Food consumption and winter mortality in bee colonies wintering in hives made from different materials with lattice and solid bottom

I. Zhelyazkova*, S. Lazarov

Department of Animal husbandry – Non-ruminants and other animals, Faculty of Agriculture, Trakia University, Student’s campus, 6000 Stara Zagora, Bulgaria

(Manuscript received 10 June 2021; accepted for publication 2 August 2021)

Abstract. The objective of the present study is to examine the changes in some indicators characterizing the winter hardiness of bee colonies settled in hives made of different material (polystyrene, wood, ceramics) and with different type of bottom (lattice or solid). Some parameters which characterize the wintering of bee colonies (amount of dead bees and quantity of food consumption in winter) have been investigated. The bee colonies were housed in 10-frame Dadant Blatt hives with a lattice and solid bottom situated at the Training Apiary of the Faculty of Agriculture, Trakia University, Stara Zagora, Bulgaria. Two inspections of the bee colonies were carried out (during wintering in November 2020 and at the beginning of the active season in March 2021). Amount of bees in the bee hive (strength) and amount of capped honey in the honeycombs were reported. In bee colonies wintering in hives with a lattice bottom, the consumption of food per 1 kg of bees was 1.639 kg (50%) higher than in hives with a solid bottom. Winter mortality of bees in hives with a lattice bottom was higher compared to this indicator in the hives with a solid bottom, 16.19±10.72% and 12.59±3.57%, respectively, which can be considered excellent wintering below 15% and good wintering in the range of 15.0-19.99%.

Effect of black pepper (Piper nigrum) extract on productive traits, economic efficiency and blood biochemical parameters of rainbow trout (Oncorhynchus mykiss W.)

Ts. Stoev, G. Zhelyazkov

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

(Manuscript received 5 June 2021; accepted for publication 10 August 2021)

Abstract. The aim of the present study was to evaluate the effect of the dietary black pepper extract supplement on the survival rate, weight gain, feed conversion ratio (FCR), economic efficiency (ECR) and blood biochemical parameters of rainbow trout, cultivated in a recirculation system. One hundred and twenty rainbow trout were distributed in two experimental variants, with two replicates of 30 fish per each. The average initial live weight of fish from the control group (C) and experimental group (P.n) were 41.55±7.96 g and 41.23±8.38 g, respectively (p>0.05). Trouts were fed extruded feed with granule size of 2 mm. Through lubrication of feed granules with 5 ml sunflower oil per 100 g feed, rainbow trouts from group P.n were supplemented with 1% powdered black pepper extract, whereas control rainbow trouts (С) received feed lubricated with the same amount of sunflower oil. Fish were fed 3 times/daily with the diet, based on 3% of biomass. The trial period was 60 days. Survival rate in trouts from both experimental groups was 100%. At the end of the trial, average live weight of fish from group P.n was by 5.84% higher compared to that of control fish the average weight of which was 117.25±19.15 g, yet differences were not statistically significant (p>0.05). The average individual weight gain of control rainbow trouts was 75.70±11.53 g, which was inferior to that of P.n fish by 8.65% (p>0.05). Better FCR was demonstrated in trouts from the group supplemented with 1% black pepper extract – 0.98±0.02, which was by 10.20% less compared to control fish (p<0.01). The addition of 1% black pepper extract to the feed of rainbow trouts tended to result a trend in better growth performance parameters in this species. ECR of group P.n was by 3.98% better than that of the control fish, which showed an ESR value of 1.51. Blood biochemical parameters of fish from both groups were not consistently different.

Application of rosemary essential oil (Rosmarinus officinalis Linnaeus, 1753) for anesthesia and transport of bighead carp (Hypophthalmichthys nobilis Richardson, 1845) fingerlings

V. Krasteva*, M. Yankova, A. Ivanova

Institute of Fisheries and Aquaculture, 4003 Plovdiv, Bulgaria

(Manuscript received 17 June 2021; accepted for publication 11 August 2021

Abstract. The aim of the present research is to study the efficacy of rosemary oil as an anesthetic for bighead carp (Hypophthalmichthys nobilis Richardson, 1845) and as an anesthetic used for transport of fingerlings. The fish used in the experiment have an average body weight (BW, g) of 42.13±17.90 and an average total length (TL, cm) of 16.54±2.32. Five treatments are conducted with five experimental concentrations: 0.20 ml.l-1, 0.30 ml.l-1, 0.40 ml.l-1, 0.50 ml.l-1 and 0.60 ml.l-1. For each concentration 10 fish are used or a total of 50 fish. For the transport experiment, 3 concentrations are used: 0.06 ml.l-1, 0.08 ml.l-1 and 0.10 ml.l-1. The applied stocking density is 3 fish/l. A total of 60 fish are used for each concentration or a total of 180 fish. The established results, for the first experiment, show that at concentration of 0.60 ml.l-1 the induction of anesthesia is the fastest (3.46 min). From all tested concentrations the recovery time is the shortest at the lowest concentration – 2.16 min (p≤0.001). The concentration of 0.10 ml.l-1 of rosemary oil can be used for transport of bighead carp fingerlings for a period from 1 to 2 hours. The concentration of 0.08 ml.l-1 can be applied when the duration of the transport is from 1 to 3 hours.

