Giane Regina Paludo

Efeito do estresse térmico e do exercício sobre parâmetros fisiológicos de cavalos do exército brasileiro

ABSTRACT - The horses of the Brazilian army are used for expositions, and frequently subjected to intense exercise. This, togetherwith environmental conditions of the Central west savanna result in the need for acclimatization. The objective of this study was todetermine what is the effect of thermal and exercise stress on four groups of stabled horses in the savanna region. 40 Adult h orses (4to 13 years of age) from the 1 st Mounted Guard Regiment (10 of each breed Thoroughbred – PSC, Crossbred – M and Brazilian Showjumper– BH) as well as 10 Bretas from the 32 nd Campaign Artillery Group, were used. All horses were kept in the Urban Military Sector inthe Federal District. The measurements made on the animals included heart and respiratory rates, rectal temperature and blood sampleswere taken at four opportunities during the day, in the morning and afternoon, before and after exercise. Genetic group influe nced alltraits except VCM, HCM e CHCM. Animals of the PSC group had higher means for leukocytes (7.83 ± 1.59), hematocytes (9.21 ±1.27), VG (40.75 ± 4.58) and hemoglobin (14.34 ± 1.67), while crossbreds had higher total plasmatic protein levels (6,93 ± 0,66 ). TheBreton breed had lowest levels for the majority traits examined. Exercise increased all traits except VCM, HCM and CHCM. Thecorrelations between traits vary greatly, the highest being between hematocytes, hemoglobin and VG (>0.58), while with total pl asmaprotein they were low (<0.26). The present work allows us to conclude that in terms of exercise of horses of the Brazilian arm y PSCare worst adapted and Breta best adapted to the conditions of this study.Key Words: acclimatization, heat stress, physiological responses

Use of multivariate analyses for determining heat tolerance in Brazilian cattle

Adaptability can be evaluated by the ability of an animal to adjust to environmental conditions and is especially important in extreme weather conditions such as that found in tropical Brazil. A multivariate analysis using physical and physiological traits in exotic (Nellore and Holstein) and naturalized (Junqueira, Curraleira, Mocho Nacional, Crioula Lageana, and Pantaneira) cattle breeds was carried out in the Federal District of Brazil to test and determine which traits are important in the adaptation of animal to heat stress as well as the ability of these traits and statistical techniques to separate the breeds studied. Both physical and physiological traits were measured on three occasions and included body measurements, skin and hair thickness, hair number and length, pigmentation, sweat gland area as well as heart and breathing rates, rectal temperature, sweating rate, and blood parameters. The data underwent multivariate statistical analyses, including cluster, discriminate, and canonical procedures. The tree diagram showed clear distances between the groups studied, and canonical analysis was able to separate individuals in groups. Coat traits explained little variation in physiological parameters. The traits which had higher discriminatory power included packed cell volume, shoulder height, mean corpuscular volume, body length, and heart girth. Morphological and physiological traits were able to discriminate between the breeds tested, with blood and size traits being the most important. More than 80% of animals of all breeds were correctly classified in their genetic group.

Componentes Reprodutivos e Produtivos no Rebanho de Corte da Embrapa Cerrados

The objective of this work was to analyze the various factors which influence calving interval (CI), true fertility (TF), ratio of birth (RBW) and weaning weight (RWW) of the calf to the calving weight of the cow, using the crossbred herd of EMBRAPA Cerrados as a model. The data, from 4469 calvings, collected between 1976 and 1999, was analyzed using the GLM, CORR and PRINCOMP procedures of SAS. The reproductive parameters investigated include ratio of calf birth weight/calving weight of cow (RBW), calf weaning weight / calving weight of cow (RWW) and TF as well as body condition scores (BC) and weights. The correlations between the traits were, generally, low, and sometimes negative with RBW and RWW while with TF they were higher. BC at calving did not affect mortality nor calf birth weight but did affect the following calving interval. The FR increased with increased calving BC as did calving interval. A lower calving interval and higher true fertility was observed with higher weaning BC score. The genetic group of the bull did not influence any of the traits analyzed, which group of the cow influenced birth weight. The environment (month, year and number of parturition) and genetics (sex) significantly influenced birth and weaning weights. The first two principal components explain 56% of the total variation between the traits examined.

