Productivity and quality of experimental sunflower hybrids in climatically different years

M. Drumeva*

Department of Plant Production, Faculty of Manufacturing Engineering and Technologies, Technical University of Varna, 1 Studentska str., 9010 Varna, Bulgaria

(Manuscript received 5 September 2020; accepted for publication 16 January 2021)

Abstract. The main purpose of sunflower breeding requires the developing of high-yielding hybrid varieties with broad ecological plasticity that would guarantee the stability of the yield and the quality of the production from them. This investigation involved 10 experimental F1 hybrid combinations developed with the participation of double haploid fertility restorer lines (DHR) obtained through the method of gamma-induced parthenogenesis in combination with embryo culture. The aim of the investigation was to study the productivity and quality of the seeds from the new experimental sunflower hybrid varieties with a view of their future use in practice. The experimental work included years 2014 and 2015, which were significantly different with regard to the climatic conditions. The experiments were carried out in the experimental field and the laboratory of the Technical University in Varna. The hybrid combinations were assessed according to the main parameters of sunflower productivity, namely seed yield (kg/ha) and oil yield (kg/ha), as well as according to the main quality parameter of sunflower seeds – oil percent in seed. Under the conditions of this investigation, the analysis of the results showed that the genotype potential of the hybrids was determining for the seed and oil yield; a relatively high effect of the year conditions was also established for the parameter oil yield. The percent of oil in seeds was determined on the basis of the genotype, and the effect of the year was considerably lower. Summing up the results from the testing of the experimental hybrids, it can be pointed out that three of the studied hybrid combinations (3607A х 112DHR, 3607A х 123DHR and 3607A х 167DHR) realized good production potential under variable agro-meteorological conditions and can find future realization in practice.

Fuel consumption of a machine-tractor unit in direct sowing of wheat

G. Tihanov1*, N. Ivanov2

1Department of Agricultural Engineering, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria
2Department of Plant production, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 7 September 2020; accepted for publication 8 January 2020)

Abstract. A study has been conducted on the fuel consumption in direct sowing of wheat with a Horsch Avatar 6.16 SD direct seeder aggregated to a John Deere 7250 R tractor. The experimental field (29.53 ha) was sown with winter soft wheat (Silverio variety) at a sowing rate of 195 kg/ha. The data from the sowing unit were collected using the JD Link telematics system, downloaded from the system and imported and compiled in a database. Fuel consumption was analyzed in accordance with the operation mode, the idle mode and the transportion mode of the machine-tractor unit. It was found that the average fuel consumption in work mode (when the seeder was sowing) was 23.08 l/h, while in transportion mode the seeding unit consumed 16.55 l/h and while the unit was idling it consumed 4.30 l/h. The results also show that the seeding unit has travelled 63 km and consumed 185 L of diesel fuel at an average diesel consumption of 23.08 l/h.

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 2020)

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.

Application of P4 rapid test and exogenous source of progesterone in prevention of early embryonic death in dairy cows

G. Bonev*

1Department of Genetics, Breeding and Reproduction, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 24 September 2020; accepted for publication 15 February 2021)

Abstract. The objectives of this study were: 1) to determine the percent of cows with low P4 at Day 7-8 post-AI; 2) to treat the animal with low progesterone for 14 days with a P4-releasing intravaginal device (PRID DELTA); 3) to analyze the influence of P4 exogenous supplementation on pregnancy rate in treated and non-treated cows and 4) to create a protocol using “P4 Rapid” test allowing increased pregnancy rate under farm conditions. For this purpose, the current study has been conducted on 155 repeat breeding Holstein cows (<3 artificially inseminated – AI) with prolonged estrus cycle (<26 days). At day 7 and 8 post-AI, the milk progesterone levels were measured (P4 Rapid test). The cows with low P4 (n=104 or 67%) were divided into two groups each n=52. In Group I the progesterone devices were inserted for two weeks and control Group II without progesterone devices. At days 40 and 50 post artificial insemination (AI) all animals (n=104) were submitted to ultrasound pregnancy detection. Pregnancy was registered in 27 animals (51.9%) for Group 1, and in 16 cows (30.7%) for Group II. P4 Rapid is a quick, easy and practically applicable test to measure milk progesterone levels in dairy farms. The method is highly accurate and detects animals with low or high P4 at Day 7-8 after insemination. It also allows identification of conditions such as ovarian cysts, ovarian hypofunction and distinguishing of cycling and non-cycling cows. The combination of P4 measurement by P4 Rapid test and treatment with exogenous P4 to increase circulating concentrations in the first few days after conception can prevent embryo death and improve reproductive efficiency in dairy cattle.

