Melina Andrea Formighieri Bertol

Association of antibodies against Neospora caninum in mares with reproductive problems and presence of seropositive dogs as a risk factor.

Sera from 112 mares from 5 horse-breeding farms was examined for the presence of antibodies to Neospora caninum and Toxoplasma gondii by an indirect fluorescent antibody test (IFAT), as well as from dogs and cattle present on these properties for the presence of antibodies to N. caninum. Among the 112 mares, 35 had a history of reproductive problems in the last breeding season and 77 had no reproductive problems. The rates of seroprevalence of N. caninum in mares with and without a history of reproductive problems were 25.71% and 6.49% and from T. gondii 2.85% and 1.29%, respectively. In dogs and cattle, the rates of seroprevalence of N. caninum were 10.52% and 15.55%, respectively. A positive correlation was found between the presence of antibodies against N. caninum (p=0.010) in mares and the occurrence of reproductive problems using the Fishers exact test. Significantly higher seroprevalence for N. caninum in mares was observed on the farm that had seropositive dogs (p=0.018). Cattle on this farm were also seropositive. No significant differences in seropositivity were found on farms where dogs were seronegative, or absent. This result suggests, for the first time, the presence of seropositive dogs as a risk factor for N. caninum in mares and the necessity for further investigation of the epidemiology of this parasite in horse-breeding farms with reproductive problems and the presence of cattle and dogs. This is the first report on the occurrence of antibodies against N. caninum in horses from the state of Santa Catarina, Brazil.

Viability of bull spermatozoa collected from the epididymis stored at 18-20°C

The aim of this study was to evaluate the viability of bull spermatozoa collected from the cauda epididymis stored at 18-20°C, which were compared with semen collected by electro-ejaculation method and preserved at 5°C. Ten pairs of testes from Tabapua bulls were removed by orchiectomy and stored for 6 (G6), 12 (G12), 18 (G18), 24 (G24) and 30 (G30) h at room temperature (18-20°C). Seven days before orchiectomy, semen was collected by electro-ejaculation method. The sperm parameters evaluated were: sperm motility, vigor, concentration, morphology and acrosome defects. Sperm motility declined (p<0.05) when spermatozoa were stored for 30 h in the epididymis. The spermatozoa from the epididymis showed lower sperm motility than that of spermatozoa collected via electro-ejaculation. There was a little expressive decrease in sperm vigor and increased in morphological defects with storage time, but the acrosome integrity was not affected. Cold storage (5°C) maintained sperm viable for 15 to 40.8 h. Thus, it was possible to recover viable sperm with 41.25% of motility from the cauda epididymis stored at room temperature of 18-20°C for 30 h. There were differences between the ejaculated and epididymal sperm for the bulls and the conservation at 5°C allowed short-term preservation of the gametes.

Parâmetros utilizados na avaliação do metabolismo do ferro em cães

The determination of iron metabolism rates associated with hematological findings is an important tool to diagnosis, control and differentiation of anemic states. This study has as objective to determine the iron parameters (serum iron, unsaturated iron binding-capacity, total iron binding-capacity, transferrin saturation rate (IST), transferrin and ferritin) in healthy dogs. It was selected 120 dogs, shared in four different groups of sex and age (30 young males and 30 adult males, 30 young females and 30 adult females). The blood samples were collected between 8 and 11h AM, with fasted dogs. The average values to serum iron, unsaturated iron binding-capacity, total iron-binding-capacity, transferring percent saturation and transferrin are 138.2µl dl-1; 371µl dl-1; 232.6µl dl-1; 37.7% e 259.6mg dl-1 respectively. These rates were evaluated according to sex and age variation. The average values submitted to Tukey test it were not significant (P<0,01). Considering a 5% level variation of error probability, the serum iron was higher in adult male dogs, comparing with young male ones (P<0,05). The ferritin values were 0ng mL-1 in human chemiluminescent immunoassay kit.

Reproductive Performance of Prebubertal and Pubertal Heifers Submitted to Timed Artificial Insemination Protocols

High numbers of prepubertal heifers at the beginning of the breeding season (BS) reduces reproductive efficiency in beef cattle.1 In Brazil, grazing Bos indicus heifers reach puberty between 22 and 36months, and the age at first calving is between 44 and 48months.2 Seasonality, poor pasture management, and poor nutrition during the heifer’s growth phase are some of the variables that lead to the delayed onset of puberty in Bos indicus cattle.3 Studies have been conducted to induce puberty in heifers, using either nutritional management strategies,4 or intravaginal progesterone (P4) devices.5 Sales et al.6 induced prepubertal Bos indicus heifers by administering P4 with estradiol cypionate (ECP) after 10days. Silveira et al.5 used prepubertal and pubertal zebu heifers for timed artificial insemination (TAI). They found a higher pregnancy rate (PR) in the groups that had received P4 with estradiol benzoate (EB) and ECP compared to prepubertal heifers only exposed to bulls. The exposure of prepubertal heifers to P4 for 8days induced and synchronized estrus. Similar effects were observed by Wheaton et al.7 and Demeterco et al.8 Treatment with a P4 intravaginal device induced prepubertal heifers to cycle and also increased the uterine diameter6 even during anestrus.9 The addition of EB at the time of P4 removal potentiates this action.3