Radica Djedovic - Academia.edu (original) (raw)

Papers by Radica Djedovic

Sperm sexing is a relatively new biotechnological procedure which offers us the possibility to ch... more Sperm sexing is a relatively new biotechnological procedure which offers us the possibility to choose the offspring sex. This method is widely used today in the insemination of the dairy cattle breeds and it is based on the difference in total DNA quantity between X and Y chromosome spermatozoa. In this research paper we have analysed the fertility, sex ratio and characteristics of female Black and White breed calves inseminated by the sexed sperm produced by 6 bulls on 6 commercial farms of the PK Belgrade. Conception rate was 44% with average gestation length of 274.9 days. Average calf birth weight was 36.75 kg. The stillbirths and twinning rates were 7.16 and 1.13%, respectively. Artificial insemination by sexed sperm assessed by c2 test highly significantly (P0.05) gestation length. Regardless the low conception rate, the application of sexed sperm in dairy cattle breeding is very significant since it enables the breeders to use the best replacement female animals what may resu...

Animals, 2021

In order to examine the biased milk production depending on the sex of calves, data on calving an... more In order to examine the biased milk production depending on the sex of calves, data on calving and milk yield characteristics of 15,181 Holstein type cows in PK Belgrade, Serbia were analyzed. A total of 30,362 lactations that were realized in the period from 1985 to 2017 were analyzed. Data were prepared and analyzed using the SAS software package (SAS Institute Inc. Software License 9.3, 2012). The expression and variability of investigated traits were determined using the PROC MEANS procedure, while the effect of individual factors on milk yield traits was analyzed using the PROC GLM procedure. Obtained results deviate from the views of the Trivers–Willard (TW) hypothesis. The results indicate that mothers invest more in female offspring by producing a higher milk and fat yield in the first and second lactation compared to male offspring. This is especially emphasized under better environmental conditions. The highest milk yield (7788 kg) and fat yield (271 kg) in the second lact...

Archives Animal Breeding, 2010

Buša is an old endangered autochthonous breed of the western Balkan, especially Bosnia-Herzegovin... more Buša is an old endangered autochthonous breed of the western Balkan, especially Bosnia-Herzegovina, Kosovo and Albania. A related breed is Gatačko, derived from Buša × Tirolean Grey crossbreds. Fifteen purebred Buša cattle and thirteen Gatačko animals were genotyped for polymorphisms at the kappa-casein gene by a Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) essay. The alleles A, B and C were found and the allelic frequencies were 0.46 (A), 0.46 (B) and 0.08 (C) in Buša cattle and 0.58 (A) and 0.42 (B) in Gatačko. Only AA, AB, BB and BC genotypes occurred. Further alleles were not detected and are therefore either absent in both populations or rare. The allele »B« found in this small population will be useful for a sire selection program in the future.

Journal of Agricultural Sciences, Belgrade, 2005

In intensive milk production particular attention is given to genetic improvement of cattle for h... more In intensive milk production particular attention is given to genetic improvement of cattle for high milk production and high quality of milk. Such trend should be followed by improvement of non genetic factors through technology and management. This is related to up to date solutions for high milk production, better cow reproduction, increase of productivity, better working conditions, better housing, efficient health protection and hygienic conditions, better technology of cow feeding, etc. It is known that two systems of cattle housing are present: free stalls and station barn with a number of modifications, among which the frequently mentioned one is semi-free stall as a combination of the two basic ones. Some variations within two systems are due to farm, climate and other differences. Based on a number of investigations, it is found that station barns have some advantage when milk yield is considered, while free stalls have preference when the reproduction of cows, productivit...

Biotechnology in Animal Husbandry, 2005

Population of domestic Simmental breed represents a dominant population of cattle in Serbia. Acco... more Population of domestic Simmental breed represents a dominant population of cattle in Serbia. According to importance of this breed, selection so far has been made in order to improve milk production. In other hand, beef and meatiness traits almost were ignored. Selection of dual-purpose cattle requires combining a various breeding goals and selection methods that are very differ from those applied in pure dairy or beef herds. Improving of beef and meatiness traits in our dominant cattle population will have great importance in future. The aim of this paper is to show possibility of selection for beef and meatiness traits in Serbian Simmental cattle.

