Pub Date : 2021-12-01DOI: 10.15547/ast.2021.04.058
N. Arzour-Lakehal, A. Boudebza
Abstract. The objective of the research was to study the physiological pattern of biochemical variables and to obtain reference intervals for young (less than 1 month) and adult (more than 1 month) broiler chickens of 2 strains. From the jugular vein, blood for analysis was collected, separated, and then immediately analyzed. The influence of age was significant for the majority of the investigated variables in the 2 groups. In Isa15 strain, a significant age-related decrease in plasma uric acid, glucose, cholesterol, triglycerides, phosphorus, potassium and iron was established. Also, a significant age-related increase in plasma calcium and ASAT was obtained in the same broiler strain. In Arbor Acres Plus strain, a significant age-related decrease in plasma glucose, cholesterol, triglycerides and phosphorus was observed. A significant age-related increase in plasma total protein, calcium and ASAT has also been reported in this broiler strain. A significant difference between the two strains was reported for plasma uric acid, glucose, cholesterol, phosphorus, magnesium and iron (p<0.05). For most estimated parameters in the 2 strains, calculation of separate reference intervals for young and adult animals was appropriate. Except for potassium in young Isa15 strain, and phosphorus in young Arbor Acres Plus strain, all variables did not follow a normal distribution. Reference intervals are presented for both ages using non-parametric or robust method. 90% confidence intervals for both groups were calculated non-parametrically, or by the bootstraping method. The established reference intervals will be a useful guide for interpreting plasma biochemical variables in different strains of broiler chickens raised in Algeria, and reared in a mild Mediterranean climate.
{"title":"Biochemical reference intervals in broiler chickens according to age and strain","authors":"N. Arzour-Lakehal, A. Boudebza","doi":"10.15547/ast.2021.04.058","DOIUrl":"https://doi.org/10.15547/ast.2021.04.058","url":null,"abstract":"Abstract. The objective of the research was to study the physiological pattern of biochemical variables and to obtain reference intervals for young (less than 1 month) and adult (more than 1 month) broiler chickens of 2 strains. From the jugular vein, blood for analysis was collected, separated, and then immediately analyzed. The influence of age was significant for the majority of the investigated variables in the 2 groups. In Isa15 strain, a significant age-related decrease in plasma uric acid, glucose, cholesterol, triglycerides, phosphorus, potassium and iron was established. Also, a significant age-related increase in plasma calcium and ASAT was obtained in the same broiler strain. In Arbor Acres Plus strain, a significant age-related decrease in plasma glucose, cholesterol, triglycerides and phosphorus was observed. A significant age-related increase in plasma total protein, calcium and ASAT has also been reported in this broiler strain. A significant difference between the two strains was reported for plasma uric acid, glucose, cholesterol, phosphorus, magnesium and iron (p<0.05). For most estimated parameters in the 2 strains, calculation of separate reference intervals for young and adult animals was appropriate. Except for potassium in young Isa15 strain, and phosphorus in young Arbor Acres Plus strain, all variables did not follow a normal distribution. Reference intervals are presented for both ages using non-parametric or robust method. 90% confidence intervals for both groups were calculated non-parametrically, or by the bootstraping method. The established reference intervals will be a useful guide for interpreting plasma biochemical variables in different strains of broiler chickens raised in Algeria, and reared in a mild Mediterranean climate.","PeriodicalId":55762,"journal":{"name":"Agricultural Science and Technology","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41471139","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-01DOI: 10.15547/ast.2021.04.065
K. Mekademi, D. Kebour, N. Ouchene-khelifi, N. Ouchene
Abstract. Antimicrobial and anti-Varroa destructor L. activity of the essential oil (EO) of clove (Syzygium aromaticum L. Myrtaceae) was evaluated in this study. Antimicrobial activity concerned 9 bacterial strains (Bacillus cereus, Escherichia coli ATCC 25911, Staphylococcus aureus 29213 ATCC, Proteus mirabilis, Serratia marcescens, Enterobacter sakazakii, Pseudomonas aeruginosa ATCC, Escherichia coli and Acinetobacter sp.), a fungal strain (Penicillium sp.) and a yeast species (Candida albicans). The extraction of the EO was carried out by the method of hydrodistillation. Results showed that EO has no toxicity on bees Apis mellifera. EO demonstrated effective and stable anti-V. destructor activity, indicating the absence of possible resistance, in contrast to what was observed for Amitraz. The inhibitory activity of EO revealed an inhibition zone of diameter varying between 20 mm and 42 mm for bacteria. However, no inhibition zones were observed for Pseudomonas aeruginosa ATCC. The inhibitory activity of EO on Penicillium sp and Candida albicans revealed an inhibition zone of 39 mm in diameter. This study shows that the EO of cloves constitutes a simple and natural treatment, without inconveniences, with a high activity antimicrobial and anti-Varroa destructor which merits it to be proposed as a means to fight against varroosis and the tested pathogens.
