Effect of Herbal Feed Additives and Sulfate Supplementation on Growth Performance and Nutrient Utilization of Cattle Calves

India possesses one of the largest populations of ruminants in the world which have an important role in the sustainability of livestock farmers and many cases are the major source of income for small and marginal farmers. These farmers rely on subsistence farming, with few or no inputs, where poor quality forages are usually available and provide the sole source of nutrition to the animal. 
 
Currently, the livestock sector’s main challenge is providing essential nutrients through feed supplementation to promote health and production to the optimum genetic potential level. Digestibility of roughages like straws is very poor, so these plant secondary metabolites (PSM) like tannin, saponin and essential oils can improve the digestibility. Essential oils (EOs) are among the most economically relevant plant-derived products, being frequently responsible for several species’ health-promoting properties (Mushtaq  et al., 2018). Microbial digestion in the rumen can be improved by using feed additives. Some additives could drive the fermentation reactions toward the formation of more efficient products by acting on the balance of the microbial population. Antibiotics have been widely used in the past as microbiota regulators. However, their use as feed additives has been banned in the EU since 2006. In this context, EOs could offer some new opportunities to replace antibiotics. EOs present a high affinity for the membrane cell of bacteria due to their hydrophobic nature and their affinity for lipids which can disrupt the cytoplasmic membrane either directly or by damaging the membrane proteins, provoking increased membrane permeability, conformational changes, leakage of cytoplasmic components, interfering with bacterial growth and activity, causing changes in the rumen population and fermentation profile. They are volatile constituents of terpenoid or non-terpenoid origin which impair the energy metabolism of archaea and have shown reductions of up to 26% in enteric methane emissions in ruminants (Patra and saxena, 2009). Fennel seed also has antimicrobial activity (Bhaisare  et al., 2015). Due to the adverse effects on feed digestion and fermentation at high doses, a single EO may not effectively and practically mitigate methane emissions from ruminants unless used at low doses in combination with other antimethanogenic compounds. Therefore, it seems that sulphate (efficient electron acceptors) along with plant secondary metabolites can act as rumen modifiers to mitigate methane production and improved nutrients utilization. 
 

Therefore, in the present study, a combination of herbal feed additive and sulfate is proposed to test in in vivo trial for their effect on nutrient utilization and the performance of calves.

Selection of experimental animals, dietary treatment and experimental design
 
Twenty four growing cattle calves (12 male Hariana calves, 8 male Sahiwal calves and 4 female Sahiwal calves) were selected from the herd maintained at Livestock Farm Complex (LFC), DUVASU Mathura (Uttar Pradesh) India. Animal care procedures were approved (approval number IAEC/22/2/18) and conducted under the established standard of the Institutional Animal Ethics Committee (IAEC), constituted as per article number 13 of the Committee for Control and Supervision of Experiments on Animals (CPCSEA) rules laid down by the Government of India. Calves with were divided into four groups (six animals each) in a randomized block design. The four groups of calves with were allotted to different treatments. Control (C) group was not supplemented with any extra things other than the present in the basal diet, T1 group were supplemented with herbal feed additive (Fennel + CLO; @ 1.0% of DMI), T2 groups were supplemented with sulfate @ 0.075% of DMI and group T3 were supplemented with diet containing herbal feed additive (Fennel + CLO; @ 1.0% of DMI) and sulfate @ 0.075% of DMI. Feeding was done as per ICAR (2013) to meet the requirement for an average daily gain (ADG) of 500 grams. The basal diet offered to experimental groups contains 40% concentrate and 60% wheat straw. The experiment was continued for 120 days where all the calves were managed under similar conditions.
     
A digestion trial of six days was conducted on all the experimental animals after 120 days of experimental feeding. During the digestion trial, daily faeces voided, feed offered and residues left were recorded. 24h faecal output of each animal was quantified and 25% of the voided faecal sample was dried in forced draught hot air oven at 60^oC. The dried faecal sample of individual animals of each day of six day collection period was bulked, sampled and ground in a hammer mill to pass through 2 mm sieve. The ground sample were stored in airtight bottles until required for chemical analysis. The growth trial lasted for 120 days during which feed intake was recorded daily for each calf. Calves’ body weight was recorded for two consecutive days fortnightly immediately before offering feed and water and these values were used to determine body weight gain. The feed offered, residues left and feces voided were analyzed for DM by drying at 100^oC for 24 h, OM by ashing at 550^oC for 3 h and CP by Kjeldahl technique, NDF was measured by the methodology of Van Soest  et al. (1991). Ingredients and chemical composition of the basal diet fed during the experimental period are analyzed by AOAC (2005) and presented in Table 1 and 2.  





 All statistical analyses were performed as per standard method by using SPSS computer package (SPSS Version 20.0, SPSS Inc, Chicago, USA). The data obtained were statistically analyzed by using one-way ANOVA procedures. Tukey’s Honest Significant Difference test was used to evaluate significant differences between means of treatments. The difference between means was declared significant at P<0.05.

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.

From this study, it can be concluded that Dietary supplementation of herbal feed additive (Fennel + CLO; @ 1.0% of DMI) and sulfate @ 0.075% of DMI have no significant (P>0.05) effect on BW, ADG, FCR, intake and digestibility of nutrients, indicating it may be used as alternate electron acceptor and rumen modifier in high roughage-based ration as it does not have harmful effect on growth and nutrient utilization on cattle calves.
 

Financial assistance for the present study was provided under University Grant supported by Indian Council of Agricultural Research, New Delhi, India. We are thankful to the faculty and staff of the Department of Animal Nutrition and Livestock Farm Complex, College of Veterinary Science and Animal Husbandry, DUVASU, Mathura, Uttar Pradesh, India.
 
Disclaimers
 
The views and conclusions expressed in this article are solely those of the authors and do not necessarily represent the views of their affiliated institutions. The authors are responsible for the accuracy and completeness of the information provided, but do not accept any liability for any direct or indirect losses resulting from the use of this content.
 
Informed consent
 
All animal procedures for experiments were approved by the Committee of Experimental Animal Care and handling techniques were approved by the University of Animal Care Committee.

The authors declare that there are no conflicts of interest regarding the publication of this article. No funding or sponsorship influenced the design of the study, data collection, analysis, decision to publish, or preparation of the manuscript.