The Effect of Adding Different Levels of Valine in Low Protein Diets on Performance, Blood Parameters and Tibial Bone Properties of Ross-308 Broiler Chickens from 8-21 Days

The present research was performed to evaluate the effect of different levels of valine in low protein diets on performance, blood parameters and tibia bone properties of Ross-308 broiler chickens from 8-21 days.

For this purpose, a total of 200 one-day-old male broilers of Ross-308 strain from 8 to 21 days of age in 4 treatments and 5 replications with 10 birds per replication were used. The experimental treatments were adjusted based on nutritional Brazilian Tables (2011) and included: control, recommended level of valine in the diet with 2% diluted crud protein, 10% more than the recommended level of valine in the diet with 2% diluted crud protein and 20% higher than the recommended level of valine in the diet with 2% diluted crud protein. Further performance traits (weight gain, feed intake and feed conversion ratio), biochemical blood parameters (triglycerides, cholesterol, total protein, albumin, superoxide dismutase, glutathione peroxides, urea and uric acid) and bone characteristics (ash, calcium and phosphorus) were measured. Statistical analysis of data in the form of a completely randomized experimental design was analyzed of variance and mean comparison test with SAS software.

The results of the present study showed that the treatment containing 10% more than the recommended level of valine in the diet with 2% diluted crud protein increased the more weight (721.8 g/b) of chickens in growth period (p<0.05). Reduction of dietary crude protein, reduced feed intake (1013.8) during the growing period (p<0.05). Supplementation of 10% more than the recommended level of valine, increased blood superoxide dismutase density (164.8 U/gr Hb). Consumption of 20% more than the recommended level of valine increased blood glutathione peroxides density (172 U/gr Hb) (p<0.05). High dietary protein (control) increased blood urea and uric acid and also increased litter nitrogen (p<0.05). It seems that the addition of valine in low crude protein diets, improved performance and increased blood antioxidant capacity (p<0.05). The 20% more than the recommended level of valine in the diets, increased the calcium density (29.3%) in the bone tibia of broiler chickens (p<0.05).

In generally, according to the results obtained in this experiment, the addition of valine in low protein diets improved performance and increased blood antioxidant capacity and increased calcium and phosphorus absorption in bone.