Productivity and feed quality of Sudan grass (Sorghum sudanense (Piper) Stapf.) and sweet sorghum forms

S. Enchev*

Agricultural Institute, 3 Simeon Veliki, 9700 Shumen, Bulgaria

(Manuscript received 24 August 2020; accepted for publication 22 February 2021)

Abstract. During the period 2017-2018, the feed quality and productivity of three Sudan grass varieties – Endje 1, Vercors and Super Sweet, one stabilized Sudan grass population – SWT, local sweet sorghum – „Zaharna metla“ population and the sweet sorghum cultivar “Shumensko sladko” were researched in Agricultural Institute – Shumen. Green mass (t/ha), dry matter (%) and dry mass production (%) as well as basic nutritional characteristics by the two swaths of the tested cultivars in brooming phase were controlled. It was found that the sweet sorghum cultivar “Shumensko sladko” gave the highest amount of green mass – 59.5 t/ha by two swaths, and the dry mass yield was the highest from the cultivar Endje 1 – 20.8 t/ha. In terms of chemical composition, the greatest variation was demonstrated in phosphorus content (0.369-0.696%, CV=27.3%), followed by crude fat (1.28-2.39%, CV=26.8%), Ca (0.889-1.572%, CV=21.8%), crude protein (6.05-9.00%, CV=14.6%), nitrogen free extracts (42.05-51.20%, CV=7.6%), crude fiber (32.64-39.26%, CV=6.1%) and mineral substances (8.17-9.61%, CV=5.9%). It can be summarized that all hybrids provide quality hay, however the Bulgarian cultivars Endje 1 and “Shumensko sladko” showed the best nutritional value – compared to Super Sweet, Vercors, SWT and “Zaharna metla”.

Grain quality of mutant lines of six-rowed barley

B. Dyulgerova*, N. Dyulgerov

Institute of Agriculture, 8400 Karnobat, Bulgaria

(Manuscript received 9 December 2020; accepted for publication 26 January 2021)

Abstract. The aim of this study was to assess the variation in grain quality traits among mutant lines of winter feed barley. Nine mutant lines derived from the advanced breeding line Kt3029 and 10 mutant lines derived from variety GA-Luttrell along with their parent forms were evaluated. The study was conducted at the Institute of Agriculture – Karnobat during the period 2015-2017. Test weight, 1000-grain weight, the content of protein, starch, lysine, fat, ash, and fibre were determined. Significant differences between the mutant lines and the parent forms for the studied traits were observed. Significantly higher protein content compared to parent was found in the grain of mutant lines 22/1-5, 22/2-10 and 22/1-12 from line Kt3029 and 26/1-1, 26/1-3 and 26/2-11 from variety GA-Luttrell. The grain of mutant line 26/2-12 had the best combination of protein and starch. Mutant lines 22/1-11 and 22/1-12 from Kt3029 and 26/1-1, 26/2-1 and 26/2-12 from variety GA-Luttrell showed a good combination between protein content and 1000-grain weight. Those mutant lines can be included in the breeding program for the development of varieties with improved feed quality.

Productive traits, blood biochemical parameters and meat quality of rainbow trout (Oncorhynchus mykiss W.) fed with supplement of nutmeg extract (Myristica fragrans)

Ts. Stoev, G. Zhelyazkov*

Department of Biology and Aquaculture, Faculty of Agriculture, Trakia University, Students campus, 6000 Stara Zagora, Bulgaria

(Manuscript received 2 September 2020; accepted for publication 16 November 2020)

