An experiment was conducted to investigate the effects of thyme (Thymus vulgaris) and satureja (Satureja khuzestanica) ethanolic extracts on the performance, blood metabolites and immune response of broiler chickens. 300 day-old Ross chicks were assigned to six dietary treatments in a randomized 2 × 3 factorial block design. Each treatment was given to five replicates of ten birds. Variables were T. vulgaris extract (0% or 1%) and S. khuzestanica extract (0%, 1% or 2%) in drinking water. Body weight (BW), feed intake (FI) and feed conversion ratio (FCR) was recorded at the end of the experiment. Serum glucose, total protein (TP), triglycerides (TG), low-density lipoprotein cholesterol (LDL-ch) and high-density lipoprotein cholesterol (HDL-ch) were measured after blood sampling at 42 days of age. Specific IgG and IgM against sheep red blood cells (SRBC) were quantified six days after the injection of SRBC into breast muscle on day 23 and day 30. The plant extracts did not affect BW, FI or FCR, or the relative weights of the cloacal bursa, spleen or thymus gland (P>0.05). S. khuzestanica extract increased TG, total cholesterol and HDL-ch (P<0.05). The plant extracts did not affect the humoral immune response against SRBC (P>0.05). However, 2% S. khuzestanica extract alone, or 1% T. vulgaris extract alone or in combination with 1% S. khuzestanica extract increased the heterophil percentage (H) and heterophil:lymphocyte ratio (H/L) (P>0.05), while it diminished the lymphocyte percentage (L) (P>0.05). Breast meat pH, redness (a*), yellowness (b*) and lightness (L*) were not affected by dietary treatments. However 2% and 1% S. khuzestanica extract respectively decreased thigh meat’s pH 24 h postmortem and its a* and b* values (P<0.05). 1% T. vulgaris extract, and 1% and 2% S. khuzestanica extract, increased pH in breast meat (P<0.05). It was concluded that under these research conditions, low levels of these extracts decreased H and H/L and may be beneficial to broiler chickens’ immunity. Manuscript profile

An experiment was conducted to investigate the effect of zinc (Zn) supplementation and different concentrations of calcium (Ca) and phosphorus (P) in wheat-based diets on the performance, immune responses and bone parameters of broiler chickens. A randomized complete block design with factorial arrangement was used (three concentrations of Zn supplementation×two concentrations of dietary Ca-P), 300 day-old broilers were assigned to six dietary treatments with five replicates of ten birds. Dietary treatments were the basal diet (control; TRT1), control plus 50 ppm Zn (TRT2), control plus 70 ppm Zn (TRT3), low Ca-P diet (0.60 to 0.30%; TRT4), low Ca-P diet plus 50 ppm Zn (TRT5) and low Ca-P diet plus 50 ppm Zn (TRT6). Ca and P in the control diet were 0.90 and 0.45% in the grower phase and 0.85 and 0.42% in the finisher phase. Changes in dietary Ca-P had no effect on body weight gain (BWG), feed intake (FI), feed conversion ratio (FCR) or serum Ca and P concentrations (P>0.05) whereas Zn supplementation increased FI (P<0.05). The addition of 50 ppm Zn increased serum P concentration (P<0.05) and dietary treatments had no effect on antibody titers against sheep red blood cells (SRBC) (P>0.05). The lowest blood heterophil (H) and the highest lymphocyte (L) percentages and lowest H:L ratio were observed in birds fed with the diet containing a standard Ca-P with 70 ppm Zn supplementation (P<0.05). Dietary treatments had no effect on bone length, thickness and breaking strength (P>0.05). Tibia and fibula ash decreased by feeding lower Ca-P than the standard diet (P<0.05). It is concluded that low Ca-P diets did not have a detrimental effect on performance or blood and bone parameters and that Zn supplementation did not improve those parameters when feed was low in Ca-P. Manuscript profile