Biotehnologija u stocarstvu, 2007

This paper reviews the main characteristics of small and/or closed livestock populations. Althoug... more This paper reviews the main characteristics of small and/or closed livestock populations. Although the emphasis during the realization of the genetic improvement in animal breeding is put on commercial breeding programmes, autochthonous breeds, races, strains, even herds of domestic animas, at the same time represent a potentially important segment for achieving the maintenance of the overall livestock production. These programmes are particularly important for the improvement of populations of animal genetic resources, as well as for the improvement of production in rural marginal areas. One of the main parameters for determining the size, and also the potential danger of a population is a so called effective size of the population (Ne). This parameter is determined according to the available number of male and female head of breeding stock in the population or in the herd and it varies under the influence of the sexes, changes in the size of the families, changes in the size of th...

The objective of this paper was to compare heifers reproductive traits and characteristics of the... more The objective of this paper was to compare heifers reproductive traits and characteristics of their calves after artificial insemination performed by conventional (non-sexed) and sexed sperm on 6 commercial farms in Serbia. Conception rate was 55% and 44% for conventional and sexed semen, an average gestation length being 274.6 and 274.9 days, respectively. Average body mass at birth was 37.47 and 36.75 kg for non-sexed and sexed semen, respectively. The rate of stillbirths and twinning was 6.19 and 3.78% for conventional and 7.54 and 1.13% for sexed semen, respectively. The use of conventional semen exerted no statistically significant (P>0.05) effect on female: male calves relationship (51.96 : 48.04) while artificial insemination by sexed semen highly significantly (P<0.01) changed calf sex-ratio (85.10 : 14.90). First-calf heifers originating from sires whose sperm was obtained in conventional way produced 7880 kg milk with 269 kg milk fat and 242 kg protein in standard la...

Biotechnology in Animal Husbandry, 2007

Data of 371 Simmental bulls tested at the A.I. Centre "Velika Plana" were analyzed in o... more Data of 371 Simmental bulls tested at the A.I. Centre "Velika Plana" were analyzed in order to estimate year and month of birth, test-group, herd of origin and body weight effects on body measurements and body development indices. These two groups of traits were considering as body development traits. All observed traits were measured at the start as well as at the end of test. Birth year was significant source of variation for all body development traits, while significance of month of birth was expressed at different statistical levels. Herd of origin effect was gradually reduced over the test, while test-group effect was significance only for body measurements. For body development indices herd of origin have no effect, while test-group effect was significant at different statistical levels. Body weight was very significant source of variation for all body development traits. .

The quality and yield of milk, and therefore of dairy products as well, depends directly on their... more The quality and yield of milk, and therefore of dairy products as well, depends directly on their protein composition. Milk gene proteins represent structural locuses that are functionally associated with milk production. In cattle selection a special importance is attached to the variability of kappa casein (κ-CN) as one of the four casein milk proteins. Genotypes of 21 Simmental breed cows, 20 crossbred cows obtained by crossing of Simmental and Red Holstein breed, and 25 cows of autochthonous Busha breed were determined for kappa casein by restriction fragment length polymorphism analysis (PCR- RFLP) of amplified DNA. The κ-CN genotype frequencies for Simmental breed were: 42.8; 47.6 and 9.6 % for AA, and BB genotype, for crossbreds: 75.0; 25.0 and 0.0% and for Busha individuals: 41.7; 50.0 and 8.3 %, respectively. Frequencies of A and B alleles, assessed on the basis of genotypic frequencies were 0.667 and 0.333 for Simmental breed, 0.875 and 0.125 for crossbreds and 0.667 and 0...

Genetika, 2021

The aim of this study was to determine the level and variability of type traits in primiparous Ho... more The aim of this study was to determine the level and variability of type traits in primiparous Holstein-Friesian cows, as well as to assess the additive genetic variance of type traits and heritability coefficients. The research was conducted on a data set of linearly evaluated primiparous Holstein-Friesian cows, which is ceded by the Main dairy cattle breed organization in the Province of Vojvodina, which is a unit of the Department of Animal Science, at the Faculty of Agriculture in Novi Sad. Data of 24226 primiparous Holstein-Friesian cows, refer to the period 2012-2015, were analysed. The phenotypic variability of the type traits, as well as effects of systemic factors affecting these traits, were analyzed using standard statistical methods in the Statistica software 13.2, and the general linear model (GLM). A Statistically highly significant effect for most of the type traits had the farm size, interaction of the year and the season of evaluation, age at linear evaluation, lact...