Influence of soybean meal replacement with high-protein sunflower meal on “Clarcs of energy distribution/protein transformation” in broiler chickens

S. Chobanova1, D. Penkov2*

1Department of Morphology, Physiology and Nutrition, Section Animal Nutrition, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria
2Department of Animal Sciences, Faculty of Agronomy, Agricultural University, 12 D. Mendeleev Str., 4000 Plovdiv, Bulgaria

(Manuscript received 28 May 2021; accepted for publication 30 June 2021)

Abstract. The aim of the study is to compare the net utilization of energy and protein in the eco-technical chain „feed-meat“ when replacing part of the soybean meal with high-protein sunflower meal in broiler fattening. One control and 3 experimental groups, 4-phases fattening with isoenergetic and isoprotein combined fodders. Main protein source in the fodders for the control group is soybean meal. Replacement with sunflower meal: First experimental group: Starter – 5%, Grower – 8%, Finisher 1 – 10% and Finisher 2 – 10%; Second experimental group: 15, 18, 25 and 25%, respectively; Third experimental group: 34.25, 27.27, 27.27 and 26%, respectively. Clarcs of energy distribution/protein transformation (CED/CPT) are the ratio between accumulated gross energy/crude protein in breast and thigh muscles and consumed metabolic energy/crude protein throughout life. The following results were established: CED “fodder – breast+thigh muscles”: Control – 0.2430, first experimental group – 0.2394, second experimental group – 0.2505, third experimental group – 0.2334; CPT – 0.6080, 0.5050, 0.5280 and 0.5490, respectively.

Photosynthetic activity and productivity of durum wheat (Triticum durum Desf.) affected by certain preparations and various terms of sowing

P. Nikolov1*, G. Delchev2

1Institute of Agriculture and Seed Science “Obrazcov Chiflik”, 7007 Ruse, Bulgaria
2Department of Plant Production, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 31 May 2021; accepted for publication 23 July 2021)

Abstract: In 2019-2020, in the experimental field of the Field Crops Institute, Chirpan a field experiment with durum wheat cultivar Predel (Triticum durum Desf.) was conducted. Three sowing dates were tested: Early sowing (05 – 10 October), Normal sowing (20-25 October – standard) and Late sowing (05-10 November). In early sowing, 2 retardants were studied: Cearon 480 SL – 1 l/ha and Medax top – 1 l/ha and 2 insecticides: Proteus 110 OD – 625 ml/ha and Mageos – 100 g/ha, as well as the mixtures between them. During late sowing, 2 stimulants were studied: Naturamin plus – 1.5 l/ha and Raiza mix – 750 ml/ha and 2 foliar liquid fertilizers: Mix for cereal SC – 1.5 l/ha and Trimax SC – 1.5 l/ha, as well as the mixtures between them. These preparations and fertilizers are applied after stage 3-4 leaves of durum wheat, in the so-called “Closure of crops”. In the case of early sowing variants, this stage occurs in autumn, and in the case of late sowing variants, the stage occurs in spring. In the early sowing of durum wheat, the leaf area, photosynthetic potential, biological and economic yield are the greatest in the combinations of retardants Cearon and Medax top with the insecticides Proteus and Mageos. In the late sowing of durum wheat, the leaf area, photosynthetic potential, biological and economic yield are the highest in the combinations of the stimulants Naturamin plus and Raiza mix with the leaf fertilizers Mix for cereals and Trimax. In these variants, the leaf area dies faster during the milk development stage. The net photosynthesis productivity in the combinations is lower than in the independent use of the respective preparations and fertilizers. The harvest index in the late and normal sowing variants is higher than in the early durum wheat sowing variants.

Evaluation of Clove (Eugenia caryophyllata) and Tobacco (Nicotiana tabacum) powders for common carp Cyprinus carpio L. anesthesia

Nasreen Mohi Alddin Abdulrahman1*, Khalidah Salim Al-Niaeem2, Amjed Kadem Resen2

1College of Veterinary Medicine, University of Sulaimani, Sulaimaniya, Iraq
2College of Agriculture, University of Basrah, Basrah, Iraq

(Manuscript received 29 April 2020; accepted for publication 26 May 2021)

Abstract. The anesthetic efficacy of two kinds of natural anesthetic Clove (Eugenia caryophyllatata) and Tobacco (Nicotiana tabacum) powders were evaluated on common carp (Cyprinus carpio L.) for handling and health management experiments. The concentrations of anesthetics were assessed by using two types of clove and tobacco anesthetics; each with three replicates for measuring induction times to anesthesia. Concentrations of 100, 200, 250, and 350 mg/l at the ratio 1:1 of the aqueous extract of both Clove (Eugenia caryophyllatata) and Tobacco (Nicotiana tabacum) to evaluate their effect on common carp anesthesia were used. The aqueous extract anesthetized fish partially in the high levels. No significant differences appeared on blood glucose, ALP, ALT and AST among different levels of the anesthesia concentrations used. As the anesthesia concentration increased, the Red blood cell (RBC) count and hemoglobin decreased.

