Additive genetic relationships between heifer pregnancy and scrotal circumference in Nellore cattle

To estimate heritability (h2) for yearling heifer pregnancy and to estimate the genetic correlation between heifer pregnancy and scrotal circumference, 18,145 records of Nellore heifers exposed to breeding at an age of approximately 14 mo and 25,466 records of contemporary young bulls were analyzed. Heifer pregnancy was considered as a categorical trait, with the value 1 (success) assigned to heifers that were pregnant after rectal palpation approximately 60 d after the end of a 90-d breeding season and the value 0 (failure) otherwise. A single-trait animal model for heifer pregnancy and a two-trait animal model including heifer pregnancy and scrotal circumference were used. Contemporary groups were defined in two ways: including (CG2) or not including (CG1) weaning management of the heifer. Heritability estimates obtained by Method R in single-trait analyses were 0.68 +/- 0.09 and 0.61 +/- 0.10 using CG1 and CG2 definitions, respectively. Heritability estimates for two-trait analyses were 0.69 +/- 0.09 (CG1) and 0.63 +/- 0.08 (CG2) for heifer pregnancy and 0.57 +/- 0.03 (both CG) for scrotal circumference. The genetic correlation estimates between the two traits were 0.20 +/- 0.12 (CG1) and 0.20 +/- 0.13 (CG2). Based on the results of this study, EPD for heifer pregnancy can be used to select bulls for the production of precocious daughters and will be more effective than selecting on scrotal circumference EPD in Nellore cattle. However, scrotal circumference can be incorporated in a two-trait analysis to increase the accuracy of prediction for heifer pregnancy EPD for young bulls. Using contemporary group without heifer weaning management gave higher h2 and, for two-trait analysis, converged more quickly.     

Variants of the recently discovered avian gyrovirus 2 are detected in Southern Brazil and The Netherlands

A genome of a virus preliminarily named avian gyrovirus 2 (AGV2), a close relative to chicken anemia virus, was recently discovered in a chicken in the state of Rio Grande do Sul, Southern Brazil. To study the occurrence of AGV2 in Rio Grande do Sul and the neighboring state Santa Catarina, a number of adult chickens (n=108 and n=48, respectively) were tested for the presence of AGV2 DNA. An AGV2-specific PCR was developed, optimized and used to analyze DNA extracted from clinical samples. AGV2 DNA was detected in 98/108 (90.7%) of samples collected in the state of Rio Grande do Sul and 29/48 (60.4%) of the samples collected in the state of Santa Catarina. In order to check whether AGV2 DNA would be detected in samples from a geographically distant region, DNA from brain samples of 21 diseased chickens from the Netherlands were tested independently, by the same method. In such specimens, 9/21 (42.9%) brain tissue samples were found to contain AVG2 DNA. Sequence analysis of some of the PCR products demonstrated that the amplified AGV2 sequences could vary up to 15.8% and could preliminarily be divided in three groups. This indicated the occurrence of variants of AGV2, which may reflect differences in geographical origin and/or in biological properties. The data presented here provides evidence that AGV2 seems fairly distributed in chickens in Southern Brazil and that AGV2 also circulates in the Netherlands. Besides, circulating viruses display genetic variants whose significance should be further examined, particularly to determine whether AGV2 would play any role in chicken diseases.     

A follow-up of Beagle dogs intradermally infected with Leishmania chagasi in the presence or absence of sand fly saliva

In this study, we compare the development of infection and/or disease in Beagle dogs intradermally infected with Leishmania chagasi, in the presence or absence of Lutzomyia longipalpis saliva, with those of intravenously infected animals.Spleen samples of all the animals inoculated with parasites had positive polymerase chain reaction tests for Leishmania DNA. Positive spleen cultures for Leishmania were detected earlier (P < or = 0.018) and were more frequent (five out of the five animals) in intravenously infected animals than in the intradermally infected animals, in presence (two out of the six animals) or absence (three out of the five animals) of salivary gland lysate of L. longipalpis. Significant increase in serum antibodies against Leishmania was observed only in the intravenously infected group (P = 0.004). In addition, dogs with infection confirmed by isolation of amastigotes or detection of parasite DNA were, nevertheless, negative for anti-Leishmania antibodies up to 5 months or more after infection. Only animals of the intravenously infected group developed progressive decreases in hematocrit (Pearson r = -0.8076, P = -0.0026) and hemoglobin (Pearson r = -0.8403, P = 0.0012) during the infection period. No significant difference in the course of infection was observed between groups of intradermally infected animals. The data presented herein confirms that the intradermal inoculation of dogs with Leishmania produces an asymptomatic form of infection. It also fails to show an advantage in using L. longipalpis saliva as an infection-enhancing agent in experimental canine leishmaniasis.     

Interactions between different media and follicle‐stimulating hormone supplementation on in vitro culture of preantral follicles enclosed in ovarian tissue derived from collared peccaries (Pecari tajacu Linneaus, 1758)

The aim was to verify the effect of follicle‐stimulating hormone (FSH) supplementation to α‐MEM+ or TCM199+ media on the in vitro development of ovarian preantral follicles (PFs) derived from collared peccaries. Ovaries (n = 5 pairs) were collected and divided into fragments destined to control group (non‐cultured) or treatments that were cultured for 7 days. The PFs morphology, growth and activation were evaluated by classical histology. The immunohistochemistry markers Ag‐NOR and PCNA were used for nuclear proliferation analysis, and the picrosirius red labelling was used for ovarian extracellular matrix (ECM) evaluation. After 7‐day culture, only the TCM199+ treatment maintained the proportion of intact PFs similar to day 1 (63.2%), but no differences were found among treatments (p > .05). In addition, a significant increase in the growing follicles proportion was verified for all the treatments, indicating follicular activation (p > .05). By the Ag‐NOR analysis, only the TCM199+/FSH maintained the nuclear proliferation similar to the first day (p > .05). The picrosirius red staining revealed that the ECM remained intact in all the treatments (p > .05). We suggest the use of TCM199+ medium supplemented of FSH for the in vitro development of peccaries PFs under 7‐day culturing conditions.     

