Evaluation of the antimicrobial and anti-Varroa destructor L. activity of the essential oil of clove (Syzygium aromaticum L. Myrtaceae)

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.

Biochemical reference intervals in broiler chickens according to age and strain

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.

Growth and yield of pomato under the Syrian coastal mountains conditions

The world has always been striving to increase and intensify agricultural production, and there are several attempts to acheive that, such as grafting tomato on potato to obtain two crops from one plant. This investigation was conducted during 2020 in open field in Nahl village, Baniyas, Tartous Governorate, Syria. The vegetative and generative growth and yield have been studied for pomato (grafted tomato on potato) and compared to each tomato and potato separately. Tomato plants were significantly superior in plant height to pomato plants after 23 days of planting until the end of the experiment. On the other hand, there were significant differences between tomato plants and pomato plants in the leaf area after 23, 51 and 65 days of planting. Also, tomato plants significantly outperformed pomato plants in the number of flowers and fruits per plant and the tomato fruit set percent. Anyway, tomato plants were significantly superior in the average yield of tomato fruits per plant (1657 g.plant-1) to pomato plants (185 g.plant-1), while there were insignificant differences in the average yield of potato tubers per plant between pomato which failed to produce tubers and potato (48.25 g.plant-1). Studying the tomato fruit fresh weight showed a significant superiority of tomato plants (54.37 g.fruit-1) to pomato plants (35.97 g.fruit-1), while there were insignificant differences in the other physical (tomato fruit height, diameter and shape index) and chemical (tomato fruit content of total acids, total soluble solids and dry matter, %) properties.

Microbiological load evaluation of white shrimp (Nematopalaemon hastatus Aurivillius, 1898) in the coastal waters of Ondo state, Nigeria

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.

Somatic cells count in milk and its relation with productive traits in dairy cows

The aim of the study was to determine the dependence between Test Day (TD) milk productivity traits and somatic cells count (SCC) in milk and also the influence of the factors: farm, parity and TD recording season of Holstein cows. The survey included a total of 484 lactating cows from 8 cattle farms in Bulgaria. A total of 3473 TD records including data on TD milk yield, fat %, protein % and SCC in milk were used. A statistically significant effect of the farm, recording season, and SCC on TD milk yield, fat % and protein % was reported. The highest TD milk yield was reported in spring (22.42 kg), followed by winter (21.95 kg). In winter and autumn were reported higher mean values for TD fat (3.77 and 3.84%) and TD protein (3.38 and 3.40%) content in milk. At the highest SCC – above 999 000 cells/ml, the highest average daily milk yield – 24.1 kg and the lowest fat (3.48%) was reported. With the highest and positive statistically significant value was the phenotypic correlation between TD milk yield and SCC (0.21). The correlation with TD fat % was statistically significant, with negative value (- 0.07).

Response of durum wheat lines to the cause agent of leaf rust Puccinia triticina

Аbstract. The response of 1262 durum wheat lines to the cause agent of leaf rust Puccinia triticina was studied. The investigation was carried under infection field conditions during 2013-2015 at Dobrudzha Agricultural Institute (DAI) – General Toshevo, Bulgaria. Over the years of investigation, a maximum high infection background was developed by the cause agent of the disease, including all pathogen pathotypes identified during this period. The race variability in the population of the pathogen during the period was determined at the Plant Pathology Laboratory of DAI according to a validated methodology for working with rusts. Seventy-one phenotypically different virulent pathotypes were established. Fifteen new races of P. triticina were also identified, which have not been present during the previous 15 years in Bulgaria. Seventeen lines and one cultivar with a certain degree of resistance to the pathogen were selected. The selected lines can be involved in the breeding programs for developing initial material with resistance to leaf rust P. triticina.

Statistical analysis of resistance variability of pepper accessions to Xanthomonas euvesicatoria and Xanthomonas vesicatoria

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.

True digestibility of the essential amino acids of high-protein sunflower meals by balanced experiments with intact and caecectomized birds from Gallus species

Using adapted methods for balanced experiments with poultry, the true digestibility coefficients of the essential amino acids of two high protein sunflower meals – 40+® and 47® have been established. The true digestibility coefficients by using two methods – with intact and randomized (caecectomized) birds have been compared. Six birds were tube fed and six – feed deprived for both of the fodders. The amino acids were established with amino analyzer AAA-881 after preliminary HCl hydrolysis. The mean digestibility of sunflower meal 40+® is higher in intact (88.11 versus 85.73 of sunflower meal 47®) compared to randomized birds (87.20 versus 85.46 of sunflower meal 47®). The differences by lots are statistically significant only in intact birds. The authors recommend for practical needs to use the average true digestibility coefficients between both meals, established with randomized birds (ileal digestibility).

Influence on Mycotox® NG effects on relative weights of some internal organs in Pekin ducks with experimentally reproduced aflatoxicosis В1

Contamination of poultry feeds with mycotoxins is a global problem faced by poultry industry due to increased demands and availability of poor-quality cereals. The aim of the present study was to evaluate the beneficial effects of a mycotoxin binder (Mycotox NG) on relative weights of internal organs in Pekin ducks with experimental aflatoxicosis. The birds were divided into one control and six experimental groups (n=10) as follows: group І (0 mg/kg AFB1 without Mycotox NG); group ІI (0.5 g/kg Mycotox NG); group ІІI (1.0 g/kg Mycotox NG); group IV (0.2 mg/kg AFB1); group V (0.4 mg/kg AFB1); group VI (0.2 mg/kg AFB1 + 0.5 g/kg Mycotox NG) and group VII (0.4 mg/kg AFB1 + 1.0 g/kg Mycotox NG). Trial duration was 42 days. It was established that ducks fed AFB1-contaminated feed had increased relative weights of liver, kidneys, pancreas, heart, gizzard and proventriculus compared to the control group. At the same time, the relative weights of immunocompetent organs (thymus, spleen and bursa of Fabricius) were reduced. The addition of Mycotox NG to the feed contaminated with AFB1 compensated partly the changes in relative weights of visceral organs. The results from the present study demonstrated that the tested toxin binder could be effective for reduction of toxic effects of aflatoxins in domestic ducks.

Effect of different fattening period duration on meat productivity of domestic quails

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.