The aim of this study was to compare the effects of dietary supplementation of ajwain (Trachyspermum ammi) and thyme (Thymus vulgaris) essential oils(EO)on nutrients digestibility, blood parameters and growth performanceof neonatal dairy calves during eight weeks. Sixty suckling dairy calves with an initial body weight (43.2±3.8 kg) were randomly allocated to five treatments including CO, control without essential oils (EO) supplementation; AJW-L, ajwain (AJW) oil mixed in milk at 1 mL/d per calf; AJW-H, AJW oil mixed in milk at 2 mL/d; THY-L, thyme (THY) oil mixed in milk at 1 mL/d and THY-H, THY oil mixed in milk at 2 mL/d. The experiment consisted of 7 d adaptation and 60 d sampling and data recording period. Experimental diets had no significant effects (P>0.05) on feed intake, average daily gain and feed conversion ratio. Dietary supplementation of both AJW and THY linearly improved (P تفاصيل المقالة

This experiment was conducted to compare the effect of supplementation of milk with thyme (THY) and oregano (ORE) essences separately or a mixture of THY and ORE essences on growth performance, haematological parameters and some blood metabolites of Holstein suckling calves. Forty-eight Holstein calves (48.31±5.82 kg) were randomly allocated to four treatments including (1) control without essential oil supplement; (2) THY oil mixed in milk at 5 mL/d/calf; (3) ORE oil mixed in milk at 5 mL/d/calf; (4) 2.5 mL THY oil + 2.5 mL/d/calf ORE oil mixed in milk (TOM). According to the results, the experimental diets had no significant effect on body weight, average daily gain, and feed conversion rate in the entire experiment (P>0.05), although the parameters of starter and total feed intake were increased (P<0.0001) in the ORE and TOM groups. Values of packed cell volume, haemoglobin, mean corpuscular volume, and lymphocyte percentage were increased (P<0.05) in the ORE group compared with the control. Also, our results demonstrate the supplementation of either oregano or thyme essential oils increased (P<0.05) serum iron concentration, alanine aminotransferase, and aspartate transaminase activities. Concentrations of total cholesterol and total triglyceride were decreased (P<0.05) in calves given both oils compared to the control group. Further confirmation of these results is warranted, and more research is needed to identify and clearly explain in the contribution of oregano or thyme oils (individual or mixtures); however our results suggested that oregano oil might be more useful as the promising feed additive for suckling calves nutrition. تفاصيل المقالة