The epidemiological characteristics of bovine leptospirosis in animals and herds in Mato Grosso do Sul were investigated to determine parameters such as disease frequency and the serovars reactant in beef cattle herds. A total of 4,629 beef cattle herds were examined against 33 Leptospira spp. serovars. The serum samples were submitted to the microscopic agglutination test (MAT) for the serological diagnosis of leptospirosis. The MAT results showed that 3,814 (82.39%) of the 4,629 animals evaluated were seropositive for the bacterium, with serological reactions mainly to serogroup Sejroe, serovar Wolffi (36.49%). The observed high frequency of reactive animals demonstrates the relevance of the infection. Therefore, general and specific measures should be implemented to contain and/or prevent infection of the animals in the studied region.

This study aimed to evaluate the effect of immunocastration on the scrotal circumference, as well as in the macroscopic and microscopic testicular features in Nellore bulls bred under a semi-confining system for 91 days. Sixty animals were divided into two groups: 30 intact animals (non-vaccinated) and 30 immunocastrated animals. The immunocastrated animals were treated with two anti-GnRH vaccine doses (BoprivaTM - Zoetis Australia Pty Ltd). The scrotal circumference (SC) was measured on days 0 and 56. Testicular parameters: biometry traits (length, width, and height – cm; volume – cm3 ) and weight (g) was measured on day 91. Three testicles from each group were histologically processed to find the seminiferous tubule diameter and epithelium thickness (µm). Data were analyzed in the Minitab® 19 statistical software. The macroscopic features (SC, and testes weight, volume, length, width, and height) and the microscopic features (seminiferous tubule diameter and epithelium thickness) were compared between the two groups through Student’s t-test and Mann-Whitney test. All the values were lower (p<0.05) in animals immunized against GnRH, except for the right testis width and seminiferous tubule diameter. Results indicate that immunization against GnRH affected testicular development.

The effect of injectable progesterone was evaluated along with estradiol benzoate (EB) on the fate of the dominant follicle (DF) present in the ovary at the beginning of low progesterone-based TAI protocol. All cattle were given 500 µg cloprostenol im (PGF; Schering-Plough Animal Health for Estrumate, Pointe-Claire, QC, Canada) twice, 11 d apart, and allocated into two groups: Estradiol group (E group, n = 11) and Estradiol-Progesterone group (EP group, n = 11). Ten days after the second PGF (Day 0), all cattle were given an intravaginal progesterone device with half progesterone concentration (Cue-Mate with a single pod containing 0.78 g progesterone). Concurrently, all cattle were given 1.5 mg im of estradiol benzoate in 3 mL of canola oil and PGF im on Day 0 of the protocol in a crossover design, in which each cow received both treatments. Cows in the EP group also received 100 mg im progesterone (Sigma) in 2 mL of canola oil. On Day 8, progesterone devices were removed and all cattle were given PGF im. All statistical analyses were performed with SAS 9.0. The DF present on Day 0 ovulated in 76% (16/21) of cows from E group and 28.6% (6/21) of cows from EP group (P = 0.002). After progesterone device removal, the size of ovulatory follicle did not differ between groups (E group, 15.5 ± 0.43 mm vs EP group, 15.8 ± 0.98 mm; P = 0.82). These follicles ovulated in 81.3 ± 3.1 h in E group and 71.0 ± 6.1 h in EP group (P = 0.13). In conclusion, injectable progesterone reduced the proportion of cows that ovulate the dominant follicle present in the ovary at the beginning of estradiol-progesterone-based protocols. However, no difference was detected on time of ovulation after progesterone device removal between groups.