Abstract. The aim of the present study was to evaluate the effect of the dietary nutmeg extract (Myristica fragrans) supplement on the survival rate, weight gain, feed conversion ratio (FCR), economic efficiency (ECR), blood biochemical parameters, chemical composition and fatty acid profile of rainbow trout (Oncorhynchus mykiss W.), cultivated in a recirculation system. One hundred and sixty rainbow trouts were distributed in two experimental variants, each with two replications with 80 fish in one group. The average initial live weight of trouts from control (C) and experimental (E) groups was 13.43±0.33 g and 13.46±0.29 g, respectively. Fish were reared in concrete tanks with effective volume of 0.8 m3, part of a recirculation system. Trouts were fed „Aqua garant UNI“ extruded feed produced by Garant-Tiernahrung Gesellschaft m.b.H. – Austria, with pellet size of 2 mm. The feed of fish from the experimental group was supplemented with 1% powdered nutmeg extract (P.I.C.Co LTD), by lubricating the pellets with 5 ml sunflower oil/100 g feed. Control rainbow trouts received feed lubricated with the same amount of sunflower oil. Fish from both groups were fed 3 times daily and their ration was 3% of body weight. The experimental period lasted 60 days. The dietary supplementation of rainbow trouts with nutmeg extract had a negative impact on growth performance and economic efficiency of farming of the species. Final live weight and average individual weight gain were lower, and FCR and ECR values were inferior vs controls. The nutmeg extract had also an adverse effect on water content and dry matter of meat from supplemented fish. A positive effect was demonstrated only on meat fat content, which was substantially lower compared to that of control fish. Despite the higher SFA as well as lower UFA, MUFA, PUFA, n-6 and n-3 fatty acid content of trout meat that received nutmeg extract with feed, the PUFA/SFA and n-6/n-3 ratios remained within the favourable range for human nutrition, e.g. >0.4 and <5, respectively.

Boar taint and meat quality characteristics of entire male and castrated male pigs


I.G. Penchev

Department of Morphology, Physiology and Nutrition, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 22 February 2019; accepted for publication 25 April 2019)


Abstract. The aim of the present research was to study the chemical composition, technological traits and intensity of boar taint of meat in entire male (EM) and surgically castrated male (CM) pigs. The study included 46 male pigs, cross F1 (Landrace x Danube White), fattened to average live weight 90 kg. In terms of chemical composition, the higher water and lipid content of the meat of entire male pigs, compared to the meat of surgically castrated male pigs was not statistically significant. A significant difference in the meat’s technological traits – pH values, water-holding capacity, cooking losses and tenderness between the two groups of male animals ware not found. The influence of the factor “castration” was reported in trait marbling of meat (p<0.001). There were statistically significant differences in the values of L*, b* and Hue angle, defining the color characteristics of the meat.

Effect of dietary phytoextracts supplementation on the chemical composition and fatty acid profile of rainbow trout (Oncorhynchus Mykiss w.), cultivated in recirculation system

  1. Georgieva, G. Zhelyazkov, Y. Staykov, D. Georgiev


Department of Biology and Aquaculture, Faculty of Agriculture, Trakia University, 6014 Stara Zagora, Bulgaria


DOI: 10.15547/ast.2018.03.041

(Manuscript received 7 June 2018; accepted for publication 28 August 2018)


Abstract. The present research aimed to examine the effect of dietary phytoextracts supplementation on the chemical composition and fatty acid profile in the meat of rainbow trout (Oncorhynchus mykiss W.), cultivated in a recirculation system. The fish were divided into 6 groups: one control (C) and five experimental groups in the food of which phytoextracts of curcumin (EC), paprika (EP), thyme (ET), oregano (EO) and garlic (EG) were added. The inclusion of phytoextracts had no significant effect on growth parameters of fish from EC, EP, ET, EO and EG groups (P>0.05). No statistical differences on water content, protein and lipids were observed in the meat of fish from the control and the experimental groups (P>0.05). Statistically significantly higher value of the dry matter was established in ET group in comparson with C, EC, EP, EO and EG groups (P≤0.001). The values of ash were significantly lower in fish from all experimental groups compared to the control group. The inclusion of phytoextracts did not affect the fatty acid profile of fish from EP, EO and EG groups (P>0.05). Exceptions are EC and ET groups, which had the lowest value of C18:3n-3 α-linolenic compared to those from the control group (P≤0.05, P≤0.001).

