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1 2 1 1Veríssimo, C.J., C.V.J. Nicolau, V.L. Cardoso and M.G. Pinheiro
1Instituto de Zootecnia. Caixa Postal 60. CEP 13460 000, Nova Odessa. São Paulo. Brazil.
E mail: cjverissimo@izsp.br
2Animal Production Master Science Unesp/Botucatu. Brazil.
Boophilus microplus. Longitud pelo. EspesorBoophilus microplus . Hair length. Coat thickness.
capa. Densidad pelo. Correlación. Grupo genético.Hair density. Correlation. Genetic group.
la densidad de pelo (HD), la longitud del pelo HLThe following haircoat characteristics, coat
thickness (CT), hair density (HD), hair length y la infestación por la garrapata Boophilus
microplus (T) determinando la correlación entre(HL), and Boophilus microplus tick infestation
(T) were measured on purebred Gyr (zebubreed) esas características de la capa. Los grupos
and crossbred Gyr x Holstein (H) cows and the genéticos fueron definidos como GG1= Gyr,
correlation between these traits were determined. GG2= cruce con 50 a 75 p.100 de Holstein y GG3=
cruce con más del 75 p.100 de Holstein. LasThe genetic groups were defined as: GG1= Gyr,
GG2= crossbred with 50 to 75 p. 100 Holstein medias para GG1, GG2 y GG3 fueron respecti
vamente: CT: 2,68±0,34mm, 2,68 ± 0,47 mm, 2,95breed and GG3= crossbred with more than 75 p.
100 Holstein. The average means for GG1, GG2 ± 0,44 mm; HD: 1140,62 ± 289, 14, 971,62 ±
2and GG3 were, respectively: CT: 2.68 ± 0.34mm, 292,48, 1071,90 ± 237,48 (pelos/cm ); HL: 4,68
2.68 ± 0.47mm, 2.95 ± 0.44mm; HD: 1,140.62 ± ± 1,22 mm, 6,81 ± 1,81 mm, 8,74 ± 2,22 mm; T: 0,47
± 0,91, 47,39 ± 54,60, 72,35 ± 45,78. Los coefi 289.14, 971.62 ± 292.48, 1,071.90 ± 237.48
2(hairs/cm ); HL: 4.68 ± 1.22mm, 6.81 ± 1.81mm, cientes de correlación fueron positivos y signi
ficativos entre T, HL, CT así como entre el grupo8.74 ± 2.22mm; T: 0.47 ± 0.91, 47.39 ± 54.60,
72.35 ± 45.78. Correlation coefficients were genético y T, HL y CT.
positive and significant between T, HL, CT, as
well as between genetic group with T, HL and CT.
Boophilus microplus tick is one ofRESUMEN
the worst parasite infesting cattle in
En la raza cebuína pura Gyr y su cruce con Brazil, due to the damages it causes, in
Holstein (H) se midió el espesor de la capa (CT), special to European cattle and their
Arch. Zootec. 51: 389 392. 2002.VERÍSSIMO, NICOLAU, CARDOSO AND PINHEIRO
crosses (Verissimo, 1993). composition, as follows: Gyr (15
Well adapted cattle to the tropics animals), crossbred Gyr x Holstein with
can be recognized by hair appearance. Holstein fraction between 50 p.100
Well adapted animals have short, thick and 75 p.100 (28 animals) and crossbred
and laid hair, while those which have Gyr x Holstein with Holstein fraction
long, thin and woolly hair suffer with above 75 p.100 (31 animals).
the hot climate (Yeates, 1955). Boophilus microplus females
There is a shortage of information bigger than 4 mm lenght were counted
on the relation between coat charac in one side of the animal in September
teristics and cattle tick resistance in 1993, when they were naturally
Brazil. Some observations on small infested, given they had not received
number of animals of some breeds any acaricide for four months.
suggested the absence of relationship During the summer of 1994 (Fe
between the number of ticks and hair bruary), three hairs samples were
score (Wilkinson, 1962; Burns et al., clipped from the scapular region of
1988). However, it has been observed each cow, using a wire cutter with a
that Gyr cattle present lower tick long and sharp extremity, specially
infestation when compared to European adapted for this use. The hair thickness
breeds and crosses, suggesting higher (HT) was measured with a pachymeter
resistance to these parasites. in the scapular region. The numeric
The objective of this work was to density (ND) was obtained by counting
measure some haircoat traits of Gyr the number of hairs of each sample,
and crossbred cattle (Holstein x Gyr) and the hair lenght (HL) by measuring
and to estimate the correlation of thesewith the pachymeter the ten longest
traits with tick infestation. hairs (Udo, 1978).
In the analysis, the genetic groups
were defined as: GG1= Gyr, GG2=
MATERIAL AND METHODS crossbred with 50 to 75 p.100 Holstein
breed and GG3= crossbred with more
This work has carried out in the than 75 p.100 Holstein.
