The effects of different levels of pennyroyal (Menta pulegium L.) and vegetable oils blend on performance, egg quality, blood biochemical and immunity parameters of laying hens

This experiment was conducted to evaluate the effects of different levels of pennyroyal and vegetable oils blend (soybean, sunflower and cotton seed oils) on performance, egg quality, blood biochemical and immunity parameters of laying hens. The experiment was carried out as a factorial (3×3) (0, 1, 2% pennyroyal) and (0, 2.5, 5% vegetable oils blend) in a completely randomized design (CRD) with 324 of Hi-line (W36) laying hens with nine treatments and three replicates (and twelve hens in each replicate) for a period of 12 weeks during weeks 25-37 of hen ages. Results indicated that the use of different levels of pennyroyal and vegetable oils blend had significant effects on performance, egg traits and blood biochemical parameters of laying hens (P<0.05). The highest egg production percent, highest egg mass and the highest amount of daily feed intake were resulted by using 1% pennyroyal. The lowest amount of daily feed intake was observed by using diet with 5% of vegetable oil blend whereas the highest amount of daily feed intake was obtained with no use of vegetable oil blend. The lowest amount of egg specific gravity and lowest eggshell softness were observed by using 2% pennyroyal. The lowest eggshell softness was obtained by using 5% vegetable oils blend and the highest eggshell softness was recorded by using 2.5% vegetable oils blend. The highest levels of triglyceride and uric acid were resulted by using 1% pennyroyal. Using different levels of nettle and vegetable oils blend had no any significant effects on immunity parameters of laying hens. There were no any interaction effects between nettle and vegetable oils blend levels on performance, egg traits, blood biochemical parameters and immunity levels of laying hens.