The main purpose of the study was to determine the effect of egg mass and egg weight groups (group I eggs under 160 g, group II eggs160 g to 180 g and group III eggs over 180 g) on incubation results, loss of egg weight (moist) during incubation, gosling hatchability, and the relative share of the gosling in the egg mass. A well fertilized egg is an embryo "package" with all the necessary nutrients that facilitate its development until it is hatched and for a few days after hatching. The results of poultry offspring production, i.e., poultry embryo development, depend during its embryonic development, – apart from its genetic basis, – on several non-genetic factors. Eggs with mass between 160 g and 180 g (group II) demonstrated the highest fertilization rate (91.28%) and the highest hatchability out of the number of incubated eggs (83.14%), while the eggs from the group I (lighter than 160 g) showed the highest number of gosling hatchability out of the number of fertilized eggs (91.08%). The lowest embryo mortality was that of group I (5.17% and 6.06%), while the highest is reported for group III (14.29% and 16.67%). The lowest relative loss of egg mass (moist) by day 25 of the incubation period was established for the group I eggs (10.98%), and the highest for the group III (11.71%), with a statistically significant (P<0.01) difference of -0.73 %. Other differences were not statistically significant (P>0.05). The gosling percentage in the egg mass was significantly higher (P<0.001) in the group III of incubated eggs (67.81%) than in group II (66.61%) and group I (65.24%). The relative gosling percentage according to the egg mass grew with the increase of the egg mass, which to a certain extent agreed with our findings, except that these authors reported a considerably lower gosling percentage.

The concept of the chapter The future and the strategy of the development of poultry production show the results obtained in analyzing the state and achievements of poultry production in the Republic of Srpska, the Republic of Serbia, the region and the world, with a special emphasis on the influence of the breeding system, that is the keeping and fattening on production and quality of poultry meat and eggs, and therefore the welfare of livestock and environmental protection according to EU standards. Unlike the Republic of Srpska, EU members are characterized by trends in the increase in all production indicators of poultry production. Also on the basis of literature it can be noticed that significant changes have occurred in poultry production in the world and in EU countries, important criteria have been established aimed at improving the quality of products (meat and eggs), guaranteeing health safety of food, preserves and improves the environment and adheres to the welfare of animals in accordance with ethical standards. Therefore, a large number of countries, regardless of whether they are members of the EU or not, devotes a great deal of attention to bear-keeping systems, with particular emphasis on the welfare of poultry, as is the case in the Republika Srpska. In addition, most authors, domestic and foreign, find that genetic and non-genetic factors (primarily the poultry keeping system) have a significant effect on the productive characteristics of the poultry, and consequently on the production of quality organic meat. At the same time, it can be noticed that the pure races (autochthonous), that is, chicken strains, are increasingly gaining importance in the production of organic (ecological) meat and eggs in many countries of the world in the semi-intensive, semi-intensive, and extensive poultry holders . It is important to note that in the last two decades, in poultry production in the world and in EU countries, under the influence of consumers' demands, there have been noticeable changes. At the same time, with the clear demand of consumers that food is not only cheap and tasty, but also environmentally sound (safe), it is necessary to provide protection of the environment, as well as the welfare of poultry. In this way new challenges have been set in front of poultry producers, ie goals - the production of poultry and eggs of high quality and level of safety, while preserving the welfare of animals, as well as environmental conditions of the environment. In the world, the entire poultry breeding is done through three basic systems, which are extensive, semi-intensive and intense. However, with the development of poultry, there is also a new divide resulting from the above claims, as well as consumers. Namely, the entire poultry is divided into conventional (intensive) and alternative (non-paternal) poultry, which includes the organic production of poultry meat and eggs, which is strictly defined by the rules, laws, regulations and directives for the concerned type of production (meat or eggs) (way) keeping individual categories of livestock. An alternative way of holding the stretcher is that the more intensive breeding is more similar to the natural way of holding the stretcher in order to satisfy all their natural needs. In this way, the welfare of animals is protected, and the productivity and quality of eggs remain at a satisfactory level. In addition, alternative load-bearing systems (floor system, drainage system - free range and organic production) are designed to balance the health and welfare of livestock with the needs of manufacturers, consumers, industry and the environment. When introducing new systems of keeping (alternative), it is necessary to familiarize themselves with the way management and procedures (cultivation technology) are, because they most often involve a high risk for productivity, egg quality and the state of health of the carrier, as well as broiler chickens. In the end, it should be emphasized that the direction of the development of poultry production in the Republic of Srpska should be focused on the inclusion of our production in the world trends defined by the consumer relationship - product quality, new EU regulations - welfare of poultry - environmental protection. The current situation and problems should be addressed through a studious and comprehensive analysis that will be the basis for adopting short-term and longterm strategies, and through appropriate programs from the current unpaid, to design a clearly defined, planned poultry production with particular reference to the possibility of developing programs from other branches of poultry production and the development of organic production. In general, it is very important to raise awareness in our country about the health and safety of foods, which can be achieved by permanent education of producers and consumers, so we hope that the production of eggs and poultry meat will be successfully developed in the future in accordance with all the above mentioned requirements.