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.

Date of ear emergence: a factor for notable changing the grain yield of modern winter wheat varieties in different environments of Bulgaria

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

1 Department of Wheat Breeding and Technology, Agronom Breeding Company, 9300 Dobrich, Bulgaria
2 Department of Plant Science, Faculty of Agronomy, Agricultural University, 4000 Plovdiv, Bulgaria

(Manuscript received 2 November 2020; accepted for publication 15 January 2020)

Abstract. Wheat is a crop with a very long growing season, during which it is subjected to prolonged exposure to many environmental factors. For this reason, the interaction of genotype with conditions is very common for any character of wheat. This study aims to determine whether the grain yield is affected by the change of the ear emergence date (EED) in various environments. In a four-year period, 30 current for national real grain production winter wheat varieties were studied. The EED and grain yield (GY) were studied as quantitative traits within five locations of the country having various soil and climatic conditions. Using several statistical programs, genotype x environment interaction of two traits was analyzed. The emphasis on data analysis was whether changes of traits due to the conditions were related and that the optimization of the ear emergence date could serve as a breeding tool for increasing grain yield. The date of ear emergence and grain yield are traits that are reliably influenced by growing conditions. The change in the date of emergence is mainly of the linear type, while the grain yield shows linear and nonlinear type changes in the same environmental conditions. It was found that the key roles in the change of characteristics are the conditions of the year, with the relatively weakest impact of the genotype on them. There is a positive relationship between the two traits, although their change depends on environmental factors. Although they change to different degrees and in relation to each other, there is a positive correlation between them. The more favorable the environmental conditions, the weaker the relationship between these two traits and vice versa. Under changing climatic conditions, the change in the relationship between the two traits is a signal of the need to create different varieties by date of ear emergence in order to obtain higher yields in the future.


Influence of heat stress on reproductive performance in dairy cows and opportunities to reduce its effects – a review

T. Penev1*, D. Dimov1, N. Vasilev2, J. Mitev1, Tch. Miteva1, I. Marinov3, M. Stojnov1

1Department of Applied Ecology and Animal Hygiene, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria
2Department of Obstetrics, reproduction and reproductive disorders, Faculty of Veterinary Medicine, Trakia University, 6000 Stara Zagora, Bulgaria
3Department of Animal Husbandry – Ruminants and Dairy Farming, Faculty of Agriculture, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 14 September 2020; accepted for publication 2 March 2021)

Abstract. The goal of this review is to consider and discuss the scientific literature related to the effect of heat stress (HS) on reproductive performance in dairy cows and opportunities to reduce its effects. The information in literature shows that the HS topic in dairy cows began to be discussed in the 1970s. As genetic progress related to productivity increases, the requirements for cows also increase, including for their reproduction performance. In the present review, a significant array of scientific papers is examined, as a result of which it is established that HS has a multifaceted effect on reproduction in dairy cows. The main role for the negative impact of HS is the effect of high ambient temperature on the hypothalamic-pituitary-ovarian axis. As a result, hormonal changes occur in the body of cows, which affect the behavior of cows in estrus, the development of follicles in the ovaries and the survival of the embryo in the uterus. These changes affect the main elements of cattle breeding such as length of days open interval, conception rate, number of inseminations required for conception. To mitigate the negative impact of HS on cows, methods have been developed for better estrus detection, for microclimate control, as well as for hormonal treatment of cows in order to increase reproductive performance. Although some progress has been made in each of the measures, HS still poses a serious reproductive problem for dairy cows, especially in the countries with warmer climates. This provokes the interest of many scientists around the world who seek to offer a solution/mitigation to this problem.

