In the present study, the effect of breed, season, and their interaction on semen volume, sperm concentration, and motility was tested. Nine bulls were tested: three Braunvieh, three Simmental (B. taurus), and three Gyr (B. indicus). These bulls were managed equally in a cold semi-arid climate, divided into hot (from November to April) and cold (from May to October) for maximum and minimum temperature and relative humidity. Semen was collected twice a week for 24 consecutive months. MANOVA by ranks was used to determine significant effects; breed had a significant effect (P<0.001) on semen parameters, and seasonal variations were not significant (P>0.05). However, there was a significant effect (P<0.001) for the interaction between breed and season. To evaluate differences between breeds, we performed Tukey's post-hoc test; all pairwise comparisons (Braunvieh-Gyr, Braunvieh-Simmental and...

This study evaluated the gut microbiota and meat quality traits in 11 healthy female cattle from the Huaral region of Peru, including 5 Angus, 3 Braunvieh, and 3 F1 Simmental × Braunvieh. All cattle were 18 months old and maintained on a consistent lifelong diet. Meat quality traits, including loin area, fat thickness, muscle depth, and marbling, were assessed in vivo using ultrasonography. Fecal samples were collected for microbiota analysis, and DNA was extracted for 16S and 18S rRNA sequencing to characterize bacterial, fungal, and protist communities. Significant correlations were observed between microbial genera and meat traits: Christensenellaceae R-7 and Alistipes were positively associated with marbling and muscle area, while Rikenellaceae RC9 showed a negative correlation with fat thickness. Among fungi, Candida positively correlated with marbling, while Trichosporon was negat...