Natural feed additives: Effects of essential oils and mannan oligosaccharides on growth performance and morphometric traits of crossbred calves

Abstract

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