The goal of this paper was to investigate the effect of genotype and the number of farrowing on the number of piglets and variability of the fertility traits of the pigs from the farm “PKB Vizelj“ in Padinska Skela (Belgrade), in the period 2007-2012. The paper investigated the following pig genotypes: Swedish Landrace (SL), Large White (LW), Duroc (D) and crosses SL x LW and (SL x LW) x D. The paper shows the variability in the total number of piglets, the number of live born and weaned piglets, determined on the sample of 3,909 litters. The results show that the SL sows averaged 10.81 piglets per litter (n=1,532), while the LW sows averaged 10.04 piglets per litter (n=379). The SL sows farrowed 0.78 more piglets per litter than the crosses of F1 generation (SL x LW). On average, 11.51 more piglets per litter (n=859) were produced by three-breed crossing of the sows of F1 generation (SL x LW) with Duroc boars than by pure breeding and two-breed crossing. The authors came to conclusion that genotype and the number of farrowing had a significant effect on fertility traits, and no significant effect on the number of stillborn piglets.

The objective of this paper is to investigate the effect of multiphase feeding, i.e. the effect of different mash feeds with multi-phase protein reduction, on growth, main carcass parts and nitrogen content in faeces of broiler chickens. The experiment was conducted on 1216 chickens of Ross 308 provenience, separated by sex. The experiment lasted for 42 days and the standard technology was used. The groups differed in a type of a mash (treatment) given in the starter period, as follows: T1 (control group) was given a mash with 23% crude proteins from day 1 to day 21; T2 - a mash with 23% proteins from day 1 to day 7, followed by a mash with 21.5% proteins given from day 7 to day 21; T3 - a mash with 23% proteins from day 1 to day 14, followed by a mash with 21.5% proteins given from day 14 to day 21; T4 - mashes changed every three days, having 23%, 22.55%, 22.10%, 21.65% , 21.20%, 20.75% and 20.30% of crude proteins, respectively. Slaughtering performance was investigated on a total of 64 broiler chickens, with eight male and eight female chickens used separately for each of the treatments. Nitrogen content in faeces was determined using the pooled sample of faeces. The obtained results showed some differences in the average daily growth of the male and female chickens when comparing the control (T1) and the experimental groups. Those differences were not statistically significant. However, when comparing the male-only groups, it was determined that the experimental group T4 had statistically significantly higher growth than T2 and T3 group. The effect of the multi-phase feeding programme on the breast, thigh and drumstick share of both male and female broilers was not significant. The applied multi-phase feeding programmes resulted in a reduction in the nitrogen content in the faeces. Considering the obtained results, it can be concluded that the multi-phase feeding programmes had no negative effect on the growth and slaughtering performances of broilers. This goes in favour of these programmes, since they can result in some positive economic and environmental effects of production.

The objective of the research is to investigate effects of phytogenic additives as broiler feed supplements on production and slaughtering performances, morphological parameters and caecal microflora of fattening chickens of Ross 308 provenance. The research was based on two trials. In both trials, two feeding treatments were studied: a control diet with no supplemental feed additives (K) and a diet with a phytogenic additive supplemented to the control diet (1000g/t of Biomin PEP 1000, during the whole period). In the first trial, a total of 304 chickens were studied, in two treatments with four repetitions per pen with 38 chickens. The second trial included 16800 chickens, and it was conducted as a macro trial, that is, a pen with 8400 chickens was the subject of the trial. The results have shown that the chickens fed with the supplemental phytogenic additive have achieved significantly more favourable feed conversion rate. Differences in body mass and mortality rate between the trial group and the control were not statistically significant. Phytogenic additives did not have significant effects on breast portion and abdominal fat. Adding the phytogenic additive did not have significant effects on morphological parameters, but there was a tendency to increasing villous height and crypt depth. In both trials, the chicken groups fed with the supplemental phytogenic additive had less of all investigated groups of bacteria, and the differences were statistically significant for Enterobacteriaceae and Staphylococcus in the first, and Enterobacteriaceae and Enterococcus in the second trial. It can be concluded that the diet with the supplemental phytogenic additive had a positive effect on broiler performances, jejunum morphology parameters and caecal microflora.

