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The effect of sex-linked dwarf gene was investigated through comparison of dwarf hens with their full-sib normal sisters obtained by mating heterozygous males (DW/dw) to normal females (DW/_) from line F (used as maternal form for production of slow-growing colored chickens) with respect to the following traits: body weight, shank and keel length at 40 weeks of age, age of sexual maturity (at 50 % production), egg production, egg weight, feed intake, feed utilization, livability, fertility, hatchability and egg quality characteristics. The results demonstrated that the dw gene caused statistically significant reduction of body weight by 29.15 %, shank length by 20.17 %, keel length by 7 % and egg weight by 5.72 % (p

The new original egg laying lines T, P and N selected at the Institute of Agriculture - Stara Zagora were used. Hybrid Т♂ × Р♀, Р♂ × Т♀ crosses were obtained and used for paternal line. Thereafter, the following breeding schedule of paternal and maternal lines was applied: Group I - (Р♂×Т♀)♂ ×N♀; group ІІ - (Т♂×Р♀)♂ ×N♀; group ІІІ - Т♂×N♀; and group ІV - Р♂×N♀. The production traits of original and hybrid birds were recorded: live weight at the age of 8 and 18 weeks, age of sexual maturity in days, 150 days egg production, average egg weight - at 2-week intervals until end of lay; livability, heterosis effect. The live weights of hybrids at 8 and 18 weeks of age were statistically significantly lower compared to original lines. The values of heterosis for this parameter were negative for all four hybrid combinations. The earliest beginning of egg lay occurred in (T♂×Р♀) ♂ ×N♀ (162.08 days of age) and Р♂×N♀ (163.11 days of age). The relative (%) heterosis for age of sexual maturity of studied hybrid combinations had moderate to low negative values. Average egg weights of hybrids were higher and the values of heterosis - positive for all four groups varying from 0.97% to 1.63%. The average 150 days egg production was lower in purebred lines compared to hybrids. The highest average 150 days egg production was determined in P♂×N♀ hybrids - 142 eggs. The heterosis effect for egg production in hybrids was significant.

Eight hundred one-day-old female chickens from two White Plymouth Rock lines (line L and line K) and their reciprocal crosses obtained from 40 male and 480 females were used to form four genetic groups (LxL, KxK, LxK and KxL). Differences among genotypes, the direct and maternal additive effects, and the heterosis were investigated with regard to the following traits: body weight from 2 to 10 weeks of age and at 18, 26 and 30 weeks of age, age at sexual maturity, egg production per hen-day until 46 weeks of age, average egg weight (between 32 and 46 weeks of age), liveability during the production period, egg fertility, hatchability of set and fertile eggs. The results demonstrated a statistically significant effect of the genotype on body weight during the different age periods (p

The primary aim of the experiment was to evaluate the potential of newly created chicken lines from the gene pool of the Agricultural Institute - Stara Zagora to create an efficiently performing commercial egg-laying hybrid. The investigation was conducted on two stages -- in 2010 and 2012, using red-coloured egg-type Line T and Line P as sire strains, and the white-coloured Line N as maternal strain for production autosexing chickens. Line T was superior to the other two lines as it had the highest live weight of both males and female chickens, and the lowest feed consumption per egg. Line N had the highest hen-housed egg production, highest laying intensity, lowest age of sexual maturity and highest hatchability. Lines P and T were superior to Line N with regard to average egg weight. The live body weight was determined at the age of 8 and 18 weeks. The egg production was monitored daily per groups on hen-day and hen-housed basis at 150 days of lay. The two-strain hybrid (P♂ x N♀) -- group IV, had the highest 150-day hen-housed and hen-day egg production -- 139.27 and 142.67 eggs, respectively. Egg weight increased with age in all four groups. Egg weight at group IV (P♂ x N♀) was superior to the other hybrids by the end of the period of lay. [ABSTRACT FROM AUTHOR]

The study aimed to investigate the effects of sex -- linked feathering alleles on laying performance, hatchability parameters and body measurements in hens from two White Plymouth Rock lines (line L and line K) used as maternal lines in broiler production. Four groups of 18-week-old hens were formed, two of each line, with genotype K/W (slow feathering) and k+/W (rapid feathering) respectively. Groups of line L included 72 hens divided into 6 boxes with 1 rooster per 12 hens, whereas line K groups comprised 96 hens of each genotype, housed in 8 boxes with one rooster per 12 hens, totally 192 birds.The K locus alleles had no significant effect on egg production traits (p>0.05). The presence of slow feathering allele resulted in lower fertility and hatchability of set eggs in both studied lines (p<0.05). A substantial effect of feathering rate alleles was observed with respect to the egg shape index (p<0.05), eggshell thickness (p<0.001) and albumen index (p<0.05). The presence of the slow feathering allele resulted in lower live body weight of birds from line K at the age of 36 weeks (p<0.05), but in longer thighs (p<0.01) and metatarsi (p<0.001) in both lines. The selection for creation of slow feathering lines for feather sexing purposes should take into consideration the effect of the K gene on studied traits. [ABSTRACT FROM AUTHOR]