Performance test of young bulls represents the first step in the process of genetic improvement o... more Performance test of young bulls represents the first step in the process of genetic improvement of cattle. This procedure is important especially for beef and dual-purpose breeds and for those traits that are measurable in the live animals. In the most case those traits are suitable for direct selection and also they have influence on the level of production later in the life of animals. One of the most important groups of traits in performance testing of bulls is growth traits. In order to estimate heritability and genetic variability of growth traits, data on 371 Simmental performance tested bulls was used. Analysed traits were birth weight, body weight at different ages, average and relative daily gains. Since the structure of data disables implementation of Animal Model procedure, additive genetic variances and heritability of traits were obtained using restricted maximum likelihood (REML) methodology applied to sire model. Heritability estimates for birth weight, test-on (120 d...

Revista Brasileira De Zootecnia-brazilian Journal of Animal Science, 2021

Estimation of genetic variability and genetic correlations between production traits (milk yield,... more Estimation of genetic variability and genetic correlations between production traits (milk yield, fat yield, fat content, protein yield, and protein content) and selected type traits (angularity, fore udder height, rear udder height, front teat placement, teat length, and udder depth) was done using data sets of 10,860 first-calving Holstein-Friesian cows raised in the territory of the Republic of Serbia. Genetic variance and covariance were obtained using the Restricted Maximum Likelihood (REML) method, VCE v6 software, and the multi-trait mixed [...]

Biotehnologija u stocarstvu

Data set including 10860 primiparous Holstein-Friesian breed cows first calved in the period from... more Data set including 10860 primiparous Holstein-Friesian breed cows first calved in the period from 2011 to 2015, was used in determining phenotypic variability and correlation between the traits of milk yield and linearly estimated traits of udder and angularity. The average values obtained for type traits (angularity, fore udder attachment, front teats placement, teats length, udder depth and rear udder height) were 6.47; 5.74; 4.96; 5.20; 5.99 and 6.25, respectively. The values obtained for phenotypic correlations between linear type traits and traits of milk yield ranged from -0.042 (udder depth and milk yield) to 0.335 (fore udder attachment and protein yield). Positive phenotypic correlation (0.293) was recorded also between fore udder attachment and milk yield which is deemed the most important trait of milk yield while the lowest correlation between milk yields was determined in relation to udder depth (-0.033). The results obtained indicate a possibility of applying direct an...

Biotehnologija u stocarstvu

The objective of this research was to determine the association between age at first calving (AFC... more The objective of this research was to determine the association between age at first calving (AFC) and milk production in the first lactation of longevity traits for Holstein cows. The research was conducted on 2307 cows raised on 4 farms in AP Vojvodina. The cows were culled in the period from 2017 to 2018. The cows belonged to the group of Holstein Friesian breed of cattle. Cow longevity was observed using three parameters: number of lactations (NL), lifetime milk yield (LMY) and length of productive life (LPL). The research involved the influence of the farm on which the animals realized their production, the season of first calving. A mean value obtained for the length of productive life in the analysed population was 1207 days (3.30 years on average). During this period the animals on average realized 2.45 lactations and produced on average 18798 kg milk. All studied traits showed a high level of variability. From these data, the study sought to determine the influence of facto...

Biotehnologija u stocarstvu

The effects of fixed non-genetic factors (farm, season of birth, year of birth, total number of l... more The effects of fixed non-genetic factors (farm, season of birth, year of birth, total number of lactations) and a continuous non-genetic factor (age at first conception) on the expression and variability of longevity traits such as age at culling, length of productive life, days in milk and cow efficiency index were investigated in 2548 Simmental cows in three farming areas. Based on the model used for the analysis of the effects of non-genetic factors, including the environment and cow age at first conception, on the expression and variability of longevity traits, the overall means for age at culling, length of productive life, days in milk and cow efficiency index were 2445.21?17.49 days, 1562.55?17.71 days, 1094.17?12.28 days and 58.68?0.32%, respectively. The effect of farming area, year of birth and lactation group on longevity traits was very significant (P<0.01), whereas the effect of season of birth was significant (P<0.05). Age at first conception had a highly signifi...