Objective of the research was to investigate the effect of phase nutrition, i.e. different mixtures used in broiler nutrition with phase reduction of protein cotnent during starter period on production peformances of fattening chickens of different genotypes and on nitrogen content in faeces. Differences between groups (treatments) were in the type of mixtures use din starter period, and according to the following program: T1 (control group) - nutrition consisted of mixtures with 23% of proteins in duration from day 1 to 21; T2 - from day 1 to 14, mixture containing 23% of protein was used, and from day 14 to 21, mixture with 20% of proteins; T3 - from day 1 to 7, mixture was used containing 23% of protein and from day 7 to 21, mixture with 20% of proteins; T4 - nutrition with mixture containing 20% of proteins in duration from day 1 to 21. During the trial period (from day 1 to 21) production parameters were followed. Nitrogen content was determined in a collective faeces sample. Results showed that chickens of different genotypes expressed different sensitivity to protein restriction. Comparing the trial groups with the control in the third week, in chickens of Ross 308 provenience significantly lower body weight was registered only in chickens of T4 group with the highest protein reduction. In Cobb 500 chickens, significantly lower body weight was determined in T3 and T4 trial groups. In case of both hybrids, in T2 group, slightly lower body weight was established, but without statistically significant difference compared to the control. Feed conversion in both genotypes was the highest in T3 and T4 treatments. The program of phase nutrition resulted in decrease of the nitrogen content in faeces. Based on obtained data it can be concluded that applied nutrition treatments with drastic protein reduction during starter period in both genotypes had negative effect on production performances. Therefore, the composition and dynamics of mixture changes must be taken into consideration when formulating the program of phase nutrition, in order to achieve both goals - decrease of protein content in feed with simultaneous diminished nitrogen excretion and achieving good results.

In the last years Japanese quail (Conturnix coturnix japonica) is becoming more popular as a source of meat and eggs. Information on egg quality characteristics has been limited mostly to chicken eggs. The aim of this paper is to enhance the knowledge on the quality of quail eggs. In this study external and internal quality traits of quail eggs from three different commercial farms will be presented. For egg mass, shape index, shell thickness, shell mass no significant difference was found between farms. For yolk colour, yolk and albumen mass, statistically significant differences were found between the three farms. The difference in shell breaking strength between farms A and B was not significant and significant differences were found between eggs from farm C. Yolk, albumen and shell percentage were in the same relation as the mass of these parameters. The worst albumen quality was recorded in eggs from farm A. The parameters yolk colour, Haugh Unit and egg proportions (albumen, yolk and shell) do not differ between chicken and quail eggs. On the other hand, parameters which differ are egg mass (about five times smaller at quail eggs), shape index, shell breaking strength and shell thickness, which was to be expected. The external and internal egg quality traits of quail eggs from three farms in Serbia do not differ from the results of quality traits from other countries. On the other hand, this investigation contributes the development of science, because it includes some parameters, which have so far not been published in literature by other researchers from this area.

The importance of NIR technology in the animal food industry is presented in this study. As the example of the calibration procedure of NIR devices a calibration model for 14 samples of soybean cake was designed. Samples were previously analyzed in the standard laboratory testing of the moisture content, content of crude proteins, crude fats and crude fibre. In this calibration procedure high determination coefficients - R2 were established for these parameters of the nutritional value of food (0.9783 for moisture, 0.9904 for crude proteins, 0.9872 for crude fats and 0.9351 for crude fibre). The comparison of values obtained by using standard laboratory methods with values obtained by NIR technology/method indicates that by using NIR devices it is possible to obtain highly reliable results, and therefore it can be used successfully in facilities for production of animal food in the control of the quality and projection of mixtures.