The research was performed with the goal of establishing the frequency of alleles for fast or slow feathering at the K locus in two lines of White Plymouth Rock hens (maternal forms) -- lines L and K, as well as their influence on the birds' live weight during growth. The rate of feathering was determined at one day of age according to the length of the primary and secondary wing feathers. The birds' weight development was controlled through individual weighing at 2, 4, 6, 8, 10, and 12 weeks of age. In male chickens of the L and K lines, a higher frequency of the slow-feathering allele was found, respectively, 0.676 and 0.503 against 0.203 and 0.306 in females. Male and female chickens of the L line with a rapid-feathering genotype had higher live body weight than those with alternative genotype at ages of 2 to 12 weeks. There were no differences between the feathering genotypes for female chickens of the K line, whereas in males there was a tendency for higher live body weight with the rapid-feathering genotype. Slow-feathering chickens of both sexes of the same line were by 81.20 g (4.10%) lighter than rapid-feathering ones at the age of 12 weeks (p<0.05). The effect of slow- or rapid-feathering alleles was not identical for both sexes and the studied lines. [ABSTRACT FROM AUTHOR]

The issue of avian gene pool preservation should be linked to the development of a new trend in selection allowing rational use of the diversity of breeds and lines. Ten original chickens lines are reared in the Poultry Breeding Unit at the Institute of Agriculture, Stara Zagora: ?Z-80 B, ?Z-80 ?, Line ?, Line D, Line G, Line NG, Line ?, Line Ss, Line ChS, Line StR controlling their productivity through reproductive traits, live body weight at the age of 1 day, 5 months and 10 months, egg production and survival rate for the production period. The reproductive traits of chickens from the gene pool are characterized with high egg fertility - from 96.56% for Line NG t? 86.98% of Plymouth Rock Line G. Among the egg-type chicken lines, the highest hatchability rate from fertile eggs was observed in Line D - 89.05%. Chickens of all lines studied exhibited low death rates. The highest egg mass was that of chickens from Line G - 63.10 g and Line ? - 61.73 g The highest egg production over the 180-day period was that of the egg-type Line ? - 146 eggs, and Line ?Z-80 B - 145.67. [ABSTRACT FROM AUTHOR]

The experiment was performed in the Poultry Breeding Unit at the Institute of Agriculture, Stara Zagora, in 2009-2010. Three different chicken genotypes obtained by a specific plan were used: line R and line T from the Rhode Island Red breed and line N from the Rhode Island White breed. For each line, 20 selection nests with 12 hens and 2 cockerels (one principal and one spare) were formed. On the basis of observed zootechnological parameters, the line T was found to be superior to the other two lines with the highest live body weight of hens and cockerels and the lowest feed consumption per egg. Line N exhibited the highest hen-housed egg production rate, the intensity of egg laying, the age of egg laying's start and hatchability. The fertility or eggs produced from this line was higher than that of Line N by 7.94%, whereas the hatchability of fertile eggs was by 2.19% higher than that of Line P. The egg mass for Line P and Line T with 60.90 g and 60.24 g (?< 0.01) was superior to Line N. [ABSTRACT FROM AUTHOR]

The experiment was performed in 2011 in the breeder farm of the Hybrid Poultry Centre at the Institute of agriculture - Stara Zagora in order to determine the effect of the different preincubation storage periods on hatchability traits of turkey eggs and the changes in egg components. Eggs from light layer (LL) line of turkeys at the age of 38 weeks used as maternal side for turkey-broilers production were used. They were divided into the following groups: eggs stored for 14, 10, and 4 days as well as fresh eggs (without storage). The storage of eggs took place in an egg storehouse with constant air temperature and humidity (17°C and 72%). The loss of weight during the storage increased as the storage duration prolonged (ᵖ<0.001). During incubation, the highest weight loss percentage was exhibited by eggs stored for 10 days (14.29%) that was statistically significantly (ᵖ<0.001) different from weight loss of fresh eggs. which lost weight. The highest fertility (92.42%) was noted in fresh eggs. A very high early embryonic death rate was observed in eggs stored for 14 days (13.63%). The hatchability of fertile eggs was the highest in fresh eggs (90.77%) and the lowest in eggs stored for 14 days (71.45%) (ᵖ<0.001). The albumen percentage of total egg weight was the highest in fresh eggs (59.09%). The albumen pH increased with the storage duration and was the highest in eggs stored for 14 days (9.25). Albumen's height decreased as storage duration became longer. For incubation to be use turkeys eggs from LL line stored at least time at 72% humidity and 17°C, because hatchability decreases with increasing duration of storage. [ABSTRACT FROM AUTHOR]

