Operational characteristics of direct sowing machine-tractor unit

G. Tihanov*

Department of Agricultural Engineering, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 13 July 2020; accepted for publication 26 October 2020)

Abstract. A study on some operational characteristics of a direct sowing machine-tractor unit has been carried out in wheat sowing. It is performed by Horsch Avatar 6.16 SD direct seeder aggregated to John Deere 7250 R tractor. It was found that 91% of the area is sown at sowing rate of 195 kg seed/ha. The remaining 9% are sown either at lower or higher rate. Engine rotations of the seed unit have been established at work mode, i.e. when the seeder is sowing, these are 1594.81 min-1, in idle state the rotations are 912.08 min-1, and in transportation mode are 1860.36 min-1. The relative share of engine use has also been determined: when the seeder is sowing, it is 56.68%, when the seeder unit is in idle mode, it is 14.54% and when the unit is in transportation mode – 28.78%, respectively. The actual operation speed of the seeder unit when sowing wheat was 10.40 km/h and the real hourly productivity – 3.7 ha/h.

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.

Effect of Gmelina leaf meal diets on productive and physiological parameters of West African dwarf goats

P.C. Jiwuba1*, W.N. Amaduronye2, R.C. Akazue1

1Department of Animal Production Technology, Federal College of Agriculture, P.M.B. 7008, Ishiagu,
Ebonyi State, Nigeria.
2Department of Animal Breeding and Physiology, Michael Okpara University of Agriculture, Umudike, Nigeria

(Manuscript received 21 June 2020; accepted for publication 2 October 2020)

Abstract. West African Dwarf (WAD) goat plays an important socio-economic role, hence the effect of 82 days of feeding Gmelina leaf meal (GLM) diets on feed intake, body weight change and blood indices of WAD goats were investigated. A total of 36 WAD goats averaging 9.04 kg in weight were randomly divided into four groups of nine goats each with three goats constituting a replicate. The groups were randomly assigned four experimental diets (T1, T2, T3, and T4, containing GLM at 0%, 12%, 24% and 36%, respectively) in a completely randomized design. Results indicated significant (p<0.05) improvement for body weights and feed conversion ratio for T2, T3, and T4. There was significant difference (p<0.05) for all the haematological parameters except packed cell volume (PCV). White blood cells (WBC) increased in their number (p<0.05) with incremental levels of GLM in the diets. All the serum biochemical indices showed significant (p<0.05) difference with glucose and cholesterol concentration reduced (p<0.05) with incremental levels of GLM. It could be concluded that GLM can be included in the diets of goats up to 36% without deleterious effects on the productive and physiological indices of WAD goats.

Characterization of testicular and epididymal parameters in Algerian Arabia bucks

N.A. Ouchene-Khelifi*, N. Ouchene, A. Dahmani

Institute of veterinary sciences, Saad Dahlab University Blida 1, Road of Soumaa, BP 270, Blida-09000, Algeria

(Manuscript received 20 June 2020; accepted for publication 24 September 2020)

Abstract. In goat production, the reproductive efficiency of bucks must be taken into account. Testicle size is the most appropriate parameter to directly improve the reproductive performance of females. In this study, body weight (BW), body condition score (BCS) and testicular and epididymal parameters of Arabia goats were studied. A total number of 200 bucks wеre randomly selected and classified into three age categories (6-12 months, 13-24 months and >2 years). BW, BCS, mean scrotal circumference, testicular volume, testicular diameter, testicular length, testicular weight, testicular density, epididymal weight, epididymal length, epididymal tail length, caput weight, corpus weight, caudal weight, Gonadosomatic Index, Epididymosomatic index and Epididymal-Testicular weight ratio were measured. A highly significant correlation was found between all parameters (p<0.05). The values of all parameters increased significantly with age, with the exception of the gonadosomatic and epididymosomatic indices, which decreased with age (p<0.05). These results provide data that can be used to anticipate an adequate ante-mortem sperm reserve based on testicular size in the preliminary selection of breeding males from the local sexually mature population.


Morphological characterization and genetic analysis in bread wheat germplasm: A combined study of heritability, genetic variance, genetic divergence and association of characters

  1. Gerema1*, D. Lule2, F. Lemessa4, T. Mekonnen3

1Bako Agriculture Research Center, Oromia, Ethiopia

2Oromia Agriculture Research Institute, Finfinne, Ethiopia

3Institute of Biotechnology, Addiss Ababa University, Ethiopia

4Department of Horticulture and plant Science, Jimma University, Jimma, Ethiopia

(Manuscript received 20 May 2020; accepted for publication 5 November 2020)

Abstract. The present study was conducted to assess the nature and magnitude of genetic variability and traits association of bread wheat genotypes for yield and related traits. A total of 180 genotypes were evaluated in alpha lattice design with three replications in 2017/18 cropping season. Data for 10 quantitative traits were collected and subjected to analysis of variance. The result from the analysis of variance revealed highly significant variability observed among genotypes for all traits studied. Phenotypic coefficient of variation (PCV) is superior over genotypic coefficient of variation (GCV) for most traits but narrow variations were found between PCV and GCV for most of the traits. Heritability in broad sense and genetic advance as percent of the mean (GA%) were relatively higher for Kernels per spike and grain filling period. Grain yield showed positive and highly significant (p≤0.01) association with number of tillers, kernel per spike and plant height both on genotypic and phenotypic levels.The path coefficient analysis showed that spike length, plant height and kernels per spike had positive direct effect on grain yield on both genotypic and phenotypic levels. Divergence analysis (D2) grouped the total test germplasm into 10 clusters. Among those, clusters IV and IX showed the highest genetic distance and thus the possibility to develop segregating populations upon the crossing of widely related genotypes in those clusters. The results could help researches to utilize the most promising wheat genotypes of this study in future breeding programmes for enhancing desirable traits.

Correlations between grain yield and related traits in winter wheat under multi-environmental traits

  1. Tsenov1*, T. Gubatov1, I. Yanchev2


1Department of Wheat Breeding and Technology, Agronom Breeding Company, 9300 Dobrich, Bulgaria

2Department of Plant Science, Faculty of Agronomy, Agricultural University, 4000 Plovdiv, Bulgaria

(Manuscript received 7 August 2020; accepted for publication 29 October 2020)

Abstract. In a series of field trials, a database of quantitative traits associated with winter wheat grain yield has been collected. The aim of the present study is to determine the relationships between the winter wheat (Triticum aestivum L.) traits of productivity in environments causing the maximum possible variation of each of the traits. In order to determine the correlations between the quantitative characters studied, all possible statistical methods have been applied (regression analysis, PCA, Multiple Correspondence analysis), which complement each other. It was found that the nature of the correlations between traits depends to a large extent on the methods for their evaluation. There are high and significant correlations between grain yields and the grain number per spike (weight of grain per spike and number of grains per m2) even under strong genotype by environment interaction of all the traits in trails. The established results are related to possible options for increasing winter wheat grain yield by breeding.