Multiphase broiler nutrition is important from the standpoint of nutrition optimization, economical efficiency of production and protection of the environment. Objective of research is to investigate the effect of multiphase nutiriton, i.e. different mixtures used in broiler nutrition, whse protein content has been reduced in several phases during first fattening stage, on production performances of broilers. Investigation was carried out on 608 individually tagged male chickens, Ross 308 strain, divided into 4 groups: T1 (control group) - nutrition with mixture containing 23% of protein from 1-21st day; T2 - nutrition with mixture containing 23% of protein from 1st to 7th day, and from 7th to 21st day diet containing 21.5% protein; T3 - nutrition with mixture containing 23% of protein from 1st to 14th day and from 14th to 21st day diet containing 21.5% protein and T4 - nutrition with mixture containing 23% of protein from 1st to 3rd day, from 4-6th day with 22.55% protein, 7-9th day with 22.10% protein, 10-12th day diet with 21.65% protein, 13 - 15th day with 21.20% protein, 16-18th day with 20.75% protein and 19th-21st day diet with 20.30% protein. Main production parameters were registered during the trial period (from 1 to 21st day).Through processing of obtained data it ewas established that chickens of the T4 group (2092.42g), had realized statistically significantly higher body mass compared to T2 (2025.00g) and T3 (2020.07g), but not in relation to control group T1 (2055.16g), during trial period of 42 days. Also, it can be concluded that in regard to daily gain in period up to 21st day, no statistically significant differences between trial groups were established, however, for the entire trial period, average daily gain of chickens in T4 group (48.84g) was statistically considerably higher compared to T2 (47.24g) and T3 (47.13g), whereas in relation to T1 no differences were established T1 (47.99). Feed conversion differed between groups, precisely in favor of the application of multiphase broiler nutrition, i.e. feed conversion of the trial group T4 (1.870) was the best compared to T1 (1.918), T2 (2.005) and T3 (1.970). Based on obtained results it can be concluded that multiphase nutrition had effect on production performances, primarily level of food utilization.

Objective of the paper was to investigate if adding of chromium in different forms (organic and inorganic) and levels (quantities) to mixtures for broilers has any effect on broiler meat traits. Investigation was carried out on 840 chickens divided into four groups - treatments. Differences between groups (treatments) were in the form (organic and inorganic) and quantity of added chromium preparation (200 and 400 ppb) in basic mixtures for chicken nutrition. At the end of fattening (42 days) 48 broilers were dissected and shares of certain tissues in breasts, thighs and drumsticks were determined as well as chemical composition and tenderness of meat. Based on obtained results it can be concluded that adding of chromium in the amount of 200ppb resulted in statistically very significant increase of share muscle tissue and decrease of share of fat tissue in breasts, also tendency of improvement of the muscle tenderness of breasts and drumsticks was registered. When chromium was added in the amount of 400ppb, tendency of decrease of fat content of white meat was registered. No statistically significant differences were established in case of addition of 200ppb of chromium in regard to share of muscle and fat tissue in breasts, chemical composition and tenderness of broiler meat.

The aim of this work was parallel investigation of the producing characteristics of light line hen hybrids. Investigation enclosed two hen proveniences: Hisex Brown and Shawer 579. Within the period of 19 up to 63 weeks we followed next parameters: egg-laying hen body mass, mortality, food consumption and egg-laying capacity. Hens body mass on the beginning of the examination, within the 19 weeks of growth was, for Hisex Brown provenience 1607g, and for Shawer 579 provenience 1563g. Hisex Brown provenience achieved about 250 g higher body mass on the end of investigation. During the experiment, mortality at Hisex Brown egg-laying hen was a little bit smaller (5,40%), while the Shawer 579 had 5,56% of dead hens. Globally, the mortality at both hen hybrids was in the range of technological normative. The average consumption of the food at Hisex Brown provenience was higher and it was 127,28g, and at Shawer 579 provenience 125,14g. The average consumption of the nutrition for egg production at both provenience was the same (150g).