Detection and molecular characterization of piroplasms species from naturally infected dogs in southeast Brazil

Rangelia vitalii is a protozoon described from dogs in the south and southeast regions of Brazil. It is phylogenetically related to Babesia spp. that infects dogs, but data on this enigmatic parasite is still limited. The aim of this work was to detect piroplasm species in dogs in the state of Rio de Janeiro, Brazil, by 18S rRNA gene-based PCR assay, restriction fragment length polymorphism (RFLP) and sequence analyses. Of 103 dogs examined, seven (6.8%) were positive for Babesia spp. by PCR. The amplified products were digested by restriction enzymes to differentiate the Babesia species, and one sample was identified as Babesia vogeli. The pattern observed for the other six amplification products did not match with pattern described for large Babesia infecting dogs. Sequencing analysis confirmed these six samples as R. vitalii, with high homologies (99-100%) with a sequence from south Brazil. This study confirms the presence of Babesia vogeli and Rangelia vitalii circulate in domestic dogs in Teresópolis, Rio de Janeiro, Brazil.

Detection of Theileria equi in spleen and blood of asymptomatic piroplasm carrier horses

This study aimed to determine whether asymptomatic horses naturally infected with Theileria equi retain infected erythrocytes in the spleen and whether the presence of the hemoparasite in this organ is associated with parasitemia. We collected samples from 25 adult horses without clinical signs of any disease. From each animal, we collected whole blood samples from the jugular vein and a splenic puncture blood sample. All samples were submited to blood cell counts and detection of Theileria or Babesia. DNA extraction and PCR were performed in all samples for identification of piroplasm infection (T. equi and B. caballi). From the 25 horses evaluated for piroplasm detection by PCR, seven horses (28%) were positive in jugular vein blood but negative in splenic blood samples, five horses (20%) were positive in splenic blood samples but negative in jugular vein blood samples, and 13 horses (52%) were positive in both jugular vein and splenic blood samples. The hematological evaluation revealed anemia in 13 of 25 (52%) infected horses, lymphopenia in five (20%), neutrophilia in two (8%), neutropenia in one (4%), and thrombocytopenia in one (4%) infected horse. The present study demonstrated that several (20%) of the asymptomatic piroplasm carrier horses did not show parasitemia, but show infected erythrocytes in the spleen.

Investigação molecular de Ehrlichia spp. e Anaplasma platys em felinos domésticos: alterações clínicas, hematológicas e bioquímicas

Ehrlichia sp. and Anaplasma platys are Gram-negative micro-organisms, obligate intracellular parasites, residing in cytoplasmic vacuoles of leukocytes and platelets, found in peripheral blood or tissue. Few reports have been made about ehrlichiosis and anaplasmosis in cats in Brazil, which are based on the presence of morulae in leukocytes and platelets, or by detecting antibodies. The objective of this study was to investigate the natural infection with Ehrlichia sp. and A. platys in cats in Campos dos Goytacazes-RJ, by hematoscopia and DNA detection of these agents. Samples of whole blood and serum from 91 cats, regardless of race, gender and age. Blood count, serum biochemistry and PCR using primers for Ehrlichia sp. and A. platys were perfomed. Data from hematoscopia showed 9.89% of morulae only in platelets. The DNA of A. platys was detected in 13.18% of the 91 samples and 44.44% of the positive at hematoscopia. The DNA of Ehrlichia sp. was not detected in any sample. All animals studied did not show clinical signs neither positive laboratory results. The data suggest that domestic cats can serve as potential reservoirs for A. platys as asymptomatic form of related diseases

Effect of prepartum somatotropin injection in late-pregnant Holstein heifers on metabolism, milk production and postpartum resumption of ovulation.

The aim of this study was to determine the effect of prepartum somatotropin injection in late-pregnant Holstein heifers on metabolism, milk production and resumption of postpartum ovulation. For this study, 31 late-pregnant Holstein heifers were used. The heifers were assigned randomly into two treatments: (1) 500 mg sc injections of somatotropin (somatotropin treatment, n = 15) at -35 and -21 days, and, if pertinent, at -7 days from expected calving date and (2) no treatment (control group, n = 16). Blood samples were collected weekly from -5 to 7 weeks after calving. Heifers with progesterone concentrations in plasma above 1 ng/ml in two consecutive postpartum samples were considered as having resumed ovarian activity. A higher proportion (P = 0.04) of heifers treated with somatotropin resumed ovarian activity in the first 7 weeks post partum (73.3%; 11/15) compared with the control group (37.5%; 6/16). A higher number (P = 0.02) of heifers in the somatotropin treatment group also ovulated during the first postpartum follicular wave (53.3%; 8/15) compared with the control group (12.5%; 2/16), as indicated by the number of heifers ovulating in the first 3 weeks post partum. Pregnancy rate was not affected by treatments (P > 0.10) and averaged 40.0% (6/15) in somatotropin-treated and 25.0% (4/16) in control heifers when evaluated up to 150 days in milk. Somatotropin treatment increased the average daily milk production by 2.8 kg/cow per day (P < 0.0001) and reduced the somatic cell count (P = 0.009). Plasma IGF-I was higher (P < 0.05) for somatotropin-treated heifers in the prepartum period. Insulin and body condition score were higher (P < 0.05) and non-esterified fatty acids were lower (P < 0.05) for somatotropin-treated cows in the early postpartum period. In conclusion, somatotropin injection during the prepartum period in late-pregnant Holstein heifers was able to increase the proportion of heifers resuming ovarian activity early post partum, inspite of higher milk production.

