DANTAS, N. L. B.; http://lattes.cnpq.br/6427303170307777; DANTAS, Nayanne Lopes Batista.
Résumé:
The aim was to evaluate and compare the physiological, hematological and performance
variables of three genetic groups of sheep: Morada Nova, Somalis and crossbreed Dorper x
Somalis in the Brazilian semiarid region submitted to diets with and without inclusion of
jitirana. The research was carried out at Sheep sector of Research Center for the development
of semi-arid, in the Center for Health and Rural Technology, Federal University of Campina
Grande, Campus of Patos- PB. Thirty male uncastrated animals with approximately 150 days
of age and mean initial live weight of 22.5 ± 2 kg, 10 of each genotype were used, a half of
which had 30% of the tifton hay replaced by jitirana hay. The temperature and relative
humidity of the air were calculated, calculated the ITGU and measured the rectal temperature
(RT), respiratory rate (RR) and heart rate (HR) and surface temperature (ST) in the morning
and afternoon shifts. Four blood samples were collected in all animals to evaluate the
hematological profile. Were analyzed daily dry matter intake (DMI), total weight gain
(TWG), daily average weight gain (DAWG), feed conversion (FC), feed efficiency (FE) and
daily water consumption (DWC). The design was completely randomized (DCR), and the
factorial scheme 3x2x2, being three genotypes and two diets and two shifts, with five
replicates each. The values for ITGU were 81 in the shade and 90 in the sun and there was a
significant difference for the studied variables in relation to the shifts, being higher in the
afternoon. The mean ST of the sheep was 35.48 in the morning and 38.11 in the afternoon,
and Morada Nova presented lower RT among the genetic groups, demonstrating greater heat
tolerance. Morada Nova sheep presented lower numbers of red blood cells, leukocytes and
lymphocytes and higher values for mean corpuscular volume (MCV), mean corpuscular
hemoglobin (MCH) and platelet anisocyte index (PAI). The inclusion of jitirana hay did not
promote changes in any haematological or performance variables analyzed. There was a
genotypic difference for all the performance variables evaluated and the crossbreed animals
presented the highest mean values for DMI, TWG, DAWG, FC and DWC. The genetic
groups studied were adapted and tolerant to the climatic conditions of the Brazilian semi-arid
region. The substitution of 30% of tifton hay by Jitirana hay did not negatively affect the
thermoregulatory capacity and did not influence the hematological profile and could be
included in the sheep diet. Thermal stress can influence the values of the hemogram of ovine
by modifying the concentration of some constituents of the blood. Different ovine races can
present different values in the hemogram according to the adaptability to the environment in
which they live and due to inherent characteristics of each breed. The Dorper x Somalis
crossbred sheep are recommended for intensive husbandry in the northeastern semiarid
conditions due to their rusticity and good productive indexes. Further studies should be
developed to establish hematological reference values for the different sheep races and to
evaluate higher percentages of inclusion of Jitirana hay in the sheep diet.