Effect of vitamin and trace mineral withdrawal from finisher diets on growth performance and immunocompetence of broiler chickens.
The present study was carried out to examine the effect of vitamin (V) or trace mineral (TM) mix removal from finisher diet (42-56 d of age) on performance and immunocompetence of broilers. The dietary treatments were: (1) the basal diet with no supplemental V or TM; (2) the basal diet fortified with V mix only; (3) the basal diet fortified with TM mix only; and (4) the basal diet fortified with V and TM mix. At 47 d, four birds from each replicate (20/treatment) were injected with Newcastle disease (ND) antigen and blood samples were collected just before and 9 d after immunisation. The results showed that V and TM mix withdrawal from finisher diet did not impair either weight gain or feed conversion efficiency from d 42 to 56. Feed intake was significantly increased when both mixes were omitted from the diet. Dietary treatments had no effect on carcase yield or proportion of breast and thigh meat and abdominal fat deposition. Packed cell volume (PCV) significantly decreased as a consequence of removal of V, TM and V+TM. Neither heterophil:lymphocyte ratio (H:L ratio), haemagglutination inhibition (HI) nor total antibody titre measured by ELISA were influenced by removal of V or TM supplements. In conclusion, the results from this study suggest that 14-d withdrawal of V or TM mix did not influence the immunocompetence of broilers.
Khajali
F
F
Department of Animal Science, Shahrekord University, Shahrekord 88186-34141, Iran. khajali@agr.sku.ac.ir
Khoshoei
E Asadi
EA
Moghaddam
A K Zamani
AK
D000821:Animal Feed; D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D000917:Antibody Formation / Q000187:drug effects / Q000502:physiology; D002645:Chickens / Q000254:growth & development* / Q000276:immunology*; D004198:Disease Susceptibility / Q000662:veterinary; D004305:Dose-Response Relationship, Drug; D005527:Food, Fortified; D006385:Hemagglutination Inhibition Tests / Q000662:veterinary; D006400:Hematocrit / Q000662:veterinary; D007121:Immunocompetence / Q000187:drug effects*; D008214:Lymphocytes / Q000097:blood / Q000187:drug effects; D008297:Male; D008903:Minerals / Q000008:administration & dosage*; D009521:Newcastle Disease / Q000453:epidemiology; D009522:Newcastle disease virus / Q000472:pathogenicity; D011201:Poultry Diseases / Q000453:epidemiology; D011897:Random Allocation; D014131:Trace Elements; D014815:Vitamins / Q000008:administration & dosage*; D015430:Weight Gain / Q000187:drug effects
D008903:Minerals; D014131:Trace Elements; D014815:Vitamins