Volume 13, Number 1, March 2021

Review

Influence of heat stress on reproductive performance in dairy cows and opportunities to reduce its effects – a review
T. Penev, D. Dimov, N. Vasilev, J. Mitev, Tch. Miteva, I. Marinov, M. Stojnov

Genetics and Breeding

Date of ear emergence: a factor for notable changing the grain yield of modern winter wheat varieties in different environments of Bulgaria
N. Tsenov, T. Gubatov, I. Yanchev

Grain quality of mutant lines of six-rowed barley
B. Dyulgerova, N. Dyulgerov

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

Nutrition and Physiology

Seasonal variations in hematological profile of Holstein dairy cows as an indicator for physiological status assessment
M. Mekroud, N. Arzour-Lakehal, N.A. Ouchene-Khelifi, N. Ouchene, A. Titi, A. Mekroud

Utilization of Corchorus olitorius leaf as binder in the diet of Oreochromis niloticus fingerlings
I.O. Oke, E. O. Adeparusi, A.A. Dada

Production Systems

Fuel consumption of a machine-tractor unit in direct sowing of wheat
G. Tihanov, N. Ivanov

Productivity and quality of experimental sunflower hybrids in climatically different years
M. Drumeva

Length-weight relationship of European catfish (Silurus glanis L.) fry reared at different stocking densities under controlled conditions
V. Krasteva, M. Yankova

Agriculture and Environment

Influence of long-term fertilization and environments on test weight of durum wheat (Triticum durum Desf.) grain
G. Panayotova, S. Kostadinova, S. Stefanova-Dobreva, A. Muhova

Productivity and feed quality of Sudan grass (Sorghum sudanense (Piper) Stapf.) and sweet sorghum forms
S. Enchev

Physiological responses of Vicia faba to copper toxicity
S. Benouis, H.A. Reguieg Yssaad, E.H. Bouziani, I. Khedim

Assessment of morphological variations in wild populations of Nile tilapia from South West Nigeria
O.M. Popoola, A. Ebiwonjumi

Product Quality and Safety

Main parameters of essential oil of two species from genus Pelargonium, cultivated in laboratory conditions
V. Badzhelova

Isolation and characterization of Lactobacillus microflora from homemade white sheep’s milk cheeses during ripening
S. Stojanovski, G. Cilev, B. Trajanoska

Nutritional and functional attributes of raw and grilled crabmeat
R.O. Moruf, M.A. Taiwo, Q. Adebayo

Agricultural Economics

Non-parametric decomposition of total factor productivity growth in yam production in North-Central Nigeria
R.G. Isonguyo, M.A Ojo., A.J. Jirgi, E.S. Yisa

Economic values of productive and functional traits in sheep of Bulgarian dairy synthetic population
S. Slavova, S. Laleva

Cover

Contents

Title Page