{"title":"Evaluation of the antimicrobial and anti-Varroa destructor L. activity of the essential oil of clove (Syzygium aromaticum L. Myrtaceae)","authors":"K. Mekademi, D. Kebour, N. Ouchene-khelifi, N. Ouchene","doi":"10.15547/ast.2021.04.065","DOIUrl":"https://doi.org/10.15547/ast.2021.04.065","url":null,"abstract":"Abstract. Antimicrobial and anti-Varroa destructor L. activity of the essential oil (EO) of clove (Syzygium aromaticum L. Myrtaceae) was evaluated in this study. Antimicrobial activity concerned 9 bacterial strains (Bacillus cereus, Escherichia coli ATCC 25911, Staphylococcus aureus 29213 ATCC, Proteus mirabilis, Serratia marcescens, Enterobacter sakazakii, Pseudomonas aeruginosa ATCC, Escherichia coli and Acinetobacter sp.), a fungal strain (Penicillium sp.) and a yeast species (Candida albicans). The extraction of the EO was carried out by the method of hydrodistillation. Results showed that EO has no toxicity on bees Apis mellifera. EO demonstrated effective and stable anti-V. destructor activity, indicating the absence of possible resistance, in contrast to what was observed for Amitraz. The inhibitory activity of EO revealed an inhibition zone of diameter varying between 20 mm and 42 mm for bacteria. However, no inhibition zones were observed for Pseudomonas aeruginosa ATCC. The inhibitory activity of EO on Penicillium sp and Candida albicans revealed an inhibition zone of 39 mm in diameter. This study shows that the EO of cloves constitutes a simple and natural treatment, without inconveniences, with a high activity antimicrobial and anti-Varroa destructor which merits it to be proposed as a means to fight against varroosis and the tested pathogens.","PeriodicalId":55762,"journal":{"name":"Agricultural Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47041933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-01DOI: 10.15547/ast.2021.04.068
A. Ajibare, O. Olawusi-Peters, K. A. Oyinlola
Abstract. This study investigated the condition factor with microbial load of Nematopalaemon hastatus (Aurivillius, 1898) collected for two years from four coastal towns in Ilaje communities of Ondo State, Nigeria. Shrimps’ weight, length and condition factor were determined using standard methods while estimation of microbial load (Total heterotrophic bacteria, coliform, Escherichia coli, Salmonella/Shigella, and fungal counts) was done using standard microbiological methods. The correlation between microbial load and condition factor was thereafter determined using regression analysis. N. hastatus exhibited allometric growth, with low but consistent condition factor. Mean heterotrophic bacteria count was 1.107×102 CFU/g and 1.079×102 CFU/g during the dry and wet season, respectively. Mean coliform count, total Salmonella-Shigella and E. coli counts were 0.398×102 CFU/g, 0.218×102 CFU/g and 0.303×102 CFU/g, respectively, during the wet season. A significant increase in counts (mean) was observed in the dry season for the coliform (0.404×102 CFU/g), total Salmonella-Shigella (0.234×102 CFU/g) and E. coli (0.326×102 CFU/g). The mean fungal count was 0.604×102 SFU/g and 0.563×102 SFU/g during the wet and dry seasons, respectively. The microbial loads were below acceptable limits; therefore, shrimps of the study area are safe for consumption. Conclusively, the condition factor of the shrimps was non-significantly influenced by the microbes. However, there is a need to regulate and/or prevent untreated sewage and effluent discharge into natural water bodies to reduce the environmental hazards it may portend and also obtain relatively safe aquatic products for consumption.
