Vladan Djermanovic

Carcass characteristics of two strains of native broilers (White Naked Neck and Black Svrljig) fattened under a semi-intensive system

This study involves the analysis of two breeds [Naked Neck (NN) and Svrljig chickens (Sv)], that is, strains [White Naked Neck (WNN) and Black Svrljig strain (BSv)] of chickens (birds) of both sexes reared under a semi-intensive system until day 84 of age. At 28 days of age, the test birds were kept in a litter housing system (about 8 birds/m 2 ), following which they were provided a free-range paddock at 4 m 2 /bird. The following parameters were evaluated in the two strains and sexes of broilers (totalling 56 chickens) aged 84 days: body weight at slaughter, carcass weight, yields of breasts, thighs, drumsticks, wings, pelvis, back, head, neck, feet, abdominal fat and giblets. At the end of the fattening period, the test broilers of both sexes of the WNN strain had higher values (P 0.05); however, a similar yield was obtained for ready to grill carcass (61.73 to 61.99%) when compared with the black Svrljig strain. The differences obtained were not statistically significant (P>0.05). In addition to the genotype (breed, strain), broiler sex had a statistically significant effect (P<0.001; P<0.01; P<0.05) on body weight, carcass yield, yields of drumsticks and thighs, wings, head, feet, giblets and abdominal fat. Specifically, male broilers were found to have higher live body weight (1669.29 to 1480.07 g), carcass weight (1342.86 to 1198.28 g), yields of head (5.13 to 4.39%), drumsticks and thighs (34.26 to 33.96%), feet (5.39 to 5.06%) and giblets (6.46 to 6.31%), whereas the relative yields of carcass (conventional processing (CP): 80.96 to 80.44%; ready to roast (RR): 73.02 to 72.19%; ready to grill (RG): 62.30 to 61.45%), wings (14.06 to 13.76%) and abdominal fat (1.13 to 1.07%) were higher in female broilers.

Some significant exterior and reproductive properties of the English Thoroughbred horse population from the stud farm 'Ljubicevo', Serbia

The investigation included 5 stallions (average age of 10.40 years) and 33 mares (average age of 10.33 years) with pedigree of the English Thoroughbred horse breed that are used for breeding on the Stud Farm Ljubicevo - Serbia. The investigation of some significant properties relating to the exterior (at stallions) and reproductive ones (at mares) were carried out in the year 2009. The following average exterior (body) measures of the stallions: the body mass (474.80 kg), withers height (160.46 cm), trunk or body length (161.88 cm), breast circumference (187.96 cm) and tibia circumference (19.22 cm) were within the standards of this horse breed of the age. The gestation period at mares, regardless the sex of a colt, averagely lasted 337.70 days. With the mares having had a male colt, the gestation lasted a little bit longer (338.92 days) than with the mares having had female colts (336.90 days). The difference in the gestation duration (2.02 days) was not statistically significant (P>0.05). Between the age of the mares and the gestation duration (regardless the sex of a colt) it was found a positive slight correlation (rp=0.320). Furthermore, between the age of the mares and the gestation duration it was found medium (rp=0.453) correlation at male colts, and quite poor correlation (rp=0.202) at female colts. Found coefficients of the phenotype correlation were not statistically confirmed (P>0.05).

The influence of age on the exploitation period in broiler reproduction of parents in Ross hybrid 308

These investigations were intended to identify the influence of parental flock age at heavy hybrid Ross 308 (usage period) on more important reproductive capabilities (carrying eggs intensity of brood eggs, egg mass, one day old chick mass, relative chick mass share in complete egg mass) and consumption of food per processed – hatched chicken (final product of production cycle). Flock usage period lasted for 40 weeks (all eggs), respectively, 38 (brood eggs) weeks and there was possibility, based on achieved results, with evaluation of phenotype correlation, to get some concrete conclusions about the age influence on analyzed parameters during mentioned flock rising period. Phenotype correlation among investigated characteristics has been identified since second half of parental flock using period, since 41st week age (20th carrying eggs week) up to the end of production process when parental flock was 61 week old (41st egg production week). Flock age has statistically important positive (P < 0.05) influence on carrying eggs intensity of brood eggs until 49st week (rp = 0.391) and on percentage of chicken feasibility regard the complete number of inputted eggs until 50th week (rp = 0.434). There was statistically significantly increasing of egg mass and one-day old incubated chicken mass (P < 0.001) as parental flock was older. Complete correlation connectivity has been identified between egg mass and absolute chick mass (P < 0.001), while very strong (P < 0.001) or strong (P < 0.01) correlative connectivity between egg mass and relative chick share [(chicken mass/egg mass) x 100]. Further more, we determined negative correlation between eggs age and food consumption per hatched chicken for all time of breeding broiler parents, except 61st week when we determined positive coefficient of phenotype correlation (rp = 0.062), but statistically inconsequent.

