Veterinary, Equine, General Agricultural and Biological Sciences, General Veterinary
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Scopus Publications
Scopus Publications
Dietary Protein Imbalance Impairs Sperm Morphology and Promotes Testicular Degeneration in Rams Edson Ramos de Siqueira Filho, Frederico Ozanam Papa, Pedro Henrique de Oliveira Baldini, Andrey Osvaldo Souza Ferro, Karina Alberti, et al. Reproduction in Domestic Animals, 2026 Reproductive efficiency is a primary determinant of profitability in ruminant production, with male fertility being a critical factor for genetic progress and herd productivity. While nutritional management is a central component in modulating reproductive capacity, the effects of excessive dietary protein on testicular function remain incompletely elucidated. This study evaluated the impact of different dietary crude protein (CP) levels on reproductive and metabolic parameters in rams. Twenty‐eight Santa Inês rams were randomly assigned to four groups ( n = 7) and fed for 120 days with isoenergetic diets containing distinct CP levels: control (13.4%), hypoproteic (11.4%), hyperproteic I (17.5%) and hyperproteic II (22.4%). Periodic evaluations of body parameters, sperm kinetics and morphology, testicular ultrasonography, testicular cytology and hormonal profiles were conducted. Diets did not influence body weight or sperm motility ( p > 0.05). However, variations in testicular echogenicity were observed ( p < 0.05), and rams fed hyperproteic diets showed a progressive and marked increase in total sperm defects, exceeding 29.5% on day 80 ( p < 0.05) compared with the control group (12.86%). Cytological analysis confirmed the presence of multinucleated giant cells and testicular degenerative changes from day 40 onwards in the hyperproteic groups. In conclusion, diets containing 17.5% and 22.4% CP are detrimental to sperm morphology and testicular integrity in rams, even in the absence of changes in body weight or detectable ultrasonographic alterations. The diet with 13.4% CP proved more suitable for maintaining testicular function and reproductive health.
Conditional Antioxidant Protection of Stallion Spermatozoa by Butylated Hydroxytoluene Under Induced Oxidative Stress Endrigo Adonis Braga de Araujo, Frederico Ozanam Papa, Pedro Henrique de Oliveira Baldini, Camila de Paula Freitas‐Dell’Aqua, Sidnei Nunes de Oliveira, et al. Reproduction in Domestic Animals, 2026 Despite advances in the method, equine semen cryopreservation still leads to a marked decline in sperm quality, partly attributed to oxidative stress, which motivates the search for lipophilic antioxidants capable of stabilizing the plasma membrane during cooling and freezing. This study performed three experiments to evaluate butylated hydroxytoluene (BHT) as an additive to commercial skim milk–based (Botu‐Sêmen) and egg yolk–based (Botu‐Crio) extenders. In Experiment 1, a dose–response curve (0.5, 1.0, and 1.5 mM) was performed using stallion semen to assess toxicity and establish a safe concentration by analysing sperm kinetics (CASA) and membrane integrity immediately after dilution and after 24 h at 5°C. In Experiment 2, BHT at 0.5 mM was tested in standardized cooling (24 h at 5°C) and freezing protocols. Stallions were classified as Good/Bad Coolers and Good/Bad Freezers, and sperm kinetics (CASA), plasma membrane integrity assessed by epifluorescence microscopy (CFDA/PI), and plasma/acrosomal integrity and oxidative stress markers assessed by flow cytometry were evaluated. In Experiment 3, spermatozoa were exposed to an oxidative challenge with arachidonic acid (50 μM for 15 min at 37°C) to elucidate the mechanism of action of BHT. BHT at 0.5 mM was pharmacologically safe; however, it did not improve cryotolerance or reduce basal oxidative stress in commercial cooling and freezing protocols ( p > 0.05). Under oxidative challenge, BHT markedly reduced lipid peroxidation and intracellular reactive oxygen species production ( p < 0.05), indicating a conditional protective effect dependent on oxidative imbalance and impaired antioxidant defences. These findings suggest that BHT acts as an antioxidant primarily under critically increased ROS generation, but does not enhance the performance of commercial cryopreservation when procedures already operate within optimal conditions.
Optimising Stallion Semen Cryopreservation: Preliminary Insights Into Pre-Centrifugation Extender Effects Bruna Merci de Zutter, Camila de Paula Freitas‐Dell’Aqua, José Antônio Dell’Aqua‐Junior, Gabriel Augusto Monteiro, Tiago Troncarelli, et al. Reproduction in Domestic Animals, 2025 This study evaluated the effects of cholesterol, pentoxifylline and casein, with or without skim milk, added to extenders during pre‐centrifugation on equine sperm cryosurvival. Seven ejaculates from four stallions ( n = 28) were divided into four groups: SM (skim milk), SMP (SM + pentoxifylline), SMCho (SM + cholesterol) and ChoCa (cholesterol + casein). After centrifugation and freezing, sperm kinematics and plasma membrane integrity were assessed immediately and 30 min post‐thaw. SMCho and ChoCa showed superior results compared with SM and SMP. These findings indicate that cholesterol‐based extenders improve post‐thaw sperm quality when added before cryopreservation.
