Growth performance
The data of Body weight change and FCR during 120 days experimental trial on growth performance are presented in Table 3 and 4. Average BW at starting of the study in (C), T1, T2 and T3 groups were 80.3, 80.3, 81.8 and 80.3 kg and at the end of the experiment were 129, 127, 129 and 127 kg respectively. The overall BW (kg) was found to be similar in all the experimental groups. Statistical analysis of data showed that variation between the groups for mean BW change was not significant (P>0.05). The feed conversion ratio of calves at different fortnight is presented in Table 4. The FCR ranged from 6.12 to 8.81, 6.12 to 9.48, 5.70 to 8.10 and 5.48 to 8.74 in C, T1, T2 and T3 groups, respectively. FCR did not differ significantly (P>0.05) between the groups. Similar to our findings,
Kumar (2017) reported no effects on body weight gain in buffalo calves fed a blend of essential oil rich poplar (
Populus deltoids) and eucalyptus (
Eucalyptus citriodora) leaves. There was no difference in the growth performance of steers among the treatments on supplementation of 0.1% allicin (
Ahn et al., 2024).
Bampidis et al. (2005) observed no change in Average Daily Gain (ADG) and feed efficiency when grow lambs were fed diets supplemented with oregano leaves (
Origanum vulgare L.) providing 144 or 288 mg of oregano oil (850 mg of carvacral) per kilogram of diet DM.
Nutrient utilization
Data of apparent nutrient digestibility across six days digestion trial is presented in Table 5 and 6. Statistical analysis of data revealed that variation between the groups for dry matter intake (kg/day) of all the groups during different fortnights of experimental feeding was not significantly different (P>0.05). DMI of control (C), T1, T2 and T3 was 3.12, 3.08, 3.18 and 3.08 kg/d, respectively. The overall DMI (kg/100 kg BW) was also found similar in all the experimental groups. The overall BW (kg) was found similar in all the experimental groups. The mean average daily gain were 410, 413, 416 and 410 g/day in (C), T1, T2 and T3 groups, respectively. The average daily weight gain of all the fortnight were not differ significantly (P>0.05) between groups. FCR of all the fortnight were approximately similar (P>0.05) between groups. The statistical analysis of the data on DM and OM digestibility per cent shows that the differences between the groups are not statistically significant (P>0.05). CP digestibility in calves from four different groups averaged 66.4, 62.4, 64.1 and 69.0 per cent, respectively and nutrients digestibility (CP, CF, EE and NDF) were found similar (P>0.05) among all four groups as mentioned. The experimental calves fed with herbal feed additive and sulfate did not have any significant effect on the DMI and ADG compared to calves in the control group. Digestibility of DM, CP, EE, CF, NFE and NDF were not impacted by supplementation of herbal feed additive and/or sulfate and digestible nutrient intake was found similar in all the experimental groups. Total DMI (kg/day), CP intake (g/day), DCP intake (g/day), TDN intake (g/day) were found similar (P>0.05) in all four, control (C1), T1, T2 and T3 groups as mentioned in table 6. In accordance with our findings,
Lakhani et al. (2019) also reported no effect on nutrient utilization and digestibility by feeding rumen modifiers and sodium sulfate. Similarily,
Wang et al. (2025) also reported no effect on nutrient utilization and digestibility by feeding essential oil. Some researchers have demonstrated improvements in performance with herbal feed additives and sulfate supplementation,
De Souza et al. (2019) supplementated diet with clove and rosemary essential oils and protected oils (eugenol, thymol and vanillin) 4gm/animal/day in Nellore heifers and found there is improved average daily gain, dry matter intake, feed efficiency and ingestive behavior activities.
Saeedi et al. (2017) observed supplementation of fennel seed powder @ 0.4% to the starter diet of Holstein dairy calves improved the feed intake, feed efficiency and growth performance and allowed the calves to be weaned at an early age.
The present study result has no effect on nutrient utilization and growth performance, it may be due to the lower doses of herbs and sulfate in the treatment groups.