The purpose of this study was to determine the effects of age and sex of the foal on the gestation length of thoroughbred mares. The study covered six stallions (of average age of 10.25 years) and 34 mares (of average age of 10.51 years) with descent records (pedigree), English Thoroughbred horses raised and actively used for breeding at a study farm called Ljubičevo, located in Serbia. The following average morphological body measures were established: body weight (473.10 kg), withers height (159.55 cm), body length (160.54 cm), chest circumference (188.00 cm), and tibia circumference (19.21 cm) were found to be within the scope of standard measures for this breed and particular ages e.g. 9 to 15. The average gestation length, regardless of the sex of the foal, was 336.57 days. The gestation of mares carrying male foals was somewhat longer (337.70 days) than of mares carrying female foals (335.80 days). The difference (1.90 days) in gestation length was not statistically significant (P>0.05). A weak positive correlation (rp=0.321) was observed between the age of the mare and the gestation length (regardless of foal sex). Additionally, a medium correlation (rp=0.444) was observed between the mare's age and the gestation length in the case of male foals, and a very weak correlation (rp=0.210) in the case of female foals.

The aim of this study was to establish incubation values of eggs (egg fertilization, absolute and relative embryo mortality, and hatchability of male and female chicks), morphometric indicators (preincubation egg mass; length, width, and egg shape index; hatched female and male chicken mass and their relative share in the egg mass before incubation), and the phenotype correlation between some traits in the younger parent flock (YF33—33 weeks) and the older flock (OF49—49 weeks) of the light Institut de Sélection Animale (ISA) Brown hybrid. With regard to incubation values, the younger flock (YF33) demonstrated better incubation results than the older flock (OF49). The egg fertilization rate was 95.24 and 94.22%, respectively, chick hatchability as the percentage of the total of incubated eggs was 86.51 and 84.89%, respectively, and chick hatchability as the percentage of the total of fertilized eggs was 90.83 and 90.09%, respectively. Embryo mortality rate was 8.73 and 9.17% (YF33), and 9.33 and 9.91% (OF49). Regardless of the parent flock age, eggs that hatched female chicks had lower values of observed morphometric traits than those that hatched male chicks, except for the egg shape index (77.49–77.47%, respectively) which was higher by 0.02% in eggs which hatched female chicks, but this difference was not statistically significant (P > 0.05). Contrary to effects of the chick sex, the parent flock age had considerably larger effect on observed morphometric traits, as all morphometric indicators of eggs and hatched chicks of both sexes in the older flock (OF59) had statistically significantly higher values (P < 0.001) than in the younger flock (YF33). The only exception is the relative share of the chicken in the egg mass where the measured difference (−0.03%) was not statistically significant (P > 0.05). The phenotype correlation coefficients determined (rp) between the egg mass before the incubation period and the egg shape index were statistically significant (P < 0.01; P < 0001), except between the egg mass of eggs which hatched female chicks and the egg shape index in the young flock (YF33), whereby the calculated coefficient (rxy = 0.107) was not statistically confirmed (P > 0.05). Furthermore, the egg mass and hatched chicken mass of both sexes increased with the age of the parent flock, and statistically significant absolute phenotype correlation (P < 0.001) was determined between these two indicators.