{"title":"Microbiological load evaluation of white shrimp (Nematopalaemon hastatus Aurivillius, 1898) in the coastal waters of Ondo state, Nigeria","authors":"A. Ajibare, O. Olawusi-Peters, K. A. Oyinlola","doi":"10.15547/ast.2021.04.068","DOIUrl":"https://doi.org/10.15547/ast.2021.04.068","url":null,"abstract":"Abstract. This study investigated the condition factor with microbial load of Nematopalaemon hastatus (Aurivillius, 1898) collected for two years from four coastal towns in Ilaje communities of Ondo State, Nigeria. Shrimps’ weight, length and condition factor were determined using standard methods while estimation of microbial load (Total heterotrophic bacteria, coliform, Escherichia coli, Salmonella/Shigella, and fungal counts) was done using standard microbiological methods. The correlation between microbial load and condition factor was thereafter determined using regression analysis. N. hastatus exhibited allometric growth, with low but consistent condition factor. Mean heterotrophic bacteria count was 1.107×102 CFU/g and 1.079×102 CFU/g during the dry and wet season, respectively. Mean coliform count, total Salmonella-Shigella and E. coli counts were 0.398×102 CFU/g, 0.218×102 CFU/g and 0.303×102 CFU/g, respectively, during the wet season. A significant increase in counts (mean) was observed in the dry season for the coliform (0.404×102 CFU/g), total Salmonella-Shigella (0.234×102 CFU/g) and E. coli (0.326×102 CFU/g). The mean fungal count was 0.604×102 SFU/g and 0.563×102 SFU/g during the wet and dry seasons, respectively. The microbial loads were below acceptable limits; therefore, shrimps of the study area are safe for consumption. Conclusively, the condition factor of the shrimps was non-significantly influenced by the microbes. However, there is a need to regulate and/or prevent untreated sewage and effluent discharge into natural water bodies to reduce the environmental hazards it may portend and also obtain relatively safe aquatic products for consumption.","PeriodicalId":55762,"journal":{"name":"Agricultural Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44785170","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-01DOI: 10.15547/ast.2021.04.060
H. Lukanov, I. Pavlova, A. Genchev
Abstract. The study was conducted with 224 domestic quails from the specialized meat-type WG line. The duration of fattening period and sex on productive traits, slaughter traits and meat quality of quails was evaluated. The study has shown that the longer duration of the fattening period in quails from the meat-type line WG was associated with lower production efficiency, with more reduction after the 35th day of life. The production efficiency in male quails was lower compared to that in females. The dispersion analysis demonstrated that the determination of 72.2% and 69.6% of dressed carcass weight and deboned meat weight, respectively, depended on fattening period duration (p<0.001). When fattening increased from 28 to 42 days, the amount of feed necessary for one bird increased by 73% and 87%, corresponding to increased costs by 64.5% and 77%. For production of 1 kg dressed quail carcasses, the necessary feed increased by 42.3-45.8% on a weight basis and by 35-37.7% on a cost basis. For production of 1 kg deboned quail meat, corresponding increases are by 42.1-49.5% and 34.8-41.2%, respectively. The period between 28 and 35 days of age was the most appropriate for planning slaughter of WG quails. During that period, the economic efficiency, although already declining, was still within acceptable limits and the increase in quantitative traits in both sexes – still relevant, making the produce more attractive for consumers. With age, the changes in colour characteristics of M. pectoralis superficialis result in darkening of meat (p<0.001). Thus, it assumes nuances specific rather for game meat. This effect is desirable, as it improves the commercial presentation of domestic quail meat in line with consumers’ attitudes.
