Algorithm of constructing hybrid effective modules for elastic isotropic composites

The algorithm of constructing of new effective elastic characteristics of two-component composites based on the superposition of the models of Reiss and Voigt, Hashin and Strikman, as well as models of the geometric average for effective modules. These effective characteristics are inside forks Voigt and Reiss. Additionally, the calculations of the stress-strain state of composite structures with new effective characteristics give more accurate prediction than classical models do

The effect of two mineral–vitamin premixes on the blood biochemical parameters, milk yield and composition of Holstein–Friesian cows in Kazakhstan

The aim of this study was to determine the effect of two mineral–vitamin premixes on the health status (blood biochemical parameters), milk yield and composition of Holstein–Friesian (HF) cows in Kazakhstan. The study was performed on Holstein–Friesian cows kept on the Bek Plus dairy farm in the village of Korzhynkol, Fyodorovsky District, Kostanay Region. Forty primiparous cows, selected from the herd, were divided by the analogue method into two groups: a control group (C) and an experimental group (E) of 20 animals each. The diets fed to group E cows were supplemented with LI-R 18 PRO and PANTO® Mineral R-77 Premium mineral–vitamin premixes. The premixes positively affected cow productivity and blood biochemical parameters, whose values were higher in group E than in group C. Higher levels of glucose, albumins and globulins exerted a beneficial influence on the health status of cows. No cases of lameness or metabolic diseases were recorded in group E. The yields of milk, protein and fat were higher in group E than in group C. Dietary supplementation with two premixes had no significant effect on the chemical composition of milk, including the values of the following parameters: somatic cell count (SCC), dry matter (DM), lactose (Lse), casein (Cin), acidity (Aty), lactic acid (LA), density (Dty), free fatty acids (FFAs), glucose (Gse) and urea (Uea).</p

Fattening, slaughter features and meat mineral composition of 3 beef cattle breeds

The aim of the work was to assess the fattening capability and slaughter value, including the meat mineral composition, of 3 beef cattle breeds. In the first stage of the experiment, the experimental materials comprised 90 bulls divided into three groups of 30 animals each, representing three beef breeds: Kazakh Hereford (KH), Kazakh Whiteheaded (KW) and imported Hereford (IH). The second stage of the study involved 60 bulls at 450 days of age (± 10 days), 10 bulls of each breed were selected randomly and slaughtered. The tested bulls were fattened from 240 to 450 days and from 450 to 540 days of age, respectively (1st and 2nd stage). The studies showed that the birth weight of bulls was relatively low (slightly above 27 kg) in all groups. Until 240 days of age, imported Hereford bulls were characterized by the highest average daily gains (904 g day-1). At 360 days of age, the average body weight of bulls fattened indoors exceeded 300 kg; Kazakh Hereford bulls had the highest body weight, and differences in the average body weight between groups were statistically significant (p ≤ 0.05). From birth to 450 days of age, the highest daily gain of 810 g was noted in imported Hereford bulls. At 540 days of age, imported Hereford bulls fed indoors (maize silage, hay and concentrate) had the highest average body weight (487.2 kg). In bulls of all breeds, metabolic profile parameters (AST, ALT, ALP, protein, content of Ca, Na, K, Mg and P) remained within the reference ranges, which points to a good health status of animals. Moderate feeding contributed to achieving the highest weight at slaughter by imported Hereford bulls (377.2 kg). Imported Hereford bulls were also characterized by the carcass dressing percentage above 56%, the highest carcass lean content, the lowest carcass fat content and the largest MLD area. Meat from imported Hereford and Kazakh Hereford bulls had the most desirable chemical composition and sensory properties

Basic and mineral composition of colostrum from cows in different ages and calving period

The aim of our research was to analyse the composition and the basic content of selected minerals of colostrum depending on the season of calving and lactation of cows. The research material consisted of 180 colostrum samples collected in the first lactation (1st) and further lactation together (FLT) of cows which calved in the summer season (S) and winter season (W). The scope of the experimental research covered determinations performed on colostrum samples collected in 4 lactation phases: 1st (1h), 8th (8h) hour as well as at 3rd (3D) and 5th (5D) day after calving. Studies have shown that the dry matter, fat, protein as well as FFA and IgG content decreased after calving. The lactose level increased and the concentration of urea remained on a relatively constant level (no statistically significant difference). The age of cows was another differentiating factor of the dry matter, fat, protein, FFA, urea and IgG content. It did not affect the change in the lactose content. It has been shown that the content of mineral components changed over the course of the colostral period. The highest values of Ca, Mg and Zn occurred in the first hour after calving, after which their content decreased. The content of K and Na was shaped slightly differently, since it was not possible to establish upward or downward trends. Significant changes also occurred in the content of elements depending on the age of cows. Colostrum with the highest Ca content may be obtained from older cows. However, the highest K, Mg and Na content was recorded in the primiparous cows’ colostrum of collected in the first hours after calving. A significantly higher content of K, Mg, Na and Zn appeared in colostrum obtained in the first hour after calving of cows in the winter calving season in comparison to the summer season

Influence of teat disinfection with iodine preparation on bacterial contamination of teats, hygenic quality and content of iodine in milk

The objective of the study was to investigate the influence of pre-milking teat disinfection on total bacterial contamination of teat skin, and to analyze the effect of pre- and post-milking teat disinfection on somatic cell count in milk. Three groups of cows in five dairy farms were used. The total bacterial contamination on cow teat skin before and after teat disinfection was determined. The number of colony forming units (cfu) was calculated per 1 ml a total for 2700 samples. The most bacteria on teat skin were effectively reduced after pre-milking teats disinfectionm almost in all groups of 5 farms (from 1.1 to 4.5 times). Summarized results showed that the number of bacteria counted on teat skin and milk somatic cell count (SCC) were significantly higher from teats with no pre- and post-milking teat disinfection in comparison with teats with pre- and post-milking teat disinfection or no pre-milking teat disinfection and post-milking teat disinfection only (p≤0.05). Pre-milking teat disinfectant with peracetic acid and hydrogen peroxide was effective in reducing total bacterial contamination on cow teat skin. The results also indicate that application with pre- and post-milking teat disinfectants provided an impact on the reduction of SCC in milk. The lowest iodine content was 0.1291 mg L-1 (group T1, whereas the highest was 0.2963 mg L-1). In our research the differences in the iodine content between farms were noted as well. For example, the highest iodine content in milk appeared at FIV farm. Statistical differences appeared at p≤0.05