Variation in the chemical composition and physical characteristics of grain from winter barley varieties

B. Dyulgerova*, N. Dyulgerov, D. Dimova

Institute of Agriculture, 8400 Karnobat, Bulgaria
(Manuscript received 4 July 2017; accepted for publication 28 August 2017)

Abstract. The aim of the study was to evaluate the range of variation in chemical composition and in physical parameters of grain associated with feed quality of barley under the conditions of Southeast Bulgaria. A set of 21 winter six-rowed barley varieties from different geographic origins were investigated. The study was conducted in the Institute of Agriculture – Karnobat, during the period 2013/2014 – 2014/2015. Grain samples of the studied varieties were analysed for crude protein, lysine, starch, crude fat, crude ash, crude fiber, hectoliter weight and 1000 grains weight. The coefficient of variation was the highest in crude fat (21.52%) followed by lysine (9.52%). Low variation among varieties was found in nitrogen-free extract (CV=1.56%) and hectoliter weight (CV=2.77%). Correlations of crude protein with lysine, starch and crude fiber were negative. Starch content was positively associated with crude fat and hectoliter weight. Significant negative correlation of nitrogen-free extract with crude fat and crude fiber was found. Differences in chemical composition and physical parameters of grain indicated that the studied varieties can provide a source of germplasm for breeding winter barley varieties with improved feed quality.

Chemical composition and technological characteristics of wines from red grape varieties, selected in Bulgaria

V. Haygarov1, T. Yoncheva1, Z. Nakov2, M. Ivanov2, D. Dimitrov1*

1Department of Enology and Chemistry, Institute of Viticulture and Enology, 1 Kala Tepe str., 5800 Pleven, Bulgaria 2Department of Cultivars and Cultivar Maintenance, Institute of Viticulture and Enology, 1 Kala Tepe str., 5800 Pleven, Bulgaria

(Manuscript received 20 May 2016; accepted for publication 5 February 2017)

Abstract. Chemical analysis of grapes and technological characterization of wines from red varieties Storgoziya, Kaylashky rubin, Trapezitza, Rubin and Bouquet, created by the method of intraspecific and interspecific hybridization at the Institute of Viticulture and Enology – Pleven, Bulgaria were made. The technological maturity of the grapes as raw material for producing quality red wines was determined. Rubin variety was with the highest sugar content – 23.10±0.73 %, titratable acids – 6.18±0.34 g/dm3 and pH 3.40±0.71. The other varieties were with optimal condition for the production of red wines in terms of sugars and titratable acids. The chemical composition and organoleptic characteristics of the experimental wine samples were established. The ethyl alcohol content in the produced wines was in the range from 12.33±0.23 vol. % (Bouquet) to 13.31±0.34 vol. % (Kaylashky rubin). The content of titratable acids was in the range of 5.33±0.43 g/dm3 (Trapezitza) up to 6.88±0.21 g/dm3 (Kaylashky rubin). There were no significant differences in the analyzed indicators and taste evaluation between experimental wines and wine of Vitis vinifera – Pinot noir grape variety used as control sample.

Biochemical and chemical investigations of pikeperch fingerlings (Sander Lucioperca L.) after wintering

A. Ivanova*, R. Atanasova

Institute of Fisheries and Aquaculture, 248 Vasil Levski, 4003 Plovdiv, Bulgaria (Manuscript received 14 September 2016; accepted for publication 13 October 2016)

Abstract. The purpose of the present study was to investigate some basic biochemical and chemical parameters of pikeperch (Sander lucioperca L.) yearlings reared in ponds after wintering. The investigation has been carried out in the Institute of Fisheries and Aquaculture, Plovdiv. The fish included in the study were randomly selected from one pond, with area of 0.40 ha. Blood samples were collected from 10 pikeperches with average weight from 80 to 100 g. Blood biochemical parameters were individually analysed. For hemoglobin determination, blood was anticoagulated with sodium citrate. Samples for body tissue analysis (without the head and viscera) were collected from 4 fish, autoclaved and used for analysis of water content, % (drying at 105 оС, 24 h; Bulgarian State Standard – SR ISO 5984), protein content, % (Kjeldahl method, Bulgarian State Standard – SR ISO 5983 semi-automated DK 6 digester unit and UDK 132 distillation system, Velp Scientifica), fats (%) by the method of Smidt-Boudzynski Ratzlaff and ash (%) by burning in a muffle furnace at 550 oС, BSS – SR ISO 6496. The average blood serum total protein was 66.1±0.12 g.l-1, blood glucose concentration was 92.8±3.42 mg.100 ml-1 (5.15 mmol.l-1) and average hemoglobin content was 44.7±0.33 g.l-1. The average protein content in analysed fish samples was 16.65±0.23 %. Protein content was the highest among studied dry matter components, followed by the ash (1.97±0.06 %) and fat content (0.84±0.03 %). The levels of blood serum total protein, blood glucose and hemoglobin content as well as body composition parameters – water, protein, fat and ash of pikeperch fingerlings (Sander lucioperca L.) after wintering reflect the specific equilibrium of plastic and energy substances after the winter period, with no deviations from the reference ranges.