Biotehnologija u stocarstvu

Due to the ecological concerns and preservation of genetic resources, the characterization of gen... more Due to the ecological concerns and preservation of genetic resources, the characterization of genetic structure of the brown trout (Salmo trutta) was carried out on the "Braduljica" fish farm. DNA was isolated from fin clips of 10 individuals, and after that molecular PCR-RFLP methods were used for distinguishing between Atlantic and Danubian lineages based on control region of the mitochondrial DNA (CR mtDNA) and lactate dehydrogenase gene of the nuclear DNA (LDH nDNA). Based on phenotypic characteristics it was estimated that out of 10 individuals included in this study five belonged to the allochtonous Atlantic lineage and remaining five belonged to the native Danubian lineage of brown trout. However, results of molecular analyses showed a high percentage of allochthonous genes among the individuals, which confirms the hybridization between these two lineages. Also, the results showed that the selection based on the phenotype is not adequate. In order to continue with proper broodstock management, it is necessary to eliminate allochtonous individuals of the Atlantic lineage from the broodstock.

Biotehnologija u stocarstvu

The farm animal welfare science has undergone a thorny path of development, often disputed becaus... more The farm animal welfare science has undergone a thorny path of development, often disputed because of its lack of measurability and the purpose of existence. At the very beginning, primarily based on moral and ethical attitudes, over time it pointed to the importance of meeting the needs of animals and the consequences of their neglect and exhaustion in the conditions of intensive livestock production. An important segment of its development was the definition and development of methodologies for the assessment of welfare indicators, which made it measurable and accepted as a scientific discipline with the knowledge applicable and useful in modern production systems. This paper is a concise review of the evolution of the animal welfare science, but also an indication of its future in the context of the development of "symbiotic" connections with the concepts of sustainable agriculture and food safety as integral parts of the modern ecological movement arose from a unified ...

Sperm sexing is a relatively new biotechnological procedure which offers us the possibility to ch... more Sperm sexing is a relatively new biotechnological procedure which offers us the possibility to choose the offspring sex. This method is widely used today in the insemination of the dairy cattle breeds and it is based on the difference in total DNA quantity between X and Y chromosome spermatozoa. In this research paper we have analysed the fertility, sex ratio and characteristics of female Black and White breed calves inseminated by the sexed sperm produced by 6 bulls on 6 commercial farms of the PK Belgrade. Conception rate was 44% with average gestation length of 274.9 days. Average calf birth weight was 36.75 kg. The stillbirths and twinning rates were 7.16 and 1.13%, respectively. Artificial insemination by sexed sperm assessed by c2 test highly significantly (P0.05) gestation length. Regardless the low conception rate, the application of sexed sperm in dairy cattle breeding is very significant since it enables the breeders to use the best replacement female animals what may resu...

Animals, 2021

In order to examine the biased milk production depending on the sex of calves, data on calving an... more In order to examine the biased milk production depending on the sex of calves, data on calving and milk yield characteristics of 15,181 Holstein type cows in PK Belgrade, Serbia were analyzed. A total of 30,362 lactations that were realized in the period from 1985 to 2017 were analyzed. Data were prepared and analyzed using the SAS software package (SAS Institute Inc. Software License 9.3, 2012). The expression and variability of investigated traits were determined using the PROC MEANS procedure, while the effect of individual factors on milk yield traits was analyzed using the PROC GLM procedure. Obtained results deviate from the views of the Trivers–Willard (TW) hypothesis. The results indicate that mothers invest more in female offspring by producing a higher milk and fat yield in the first and second lactation compared to male offspring. This is especially emphasized under better environmental conditions. The highest milk yield (7788 kg) and fat yield (271 kg) in the second lact...