Estimation of efficiency and transportation cost as factors in cereal marketing in a typical rural Nigeria

M.R. Ja’afar-Furo1*, Y. Yohanna1, A. Sulaiman2, A. Abdullahi3

1Department of Agricultural Economics and Extension, Faculty of Agriculture, Adamawa State University,
PMB 25, Mubi, Nigeria
2Department of Agricultural Economics and Extension, School of Agriculture and Agricultural Technology, Abubakar Tafawa Balewa University, Bauchi, Nigeria
3Department of Business Administration, Faculty of Social and Management Sciences, Adamawa State University, PMB 25, Mubi, Nigeria

(Manuscript received 26 April 2020; accepted for publication 15 October 2020)

Abstract. This study estimated the efficiency of cereal marketing and effect of transportation cost on gross receipts of traded grains in a typical rural Nigeria. A total of 120 cereal marketers were selected through a simple random method. A structured questionnaire was used for collection of data which was complemented by oral interview and group discussion for a period of one month (24th July – 23rd August 2019). Descriptive statistics, Marketing efficiency, and Multiple Regression were employed in making data analysis. Results indicated that most of the respondents were males (70.85%), married (66.67%) with a household size of 6-10 persons, and within the age range of 40-49 years (51.67%) with a larger proportion (41.67%) having had secondary education. The majority (54.17%) had cereal marketing as their main occupation and sourced business capital from personal savings. The most prioritized method of transportation among the marketers was the use of motor vehicles, and maize was ranked as the most traded staple among the respondents. Regression results revealed coefficients of 0.3758 and 0.5296 for transportation cost and miscellaneous services which were both significant at p<0.001 as the most influential variables to gross receipts of cereal marketing in the surveyed area. Further, the findings showed a marketing efficiency of 728.80%, implying a very highly efficient or profitable marketing system among the cereal marketers. The most notable challenges experienced were high transportation cost (83.33%), insecurity, inadequacy of capital among the marketers, and poor transportation facilities in descending order. Conclusively, it could be said that slightly enlightened married men who sourced capital from their personal savings dominated cereal marketing in typical rural Nigeria. And the cereal marketing was confirmed to be highly efficient in the area studied. It is, therefore strongly endorsed that agencies that intend to improve cereal marketing in the area under consideration and other rural communities in the country should address the challenges highlighted.

Influence of the age of first insemination and first calving in Holstein – Friesian heifers on farm economic efficiency

K. Stankov*

Department of Management, Faculty of Economics, Trakia University, 6000 Stara Zagora, Bulgaria

(Manuscript received 15 June 2019; accepted for publication 23 September 2020)

Abstract. The present study aims to assess the influence of the age of first insemination and first calving in Holstein-Friesian heifers on the cost of breeding and the cost of their marketing as breeding animals. For this purpose, a study was conducted on 7 farms (A, B, C, D, E, F, G) situated in Central and Southern Bulgaria in which Holstein-Friesian cattle are bred. The results of the study indicated that the age of first insemination in the controlled farms was 17.2 months on average, and the age of first calving (AFC) was 26.6 months, which was within the established norms for the Holstein-Frisian breed raised in the country. The heifers from farm A, which entered breeding age the earliest (at 16 months), as well as the age of first calving (25.3 months) had the longest utilisation period – 4.9 lactations. However, they did not develop the highest milk yield either and the economic performance from their raising was low. The heifers on farm F, with age of first insemination of 17.3 months, and first calving age of 26.8 months, and the ones from farm G, with ages 17.4 and 26.6 months, respectively, developed maximum milk yield per lactation. The expenses for raising a heifer of the Holstein-Frisian breed varied from BGN 1922 up to BGN 2389, with an average sum of cost for the studied farms amounting to BGN 2123. This indicated that the raising of heifers from a high-yield breed was an expensive undertaking, but when taking the necessary care for their breeding at a younger age during the period of use they developed higher milk productivity.