Descriptive comparison of serum progesterone levels during intravaginal device insertion in mares G. Pavel, D. Bratu, D. Bejenariu, A.C. Grădinaru Arquivo Brasileiro De Medicina Veterinaria E Zootecnia, 2023 Various studies demonstrated risks and benefits in the use of bee venom, a natural product characterized by a complex organic structure. In this study, we aimed to test the effects of bee venom administration in rabbits. Hematological investigations were carried out by determining specific blood indicators at different time intervals and at varying doses of venom. The obtained results showed a toxic action dependent on the dose and the daily cumulative effect; in the case of erythrocyte and platelet parameters, bee venom progressively generated the onset of thrombocytosis and reduced hemolysis for the short term. In the case of leukocytes, the administration of bee venom caused an increase of WBC count, segmented neutrophils and Ne/Lymph ratio, proportional to the dose and time of bee venom inoculation, but within the reference range; the average values of unsegmented neutrophils and basophils was above the upper limit of the normal range, with oscillating changes during the experiment; monocytosis and eosinophilia was also noted at different doses and times of venom inoculation. The investigations carried out 7 days after stopping the administration of bee venom revealed, in many cases, a progressive return to normal for the hematological parameters, except blood platelets.
In vitro sperm characteristics and in vivo fertility of sex-sorted and conventional semen in suckled Nelore cows at a traditional schedule for timed-AI with estrus detection J.H.W. Diniz, J.A.N. Riveros, A.C.B. Teixeira, I.C. Pereira, A.M. Borges, et al. Arquivo Brasileiro De Medicina Veterinaria E Zootecnia, 2022 The aim of this study was to assess in vitro sperm characteristics and pregnancies/AI (P/AI) of conventional and sex-sorted semen at timed-AI of suckled, multiparous Nelore cows. All cows (n=348) were submitted to a traditional estradiol/progesterone(P4)-based protocol. At 48h after P4-device removal, the estrous behavior was recorded, and AI was performed with conventional or sex-sorted semen from two bulls. The following sperm assessments were performed: CASA, Hyposmotic Test, sperm morphometry and chromatin structure by TB staining. P/AI were reduced (P<0.001) for sex-sorted compared to conventional semen in cows expressing estrus (27vs47%) or not (11vs.37%). Membrane integrity (Bull1: 30.3±9.6 vs. 52.3±12.4%, P=0.01; Bull2: 24.5±3.0 vs. 48.7±1.6%, P=0.006) and sperm concentration (Bull1: 23.2±0.6 vs. 43.0±0.8x10⁶sperm/mL, P<0.001; Bull2: 25.1±2.8 vs. 42.1±0.7x10⁶sperm/mL; P<0.001) were reduced in sex-sorted compared to conventional semen, for both bulls. Total and progressive motility were reduced in sex-sorted semen for Bull1 (TM: 49.7±15.9 vs. 94.9±1.9%, P=0.007; PM: 16.7±3.4 vs. 44.1±13.2%, P=0.009) and no differences were detected for Bull2 (TM: 45.0±17.5 vs. 68.2±19.1%, P=0.098; PM: 12.8±4.7 vs. 30.0±13.0%, P=0.065). Sperm ellipticity from sex-sorted was lower than conventional semen for Bull2 (0.306±0.01 vs. 0.342±0.02, P=0.02) and no difference was detected for Bull1 (0.332±0.01 vs. 0.330±0.01, P=0.55). Reduced in vivo fertility was observed for sex-sorted semen, regardless of estrous behavior. In vitro sperm quality of sex-sorted semen was compromised for both bulls, but differently affected for each sire.
Intravaginal progesterone device (1.9g) and estradiol benzoate for follicular control in the mare during spring and summer A.C.B. Teixeira, J.A.N. Riveros, J.H.W. Diniz, A.P. Fonseca, D.F. Silva, et al. Arquivo Brasileiro De Medicina Veterinaria E Zootecnia, 2021 The objective of this study was to evaluate follicular growth and ovulatory rates in mares treated with an intravaginal progesterone device (P4) during the 10-day period, associated with the use of estradiol benzoate (EB). The results were compared during the transition period (ET) in the spring and the breeding season in the summer (ER). The variables were submitted to ANOVA (Tukey's test), considering P<0.05. No ovulation occurred during the permanence of the P4 implant in both experimental periods. The ovulatory rate in the ER was 100% (n = 8) and in the ET 62.5% (n = 5; P = 0.0547). Significant differences were observed (<0.001), in both periods, comparing follicular growth rates during the permanence of P4 device (ER: 1.33 ± 0.89mm/d; ET: 1.00 ± 0.81mm/d) to the period without P4 (ER: 3.63 ± 1.33 mm/d; ET: 3.31 ± 1.66 mm/d). The present study demonstrated applicability and efficiency of a hormonal protocol using P4 intravaginal device and EB for follicular control in mares, both during ET and ER.
Pemphigus foliaceus in a horse Gabriel Augusto Monteiro, Maria Verônica de Souza, Lissandro Gonçalves Conceição, Camila de Lacerda Balbi e Rocha Borba, Maria Aparecida Scatamburlo Moreira Ciencia Rural, 2007