Archives Animal Breeding, 2010

Buša is an old endangered autochthonous breed of the western Balkan, especially Bosnia-Herzegovin... more Buša is an old endangered autochthonous breed of the western Balkan, especially Bosnia-Herzegovina, Kosovo and Albania. A related breed is Gatačko, derived from Buša × Tirolean Grey crossbreds. Fifteen purebred Buša cattle and thirteen Gatačko animals were genotyped for polymorphisms at the kappa-casein gene by a Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) essay. The alleles A, B and C were found and the allelic frequencies were 0.46 (A), 0.46 (B) and 0.08 (C) in Buša cattle and 0.58 (A) and 0.42 (B) in Gatačko. Only AA, AB, BB and BC genotypes occurred. Further alleles were not detected and are therefore either absent in both populations or rare. The allele »B« found in this small population will be useful for a sire selection program in the future.

Journal of Agricultural Sciences, Belgrade, 2005

In intensive milk production particular attention is given to genetic improvement of cattle for h... more In intensive milk production particular attention is given to genetic improvement of cattle for high milk production and high quality of milk. Such trend should be followed by improvement of non genetic factors through technology and management. This is related to up to date solutions for high milk production, better cow reproduction, increase of productivity, better working conditions, better housing, efficient health protection and hygienic conditions, better technology of cow feeding, etc. It is known that two systems of cattle housing are present: free stalls and station barn with a number of modifications, among which the frequently mentioned one is semi-free stall as a combination of the two basic ones. Some variations within two systems are due to farm, climate and other differences. Based on a number of investigations, it is found that station barns have some advantage when milk yield is considered, while free stalls have preference when the reproduction of cows, productivit...

Biotechnology in Animal Husbandry, 2005

Population of domestic Simmental breed represents a dominant population of cattle in Serbia. Acco... more Population of domestic Simmental breed represents a dominant population of cattle in Serbia. According to importance of this breed, selection so far has been made in order to improve milk production. In other hand, beef and meatiness traits almost were ignored. Selection of dual-purpose cattle requires combining a various breeding goals and selection methods that are very differ from those applied in pure dairy or beef herds. Improving of beef and meatiness traits in our dominant cattle population will have great importance in future. The aim of this paper is to show possibility of selection for beef and meatiness traits in Serbian Simmental cattle.

Biotehnologija u stocarstvu, 2007

This paper reviews the main characteristics of small and/or closed livestock populations. Althoug... more This paper reviews the main characteristics of small and/or closed livestock populations. Although the emphasis during the realization of the genetic improvement in animal breeding is put on commercial breeding programmes, autochthonous breeds, races, strains, even herds of domestic animas, at the same time represent a potentially important segment for achieving the maintenance of the overall livestock production. These programmes are particularly important for the improvement of populations of animal genetic resources, as well as for the improvement of production in rural marginal areas. One of the main parameters for determining the size, and also the potential danger of a population is a so called effective size of the population (Ne). This parameter is determined according to the available number of male and female head of breeding stock in the population or in the herd and it varies under the influence of the sexes, changes in the size of the families, changes in the size of th...

The objective of this paper was to compare heifers reproductive traits and characteristics of the... more The objective of this paper was to compare heifers reproductive traits and characteristics of their calves after artificial insemination performed by conventional (non-sexed) and sexed sperm on 6 commercial farms in Serbia. Conception rate was 55% and 44% for conventional and sexed semen, an average gestation length being 274.6 and 274.9 days, respectively. Average body mass at birth was 37.47 and 36.75 kg for non-sexed and sexed semen, respectively. The rate of stillbirths and twinning was 6.19 and 3.78% for conventional and 7.54 and 1.13% for sexed semen, respectively. The use of conventional semen exerted no statistically significant (P>0.05) effect on female: male calves relationship (51.96 : 48.04) while artificial insemination by sexed semen highly significantly (P<0.01) changed calf sex-ratio (85.10 : 14.90). First-calf heifers originating from sires whose sperm was obtained in conventional way produced 7880 kg milk with 269 kg milk fat and 242 kg protein in standard la...