This study presents research results of quality and incubation values for Isa Brown hybrid eggs.Eggs were produced in the 33rd week of age at the production peak.Research was conducted on the sample of 252 incubation eggs (240 fertilized eggs).Chick hatchability compared to the number of inserted eggs was 86.51%, and compared to the number of fertilized eggs 90.83%.Average values for quality parameters of brooding eggs and incubation results were as follows: egg weight before insertion 58.41 g, egg length 5.49 cm, egg width 4.29 cm, egg shape index 78.16%and egg volume 53.14 cm 3 , one day old chick weight was 39.15 g, absolute egg weight loss was 6.60 g, relative egg weight loss was 11.31% and relative chick share in the egg weight was 67,03%.Statistically justified (P<0.001;P<0.01; P<0.05) correlation (complete one) was determined between egg weight and egg width (0.908), egg weight and egg volume (0.923) and egg weight and chick weight (0.918), very strong correlation was determined between egg weight and egg length (0.870), strong correlation was determined between egg weight and absolute egg weight loss (0.690), weak correlation was determined between egg shape index and egg width (0.395), and very weak correlation was determined between egg weight and egg shape index (0.188), egg weight and relative egg weight loss (-0.166), egg shape index and egg length (-0.147) and egg shape index and chick weight (0.189).Between egg weight and relative chick share in the egg weight, egg shape index and absolute egg weight loss, egg shape index and relative chick share in the egg weight no statistically justified (P>0.05)correlation was determined.

The purpose of this review is to review the current state and achievements in poultry production in Serbia and worldwide, primarily the EU. Particular emphasis is placed on impacts of different rearing system, i.e. housing and fattening, on the production and the quality of the poultry meat and eggs and, simultaneously, on the welfare of poultry and environmental protection according to EU standards. According to the latest available data, total number of poultry produced in Serbia in 2015 was 17,450,000 units and production of meat amounted to around 86,000 t, while consumption was 12.12 kg per person. Egg production in 2015 was approximately 1.7 billion eggs, which is around 202 eggs per hen. A total of 13.1 million tons of poultry meat was produced in EU in 2015. It is evident from the literature that the poultry production in EU and worldwide has undergone significant changes, and clear criteria have been established to improve the quality of the products (meat and eggs), to guarantee the safety of the food, to protect the environment, and to ensure animal welfare in line with the relevant ethic norms. For these reasons, many countries within EU and worldwide, including Serbia, attach importance to housing systems for laying hens, with particular concern for animal welfare. Alternative housing systems (floor, aviary, free range and organic production) are increasingly used in the production of poultry meat and eggs instead of conventional systems. This is because it is considered that alternative housing systems may have positive effect on the productive traits of the poultry and, consequently, on the production of the quality organic meat. Furthermore, it is evident from research that pure (indigenous) breeds and strains are given growing importance in the production of organic meat and eggs in semi-intensive, semi-extensive and even in extensive rearing systems.

The purpose of this review is to review the current state and achievements in poultry production in Serbia and worldwide, primarily the EU. Particular emphasis is placed on impacts of different rearing system, i.e. housing and fattening, on the production and the quality of the poultry meat and eggs and, simultaneously, on the welfare of poultry and environmental protection according to EU standards. According to the latest available data, total number of poultry produced in Serbia in 2015 was 17,450,000 units and production of meat amounted to around 86,000 t, while consumption was 12.12 kg per person. Egg production in 2015 was approximately 1.7 billion eggs, which is around 202 eggs per hen. A total of 13.1 million tons of poultry meat was produced in EU in 2015. It is evident from the literature that the poultry production in EU and worldwide has undergone significant changes, and clear criteria have been established to improve the quality of the products (meat and eggs), to guarantee the safety of the food, to protect the environment, and to ensure animal welfare in line with the relevant ethic norms. For these reasons, many countries within EU and worldwide, including Serbia, attach importance to housing systems for laying hens, with particular concern for animal welfare. Alternative housing systems (floor, aviary, free range and organic production) are increasingly used in the production of poultry meat and eggs instead of conventional systems. This is because it is considered that alternative housing systems may have positive effect on the productive traits of the poultry and, consequently, on the production of the quality organic meat. Furthermore, it is evident from research that pure (indigenous) breeds and strains are given growing importance in the production of organic meat and eggs in semi-intensive, semi-extensive and even in extensive rearing systems.

