian
Pony breed.
Valores de referência hematológicos e bioquímicos para a raça Pônei Brasileiro
Hematologia e bioquímica em pôneis brasileiros
Resumo. O objetivo neste estudo foi caracterizar o perfil hematológico de um rebanho de equinos da raça Pônei
Brasileiro no norte do estado do Rio de Janeiro, Brasil. As amostras de sangue foram separadas em categorias:
garanhões adultos, éguas gestantes e éguas não gestantes. Os parámetros avaliados foram glóbulos vermelhos
(RBC), volume globular (PCV), hemoglobina (Hgb), volume corpuscular principal (VCM), hemoglobina corpuscular
média (HCM), concentração de hemoglobina corpuscular média (CHCM), glóbulos brancos (WBC), e contagem
diferencial de basófilos (Baso), eosinófilos (Eos), células em banda (Bands), neutrófilos segmentados (Neut),
linfócitos (Lym), monócitos (Mono) e plaquetas (Plat). Os parâmetros bioquímicos de Uréia (Urea), alanina
aminotransferase (ALT), aspartato aminotransferase (AST), gama glutamil transpeptidase (GGT) e creatinina foram
mensurados em éguas gestantes e não gestantes. A análise de variância foi realizada para comparar parâmetros
hematológicos e bioquímicos de equinos machos e fêmeas. . Efeito significativo do sexo foi verificado sobre
hemácias, hemoglobina, VCM e MHCH (médias mais elevadas foram observadas em fêmeas), mas PVC e MHC
foram semelhantes entre animais machos e fêmeas. O fator sexo também afetou leucócitos, eosinófilos e neutrófilos.
A prenhes afetou AST, mas os resultados de Uréia, GGT ou Creatinina foram semelhantes. De acordo com os
resultados obtidos neste estudo, as análises do hemograma e da bioquímica do Pônei Brasileiro revelam
especificidades entre os fatores em estudo e em comparação com outras raças de cavalos. Assim, esses resultados
podem ser utilizados como valores de referência para a raça Pônei Brasileiro.
Palavraschave: cavalos, leucograma, bioquímica, pônei.
ISSNL 10221301. Archivos Latinoamericanos de Producción Animal. 2023. 32 (1): 17
Hematological and biochemical reference values for the Brazilian Pony breed
The animals, the animals of the Brazilian Pony breed,
were raised in the municipality of Campos dos
Goytacazes, northern Rio de Janeiro state, Brazil (21o 45
´15´´ South latitude, 41o 19´28´´ West longitude, and 13
meters above sea level). The feeding of the animals was
the same for males and females. All animals were
maintained in pastures with Coast Cross grass
(Cynodon dactylon) throughout the experiment.
According to the scale of Köppen and Geiger, the
climate of this region is classified as Aw, with the mean
annual minimum temperature of 20° C and mean
annual maximum temperature of 36° C). The average
annual rainfall is 1,073 mm, with more rainfall in the
summer than winter. The precipitation varies 156 mm
between the driest month and the wettest month. This
experiment was carried out in the autumn period
(April to June).
Brazilian Pony animals were evaluated and separa
ted in the following categories: 1 stallions (N= 20,
aged 613 years); 2 pregnant mares (PM, N= 44, aged
619 years) (Figure 1). The animals were clinically
examined, performed by veterinarians or specialized
techniques, before the experiment and only healthy
ones were used. Clinical examination was performed
and the body condition score, cardiac frequency and
respiratory frequency were measured to determine
health. Normal ranges for hematology and plasma
chemistry consider the values published by
Southwood, L.L. 2013.
Sample collection and handling
A blood sample was taken from all subjects between
8:00 am and 10:00 am and were then taken once a month
between February and November for examination.
Blood samples were obtained from all animals by jugular
venipuncture and stored in Vacutainer tubes. For
hematological study blood was collected in sterile vial (5mL)
using pot