Biotechnology in Animal Husbandry, 2007

Data of 371 Simmental bulls tested at the A.I. Centre "Velika Plana" were analyzed in o... more Data of 371 Simmental bulls tested at the A.I. Centre "Velika Plana" were analyzed in order to estimate year and month of birth, test-group, herd of origin and body weight effects on body measurements and body development indices. These two groups of traits were considering as body development traits. All observed traits were measured at the start as well as at the end of test. Birth year was significant source of variation for all body development traits, while significance of month of birth was expressed at different statistical levels. Herd of origin effect was gradually reduced over the test, while test-group effect was significance only for body measurements. For body development indices herd of origin have no effect, while test-group effect was significant at different statistical levels. Body weight was very significant source of variation for all body development traits. .

The quality and yield of milk, and therefore of dairy products as well, depends directly on their... more The quality and yield of milk, and therefore of dairy products as well, depends directly on their protein composition. Milk gene proteins represent structural locuses that are functionally associated with milk production. In cattle selection a special importance is attached to the variability of kappa casein (κ-CN) as one of the four casein milk proteins. Genotypes of 21 Simmental breed cows, 20 crossbred cows obtained by crossing of Simmental and Red Holstein breed, and 25 cows of autochthonous Busha breed were determined for kappa casein by restriction fragment length polymorphism analysis (PCR- RFLP) of amplified DNA. The κ-CN genotype frequencies for Simmental breed were: 42.8; 47.6 and 9.6 % for AA, and BB genotype, for crossbreds: 75.0; 25.0 and 0.0% and for Busha individuals: 41.7; 50.0 and 8.3 %, respectively. Frequencies of A and B alleles, assessed on the basis of genotypic frequencies were 0.667 and 0.333 for Simmental breed, 0.875 and 0.125 for crossbreds and 0.667 and 0...

Genetika, 2021

The aim of this study was to determine the level and variability of type traits in primiparous Ho... more The aim of this study was to determine the level and variability of type traits in primiparous Holstein-Friesian cows, as well as to assess the additive genetic variance of type traits and heritability coefficients. The research was conducted on a data set of linearly evaluated primiparous Holstein-Friesian cows, which is ceded by the Main dairy cattle breed organization in the Province of Vojvodina, which is a unit of the Department of Animal Science, at the Faculty of Agriculture in Novi Sad. Data of 24226 primiparous Holstein-Friesian cows, refer to the period 2012-2015, were analysed. The phenotypic variability of the type traits, as well as effects of systemic factors affecting these traits, were analyzed using standard statistical methods in the Statistica software 13.2, and the general linear model (GLM). A Statistically highly significant effect for most of the type traits had the farm size, interaction of the year and the season of evaluation, age at linear evaluation, lact...

Performance test of young bulls represents the first step in the process of genetic improvement o... more Performance test of young bulls represents the first step in the process of genetic improvement of cattle. This procedure is important especially for beef and dual-purpose breeds and for those traits that are measurable in the live animals. In the most case those traits are suitable for direct selection and also they have influence on the level of production later in the life of animals. One of the most important groups of traits in performance testing of bulls is growth traits. In order to estimate heritability and genetic variability of growth traits, data on 371 Simmental performance tested bulls was used. Analysed traits were birth weight, body weight at different ages, average and relative daily gains. Since the structure of data disables implementation of Animal Model procedure, additive genetic variances and heritability of traits were obtained using restricted maximum likelihood (REML) methodology applied to sire model. Heritability estimates for birth weight, test-on (120 d...

Revista Brasileira De Zootecnia-brazilian Journal of Animal Science, 2021

Estimation of genetic variability and genetic correlations between production traits (milk yield,... more Estimation of genetic variability and genetic correlations between production traits (milk yield, fat yield, fat content, protein yield, and protein content) and selected type traits (angularity, fore udder height, rear udder height, front teat placement, teat length, and udder depth) was done using data sets of 10,860 first-calving Holstein-Friesian cows raised in the territory of the Republic of Serbia. Genetic variance and covariance were obtained using the Restricted Maximum Likelihood (REML) method, VCE v6 software, and the multi-trait mixed [...]