The main purpose of the study was to determine the effect of egg mass and egg weight groups (group I eggs under 160 g, group II egg mass 160 g to 180 g and group III eggs over 180 g) on incubation results, loss of egg weight (moist) during incubation, gosling hatchability and the relative share of the gosling in the egg mass. Eggs with mass between 160 g and 180 g (group II) demonstrated the highest fertilisation rate (91.28 %) and the highest hatchability out of the number of incubated eggs (83.14 %), while the eggs from the group I (lighter than 160 g) showed the highest number of gosling hatchability out of the number of fertilised eggs (91.08 %). The lowest embryo mortality was that of the group I (5.17 % and 6.06 %), while the highest is reported for the group III (14.29 % and 16.67 %). The lowest relative loss of egg mass (moist) by day 25 of the incubation period was established for the group I eggs (10.98 %), and the highest for the group III (11.71 %), with a statistically significant (P Lass Than 0.01) difference of -0.73 %. Other differences were not statistically significant (P>0.05). Gosling percentage in the egg mass was significantly higher (P Lass Than 0.001) in the group III of incubated eggs (67.81 %) than in the group II (66.61 %) and the group I (65.24 %).

Research was conducted on two broiler parent flocks of Ross 308 and Cobb 500 hybrids.At the beginning of productive cycle (24 weeks of age) for Ross 308 hybrid average body weight of laying hens was 2680.40g, while for Cobb 500 hybrid it was 2697.80g.In the middle of the productive cycle (42 nd week) body weight was 3565.10 g (Ross 308) and 3599.05g (Cobb 500), while at the end of productive cycle (61 st week) body weight for Ross 308 hybrid was 3841.50 g, and for Cobb 500 3850.00g.Determined differences in body weights of laying hens in specific periods of productive cycle (17.40g, 33.95 g and 8.50 g), as well as difference in weight for entire productive period (23.26 g) were not statistically significant (P>0.05).More thorough research of broiler laying hen body weight influence on productive performances was done by determining phenotype correlation coefficient between researched parameters.Therefore between hen body weight and most of productive parameters statistically significant (P<0.001;P<0.01; P<0.05) phenotype correlation coefficients were determined, while between body weight of laying hens and laying intensity of breeding and fertilized eggs determined correlation coefficients were not statistically significant (P>0.05).

Certain investigations have been conducted in two broiler breeder flocks of Ross 308 and Cobb 500 hybrids. At the beginning of the production cycle (24 weeks of age), an average laying hens? body weight of 2680.40 g was found in the case of Ross 308 hybrid, and 2697.80 g in the case of Cobb 500 hybrid. During 42nd week of age (the middle of the production cycle), the body weight of laying hens was 3565.10 g (Ross 308) and 3599.05 g (Cobb 500), while at the end of the production cycle (61 weeks of age) the body weight of laying hens of Ross 308 hybrid was 3841.50 g, and 3850.00 g of Cobb 500. Identified differences in body weight of laying hens (17.40 g, 33.95 g, 8.50 g) in certain periods of the production cycle, as well as the difference in body weight of laying hens for the entire production cycle (23.26 g) were not statistically significant (P>0.05). More specific observation of the effect of body weight of laying hens on productive capacity of broiler breeders was determined by calculating the coefficients of phenotype correlation between the indicators studied. Thus, statistically significant (P<0.001, P<0.01, P<0.05) coefficients of phenotype correlation between the body weight of laying hens and the majority of production indicators have been determined, while statistically significant (P<0.001, P<0.01, P<0.05) correlation coefficients between the body weight of laying hens and the intensity of laying capacity for hatching and fertilized eggs have been determined, but for a shorter period of the production cycle.

