Compare performance and nutrient digestibility of fattening lambs and kids using different levels of thyme extract

The aim of this study was to investigate the effect of different levels of thyme (Thymus vulgaris) extract on growth performance, feed intake, daily weight gain and digestibility of nutrients in fattening lambs and kids. For this purpose, 15 goat kids (average initial BW of 17.3 ± 1.2 Kg, 3 month- old) and 15 Dalagh lambs (average initial BW of 21.4 ± 1.5 Kg, 3 month- old) were randomly assigned to 3 dietary treatments: 1) control (without thyme extract), 2) supplemented with 250 ml thyme extract, 3) supplemented with 500 ml thyme extract. Animals were kept in individual pens with self-mangers for 84 days. Experimental results showed that different levels of thyme extract had a significant effect on daily weight gain and feed intake throughout the period in both species, so that in animals fed 250 ml of thyme extract was higher than other treatments (P <0.0001). Dietary treatments containing 500 ml of thyme extract had the lowest weight gain and final weight and feed intake throughout the period. Also, lambs had better weight gain and more food intake than kids. Thyme extract reduced the digestibility of organic matter and NDFand increased the digestibility of dry matter (P <0.0001) and the effect of the species on nutrient digestibility was not significant.Overall, the results showed that the best level of thyme extract in animals diets was 250 ml, and at this level the best growth performance was achieved. The lambs were also more affected by the thyme extract than the kids.