{"title":"Effect of different fattening period duration on meat productivity of domestic quails","authors":"H. Lukanov, I. Pavlova, A. Genchev","doi":"10.15547/ast.2021.04.060","DOIUrl":"https://doi.org/10.15547/ast.2021.04.060","url":null,"abstract":"Abstract. The study was conducted with 224 domestic quails from the specialized meat-type WG line. The duration of fattening period and sex on productive traits, slaughter traits and meat quality of quails was evaluated. The study has shown that the longer duration of the fattening period in quails from the meat-type line WG was associated with lower production efficiency, with more reduction after the 35th day of life. The production efficiency in male quails was lower compared to that in females. The dispersion analysis demonstrated that the determination of 72.2% and 69.6% of dressed carcass weight and deboned meat weight, respectively, depended on fattening period duration (p<0.001). When fattening increased from 28 to 42 days, the amount of feed necessary for one bird increased by 73% and 87%, corresponding to increased costs by 64.5% and 77%. For production of 1 kg dressed quail carcasses, the necessary feed increased by 42.3-45.8% on a weight basis and by 35-37.7% on a cost basis. For production of 1 kg deboned quail meat, corresponding increases are by 42.1-49.5% and 34.8-41.2%, respectively. The period between 28 and 35 days of age was the most appropriate for planning slaughter of WG quails. During that period, the economic efficiency, although already declining, was still within acceptable limits and the increase in quantitative traits in both sexes – still relevant, making the produce more attractive for consumers. With age, the changes in colour characteristics of M. pectoralis superficialis result in darkening of meat (p<0.001). Thus, it assumes nuances specific rather for game meat. This effect is desirable, as it improves the commercial presentation of domestic quail meat in line with consumers’ attitudes.","PeriodicalId":55762,"journal":{"name":"Agricultural Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43081931","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-12-01DOI: 10.15547/ast.2021.04.055
K. Vasileva, N. Bogatzevska
Abstract. The limit values of resistance groups were established to Xanthomonas euvesicatoria and Xanthomonas vesicatoria by mean score – ms based on conducted statistical analysis of 155 selection lines of Bulgarian, introduced hybrids and pepper varieties: I- immune; R- resistant; MS- medium sensitive; S- sensitive; SS- strongly sensitive. The genetic diversity between the two bacteria suggest the use of separate resistant groups to determine the resistance. Data on the mean score of infestation on 116 pepper accessions to X. euvesicatoria and 155 (the previous 116 included) to X. vesicatoria were processed and the resistance groups were defined. Breeding pepper accessions with complex resistance requires the application of the established resistance groups to both pathogens. The limit values of the groups by ms based on the statistical analysis of the data on the resistance of pepper accessions to X. euvesicatoria and X. vesicatoria were specified.
{"title":"Statistical analysis of resistance variability of pepper accessions to Xanthomonas euvesicatoria and Xanthomonas vesicatoria","authors":"K. Vasileva, N. Bogatzevska","doi":"10.15547/ast.2021.04.055","DOIUrl":"https://doi.org/10.15547/ast.2021.04.055","url":null,"abstract":"Abstract. The limit values of resistance groups were established to Xanthomonas euvesicatoria and Xanthomonas vesicatoria by mean score – ms based on conducted statistical analysis of 155 selection lines of Bulgarian, introduced hybrids and pepper varieties: I- immune; R- resistant; MS- medium sensitive; S- sensitive; SS- strongly sensitive. The genetic diversity between the two bacteria suggest the use of separate resistant groups to determine the resistance. Data on the mean score of infestation on 116 pepper accessions to X. euvesicatoria and 155 (the previous 116 included) to X. vesicatoria were processed and the resistance groups were defined. Breeding pepper accessions with complex resistance requires the application of the established resistance groups to both pathogens. The limit values of the groups by ms based on the statistical analysis of the data on the resistance of pepper accessions to X. euvesicatoria and X. vesicatoria were specified.","PeriodicalId":55762,"journal":{"name":"Agricultural Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45376211","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-01DOI: 10.15547/ast.2021.03.037