U cilju utvrđivanja osobina kvaliteta konzumnih jaja lakog linijskog hibrida Lohmann Brown sprovedena su istraživanja na živinarskoj farmi privatnog gazdinstva «Rakić komerc» doo, Batković, Bijeljina, Republika Srpska (BiH). U toku produkcije jaja posebna pažnja je obraćena na četiri glavne proizvodne faze, i to: 20. nedelja – SN20 (početak nosivosti), 28. nedelja - SN28 („pik“ maksimum), 48. nedelja – SN48 (sredina) i 72. nedelja starosti nosilja – SN72 (kraj proizvodnog ciklusa). U navedenim periodima, metodom slučajnog uzorka uzet je odgovarajući broj nosilja, odnosno jaja za istraživanja, analizu i statističku obradu utvrđenih podataka za ispitivane parametre. Pored mase, utvrđene su pojedine osobine kvaliteta jaja: masa jaja (g), dužina jajeta (mm), širina jajeta (mm), indeks oblika jajeta (%), boja ljuske (poen), čistoća ljuske (poen) i boja žumanca (1-15 Roshe, pri starosnom dobu nosilja (SN20-72). Rezultati istraživanja pokazuju da razlike u prosječnoj masi jaja porijeklom od različite starosti nosilja su bile statistički signifikantne (P < 0,001). Analizirano komercijalno jato nosilja u proizvodnji konzumnih jaja, posmatrano u cjelini, ostvarilo je zadovoljavajuće rezultate kada su u pitanju parametri kvaliteta.

Main goal of this research was to determine the influence of Cobb 500 hybrid broiler parent age (BPA) and egg storage (ES) period, the impact of egg maturity on egg fertilization and chick hatching, as well as on embryonal mortality of chicks during incubation period. There were three phases of production cycle, three different ages of broiler parents 25, 41 and 58 weeks (BPA25, BPA41, BPA 58). The eggs there were differentiated according to storage time: eggs stored up to 7 days and eggs stored over 7 days (ES<7; ES>7). Using the random sample method, 1.050 eggs were chosen (total number of chosen eggs was 6.300), with the aim to determine above mentioned reproductive parameters, one day old chick weight and relative share of chick weight in total egg weight were determined. Age of broiler parents had the highest influence on egg fertility as the highest number of fertilized eggs was recorded during the middle of production cycle (BPA41 = 97.05%), then at the beginning of the cycle (BPA25 = 96.09%), and lowest number of fertilized eggs was during the last phase of the cycle (BPA58 = 93.00%). The storage period of the eggs did not have any influence on egg fertility. However, the age of broiler parents and storage period had significant influence on hatching, therefore it influenced embryonal mortality during incubation period. Without considering the storage period, the lowest embryo mortality was detected with eggs that originated from BPA41 - 13.05%, eggs that originated from BPA58 had significantly higher embryo mortality rate 15.87%, and the highest mortality rate was noted with eggs that originated from BPA25 16.93%. However, extended storage period for the eggs or egg maturity (ES<7 and ES>7) had influence on total embryonal mortality rate in all three phases of the production cycle. Moreover, broiler parent age had statistically significant influence on increase of egg weight (P<0.001) and hatched chick weight (P<0.001), while the relative share of chick weight in total egg weight was decreased, therefore storage period in all three phases of production cycle had negative influence on chick percent, with increase of storage time of the egg, relative share of chick weight in total egg weight decreased, especially during start BPA25 and end BPA58 phase of the production cycle (P<0.001).

