Positive Effect of Plant-Based Diet on the Performance and Health of Laying Hens

An entirely plant-based feed mixture was prepared to minimize the potential risk of transmitting prion infections through animal feed. It consisted of two protein components (soya extracted meal and lupin seed meal) and was compared with a diet containing animal protein components (fish meal). The objective of the present work was to prepare and verify the effect of the entirely plant-based diet on the performance, selected qualitative indicators of eggs and the hens' state of health. A specially prepared feed mixture containing fish meal was used as a control diet. The tested plant-based diet administered to experimental hens produced no negative effect on egg production variables such as number of eggs per hen or laying performance. The weight of eggs laid by experimental hens was significantly higher (61.66 g, P &#x2AAC 0.01), as compared with the control group (60.03 g). The higher average weight of eggs in the experimental group increased the production of egg mass per layer by 540 g in 252-day experimental period. the beneficial effect of the plant-based diet was demonstrated particularly in the improved egg quality, manifesting itself in a highly significant improvement in yolk colour (P &#x2AAC 0.01) and a significant decrease (P &#x2AAC 0.05) in cholesterol level in egg yolk. Haematological examination did not indicate statistical differences between experimental and control layers in red blood cell indices such as RBC, haemoglobin, hematocrit, MCHC, MCH, and MCV, while white blood cell indices showed a highly significant increase (P &#x2AAC 0.01) in Le in experimental hens. Biochemical tests performed in blood plasma revealed significantly lower molar concentrations of glucose (P &#x2AAC 0.05) and highly significantly lower levels of total lipids, cholesterol, lipoproteins (HDL and LDL) in experimental hens (P &#x2AAC 0.01), as compared with the control group. The results of the study confirm that animal protein in diet for laying hens can be replaced by combination of vegetable protein feeds (soybean and lupin protein) without a negative impact on their performance and health, thereby contributing to solving issues of food safety (a prevention of prion infections)

Design of Semi-active Magnetorheological Valve with Non-magnetic Bypass

The paper presents a methodology of designof a semi-active magnetorheological (MR) valve. Themethodology was composed of the non-Newtonian fluid flowanalysis and FEM analysis of a magnetic circuit. Based onthe present methodology a MR valve was designed. The MRvalve achieves damping force 1600 N at a velocity of 0.15m/s. The time response was determined to 6 ms

Predation life history responses to increased temperature variability

The evolution of life history traits is regulated by energy expenditure, which is, in turn, governed by temperature. The forecasted increase in temperature variability is expected to impose greater stress to organisms, in turn influencing the balance of energy expenditure and consequently life history responses. Here we examine how increased temperature variability affects life history responses to predation. Individuals reared under constant temperatures responded to different levels of predation risk as appropriate: namely, by producing greater number of neonates of smaller sizes and reducing the time to first brood. In contrast, we detected no response to predation regime when temperature was more variable. In addition, population growth rate was slowest among individuals reared under variable temperatures. Increased temperature variability also affected the development of inducible defenses. The combined effects of failing to respond to predation risk, slower growth rate and the miss-match development of morphological defenses supports suggestions that increased variability in temperature poses a greater risk for species adaptation than that posed by a mean shift in temperature

Molecular dynamics of silicate glass structure

This work studies the structure of silicate glasses by means of molecular dynamics simulation (MD). The structure of simulated alkali-silicate glasses was investigated using Q-species (Q") distribution where "Q" denotes SiO4 tetrahedra and n is number of bridging oxygen atoms. The structure of MD glass at room temperature shows much lower fraction of Q3 units than the structure of real glass. Nevertheless, it was confirmed that small alkali cations produce more extensive decrease of the Q3 amount of compared with larger alkali cations and that it is caused by their effort to surround themselves with NBO atoms. Silicate network defects {Si}5 present in MD glasses were discussed with respect to alkali concentration and cationic field strength of alkali modifiers