Response of mid-lactation primiparous Holstein cows to the supplementation of rumen-protected methionine during the summer

by Caio R. Monteiro, Victor Augusto de Oliveira, Rabeche Schmith, João Pedro A. Rezende, Tales L. Resende, João A. Negrão, Marina A. C. Danés

This study aimed to evaluate the effects of rumen-protected methionine (RPM) supplementation on productive and physiological responses of primiparous Holstein cows during summer. We hypothesized that RPM supplementation would maintain or improve milk yield and composition due to beneficial physiological, redox, and inflammatory responses in cows exposed to summer heat. The trial was conducted in a randomized block design during nine weeks in Brazil using 80 primiparous cows (182 ± 64 DIM; 42.9 ± 4.7 kg/d milk). Cows were blocked by milk yield and DIM and assigned to a control diet (CON; no added RPM) or the same diet supplemented with RPM (Mepron®, Evonik) at 0.75 g/kg diet dry matter, targeting 20 g/cow/day (product contains 62% metabolizable methionine) to the average cow. Milk yield and composition, vaginal temperature, respiratory rate, and plasma samples were collected in weeks 3, 6, and 9. Data were analyzed using mixed models including treatment, week, and their interaction as fixed effects, and block and cow as random effects. Cows were maintained under naturally occurring summer conditions. Environmental monitoring during weeks 3, 6, and 9 indicated elevated temperature–humidity index (THI) values, with values remaining above the heat-stress threshold (THI > 68) for 68.3% of the monitored hours (mean THI = 70.6; range 61.0–84.4). Overall (least squares mean across weeks 3, 6, and 9), RPM increased milk yield by 2.0 kg/d (44.9 vs. 42.9 kg/d), protein yield by 50 g/d (1,464 vs. 1,414 g/d), lactose yield by 108 g/d (2,109 vs. 2,001 g/d), and total solids yield by 176 g/d (5,331 vs. 5,155 g/d). Lactose concentration was lower in RPM (4.71 vs. 4.76%). Fat yield was unaffected, but a treatment × week interaction was observed for fat content. Milk fatty acid (FA) profile was unchanged, although treatment × week interactions were observed for individual fatty acids (C16:0, C18:0, C18:1, and preformed FA). Plasma glucose was lower, and insulin was higher in RPM than in CON cows (39.3 vs. 43.2 mg/dL and 0.52 vs. 0.35 ng/mL, respectively). Antioxidant capacity improved, with RPM cows having greater ferric reducing antioxidant power (32.9 vs. 28.5 µM) and lower malondialdehyde (2.48 vs. 2.78 nmol/mL). Other biochemical, inflammatory, and immune markers were unaffected. Respiratory rate was slightly higher in RPM than in CON cows (55 vs. 50 breaths/min). Mean vaginal temperature did not differ between treatments; however, a treatment × time × hour interaction was observed. Supplementation with RPM improved milk and solids yield, and enhanced antioxidant capacity and insulin levels, supporting its use to improve metabolic resilience under warm conditions.

Preclinical safety and burn wound healing activity of “Novostron”, a novel topical iodine-based therapeutic

by Nailya Ibragimova, Arailym Aitynova, Seitzhan Turganbay, Marina Lyu, Alexandr Ilin, Tamari Gapurkhaeva, Galina Ponomareva, Karina Vassilyeva, Diana Issayeva, Amirkan Azembayev, Serzhan Mombekov, Aralbek Rsaliyev, Nurgul Sikhayeva, Yergali Abduraimov, Saki Raheem

Iodine-based antiseptics are essential in wound care but are often limited by cytotoxicity, instability, and rapid iodine release. Novostron is a novel polymer–iodine complex incorporating dextrin, polyvinyl alcohol, and metal ions, designed to enable controlled iodine release. Structural integrity and composition were confirmed by ¹H and ¹³C NMR spectroscopy and physicochemical analysis, indicating a molecular weight of ~9500 g/mol, a pH of 4.23, and an iodine content of 8.13%. Pharmacokinetic analysis in rabbits demonstrated that following a single dermal application, systemic iodine absorption was minimal, with peak blood iodine concentrations remaining within physiological limits and rapid elimination within 24 hours. Evaluation of thyroid function revealed no significant changes in serum T₃, T₄, or TSH levels compared with those of the controls, confirming that topical application of Novostron does not disrupt thyroid homeostasis. In compliance with OECD guidelines in rabbits, guinea pigs, and rats, Novostron showed no signs of dermal irritation, skin sensitization, or systemic toxicity (LD₅₀ > 2000 mg/kg). In a rat cotton pellet granuloma model, Novostron significantly reduced the inflammatory mass (23.65% inhibition), supporting its anti-inflammatory potential. In a murine burn model, Novostron accelerated wound contraction (25.95% at day 10), increased epidermal thickness, and enhanced collagen deposition (~44%), outperforming controls and matching or exceeding betadine. These findings suggest that Novostron promotes tissue repair by modulating inflammation. Overall, Novostron demonstrated a favourable preclinical safety and efficacy profile, and its polymer–iodine composition, which enables controlled release and localized activity highlights its potential as a promising topical therapeutic. However, the study was limited to animal models and short-term observation; further long-term and clinical investigations are needed to confirm its translational potential in human wound healing.