Insulin-like growth factor and growth hormone receptor in postpartum lactating beef cows

The objective of this study was to evaluate the plasma concentrations of insulin-like growth factor-I (IGF-I), and the mRNA hepatic expression of IGF-I and of the growth hormone receptors GHR and GHR 1A, in postpartum beef cows. Four Angus and four crossbred (Angus x Nelore) postpartum suckled beef cows were used. Liver and blood samples were collected every 10 days, from calving to 40 days postpartum, for gene expression and for β‑hydroxybutyrate and IGF‑I assays, respectively. Samples for progesterone assay were collected every other day, from day 10 to 40 postpartum. Three cows ovulated before 40 days postpartum. IGF-I concentration was higher in Angus x Nelore than in Angus cows. There was no difference in the expression of GHR, GHR 1A and IGF-I according to breed or ovulatory status. IGF-I concentrations were higher in crossbred cows, but have not changed according to postpartum ovulatory status. Moreover, changes in postpartum IGF-I concentrations are not associated with changes in liver GHR, GHR 1A and IGF-I mRNA expression in either breed.

Síndrome do abscesso pituitário em bezerros na Região Centro-Oeste

Pituitary abscess syndrome is a neurologic disease responsible for sporadic cases and outbreaks especially in calves leading to high mortality rates. This paper aimed to report the occurrence and the clinical, laboratorial and pathologic findings in three 8 to 11-month-old calves with pituitary abscess syndrome from Mid-Western Brazil. The most important clinical findings were nervous signs of cerebral and brainstem origin with clinical evolution of 7-20 days. Hematology revealed leucocytosis by neutrophilia and hyperfibrinogenemia. Cerebrospinal fluid analysis showed neutrophilic pleocytosis. Arcanobacterium pyogenes was isolated from cerebrospinal fluid. One calf recovered after antibiotic treatment. Mortality rate was 66.6% (2/3). Necropsy findings included single para-hypophyseal abscesses or located in the glandular parenchyma; one calf showed necrotizing rhinitis and another abscedative pneumonia. Histological exams of the central nervous system reveal complete absence of normal pituitary tissue due to the wide necrosis and neutrophilic inflammatory infiltrate. The authors reiterate the importance of adequate management practices to reduce incidence of several diseases especially in calves, including the pituitary abscess syndrome.

Effect of exogenous insulin and fasting on growth hormone receptor and IGF-I expression in the pre-ovulatory follicle of ewes

The aim of this study was to investigate the effect of fasting and exogenous insulin administration on the expression of growth hormone receptor (GHR) and IGF-I mRNA in the pre-ovulatory follicle of ewes. Fifteen ewes received an intravaginal progesterone releasing device that was removed 6 days later (day of removal = day 0). On day -2, the ewes were divided into three groups: (i) fasting group (n = 5) that was fasted from day -2 to day 2; (ii) control group (n = 5) that received a maintenance diet; and (iii) insulin group (n = 5) that received insulin injections (0.25 IU/kg) every 12 h from day -2 to day 2 under the same diet as the control group. Follicular samples were obtained on day 2. Fasting increased plasma non-esterified fatty acids concentrations from day -1 to day 2 (P < 0.001). There was no difference (P > 0.05) in the number of follicles, although there was a tendency for an increase in the pre-ovulatory follicle diameter for the insulin group in comparison to the control group (P = 0.12). Thecal GHR mRNA expression was very low and was considered insignificant. Moreover, granulosa cells GHR mRNA expression increased (P < 0.05) in the insulin group. Expression of IGF-I mRNA was not different among groups in both tissues. In conclusion, insulin administration increases GHR mRNA but not IGF-I mRNA expression in granulosa cells of the pre-ovulatory follicle. However, fasting did not change the pattern of GHR/IGF-I mRNA expression in the pre-ovulatory follicle.