Vol. 9, Issue 10, Part E (2025)

The present study was undertaken to evaluate the effect of dietary supplementation of essential oils of Mentha piperita (MPEO), Cymbopogon citratus (CCEO) and prebiotic mannan oligosaccharides (MOS) on growth performance and morphometric traits of crossbred calves. A total of 30 crossbred calves (15-90 days old) were selected and randomly allotted to five treatment groups with six animals each. The trial was conducted for a period of 90 days at the Instructional Dairy Farm, College of Veterinary and Animal Sciences, G.B.P.U.A&T Pantnagar, Uttarakhand. The treatments comprised: T₀ (basal feed), T₁ (basal feed + MPEO @ 0.2% of calf starter), T₂ (basal feed + CCEO @ 0.2% of calf starter), T₃ (basal feed + MOS @ 6 g/calf/day), and T₄ (basal feed + MPEO @ 0.1% + CCEO @ 0.1% of calf starter + MOS @ 3 g/calf/day). Calves were maintained in individual pens under uniform housing and feeding conditions, and body measurements along with body weights were recorded at fortnightly intervals. Results indicated that body length, height at withers, and hip height did not differ significantly among groups. However, heart girth was significantly (p<0.01) improved in T₂ and T₄, while paunch girth increased significantly (p<0.05) in T₂ and T₄ compared to the control. Supplementation of essential oils (MPEO, CCEO) and MOS significantly enhanced growth performance in crossbred calves, with the highest body weight, fortnightly and average daily gain observed in the combined supplementation group (T₄). Supplementation of C. citratus EO, alone or in combination with M. piperita EO and MOS, positively influenced growth and body morphometric traits of crossbred calves, indicating their potential as effective natural growth-promoting feed additives.