Instituto de Zootecnia (Estação Expe The Pearson's correlation coeffi
rimental de Zootecnia de Ribeirão cients between the characteristics were
Preto), located at Ribeirão Preto, São calculated using the SAS program
?Paulo State, Brazil. Ribeirão Preto is (Statistical Analyses System).
located in latitude 21º 11' S and longitude
47º 48' W, with an average altitude of
621 m. The climate can be classified as RESULTS AND DISCUSSION
tropical savanna with a dry winter and
a rainy summer. The annual averages Table I presents the averages and
of temperature and rain precipitation standard deviations of the studied traits
are 22º C and 1500 mm respectively. for each genetic group, while table II
The animals evaluated were 74 shows the correlation coefficients
cows, with age varying from 15 to 162between the characteristics.
months, grouped according to breed Zebu cattle (GG1) had the lowest
Archivos de zootecnia vol. 51, núm. 195, p. 390.TICK INFESTATION ON GYR (ZEBU) AND CROSSBRED (HOLSTEIN X GYR) CATTLE
Table I. Mean and standard deviation for the studied characteristics: coat thickness (CT),
hair density (HD), hair length (HL) and tick infestation (T), according to the genetic group
(GG). (Medias y desviaciones típicas para las características estudiadas: espesor de la capa, densidad
del pelo, longitud del pelo e infestación por garrapatas, de acuerdo con el grupo genético).
GG1 (n = 15) GG2 (n = 28) GG3 (n = 31)
CT (mm) 2.68 0.34 2.68 0.47 2.95 0.44
2HD (hairs/cm) 1,140.62 289.14 971.62 292.48 1,071.90 237.48
HL (mm) 4.68 1.22 6.81 1.81 8.74 2.22
T 0.47 0.91 47.39 54.60 72.35 45.78
average of tick infestation (0.47 ticks), proportion to the addition in Holstein
while crossbred (GG3) presented the breed, are well known.
highest one (72.35 ticks). GG2 animals In the present study, hair length and
had an intermediate average number coat thickness were positive related
of ticks (47.39). The correlation with tick infestation (r= 0.35, p< 0.01
between the tick infestation and geneticand r= 0.29, p< 0.05, respectively).
group was positive and significant (r= Spickett et al. (1989) also found a
0.51, p< 0.0001). The strong resistance positive relation between hair length
that zebu cattle presents to Boophilus and tick infestation in European
microplus tick infestation (Villares, (Hereford) and native (Bonsmara and
1941, Veríssimo, 1993), as well as the Nguni) cattle, being the European breed
resistance of their crosses with more susceptible to the tick and having
Holstein (Lemos et al. , 1985, Oliveira longer hairs than the native breed.
e Alencar, 1990), which decreases in O'Kelly and Spiers (1983) demons
traded that it had fixed fewer ticks in a
shaved area (short hair) than in a no
shaved area (long hair), in European,
Table II. Correlation coefficients between
crossbred or zebu cattle.
the studied characteristics. (Coeficientes de
From the results it was concluded
correlación entre las características estudia
that Gyr cattle had shorter hair and a
lower tick infestation when compared
to the other studied animals. In theHD HL T GG
crosses, tick infestation and hair length
increased as the Holstein fractionCT 0.25* 0.40** 0.29* 0.26*
HD - 0.22 0.13 0.04 increased. Among the studied haircoat
HL - 0.35** 0.63*** traits, hair length had the highest
T - 0.51*** correlation with tick infestation,
suggesting that this trait may be involved
*p< 0.05; **p< 0.001; ***p< 0.0001.
in the tick resistance of cattle.
Archivos de zootecnia vol. 51, núm. 195, p. 391.VERÍSSIMO, NICOLAU, CARDOSO AND PINHEIRO
Burns, B.M., J.E. Vercoe and C.R. Holmes. 1988. tepoort J. Vet. Res., 56: 245 250.
Udo, H.M.J. 1978. Haircoat characteristic inProductive adaptive trait differences of
Simmental, Hereford and Africander x Friesian heifers in the Netherlands and Kenya.
H. Veenman & B.V. Zonen Ed., Wageningen,Hereford cattle. J. Agric. Sci ., 111: 475 480.
Lemos, A.M., R.L. Teodoro, G.P. Oliveira and F.E. Netherlands, 135 p.
Veríssimo, C.J. 1993. Prejuízos causados peloMadalena. 1985. Comparative performance
of six Holstein Friesian x Guzera grades in carrapato Boophilus microplus. Zootecnia,
31: 97 106.Brazil. Anim. Prod., 41: 187 191.
O'Kelly, J.C. and W.G. Spiers. 1983. Observations Villares, J.B. 1941. Climatologia zootécnica III.
Contribuição ao estudo da resistência eon body temperature of the host and resis
tance to the tick Boophilus microplus (Acari: suscetibilidade genética dos bovinos ao
Boophilus microplus. Bol. Ind. Anim., 4: 60 Ixodidae). J. Med. Entomol., 20: 498 505.
Oliveira, G.P. e M.M. Alencar. 1990. Resistência 79.
Yeates, N.T.M. 1955. Photoperiodicity in cattle I.de bovinos de seis graus de sangue Holandês
x Guzerá ao carrapato (Boophilus micro Seasonal changes in coat character and
their importance in heat regulation. Aust. J.plus) e ao berne ( Dermatobia hominis). Arq.
Bras. Med. Vet. Zoot ., 42: 127 135. Agric. Res., 6: 891 903.
Wilkinson, P.R. 1962. Selection of cattle for tickSpickett, A.M., D. Klerk, C.B. Enslin and M.M.
Scholtz. 1989. Resistance of Nguni, resistance and the effect of herds
susceptibility on Boophilus population. Aust.Bonsmara and Hereford cattle to ticks in a
bushveld region of South Africa. Onders J. Agric. Res., 13: 974 983.
Recibido: 27 7 01. Aceptado: 28 9 01.
Archivos de zootecnia vol. 51, núm. 195, p. 392.