Czech Journal of Animal Science - In Press
Effects of Omega-3 Fatty Acids on Fresh Bull Semen Quality: A Systematic Review and Meta-AnalysisReview
Jabulani Ngcobo, Thobela Louis Tyasi
Polyunsaturated fatty acids (PUFAs), including omega-3, are known to yield health benefits to mammals, including bulls and human beings. This meta-analysis was done to determine the influence of omega-3 fatty acids (OMFA) on bull semen quality. The research question formulated for this meta-analysis was centered on the Population-Intervention-Comparison-Outcome (PICO) framework. To determine the influence of omega-3 fatty acids on semen quality, a meta-analysis was conducted using the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA) guidelines. The different effects were analyzed using a random effects model. The variations among included studies were tested using heterogeneity (I2). Semen volume (MD = 0.34, 95% CI: 0.18; 0.49), sperm concentration (MD = 97.09; 95% CI: 81.85; 112.33), live sperm (MD = 11.93; 95% CI (7.30; 16.55)), sperm motility (MD = 9.24; 95% CI: 9.39; 11.09) and plasma membrane integrity (MD = 11.01; 95% CI: 6.19; 15.83) increased drastically on the omega-3 fatty acids supplemented group. Notably, the progressive motility (MD = 1.90; 95% CI: -3.24; 5.61) was the only sperm parameter showing a non-significant influence when omega-3 fatty acids were supplemented. It was then concluded that omega-3 fatty acids supplementation can be used to improve most of the semen parameters in bulls.
Evaluation of changes in dry matter and nutrient content during the growth dynamics of silage maizeOriginal Paper
Andrej Mitrík, Tomáš Mitrík, Iveta Maskaľová
The aim of this study was to identify and quantify the relationships between the nutrient content and the DM (dry matter) content of various maize hybrids (Zea mays L.) in the dynamics of vegetative maturity and various soil-climatic growing conditions. Over the course of 7 growing seasons (years), a set of 1 972 samples of whole silage maize plants consisting of 206 different hybrids grown in two contrasting regions (lowland and foothill areas) was analysed. The focus was on DM content and the content of key energy nutrients (WSC – water soluble carbohydrates, starch, NDF – neutral detergent fibre) and their interactions. Results show that the transformation of WSC into starch has four key points: (1) it begins at a DM content of 150 g/kg; (2) it peaks at a DM content of approximately 235 g/kg; (3) it begins to decrease significantly from a DM content of 300 g/kg; and (4) it practically stops rapidly after exceeding a DM content of 350 g/kg. In the dynamics of vegetative development of maize plants, the DM content is very closely related to the WSC content (R² 0.728) and the starch content (R² 0.873). With the gradual increase in vegetative maturity and DM content in maize plants, the transformation of WSC into starch dynamically increases. These characteristics, with small deviations, were also confirmed at different levels of evaluation (all analyses, regions, seasons and individual hybrids). These results show that a DM content of 300 to 350 g/kg can be considered the optimal harvesting window for maize ensiling and the optimal phase of silage maturity for whole maize plants, because once the DM content exceeds 350 g/kg; the transformation of WSC into starch stops and the drying phase of plants begins.