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ABSTRACT: The aim of this study was to evaluate the addition of caraway (1%) in fast-growing and slow-growing broiler chickens’ diet and its effect on performance parameters, blood biochemical profile, and relative organ sizes and ileum morphology in slow-growing broilers. Two separated experiments were performed. On the first day of age, the broilers were divided into 2 equal groups (Control and Caraway) with 6 replicates per treatment in both experiments. Experiment I: The total of 276 male fast-growing Ross 308 broiler chickens were used. The trial lasted from the first day to 35th day of chickens’ age. Experiment II: The total of 216 male slow-growing (Hubbard JA 57) broilers were used. The trial lasted from the first to 50th day of chickens’ age. Mean liveweight, weight gain, feed conversion ratio, blood biochemical parameters, and relative organ sizes were not significantly different in these trials. The group of slow-growing broilers supplemented with 1% of caraway in the diet showed longer villi and deeper crypt in the ileum after 50 d of life. Based on our results, it can be stated that the proportion of 1% caraway in fast-growing and slow-growing broiler chickens’ diet did not influence performance parameters, blood biochemical profile and relative organ sizes. In case of the experiment with the slow-growing broilers supplemented with caraway, a significant difference in the height of the villi and the depth of the crypts was found. Caraway can be included in the broiler chickens’ diets without negative effects, but further study of the effect on the intestinal morphology is necessary.

The article presents the results of studying the indicators of the crumbling of granules and the specific energy costs of experimental batches of granulated feed for broilers. The process of granulation of compound feed for broilers was studied using the statistical planning method of a multifactorial experiment using a granulation line, including a granulator press. The dependence of the crumbling of granules and the energy consumed on the selected factors has been established. The moisture content of the feed mixture W (%) and steam pressure P (MPa) were chosen to optimise the granulation process. A matrix plan of the experiment was compiled. With the optimal values of the factors obtained in the study using the experimental planning method, an experimental batch of granulated feed was developed. At the selected levels of factors, the calculated value of the crumbling of granules was 20.11%, which fits into the optimum according to the standard of the crumbling of granulated feed for poultry (no more than 22%). The specific electricity consumption was 9.23 kWh/ton. Experiments have shown that the discrepancies between the experimental and calculated data are insignificant and within these indicators' experimental error determination. Mathematical modelling of the granulation process of loose compound feed for broilers made it possible to solve an important practical problem – to optimize the granulation mode, which ensures the production of good quality granules with minimal energy consumption. The obtained optimal granulation parameters can serve as the basis for producing granulated feed for broilers.

The aim of the study was to determine the calcium requirements in preparation period of the sexual mature and egg-laying and evaluate development of calcium retention in the first laying period of the hybrid combination Bovans Brown hens. The experimental trial lasted from 14 to 30 weeks of hens age. The animals were fed ad libitum with a pelleted complete feed mixture with 42 g/kg of calcium content. The amount of calcium retained by pullets gradually increased along with feed intake depending on age and preparation for sexual maturity and was around 0.39 ± 0.19 g Ca in the first period. Ca retention increased up to an average of 0.85 g Ca from 8 day before laying the first egg. Retention dropped sharply on the day of laying the 1st egg and a negative Ca balance occurred. Shell output was 1.75 ± 0.21 g/day for the beginning of laying and subsequently increased to 2.23 ± 0.08 g/ day during evaluate peak laying. The range weight of the first laid eggs was 45 ± 5 g. Percentage of eggshell move around an average of 10 ± 0.37% throughout the observed period. The daily calcium intake of pullets was 3.56 ± 0.26 g/day. With the beginning of laying, the daily intake increased to an average of 4.51 ± 0.43 g/day Ca. Before reaching sexual maturity, the calcium apparent digestibility of laying hens was relatively low, averaging around 22%, but the moment the hens began to lay, the apparent calcium digestibility began to increase to an average of 50%. Feeding a non-standard feed mixture with a higher calcium content than usual in mixtures for pullets did not have a negative effect on the finishing of animal development, the onset of sexual maturity, or deterioration of the observed parameters of eggs quality.

The study is focused on how the physical structure of the feed affects the health status of broiler chickens. The aim of this study was to evaluate the influence of feed particle size in broiler diets on gastrointestinal tract morphology, digesta viscosity, and blood biochemical parameters. A total of 90 one-day-old male Ross 308 broiler chickens were randomly divided into three different experimental groups (with five replicates per pen), with 6 birds per cage. The first experimental group (Coarse) was fed with the coarsest particle size, with feed with a geometric mean diameter (GMD) of 1111.26 µm, the next group (Medium) was fed with a less coarse feed size of GMD 959.89 µm, and the last group (Fine) was fed a diet with a fine feed particle size of GMD 730.48 µm. The use of coarse feed particle size in the diet had a positive effect on the gizzard weight and small intestinal villi height and crypt depth, which increased the surface area intended for digesting nutrients. The use of finely ground particles in the feed increased the level of gamma-glutamyl transferase and at the same time, decreased the level of urea, which could indicate adverse changes in the liver.