title: Effect of probiotics and thyme essential oil on the essential amino acid content of the broiler chicken meat.
abstract: BACKGROUND
  Differences in the types and percentages of essential amino acids (EAAs) in food could influence the value of protein consumed and proteins with a high content of EAAs are the most important components of poultry meat. The use of probiotics for meat and carcass quality improvement has been questioned, while feed supplementation with thyme essential oil (TEO) could be considered as useful natural supplement to be applied in the poultry industry to improve meat quality.
  
  
  METHODS
  Day-old broilers Ross 308 (n = 400) were randomly divided into four groups based on the feed supplement as follows: control, probiotics 0.05%, TEO 0.05% and combination of probiotics and TEO, while the fattening period was 42 days. Six birds of both sexes from each group were selected as a sample, slaughtered and then stored (-18°C) for 6 months till the analysis. The muscular homogeneous sample (50 g) from the breast and thigh of each sample bird was analysed by the Fourier Transform Infrared Spectroscopy method using the device Nicolet 6700. The essential amino acids content was determined and the quality indicators include chemical score, amino acid score, EAA index and biological value were calculated.
  
  
  RESULTS
  The obtained results show that for all the tested EAAs of the breast and thigh muscles, the content numerically increased gradually and progressively within the groups as the control scored the minimum followed by the probiotics group, then the combination group and finally the TEO group which scored the highest results.
  
  
  CONCLUSIONS
  It can be concluded that the TEO promoted the increase of all the EAAs and consequently the quality indicators with significant different compared with the control group and significantly different for some EAAs and quality indicators compared with the probiotics group and the combination group.
authors.affiliation: Department of Food Hygiene and Safety, Slovak University of Agriculture in Nitra, Slovak Republic.|Department of Food Science and Technology, Sudan University of Science and Technology, Khartoum, Sudan.
authors.forename: Ebrahim
authors.initials: E
authors.lastname: Alfaig
authors.affiliation: Department of Food Hygiene and Safety, Slovak University of Agriculture in Nitra, Slovak Republic.
authors.forename: Maria
authors.initials: M
authors.lastname: Angelovičova
authors.affiliation: Department of Food Hygiene and Safety, Slovak University of Agriculture in Nitra, Slovak Republic.
authors.forename: Martin
authors.initials: M
authors.lastname: Kral
authors.affiliation: Department of Animal Husbandry, Slovak University of Agriculture in Nitra, Slovak Republic.
authors.forename: Ondrej
authors.initials: O
authors.lastname: Bučko
mesh_terms: D000601:Amino Acids, Essential / Q000378:metabolism*; D000821:Animal Feed; D000822:Animal Husbandry; D000818:Animals; D002645:Chickens; D019587:Dietary Supplements; D005260:Female; D008297:Male; D008460:Meat / Q000032:analysis*; D018482:Muscle, Skeletal / Q000378:metabolism*; D009822:Oils, Volatile / Q000494:pharmacology*; D010936:Plant Extracts / Q000494:pharmacology*; D019936:Probiotics; D046930:Thymus Plant / Q000737:chemistry*
chemical_list: D000601:Amino Acids, Essential; D009822:Oils, Volatile; D010936:Plant Extracts
keywords: EAA index; Fourier transform infrared (FTIR) spectroscopy; Ross 308; amino acids; broilers; probiotics; thyme oil