title: Effect of dietary nutrient density and vitamin premix withdrawal on performance and meat quality of broiler chickens.
abstract: BACKGROUND
  The objective of this study was to evaluate the effects of feeding high- and low nutrient density diets, and three different vitamin premix withdrawal regimes on broiler performance and meat quality. Male broiler chicks (480 days old) were reared on the floor in a 2 × 3 factorial arrangement for 42 days. Chickens were slaughtered at 42 days of age and meat samples kept at -20 ± 1°C and analysed after 1, 90 and 180 days of storage.
  
  
  RESULTS
  Broiler performance was significantly affected by dietary nutrient density. Vitamin premix withdrawal had no significant effect on body weight. The results showed no significant differences between nutrient density and vitamin premix withdrawal on lightness (L*), redness (a*) and yellowness (b*). Oxidative stability of thigh muscle lipids during frozen storage was significantly affected by nutrient density, while vitamin premix withdrawal had no significant impact on lipid oxidation. High nutrient density diet led to a significantly (P < 0.05) decreased pH compared with the low nutrient density diet.
  
  
  CONCLUSIONS
  Increasing dietary nutrient density improved broiler performance but impaired meat quality while vitamin premix withdrawal during finisher periods had no negative effect on broiler performance and meat quality.
authors.affiliation: Faculty of Animal Science, Gorgan University of agricultural Sciences and Natural Resources, Gorgan 4918943464, Iran. reza_mirshekar@yahoo.com
authors.forename: Reza
authors.initials: R
authors.lastname: Mirshekar
authors.forename: Behrouz
authors.initials: B
authors.lastname: Dastar
authors.forename: Bahareh
authors.initials: B
authors.lastname: Shabanpour
authors.forename: Saeed
authors.initials: S
authors.lastname: Hassani
mesh_terms: D000822:Animal Husbandry; D000818:Animals; D002645:Chickens / Q000254:growth & development* / Q000378:metabolism; D004032:Diet / Q000662:veterinary*; D004041:Dietary Fats / Q000032:analysis; D002149:Energy Intake; D063427:Food Quality; D061353:Food Storage; D005628:Frozen Foods / Q000032:analysis; D006863:Hydrogen-Ion Concentration; D007492:Iran; D050356:Lipid Metabolism; D008297:Male; D008460:Meat / Q000032:analysis*; D018482:Muscle, Skeletal / Q000254:growth & development* / Q000378:metabolism; D010084:Oxidation-Reduction; D010858:Pigmentation; D013997:Time Factors; D014815:Vitamins / Q000008:administration & dosage / Q000378:metabolism*; D015430:Weight Gain
chemical_list: D004041:Dietary Fats; D014815:Vitamins
keywords: broiler performance; meat quality; nutrient density; vitamin premix withdrawal