DOI: 10.7904/2068–4738–VII(14)–53

Samuel O. OLUFEAGBA, Victor Tosin OKOMODA*

 Department of Fisheries and Aquaculture, University of Agriculture, Makurdi, NIGERIA

*Corresponding author E–mail: okomodavictor@yahoo.com, Phone No: +2348033319959

Abstract. Reciprocal hybridization of Clarias batrachus and C. gariepinus was carried out to obtain hybrid progenies for the purpose of culture. The viable hybrid was obtained only in the cross between ♂ C. gariepinus × ♀ C. batrachus, while hybrids between ♀ C. gariepinus × ♂ C. batrachus all died few hours after hatching. The viable hybrid was cultured for five months and parentage confirmation attempted by DNA extraction and PCR amplification of the cytochrome b using markers designed from the known sequence of C. batrachus. The only gel electrophoresis band observed in the hybrid was at the same level with that shown in C. batrachus (1000 bp), hence, confirming parentage status of the hybrid (as cytochrome b is only inherited from maternal parent). Amplification at 300 bp was also visible in the pure C. gariepinus suggesting that primer could have been useful in determining parentage of the ♀ C. gariepinus × ♂ C. batrachus hybrid if they had survived.

Keyword: Hybridization; Cytochrome b; African catfish; Asian catfish.

DOI: 10.7904/2068–4738–VII(14)–38

Boryana CHURKOVA¹*, Tatyana BOZHANSKA², Yordanka NAYDENOVA³

 ^1,2Research Institute of Mountain Stockbreeding and Agriculture, 5600, Troyan, BULGARIA

³Institute of Forage Crops, 5800, Pleven, BULGARIA

*Corresponding author: bchurkova@abv.bg

Abstract. During the period 2010–2012 in the Research Institute of Mountain Stockbreeding and Agriculture–Troyan was conducted a study on the Forage (energy and protein) Feeding Value of the Following Bird’s–foot trefoil (Lotus corniculatus L.) Cultivars Introduced in Bulgaria: ‘Bright’, ‘Georgia 1’ (USA), ‘Nueltin’ (USA), ‘Witt’, ‘Pardee’ (USA), ‘Roseau’ (USA), ‘Steadfast’, ‘Trevig’ (USA) with origin the USA. The changes of proteins and fibers, analyzed by means of classical chemical analysis such as, Weende and Van Soest analysis, in vitro enzyme digestibility of organic substance of eight bird’s–foot–trefoil cultivars were compared with indicators of the standard cultivar ‘Targovishte 1’. The crude protein content in the studied bird’s–foot–trefoil cultivars varied from 16.66 (‘Witt’) to 20.50 % (‘Pardee’) dry matter. Average for the period ‘Witt’ cultivar was distinguished by the lowest content of crude fiber (5.48 % below the standard) and the highest dry matter digestibility–63.29 % (1.14 % over the standard). The share of neutral detergent fibers in dry matter of bird’s–foot trefoil cultivar of ‘Pardee’ was 7.4 % less in comparison with ‘Targovishte’ cultivar. In cell wall composition of ‘Roseau’ cultivar, hemicellulose prevailed at the highest level, and fiber fractions of ADF and ADL were at the lowest level, which presupposed a high quality and good forage digestibility. According to net energy feeding value, the average values of studied cultivars did not exceed the standard cultivar. ‘Pardee’ cultivar had the highest feeding value: TDP (PBD): 160.0 g kg^–1, PDIN: 128.7 and PDIE: 101.5 g kg^–1.

Keyword: bird’s–foot trefoil cultivars, chemical composition, in vitro digestibility, energy and protein nutritional value.

DOI: 10.7904/2068–4738–VII(14)–24

Boryana CHURKOVA¹, Tatyana BOZHANSKA²

 ^{1, 2}Research Institute of Mountain Stockbreeding and Agriculture, 5600 Troyan, BULGARIA

*Corresponding author e–mail: bchurkova@abv.bg

Abstract. In the experimental field of RIMSA–Troyan was studied the herbicidal effect of Aramo 45 (45 g/L Tepraloxydim) at doses of 1 and 2 L/ha, and Dual Gold 960 EC (960g/L s–metolachlor)–2 and 3 L/ha, during the period of 2013–2015 on light grey pseudopodzolic soil, over the weed infestation level and productivity of bird’s–foot–trefoil. It was found that both herbicides in both doses showed good selectivity in relation to bird’s–foot trefoil. Most pronounced was the effect by the applied herbicides regarding the degree of weed infestation in the year of sowing, as the treatment by Aramo 45 at a dose of 2 L/ha and Dual Gold 960 EC at a dose of 2 L/ha provided a degree of weed infestation of 6.68 and 16.11 %. The vegetation treatment of a grassland of bird’s–foot–trefoil by Aramo 45 herbicide at a dose of 1 and 2 L/ha led to an increase in dry matter yield with 21.85 and 18.21 %, and with Dual Gold 960 EC EK it was 24.28 and 30.29 %. Dual Gold 960 EC showed a greater effect from both tested herbicides over the dry matter yield, applied at a dose of 3 l/ha at a phase of 2–4 leaf stage of bird’s–foot trefoil. That herbicide could be recommended for the application in the practice in creating weed–free crops of bird’s–foot–trefoil for forage production.

Keyword: bird’s–foot–trefoil, herbicides, selectivity, degree of weed infestation, dry matter yield

DOI: 10.7904/2068–4738–VII(14)–5

Natalia GEORGIEVA, Ivelina NIKOLOVA, Yordanka NAYDENOVA

 Institute of Forage crops, Gen. V. Vazov Street, 89, 5800–Pleven, BULGARIA

*Corresponding author: imnatalia@abv.bg

Abstract. The chemical composition, plant cell–wall fiber components content, in vitro enzyme digestibility, potential protein and energy feeding value of forage of seven vetch cultivars were evaluated. Vicia sativa L. (cultivars Liya, Lorina, Vilena, Moldovskaya, Obrazets 666) and Vicia villosa Roth. (cultivars Violeta and Viola) were planted at the experimental field of the Institute of Forage Crops, Pleven (Bulgaria) during 2012–2014 period. The origin of Obrazets 666 is Bulgaria and of the rest six cultivars–Moldova. Vicia villosa cultivars revealed a greater content of CP and fiber components, measured as NDF, ADF and ADL (211.4, 451.9, 378.5, 74.0 g kg^–1 DM respectively) in comparison with Vicia sativa cultivars (189.5, 409.2, 352.4, 67.9 g kg^–1 DM respectively). Quality of the herbage in terms of digestibility was 63.9% IVDMD for Vicia sativa and 52.9 % IVDMD for Vicia villosa. The nutritive value based on arithmetical rank sum of all studied parameters (chemical composition, in vitro enzyme digestibility, protein and energy feeding value) showed better forage quality of V. sativa compared to V. villosa. With the highest nutritive value was distinguished cultivars Liya, Vilena and Moldovskaya, which could be used as germplasm in future breeding programmes for quality improvement.

Keyword: fiber, digestibility, vetch, feeding value.