Publications by authors named "Humberto B Magalhaes"

3 Publications

  • Page 1 of 1

Electrolytes and pH of Mammary Gland Secretions Assessments to Detect Impending Parturition and Associations With Placental and Neonate Features in Donkeys.

J Equine Vet Sci 2021 07 28;102:103636. Epub 2021 Apr 28.

Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois Urbana- Champaign, Urbana IL. Electronic address:

The objectives of this study were to determine (i) the usefulness of serial assessment of mammary gland electrolytes concentrations and correspondent pH to detect impending parturition in jennies; and (ii2) the associations between mammary gland secretions, and gestation length, foal sex, maternal, placental, and foal birth weights. Multiparous jennies (n = 37) were monitored daily from 350 to 355 days of gestation until parturition. The pH of mammary gland secretions was assessed daily with a hand-held device. Aliquots of mammary secretions were frozen daily and then retrospectively assessed for electrolyte concentrations (Ca, Mg, K, and Na) with an automated analyzer from five days until the last sampling pre-partum. Mammary gland electrolytes and pH were analyzed with mix-models. The gestational length, newborn, maternal, and fetal membranes weights were analyzed with t-test grouped by foal's sex. Associations across all variables were assessed with Pearson's coefficient of correlation. Sensitivity, specificity, and negative predictive value (NPV) and positive predictive values (PPV) were evaluated for pH (≤ 6.4), Ca (>10 mmol/L), and a combination of both. Each jenny had pH profiles assessed visually and classified as fast pH drop (1), slow pH drop (2), and alkaline pH (3) as previously described for horses. The overall gestation length was 374 ± 8.7 days, ranging from 357 to 390 days. There were no differences for gestation lengths for jennies delivering colts (374 ± 2.1 range 357-385 days), versus the ones delivering fillies (373 ± 2.3 range 358-390 days) (P > .05). Of all the foals, there were 61.8% colts and 38.2% fillies. The ratio of foal birthweight with the dam's bodyweight was 9.7%, and the ratio with fetal membranes was 11%. The majority of parturitions happened during the night (91.9%). There was a significant reduction in Na and an increase in Ca, Mg, and K concentrations leading to foaling. The pH showed a 90% sensitivity for foaling within 24 hours, whereas the specificity was 70%, and the PPV and NPV values were 40% and 97%. Of interest, Ca (>10 mmol/l) displayed a sensitivity and specificity of 71% and 85%, whereas the PPV and NPV were 72% and 84%. In the present study, jennies exhibited profiles 1 to 3 as previously described for mares. Herein, 65% of the jennies displayed profile 2 and foaled with a mean acidic pH of 6.4 ± 0.02. Conversely, 32% of the jennies showed a fast reduction in the pH of mammary secretion (profile 1) from day -1 (7.3 ± 0.2) to the day of foaling with an average pH of 6.6 ± 0.08. One jenny foaled with high and alkaline pH (i.e., 7.5). There were weak and negative correlations between pH and Ca, Mg, and K (P < .05). In addition, Ca displayed a weak but significant correlation with Mg, Na, and K. In conclusion, daily pH measurements of the mammary gland secretions can predict foaling in jennies, whereas Ca was not as useful. Contrary to horses that most mares present a fast pH profile, most jennies showed a slow pH profile. The sex of foal did not affect the gestational length and fetal/maternal and fetal membrane proportions in donkeys.
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July 2021

Daily Sperm Output, Spermatogenic Efficiency, and Sexual Behavior of Dezhou Donkey Jacks Mounting Jennies in Estrus.

J Equine Vet Sci 2021 06 19;101:103420. Epub 2021 Feb 19.

Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois Urbana, Champaign, IL. Electronic address:

This study aimed to assess the sexual behavior of jacks mounting jennies in estrus and determine the daily sperm output (DSO) and spermatogenic efficiency using two equations to calculate testicular volume (TV). Eight sexually rested mature jacks, aging 5 to 10 years old, had semen collected once a day for 10 consecutive days using jennies in good standing estrus for mounting. Sexual behavior and semen parameters were assessed during each collection. Testicular measurements of height, width, and length were taken immediately before the first semen collection, and these measurements were used to calculate TV. After that, the TV was used to predict the DSO. The average total sperm number (TSN) obtained on days 8 to 10 was deemed the actual DSO. Differences in the predicted vs. the actual DSO were used to calculate the spermatogenic efficiency. In addition, the actual DSO was also used to calculate the number of inseminating doses a jack could produce for both on- and off-site breeding. Jack's sexual behavior and sperm motility did not vary across collection days. Sperm concentration and TSN reduced over time (P < .05). The actual DSO was 9.1 ± 4.1 billion, and the predicted DSO varied from 4.7 to 18 billion. Spermatogenic efficiency varied from 50 to 150% based on jack and the equation used to calculate TV. The number of inseminating doses ranged from 15 to 47 at 300-500 million progressively motile sperm (pms)/dose for on-site breeding. In contrast, the number of breeding doses with cooled-shipped semen (1 billion pms/dose) varied from 4 to 14 doses across donkeys. In conclusion, sexual behavior was not affected by daily semen collections. Sexual rest did not affect sperm motility. The predicted DSO varied with the equation used to determine TV. Clinically normal donkeys have high spermatogenic efficiency, which confirms previous histology reports.
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June 2021

Effects of long-distance transportation on blood constituents and composition of the nasal microbiota in healthy donkeys.

BMC Vet Res 2020 Sep 15;16(1):338. Epub 2020 Sep 15.

College of Veterinary Medicine, Yangzhou University, 225009, Yangzhou, P.R. China.

Background: This study aims to determine the effects of transportation on the nasal microbiota of healthy donkeys using 16S rRNA sequencing.

Results: Deep nasal swabs and blood were sampled from 14 donkeys before and after 21 hours' long-distance transportation. The values of the plasma hormone (cortisol (Cor), adrenocorticotrophic hormone (ACTH)), biochemical indicators (total protein (TP), albumin (ALB), creatinine (CREA), lactic dehydrogenase (LDH), aspartate transaminase (AST), creatine kinase (CK), blood urea (UREA), plasma glucose (GLU)) and blood routine indices (white blood cell (WBC), lymphocyte (LYM), neutrophil (NEU), red blood cell (RBC), hemoglobin (HGB)) were measured. 16S rRNA sequencing was used to assess the nasal microbiota, including alpha diversity, beta diversity, and phylogenetic structures. Results showed that levels of Cor, ACTH, and heat-shock protein 90 (HSP90) were significantly increased (p < 0.05) after long-distance transportation. Several biochemical indicators (AST, CK) and blood routine indices (Neu, RBC, and HGB) increased markedly (p < 0.05), but the LYM decreased significantly (p < 0.05). Nine families and eight genera had a mean relative abundance over 1%. The predominant phyla in nasal microbiota after and before transportation were Proteobacteria, Firmicutes, Actinobacteria, and Bacteroidetes. Transportation stress induced significant changes in terms of nasal microbiota structure compared with those before transportation based on principal coordinate analysis (PCoA) coupled with analysis of similarities (ANOSIM) (p < 0.05). Among these changes, a notably gain in Proteobacteria and loss in Firmicutes at the phylum level was observed.

Conclusions: These results suggest transportation can cause stress to donkeys and change the richness and diversity of nasal microbiota. Further studies are required to understand the potential effect of these microbiota changes on the development of donkey respiratory diseases.
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September 2020