Effects of liquid organic mineral complex (MultiMix®) on milk yield, composition and cheesemaking capacity of milk in dairy cows

T. Angelova1*, K. Nedelkov2, D. Yordanova1, V. Karabashev1, J. Krastanov1

1Agricultural Institute, 6000 Stara Zagora, Bulgaria
2Department of Nutrition, dietetics and veterinary expertise of feed, Faculty of Veterinary Medicine, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 26 October 2020; accepted for publication 22 April 2021)

Abstract. The objective of this experiment was to investigate the effects of liquid organic mineral complex (MultiMix®) on the milk yield, composition and cheesemaking capacity of milk in dairy cows. Thirty Holstein cows (8 primiparous and 22 multiparous) were used in a randomized complete block design experiment with 15 cows per treatment. Feeding was ad libitum targeting 5% refusals. Milk yield data and samples for fat, true protein, solids not fat (SNF), lactose content and parameters characterizing the milk’s coagulation properties were collected throughout the experiment. Data suggested that MultiMix® administered through the cows’ drinking water had a positive effect on the milk productivity with a high degree of significance (p<0.001). A positive effect on the indicators characterizing the quality composition of milk has also been observed (p<0.001). Additionally, the cheesemaking capacity of milk was enhanced by supplementing animal water with MultiMix® (p<0.001). Overall, the new liquid organic mineral complex used in the present experiment showed promising results for improvement of milk production and composition in dairy cows but further studies are needed to unveil the physiologic mechanisms underlying these beneficial effects.

Utilization of Corchorus olitorius leaf as binder in the diet of Oreochromis niloticus fingerlings

I.O. Oke*, E.O. Adeparusi, A.A. Dada

Department of Fisheries and Aquaculture Technology, Federal University of Technology, P.M.B. 704, Akure, Ondo State Nigeria

(Manuscript received 16 October 2020; accepted for publication 22 February 2021)

Abstract. This study was carried out to evaluate the physical properties and dietary value of feeds made using Corchorus olitorius as binders in fish feeds. Six isonitrogenous diets were prepared using maize wheat or maize and wheat as energy source. The diets were designated as MAI, WHC, MAW, MAC, WHC and MWC. With the first three being bounded with corn starch and the last three being bounded with C. olitorius leaves soaked for 24 hours and pelleted. Physical properties evaluated are sinking rate, water absorption index, water stability, bulk density, thickness strength, friability and hardness. There was significant differences (p<0.05) in the water stability, water absorption index and thickness swelling of the diet. The highest water stability value was recorded in diet MAW. For growth parameters and nutrient utilization by fish fed experimental diets, diet MWC had a significantly higher mean final weight (9.42±0.41g), mean weight gain (5.43±0.41g), feed efficiency ratio (0.93±0.13) and specific growth rate (1.22±0.06%d-1). There was no significant difference in the feed conversion ratio, mean feed intake, and survival rate. The result shows that diet bounded with C. olitorius leaf had better utilization compared to corn starch bounded feed.

Seasonal variations in hematological profile of Holstein dairy cows as an indicator for physiological status assessment

M. Mekroud1, N. Arzour-Lakehal1, N.A. Ouchene-Khelifi1,2, N. Ouchene1,2*, A. Titi1, A. Mekroud1

1PADESCA laboratory, Institute of Veterinary Sciences, Road of Guelma 25100 El Khroub, University of Mentouri Brothers, Constantine 1, Algeria
2 Institute of Veterinary Sciences, University of Saad Dahlab Blida 1, Road of Soumaa, BP 270, 09000, Blida, Algeria

(Manuscript received 1 July 2020; accepted for publication 25 January 2021)

Abstract. This study aims to investigate, for the first time in Algeria, the effect of seasonal climatic changes on the hematological profile of Holstein dairy cows as an indicator for their physiological status assessment. The study was conducted between November 2018 and October 2019 and was performed on a lot of 14 dairy cows. Blood samples were collected quarterly during this study period. The data regarding seasonal changes in hematological parameters were not significant concerning red blood cell count (RBC), hemoglobin concentration (Hb) and mean corpuscular volume (MCV). However, variations were significant for hematocrit (HCT), mean corpuscular hemoglobin content (MCH), mean corpuscular hemoglobin concentration (MCHC) and blood platelets (PLT). The percentage of HCT was higher in autumn (27.99%) and spring (28.58%) compared to winter (26.52%) and summer (26.75%), (p<0.05). MCH, MCHC and PLT levels were higher in summer compared to the other seasons (p<0.05), (p<0.01) and (p<0.001), respectively. The highest number of WBC was generally observed in summer and autumn and the lowest in winter and spring (p<0.01). The ratio neutrophils/lymphocytes (N:L) was equal to 1.01, 0.79, 0.98 and 0.89 in autumn, winter, spring and summer, respectively of which this difference was not significant. This study might be helpful for providing base line information on the hematological profile of dairy cattle for the evaluation of physiological status.

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.