A. Zhivondov, S. Savchovska, S. Pandova, D. Petkova, P. Doykina, I. Manolov
Abstract. The article presents a three-year traceability (2018, 2019, 2020) of biometric results of the fruits of eight peach and nectarine varieties. The study covers the fifth, sixth and seventh vegetation period from the period of full fruiting. Varieties included in this investigation were “Filina” (peach, clingstone), “Gergana” (nectarine, clingstone), “July Lady” (peach, semi-clingstone), “Ufo 4” (flat peach, semi-clingstone), “Laskava” (peach, freestone), “Morsiani 90” (nectarine, freestone), “Flat Queen” (flat peach, freestone), and “Evmolpiya” (peach, freestone). The experimental collection plantation was created in the spring of 2014 on the territory of the Fruit Growing Research Institute, Plovdiv, (lat. 42.10384828045957 and long. 24.72164848814686). The data analysis shows that the varieties “Laskava” and “Evmolpiya” produce fruits with the highest weight – 319.60 g and 303.60 g, respectively. Medium weight is registered in the “Morsiani 90” variety (226.07 g) and the “July Lady” variety (193.87 g). “UFO 4” is characterized with the smallest fruits – an average of 143.83 g and the highest flesh yield. Considering the fact that the “Filina” variety is very early ripening, its fruits can be treated as large for the season – 170.21 g. The stones of the “July Lady”, “Morsiani 90” and “Evmolpiya” varieties have the largest average mass
{"title":"Biometric data of peach and nectarine fruit and stones","authors":"A. Zhivondov, S. Savchovska, S. Pandova, D. Petkova, P. Doykina, I. Manolov","doi":"10.15547/ast.2021.03.037","DOIUrl":"https://doi.org/10.15547/ast.2021.03.037","url":null,"abstract":"Abstract. The article presents a three-year traceability (2018, 2019, 2020) of biometric results of the fruits of eight peach and nectarine varieties. The study covers the fifth, sixth and seventh vegetation period from the period of full fruiting. Varieties included in this investigation were “Filina” (peach, clingstone), “Gergana” (nectarine, clingstone), “July Lady” (peach, semi-clingstone), “Ufo 4” (flat peach, semi-clingstone), “Laskava” (peach, freestone), “Morsiani 90” (nectarine, freestone), “Flat Queen” (flat peach, freestone), and “Evmolpiya” (peach, freestone). The experimental collection plantation was created in the spring of 2014 on the territory of the Fruit Growing Research Institute, Plovdiv, (lat. 42.10384828045957 and long. 24.72164848814686). The data analysis shows that the varieties “Laskava” and “Evmolpiya” produce fruits with the highest weight – 319.60 g and 303.60 g, respectively. Medium weight is registered in the “Morsiani 90” variety (226.07 g) and the “July Lady” variety (193.87 g). “UFO 4” is characterized with the smallest fruits – an average of 143.83 g and the highest flesh yield. Considering the fact that the “Filina” variety is very early ripening, its fruits can be treated as large for the season – 170.21 g. The stones of the “July Lady”, “Morsiani 90” and “Evmolpiya” varieties have the largest average mass","PeriodicalId":55762,"journal":{"name":"Agricultural Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43515723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-01DOI: 10.15547/ast.2021.03.036
V. Dimitrova, R. Dragov
Abstract. Cotton breeding in Bulgaria is mainly aimed at improving the earliness, productivity and fiber quality of modern varieties. The creation of new genetic diversity is one of the basic prerequisites for the success of breeding programs. The aim of the study was to evaluate cotton lines obtained by intraspecific and remote hybridization combined with backcross technology, with a view to their most effective usage in selection. Twenty-three lines were included in competitive variety trials conducted during the 2014-2017 period. The averaged results showed that lines 550, 639, 641, obtained by remote hybridization, appeared to be very promising. These three lines were distinguished by the best combination of productivity, fiber length and fiber lint percentage, and by these three indicators they exceeded the standard variety Chirpan-539. A new cotton variety Aida (No. 457) was approved, which in seed cotton yield and fiber yield, and technological fiber properties surpassed the standard varieties Chirpan-539 for earliness and productivity and Avangard-264 for fiber quality. The candidate variety 535 continued the state variety testing. Two new candidate cotton varieties No. 550 and No. 553 were released. In the state variety testing the three candidate varieties confirmed their qualities. The obtained lines, distinguished by one trait or by a complex of qualities, enriched the gene pool of Bulgarian cotton.