The experiment was performed with breeder hens of line K - White Plymouth rock, from the gene pool of the Poultry Hybrid Centre, used as maternal form for broiler production. Control hens received a traditional compound feed, and the experimental group - compound feed supplemented with 500 g probiotic/tonne. The biologically active substances of the bioproduct were: active microflora - Lactobacillus delbrueckii subsp. bulgaricus with total counts of 6.5x105, Streptococus thermophilus with total counts 3.4x108, vitamins and amino acids. The aim of the study was to investigate the effect of this probiotic on productive and morphological traits of produced eggs. The egg mass in experimental group was 2955.56 g, due to the higher egg laying intensity. The lower feed conversion per egg resulted in lower feed conversion per kg egg mass - by 0.515 g in experimental group. It could be concluded that the dietary supplementation with the probiotic increased the survival of experimental hens. By the end of the experimental period, egg mass increased statistically significantly in breeders that received the supplement (p<0.001). [ABSTRACT FROM AUTHOR]

Introduction: Recent investigations have demonstrated both congenital and acquired forms of toxoplasmosis lead to changes in behavior and psychomotor skills, similar to those seen in schizophrenia. Objectives: To seek a possible relationship between the infection with T. gondii and the severity of schizophrenia. Methods: We examined 108 patients with schizophrenia and 108 control subjects. An immunoenzyme method (ELISA) was used to investigate a potential presence of anti-toxoplasmosis IgG and IgM. Patients with schizophrenia were additionally examined via Positive and Negative Syndrome Scale (PANSS). Results: The analyze revealed a statistically significant higher frequency of carriership of anti-toxoplasmosis IgG in the patients with schizophrenia, as compared with the controls, p=0.01. The presence of high levels of anti-toxoplasmosis IgG antibodies was found in 69.23% of patients with schizophrenia and in 56.10% of mentally healthy subjects. The difference in concentrations of anti-toxoplasmosis IgG in both groups was not statistically reliable (p > 0.05). Conclusions: Our investigation of positive and negative syndromes did not reveal statistically significant differences between the patients with schizophrenia IgG carriers those with negative serological test results. A statistically reliable difference was found by comparing the results from evaluation of the symptoms of disorganization (p = 0.01). Sex, age and education did not influence the ability to carry anti-toxoplasmosis antibodies in patients with. [ABSTRACT FROM AUTHOR]

The experiment was performed in the selection farm of the Agricultural Institute, Stara Zagora, "Poultry breeding and production technologies" section in 2008. Eggs produced by turkeys of the Heavy Meat (HM) strain at the age of 32 and 44 weeks were used. The incubation traits were studied on all newly-laid eggs with hatching potential. The early embryonic death rate (EED) was determined at first week of incubation at following defined periods: I - formation of embryonic disk (incubation days 0-3) and II - after formation of the embryonic disk (incubation days 4-7). The embryonic death was determined by examinations by Day 25 and by the time of placing eggs in the hatching chamber. The eggs of the Heavy Meat hybrid turkeys, aged 32 weeks, showed a higher fertilization rate - 91.92%, higher early embryonic death rates: 1.35% up to the 3rd day of incubation and 2.02% up to the 7th day, vs. 0.88% (up to day 3) and 0.88% (up to day 7) in eggs laid by turkeys aged 44 weeks. The hatchability of placed and fertilized eggs was higher for eggs from younger layers (age of 32 weeks) compared to those laid by turkeys at the age of 44 weeks. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the affect of hereditary musculoskeletal diseases (HMSD) to the blood serum parameters and enzyme activity in turkey parents from light laying and heavy meat breed, as well as the impact of conditions of environmental comfort and environmental stress on biochemical changes in turkey broilers. Muscular dystrophy expression was on the 80-th day, and on the 46-th day in parents and broiler, respectively. Data on the level of liver enzyme creatine kinase (CK) in the group of turkeys with HMCD showed a decrease compared with control group. The increase is observed in the change of the enzyme activity of aspartate aminotransferaze (ASAT) and alanine aminotransferaze (ALAT). In turkey broilers under the stress conditions, the changes of enzymes were more severe, instead of the lower rate of muscular dystrophy compared to parents. [ABSTRACT FROM AUTHOR]

The experiment was performed with four groups of broiler turkeys: I - control, reared under conditions of ecological comfort, II - control, reared under conditions of ecological stress, III-birds suffering from muscular dystrophy (MD), reared under conditions of ecological comfort, and IV-birds with MD, reared under conditions of ecological stress. The turkeys from groups I and III were kept in the same room separated into two sections, where the microclimate was set in accordance with the zoohygienic requirements. Groups II and IV were kept in another room, where the microclimate deviated from the norms: higher temperature, lower air humidity, and a concentration of ammonia close to the maximum allowed. The conditions of ecological comfort had a positive effect on the live weight of the birds during the first 14 days for both healthy and MD birds. During the first 14 days of rearing under ecological stress, weight gain was increased, regardless of whether they suffered from muscle dystrophy or not. However, during the following period until the 70th day, rearing under such conditions marked a slower development for diseased birds. [ABSTRACT FROM AUTHOR]