Biotehnologija u stocarstvu

Data set including 10860 primiparous Holstein-Friesian breed cows first calved in the period from... more Data set including 10860 primiparous Holstein-Friesian breed cows first calved in the period from 2011 to 2015, was used in determining phenotypic variability and correlation between the traits of milk yield and linearly estimated traits of udder and angularity. The average values obtained for type traits (angularity, fore udder attachment, front teats placement, teats length, udder depth and rear udder height) were 6.47; 5.74; 4.96; 5.20; 5.99 and 6.25, respectively. The values obtained for phenotypic correlations between linear type traits and traits of milk yield ranged from -0.042 (udder depth and milk yield) to 0.335 (fore udder attachment and protein yield). Positive phenotypic correlation (0.293) was recorded also between fore udder attachment and milk yield which is deemed the most important trait of milk yield while the lowest correlation between milk yields was determined in relation to udder depth (-0.033). The results obtained indicate a possibility of applying direct an...

Biotehnologija u stocarstvu

The objective of this research was to determine the association between age at first calving (AFC... more The objective of this research was to determine the association between age at first calving (AFC) and milk production in the first lactation of longevity traits for Holstein cows. The research was conducted on 2307 cows raised on 4 farms in AP Vojvodina. The cows were culled in the period from 2017 to 2018. The cows belonged to the group of Holstein Friesian breed of cattle. Cow longevity was observed using three parameters: number of lactations (NL), lifetime milk yield (LMY) and length of productive life (LPL). The research involved the influence of the farm on which the animals realized their production, the season of first calving. A mean value obtained for the length of productive life in the analysed population was 1207 days (3.30 years on average). During this period the animals on average realized 2.45 lactations and produced on average 18798 kg milk. All studied traits showed a high level of variability. From these data, the study sought to determine the influence of facto...

Biotehnologija u stocarstvu

The effects of fixed non-genetic factors (farm, season of birth, year of birth, total number of l... more The effects of fixed non-genetic factors (farm, season of birth, year of birth, total number of lactations) and a continuous non-genetic factor (age at first conception) on the expression and variability of longevity traits such as age at culling, length of productive life, days in milk and cow efficiency index were investigated in 2548 Simmental cows in three farming areas. Based on the model used for the analysis of the effects of non-genetic factors, including the environment and cow age at first conception, on the expression and variability of longevity traits, the overall means for age at culling, length of productive life, days in milk and cow efficiency index were 2445.21?17.49 days, 1562.55?17.71 days, 1094.17?12.28 days and 58.68?0.32%, respectively. The effect of farming area, year of birth and lactation group on longevity traits was very significant (P<0.01), whereas the effect of season of birth was significant (P<0.05). Age at first conception had a highly signifi...

Biotehnologija u stocarstvu

Due to the ecological concerns and preservation of genetic resources, the characterization of gen... more Due to the ecological concerns and preservation of genetic resources, the characterization of genetic structure of the brown trout (Salmo trutta) was carried out on the "Braduljica" fish farm. DNA was isolated from fin clips of 10 individuals, and after that molecular PCR-RFLP methods were used for distinguishing between Atlantic and Danubian lineages based on control region of the mitochondrial DNA (CR mtDNA) and lactate dehydrogenase gene of the nuclear DNA (LDH nDNA). Based on phenotypic characteristics it was estimated that out of 10 individuals included in this study five belonged to the allochtonous Atlantic lineage and remaining five belonged to the native Danubian lineage of brown trout. However, results of molecular analyses showed a high percentage of allochthonous genes among the individuals, which confirms the hybridization between these two lineages. Also, the results showed that the selection based on the phenotype is not adequate. In order to continue with proper broodstock management, it is necessary to eliminate allochtonous individuals of the Atlantic lineage from the broodstock.

Biotehnologija u stocarstvu

The farm animal welfare science has undergone a thorny path of development, often disputed becaus... more The farm animal welfare science has undergone a thorny path of development, often disputed because of its lack of measurability and the purpose of existence. At the very beginning, primarily based on moral and ethical attitudes, over time it pointed to the importance of meeting the needs of animals and the consequences of their neglect and exhaustion in the conditions of intensive livestock production. An important segment of its development was the definition and development of methodologies for the assessment of welfare indicators, which made it measurable and accepted as a scientific discipline with the knowledge applicable and useful in modern production systems. This paper is a concise review of the evolution of the animal welfare science, but also an indication of its future in the context of the development of "symbiotic" connections with the concepts of sustainable agriculture and food safety as integral parts of the modern ecological movement arose from a unified ...