The main objective of this study was to analyze the results of table egg production Lohmann Brown hybrid chickens before and after forced moulting, or study of the impact of forced molting on productivity and the duration of its lifetime hens. The surveys cover three periods, namely: - the first production of eggs in the first year (from 19 -71. Weeks of age hens); the second - moulting period (from 72 -76. Sunday); the third - after the forced molting period (from 77 -106. weeks of age hens). The experiment was conducted on a total of 44,400 commercial laying hens reared in a cage system, 'enriched' cages, family farm 'Rakic-Commerce' (Batkovic, Bijeljina, Republic of Serbian, BiH). From 19 to 48 weeks of age with a hen housed load intensity was 85,11%, from 19 to 71 weeks of age to 82.49%, while the second phase capacity uu after moulting after laying hen housed intensity of the load was 74.36%. From 19 to 48 weeks of age mortality rate was 4.21%, up 8.47% 71 weeks, during moulting 1.35%, from 77 to 106 weeks of age 3.24%. Between the age of hens and intensity of capacity in the first 30 weeks egg production was determined by the mean positive correlation connection (rp = 0.470) (P <0.01). In other phases of the production cycle of these indicators did not exist or were very weak negative correlation.

Examinations were conducted in two flocks of broiler parents' hybrids Ross 308 and Cobb 500. At the beginning of the production cycle (24th weeks of age) was determined that the average hens body weight of hybrid Ross 308 was 2680.40 g, and to hybrid Cobb 500 was 2697.80 g. At 42nd weeks of age (middle of the production cycle) hens body weight was 3565.10 g (Ross 308) and 3599.05 g (Cobb 500), while at the end of the production cycle (61st weeks of age) hens body weight of hybrid Ross 308 was 3841.50 g, and to the Cobb 500 was 3850.00 g. Determined differences of hens body weight (17.40 g, 33.95 g and 8.50 g) in specific periods of the production cycle, and the difference in hens body weight for the entire cycle (23.26 g) weren't statistically significant (P>0.05). Specific consideration of the impact of hens' body weight on reproductive performances of broiler parents was determined by calculating the coefficients of phenotypic correlation among the tested indicators. Thus, between hens body weight and most reproductive indicators of broiler parents were determined statistically very significant (P<0.001) coefficients of phenotypic correlation, while between hens body weight and the percentages of chickens feasibility from fertilized eggs were determined significant (P<0.001; P<0.01; P<0.05) correlation coefficients for a slightly shorter period than anticipated production cycle.

In order to determine the properties of egg quality of light line hybrid Lohmann Brown, a research was conducted on a private poultry farm "Rakić komerc" doo, Batković, Bijeljina, the Republic of Srpska (BiH). During the production of eggs, special attention was paid to the four main production stages, namely: 20 th week SN20 (start load), 28 th week SN28 ("pixels" maksimum), 48 th week SN48 (center) and 72 nd week of hens age SN72 (the end of the production cycle). In these periods, the appropriate number of hens or eggs was taken by a random sample for research, analysis and statistical analysis of the established data for the tested parameters. In addition to the mass, individual egg quality traits were determined: egg weight (g), egg length (mm), egg width (mm), egg shape index (%), color scales (point), the purity of the shell (points) and yolk color (1-15 rosh, at hens age (SN20-72). The results showed that differences in the average weight of eggs originating from hens of different ages were statistically significant (P < 0.001). Analyzed commercial flock of laying hens producing eggs for human consumption, viewed as a whole, achieved satisfactory results in terms of egg quality parameters.

This study was to determine how to investigate the effect of using triticale on growth performance, production and slaughter characteristics of broiler chicks.The research was carried out on 400 for feeding chickens, hybrid Ross 308.The first diet was the standard starter, grower I, grower II and finisher and served as control.The other rations contained 7.5%, 12%, 15% and 18% triticale as graded replacement for maize and wheat.The experiment lasted eating chicken 49nd days.Based on recorded productive traits of examined chicken groups in this investigation conclusion can be drawn that the best results is achieved C-group of chicken for mortality, feed conversion, production index, average body weight of chicken before butchery, handled and cooled carcass weight after 49 days of age.