Some results of evaluation of new-introduced apricot cultivars under conditions of Plovdiv region

V. Bozhkova*, M. Nesheva

Fruit Growing Institute, 4004 Plovdiv, Bulgaria
(Manuscript received 15 May 2016; accepted for publication 24 August 2016)

Abstract.ApricotisnottypicalspeciesforSouthCentralRegionofBulgaria,wherethePlovdivregionoccupiesalargepart oftheterritory,butlast5yearsthe area and production remain stable. In this study, are presented the first results of investigation on seven new introduced apricot cultivars ‘Bergecot’, ‘Flavor cot’, ‘Jenny cot’, ‘Lady cot’, ‘Perle cot’, ‘Sweet cot’ and ‘Tom cot’, carried out at the Fruit Growing Institute in Plovdiv. The investigation included phelogical data, fruit dimensions, chemical composition and sensory evaluation of the fruits. The studied cultivars more often entered the stage of flowering after second part of March and the differences between them were insignificant – one or two days. Among the investigated cultivars four of them ripened in the third decade of June, ‘Lady cot’ ripened in the beginning of July, ‘Bergecot’ in the end of July and ‘Jenny cot’ in the first half of August. The largest fruits had cultivar ‘Lady cot’ – 57.86 g, andthesmallestone’Flavorcot’–37.64g.Thetotalsolublesolids(TSS)contentinthepresentstudyvariedfrom13.4°Brixin’Perlecot’to23.3°Brix in’Jeny cot’ cultivar. The highest vitamin C content was found in ‘Bergecot’ – 29.40 mg/100 g and it is statistically proved. According to the final evaluation the cultivars ‘Bergecot’ and ‘Sweet cot’ have exellent sensory characteristics and the other 5 cultivars are classified in the group of first class. According to the obtained data, all evaluated cultivars in this study are suitable for growing under the conditions of Plovdiv region. The most attractive and quality fruits have cultivars ‘Lady cot’, ‘Perle cot’, ‘Bergecot’ and ‘Sweet cot’.


Performance of eleven plum cultivars under agroclimatic conditions of Plovdiv region, Bulgaria

V. Bozhkova*, P. Savov

Fruit Growing Institute, 4004 Plovdiv, Bulgaria
(Manuscript received 13 May 2016; accepted for publication 8 June 2016)

Abstract. Plum is a traditional fruit crop in Bulgaria. The South Central Region represents 22.2% of the total area occupied with plum trees. In this study the results of a four years’ investigation on ten plum cultivars carried out at the Fruit Growing Institute in Plovdiv are presented. Stanley was used as a standard. The observed phenological characteristics included flowering and fruit ripening. The cultivars Tophit plus and Toptaste are the earliest flowering, whereas Topstar plus is the latest one. Fruits of Topfirst cultivar ripen at the beginning of July, those of Top and Tophit plus in September and all the rest in August. According to biometrical analyses, fruit weight of Topgigant plus and Tophit plus is over 60g. The total soluble solid content in the studied cultivars varies from 15.7% in Top cultivar to 24.75% in Toptaste. Yield was determined and expressed in kg per tree. Over 30 kg per tree was harvested from the cultivars Stanley, Jojo, Topgigant plus and Tophit plus. The lowest yield was obtained from the cultivars Top, Topfive and Toptaste. In 2012, the percentage of flower buds destroyed by frost was evaluated. The lowest degree of damages was reported in the cultivars Tophit plus, Topgigant plus and Mirabelle de Nancy (below 10%), and the greatest damages in Toptaste (51%). According to the obtained results, the most suitable plum cultivars recommended to be grown in Plovdiv region, are Jojo, Topgigant plus and Tophit plus, as well as the cultivar Bellamira from the group of Mirabelle plum.