The sperm chromatin structure assay does not detect alterations in sperm chromatin structure induced by hydrogen peroxide.

The objective of this study was to investigate the effects of hydrogen peroxide (H2O2) on the chromatin structure of sperm. For this purpose, 44 cryopreserved bovine ejaculates were analyzed immediately post-thaw (control sperm, CON S), after 1 h of post-thaw incubation (non-oxidized sperm, NOX S), and after 1 h of post-thaw incubation in different concentrations of H2O2 (OX S; 50, 100 µM, 1000 µM H2O2). Sperm motility was determined using computer-assisted sperm analysis. Sperm plasma membrane and acrosome integrity were assessed by flow cytometry after staining with propidium iodide and fluorescein isothiocyanate-conjugated peanut agglutinin. Chromatin damage was assessed using the sperm chromatin structure assay (SCSA), and DNA damage was evaluated using the single cell gel electrophoresis (Comet) assay. Sperm motility and plasma membrane and acrosome integrity decreased while chromatin damage and DNA damage increased after 1 h of incubation (P < 0.05). The addition of H2O2 adversely affected all parameters (P < 0.05) except for chromatin structure. The role of H2O2 in sperm chromatin damage was investigated by supplementation of 10 IU catalase, which reversed the damage (P < 0.05). Interestingly, the chromatin decondensation induced by 10 mM dithioreitol, evidenced by an increase in chromatin damage in the SCSA (P < 0.05), was reversed by H2O2. In conclusion, H2O2 causes alterations in sperm functional status and DNA integrity. However, our results show that high concentrations of H2O2 can induce chromatin condensation, and thus the use of the SCSA for the assessment of H2O2-induced chromatin damage should be carefully considered.

[Effect of a multimodal pain management protocol and age on wound healing after thermal disbudding of female German Holstein calves]. / Einfluss eines multimodalen Schmerz­managements sowie des Alters zum Zeitpunkt des Eingriffes auf die Wundheilung nach thermischer Zerstörung der Hornanlage bei weiblichen Deutsch-Holstein-Kälbern.

INTRODUCTION: Hot-iron disbudding of calves is a stressful and painful procedure and leaves a burn wound. Pain management procedures and the effects of hot-iron disbudding on biochemical markers of pain perception and stress response have been widely investigated in recent years. The aim of this study was to investigate the potential effects of pain management and age of the calf on the healing of burn wounds caused by disbudding. 327 healthy female German Holstein calves were included in this randomised, triple-blinded, prospective study. Calves were either disbudded at the age of four to 10 or 15 to 28 days using a gas-powered hot iron. Each calf was randomly allocated to one of nine possible treatment groups (BG). All calves received either the active ingredients to be tested (xylazine hydrochloride with 0.2 or 0.05 mg / kg body mass (BM) intramuscular for sedation, procaine hydrochloride (2 %) each 8 ml locally on both sides subcutaneously (SC) to the cornual nerves, meloxicam with 0,5 mg / kg BM SC for anti-inflammatory purposes) or an identical amount of saline solution (placebo). Calves in the group `thermE` and `ScheinE` received only placebo. In group `ScheinE` disbudding was simulated and in `thermE` it was carried out. The calves were clinically monitored starting one day before and ending 28 days after the procedure and the burn wounds were assessed. Both the rectal temperature and parameters of wound healing changed significantly during the study period and had characteristic profiles over time. Wound healing was not influenced by the different analgesic protocols, indicating that a multimodal analgesia does not pose a risk for wound healing after thermal disbudding. There were no observed differences between the age groups. The results of this study show, that disbudding of young calves and a multimodal pain management protocol does not affect wound healing in calves.

INTRODUCTION: L'ébourgeonnage thermique des veaux est une procédure stressante et douloureuse qui laisse une brûlure. Les procédures de gestion de la douleur et les effets de l'ébourgeonnage thermique sur les marqueurs biochimiques de la perception de la douleur et de la réponse au stress ont été largement étudiés ces dernières années. Le but de cette étude était d'étudier les effets potentiels de la gestion de la douleur et de l'âge du veau sur la cicatrisation des brûlures causées par l'ébourgeonnage. 327 veaux Holstein allemands femelles en bonne santé ont été inclus dans cette étude prospective randomisée en triple aveugle. Les veaux ont été soit ébourgeonnés à l'âge de 4 à 10 jours ou de 15 à 28 jours à l'aide d'un thermocautère à gaz. Chaque veau a été réparti au hasard dans l'un des neuf groupes de traitement possibles (BG). Tous les veaux ont reçu soit les principes actifs à tester (chlorhydrate de xylazine à 0,2 ou 0,05 mg/kg de masse corporelle (BM) par voie intramusculaire pour sédation, chlorhydrate de procaïne (2 %) 8 ml localement des deux côtés par voie sous-cutanée (SC) jusqu'aux nerfs cornuaux , méloxicam à 0,5 mg/kg de masse corporelle SC à visée anti-inflammatoire) ou une quantité identique de solution saline (placebo). Les veaux du groupe « thermE ¼ et « ScheinE ¼ ont reçu uniquement un placebo. Dans le groupe