Intranasal Osteosarcoma in a Dog—A Case Report

Osteosarcoma is the most commonly reported bone tumor in dogs, typically affecting the axial and appendicular skeleton. Involvement of the paranasal sinuses and the nasal cavity is extremely rare. This report describes a 6-year-old, female, cross-breed dog presented with signs of 90 days duration and diagnosed with a mass located in the right nasal cavity. Radiography, rhinoscopy, and computed tomography findings suggested the presence of an intranasal tumor. Osteosarcoma in the nasal cavity was diagnosed based on histopathological examination and clinical and imaging findings. Survival time was 12 months from diagnosis.     

Influence of Apoptosis in Bovine Embryo's Development

The correlation between apoptosis and early bovine embryonic loss is still not fully elucidated. In the present study, the relationship between the arrest of bovine embryos at the different stages of development and apoptosis was evaluated. We used embryos 7 days after in vitro maturation and fertilization, and morphologic and biochemical apoptotic analyses were performed by using a phase contrast microscope and by the terminal transferase dUTP nick end‐labelling respectively. For the statistic, the apoptotic cell ratio (ACR) was determined as the percentage of apoptotic cells per embryo. To evaluate the relation between ACR and fragmentation pattern, embryos were divided into five groups, groups I–V. To assess the relation between ACR and cytoplasmatic fragmentation, embryos were divided into three groups, according to the fragmentation percentage (<5%; 5–15% and >15%). Of the total 139 embryos included, 65 arrested at 2–8 cells; 14 arrested at 9–16 cells; 18 compacted morula and 42 were non‐arrested blastocysts. The average number of embryonic fragmentation at different stages of the development, 2–8 cells, 9–16 cells, compacted morula and blastocyst, was 16.0 ± 1.5, 28.7 ± 4.4, 4.4 ± 2.4 and 1 ± 0.3 respectively. The embryos at the stage of arrested 9–16 cells and compacted morula had higher ACR than those at the blastocyst stage, excluding the stage of 2–8 cells (the genome is not yet active). The correlation detected between embryonic development and ACR was 0.92 (p < 0.01). It was observed that embryos possessing high fragmentation showed the higher ACR value (r = 0.98, p < 0.05). Comparing the results between fragmentation percentage and ACR, it was observed that the embryos with higher percentage of fragmentation corresponded to higher ACR (r = 0.97, p < 0.01). These results clearly demonstrated that bovine embryonic arrest at different stages of development is correlated with the apoptotic mechanisms.     

In Vitro Effect of the Reproductive Hormones on the Oxidative Burst Activity of Polymorphonuclear Leucocytes from Cows: A Flow Cytometric Study

In this study, the effect of reproductive hormones and substances with hormonal activity on the oxidative burst activity of blood polymorphonuclear leucocytes (PMN) high yielding dairy cows was evaluated. Different concentrations of: progesterone, oestradiol 17β, FSH, LH, GnRH, cortisol and PGF2α were incubated in vitro for 4 h with PMN of seven high milk yielding cows, during the period of anoestrous postpartum. Controls were run in parallel in which each hormone was replaced by its solvent. After incubation with hormones the competence of PMN to generate H₂O₂ was monitored by flow cytometry. A down‐regulation on the oxidative burst activity of PMA‐stimulated PMN was observed when cells were incubated with progesterone. Significant (p ≤ 0.001) differences between control and progesterone incubated cells were observed from 6.56 μg/ml. The same predisposition was observed when PMNs were incubated with cortisol. Besides for all concentrations employed, a decrease in the burst activity was observed, only beyond 0.19 mg/ml, statistical differences between the results obtained by the control and the cortisol incubated cells were obtained. Concerning oestradiol 17β, an increase on H₂O₂‐production was observed when PMN were incubated with 15 pg/ml and 45 pg/ml of this steroid (p ≤ 0.05), followed by a depression of the cell’s activity when unphysiological concentrations were employed. Significant (p ≤ 0.05) differences between the obtained with the control and oestradiol 17β incubated cells were observed only in the highest concentration of oestradiol. No statistical differences were observed in the metabolic burst activity of PMN incubated with FSH, GnRH and LH when compared with the results obtained by the control.     

Leptospirosis as the most frequent infectious disease impairing productivity in small ruminants in Rio de Janeiro,Brazil

Despite the importance of small ruminants breeding in developing countries, milk/meat productivity remains unsatisfactory. Infectious diseases, such as leptospirosis, brucellosis, and small ruminant lentiviruses (SRLVs), contribute to this scenario. The objective of the present study was to determine the role of each of these diseases in the productivity of small ruminants breeding in Rio de Janeiro, Brazil. In goats, 343 samples were tested for leptospirosis, 560 for Brucella abortus, and 506 for caprine arthritis-encephalitis (CAE), whereas in sheep, 308 samples were tested for leptospirosis, 319 for B. abortus, 374 for Brucella ovis, and 278 for Maedi-Visna (MV). Regarding leptospirosis, 25.9% of goats and 47.4% sheep were seroreactive, with serovar Hardjo the most prevalent in both species. Anti-B. abortus agglutinins were found in 0.7% of all samples, exclusively in goats. In relation to SRLVs, 8.6% of goats and 3.2% of sheep samples were positive for CAE and MV, respectively. Leptospirosis was the major infectious problem in the small ruminants sampled and may contribute to impaired productivity of these animals.