{"title":"Breeding assessment of new promising cotton lines","authors":"V. Dimitrova, R. Dragov","doi":"10.15547/ast.2021.03.036","DOIUrl":"https://doi.org/10.15547/ast.2021.03.036","url":null,"abstract":"Abstract. Cotton breeding in Bulgaria is mainly aimed at improving the earliness, productivity and fiber quality of modern varieties. The creation of new genetic diversity is one of the basic prerequisites for the success of breeding programs. The aim of the study was to evaluate cotton lines obtained by intraspecific and remote hybridization combined with backcross technology, with a view to their most effective usage in selection. Twenty-three lines were included in competitive variety trials conducted during the 2014-2017 period. The averaged results showed that lines 550, 639, 641, obtained by remote hybridization, appeared to be very promising. These three lines were distinguished by the best combination of productivity, fiber length and fiber lint percentage, and by these three indicators they exceeded the standard variety Chirpan-539. A new cotton variety Aida (No. 457) was approved, which in seed cotton yield and fiber yield, and technological fiber properties surpassed the standard varieties Chirpan-539 for earliness and productivity and Avangard-264 for fiber quality. The candidate variety 535 continued the state variety testing. Two new candidate cotton varieties No. 550 and No. 553 were released. In the state variety testing the three candidate varieties confirmed their qualities. The obtained lines, distinguished by one trait or by a complex of qualities, enriched the gene pool of Bulgarian cotton.","PeriodicalId":55762,"journal":{"name":"Agricultural Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42285252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-01DOI: 10.15547//ast.2021.03.047
G. Dineva, K. Peychev, D. Georgiev
Abstract. Milking machines equipped with new and used milking liners with a round cross section were studied. The used milking membranes were operated for 3 months on a farm for rearing 60 cows (Holstein cattle) with double milking per day. The experiment involved recording the standard pulsation phases “a”, “b”, “c” and “d” (in absolute units) in the frequency range from 1 Hz to 2.5 Hz, in a vacuum mode of 40 kPa and 50 kPa and at a pulsation ratio of 50/50%. It was found that the transients (phase “a” and phase “c”) are faster and the established phases (phase “b” and phase “d”) are longer in milking units equipped with used milking liners. The conclusions are related to the service life of the milking liners.
{"title":"Pulsation parameters of new and used milking liners with round cross section","authors":"G. Dineva, K. Peychev, D. Georgiev","doi":"10.15547//ast.2021.03.047","DOIUrl":"https://doi.org/10.15547//ast.2021.03.047","url":null,"abstract":"Abstract. Milking machines equipped with new and used milking liners with a round cross section were studied. The used milking membranes were operated for 3 months on a farm for rearing 60 cows (Holstein cattle) with double milking per day. The experiment involved recording the standard pulsation phases “a”, “b”, “c” and “d” (in absolute units) in the frequency range from 1 Hz to 2.5 Hz, in a vacuum mode of 40 kPa and 50 kPa and at a pulsation ratio of 50/50%. It was found that the transients (phase “a” and phase “c”) are faster and the established phases (phase “b” and phase “d”) are longer in milking units equipped with used milking liners. The conclusions are related to the service life of the milking liners.","PeriodicalId":55762,"journal":{"name":"Agricultural Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48230022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-01DOI: 10.15547/ast.2021.03.048
Galya Hristova, M. Dallev, G. Tihanov
Abstract. A turf seed drill (STS-80) has been designed, in which the seeds from the sowing machines are sent to the soil through seed pipes. The size of the seeds is relatively small, therefore it is a requirement for them to be sown at a depth between 0.5 cm and 1.5 cm. The drill allows the following operations to be performed simultaneously: soil furrowing, seed sowing, and soil compaction with a compaction roller. The structure of the individual bodies that make up the aggregate is essential for the smooth running of the work process. Two rollers have been developed, which allow the providing of the necessary agro-technical requirements for sowing grass seeds. The role of the roller mounted in the front part of the drill is to make furrows in the soil at a depth of 1.5 cm, where the grass seeds fall. The roller, located in the rear of the unit, dulls the surface of the soil after the seeds enter it. This creates additional dynamic force, which increases the degree of soil compaction and the intensity of destruction of soil aggregates at a certain mass of the roller.
