Research On Animal Production

  This study was carried out to determine the effects of supplementing fish oil and thyme extract on dry matter, organic matter and nutrient digestibility, chewing activity and rumen metabolites in Mahabadi goat kids. For this aim, twenty-eight Mahabadi goat kids (average initial BW of 17/8 +- 2/8 kg, 4-5mo) were randomly assigned to four treatments: 1) control (basal diet), 2) supplemented with 0.2% thyme extract , 3) supplemented with 2% fish oil and 4) supplemented with 0.2% thyme extract and 2% fish oil. Animals were kept in individual pens with self-mangers for 94 d. Addition of fish oil decreased NDF digestibility (P=0.01) and increased EE digestibility (P=0.05) versus the control. Ruminal ammonia concentration decreased by thyme extract (P=0.05). Addition of thyme increased acetate concentration (P=0.09) and acetate to propionate ratio (P=0.07). It was found that diets 2 and 3 significantly decreased protozoa count compared with diet 1 (P=0.05). Time to eat (minutes per day) was not affected by treatments, but chewing time significantly decreased by with thyme essence (P<0.05). The results of this experiment indicate that supplementation of goat kid diet with fish oil and thyme extract decreased NDF digestibility and increased EE digestibility and increased rumen acetate concentration.