Rooster body weight influence on the reproductive performance of the broiler parents.

In this research influence of the rooster body weight on reproductive performance of broiler parents was examined for Ross 308 and Cobb 500 hybrids. At the beginning of the productive cycle (24 weeks of age) for roosters Ross 308 hybrids average body weight of 3,030.00 g has been determined, while for Cobb 500 rooster average body weight was 3,045.00 g. In the 42 nd week of age (middle of productive cycle), body weight of Ross 308 roosters was 4,306.00 g and 4,323.00 g for Cobb 500 roosters, while at the end of productive cycle in the 61 st week of age Ross 308 hybrids had average 4.908,00 g and Cobb 500 had 4,918.50 g. Determined differences in body weight of roosters (15.00 g, 17.00 g and 10.50 g) in specific periods of productive cycle, as well as difference in body weight for the entire productive cycle (19.97 g) were not statistically significant (P>0.05). Between rooster body weight and fertilized eggs laying intensity positive statistically significant (P<0.001; P<0.01; P<0.05) correlation coefficients were determined. Between rooster body weight and hatchability percentage of the chicks positive statistically significant (P<0.001; P<0.01; P<0.05) correlation coefficients were determined for both hybrids. However, based on correlation coefficient it has been determined that rooster body weight had positive influence on laying intensity of fertilized eggs till 58 th week of age (Ross 308) and 60 th week of age (Cobb 500), while on hatchability of chicks it had positive influence till 58 th week of age for both hybrids.

Effect of body weight of laying hens on production traits of broiler parents

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.

Phenotype variability and relations between basic parameters of morphological development in young Balkan donkeys.

Balkan donkey is native breed of donkeys evolutively adapted to modest breeding conditions and different climatic systems including harsh and severe climate of Serbian mountains. Unfortunately, the purposes for breeding small donkeys have been lost during the 20th century so the population is regressing. There has been no selective breeding of the autochthonous donkeys in Serbia therefore the data on breed characteristics are recent and few. The monitoring of morphological characteristics of autochthonous Balkan donkey population in Serbia have been performed in aim to characterize the population and to define the importance of autochthonous donkeys as national genetic resource . The morphometric parameters evaluated i.e. height at withers (HWi) body length (BLe), thorax girth (TGi), cannon perimeter (CPe) and body weight (BW) in young Balkan donkeys bred in traditional conditions were used for establishment of the following body indexes: Index of Body Frame (IBF), Index of Body Compactness (BCI), Index of Conformation (CoI) and Dactyl-costal Index (DCI) reflecting body development and conformational relations in Balkan donkey population in Serbia.

Feather loss in laying hens

The paper examined the incidence of different forms of feather loss and cannibalism in laying hens aged 74 weeks following moulting and in laying hens following exploitation for a period of one year. The forms of feather loss were considered in detail through a repeated examination of video recordings and they were sorted according to localization - to feather loss on the ventral part of the neck, on the dorsal part of the neck, and on the back between the wings. Feather loss on the ventral part of the neck was established in 47.9% hens, and in the dorsal part in 16.77% hens of the 167 laying hens aged 74 weeks following moulting. The group of 129 laying hens that were observed following one-year exploitation exhibited considerably more frequent feather loss, in 96.90% hens it was localized on the ventral part of the neck, in 60.47% hens on the dorsal part of the neck, and in 20.16% hens it was localized on the back between the wings. A comparison of the results of the incidence of co localized forms of feather loss in the one and the other group of laying hens using the t-test showed statistically very significant differences. A detailed consideration of the video recordings using the method of sequence analysis did not reveal any cannibalism in either group of laying hens.