{"title":"Design parameters of furrow forming and compacting roller of the combined seeder STS-80","authors":"Galya Hristova, M. Dallev, G. Tihanov","doi":"10.15547/ast.2021.03.048","DOIUrl":"https://doi.org/10.15547/ast.2021.03.048","url":null,"abstract":"Abstract. A turf seed drill (STS-80) has been designed, in which the seeds from the sowing machines are sent to the soil through seed pipes. The size of the seeds is relatively small, therefore it is a requirement for them to be sown at a depth between 0.5 cm and 1.5 cm. The drill allows the following operations to be performed simultaneously: soil furrowing, seed sowing, and soil compaction with a compaction roller. The structure of the individual bodies that make up the aggregate is essential for the smooth running of the work process. Two rollers have been developed, which allow the providing of the necessary agro-technical requirements for sowing grass seeds. The role of the roller mounted in the front part of the drill is to make furrows in the soil at a depth of 1.5 cm, where the grass seeds fall. The roller, located in the rear of the unit, dulls the surface of the soil after the seeds enter it. This creates additional dynamic force, which increases the degree of soil compaction and the intensity of destruction of soil aggregates at a certain mass of the roller.","PeriodicalId":55762,"journal":{"name":"Agricultural Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44671020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2021-09-01DOI: 10.15547/ast.2021.03.044
G. Tihanov, Galya Hristova
Abstract. A study has been conducted for some operational indicators of a machine-tractor unit (MTU) for direct sowing of barley. The data for this study has been collected and retrieved by using the JD Link telematics system from two different fields sown with barley: field A with irregular shape and area of 13.75 ha and field B with rectangular shape and area of 16.26 ha. It was found that for both fields the values for the most monitored parameters were very close as follows: for the engine speed of the sowing unit during working stroke – 1553.65 min-1 (A) and 1586.11 min-1 (B) (the difference is <2.08%); for the idle mode of the sowing unit – 900.08 min-1 (A) and 905.63 min-1 (B) (the difference is <0.62%); for the actual working speed – 9.97 km/h (А) and 10.16 km/h (В) (the difference is <1.9%), registered when the MTU is performing the technological operation “sowing”; those parameters of MTU are nor influenced by the field size and shape. Larger differences in values between the two fields were established in terms of the relative share of engine used – 19.98% (A) and 21.55% (B) (the difference is <7.3%) and for the consumed diesel fuel (in field А it was 7.2% liters higher than in field В, respectively, 11.7% higher referring to the average diesel fuel consumption – liters per hour). The actual hourly productivity in field A was 20% lower than in field B – 3.05 vs 3.81, which is due to the fact that in the field with irregular shape – A the sowing unit made more turns at the end of the levels than in the field with rectangular shape – B.
{"title":"Operational characteristics of a machine-tractor unit for direct sowing of barley using the JD LINK telematics system","authors":"G. Tihanov, Galya Hristova","doi":"10.15547/ast.2021.03.044","DOIUrl":"https://doi.org/10.15547/ast.2021.03.044","url":null,"abstract":"Abstract. A study has been conducted for some operational indicators of a machine-tractor unit (MTU) for direct sowing of barley. The data for this study has been collected and retrieved by using the JD Link telematics system from two different fields sown with barley: field A with irregular shape and area of 13.75 ha and field B with rectangular shape and area of 16.26 ha. It was found that for both fields the values for the most monitored parameters were very close as follows: for the engine speed of the sowing unit during working stroke – 1553.65 min-1 (A) and 1586.11 min-1 (B) (the difference is <2.08%); for the idle mode of the sowing unit – 900.08 min-1 (A) and 905.63 min-1 (B) (the difference is <0.62%); for the actual working speed – 9.97 km/h (А) and 10.16 km/h (В) (the difference is <1.9%), registered when the MTU is performing the technological operation “sowing”; those parameters of MTU are nor influenced by the field size and shape. Larger differences in values between the two fields were established in terms of the relative share of engine used – 19.98% (A) and 21.55% (B) (the difference is <7.3%) and for the consumed diesel fuel (in field А it was 7.2% liters higher than in field В, respectively, 11.7% higher referring to the average diesel fuel consumption – liters per hour). The actual hourly productivity in field A was 20% lower than in field B – 3.05 vs 3.81, which is due to the fact that in the field with irregular shape – A the sowing unit made more turns at the end of the levels than in the field with rectangular shape – B.","PeriodicalId":55762,"journal":{"name":"Agricultural Science and Technology","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49560686","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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