Effect of Supplementation of Herbal Products as Feed Additive on Rumen Metabolites in Marwari Goats

Achieving the optimum production at a minimum cost with little or no adverse effects on the environment is the indicative of successful animal production (Wanapat et al., 2013). Small ruminants such as goats play an important role in the agricultural systems particularly in the economics of developing countries (Handekar et al., 2010). Goats are farmed throughout the world for being important source of milk, meat, fibre as well as of proteins along with their capability of adapting in different environmental conditions (Bhardwaz et al., 2018). The overall performance of ruminants is influenced by the type and amount of feed supplementation (Ngwa et al., 2003), depending on the digestibility of feed and rumen fermentation characteristics. An adequate supply of nutrients for livestock is very difficult to the livelihoods of millions of people across the developing world due to large deficiency of feed and fodder. Frequent natural disasters such as droughts and floods further widen the gap between demand and supply of feed and fodder. Due to this reason, animals are mainly fed on such inferior quality feed or by products, which are low in energy and essential nutrients. Therefore, it is desirable to maximize the utilization of nutrients from available feed stuffs either by utilizing complete feed system or by using various feed additives (Manju et al., 2013). The growing public awareness over chemical residues in animal products and threats of antibiotic-resistant bacteria have renewed interest in exploring safer alternatives to chemical feed additives in ruminant livestock (Sachan et al., 2014). Since synthetic antibiotics as feed additives were banned by the European Union in 2002 (Russell and Houlihan, 2003), scientists have been diverted their interest in evaluating the potential of natural antimicrobials, such as herbs and plant extracts, which have been used for many years for various purposes in human diets. Among non antibiotic feed additives, the herbs or herbal preparations have a huge potential to alter ruminal fermentation and improve nutrient utilization in ruminants. Bioactive compounds (e.g. thymol, cinnamaldehyde, cineol, methyl eugenol, anethol, allicin etc.) present in herbs have been used as immunomodulator to prevent diseases, enhance performance in stress related syndromes and increase resistance against infection (Anjali Kumari et al., 2018). A symbiotic relationship has been found between ruminants and the microbes present in their gut. These microbes in the rumen are responsible for carbohydrates fermentation to produce volatile fatty acids (VFAs), which be responsible for more than half of the total metabolisable energy provided to ruminants. VFAs are weak acids, they disintegrate in the rumen and thus, releasing protons that reduce the pH (Penner et al., 2009). Administration of feed additives altered rumen microbial activity which leads to alteration in fermentation process and in turn increase feed utilization efficiency. So, the objective of present study was to ascertain the effect of various herbal products supplementation on the rumen fermentation pattern by estimating various rumen parameters.

The study was carried out in the Department of Animal Nutrition, College of Veterinary and Animal Sciences, Bikaner. Twenty male Marwari goats of same breed, age group (18-24 months) and of uniform conformation were divided on body weight basis into 5 groups (T₁, T₂, T₃, T₄ and T₅) of four animals in each group. Groups were T₁ (Complete feed without herbal product), T₂ (Complete feed + Himalayan Batisa @ 10 mg/g substrate), T₃ (Complete feed + Appetonic Vet powder @ 10 mg/g substrate), T₄ (Complete feed + Ruchamax @ 3 mg/g substrate) and T₅ (Complete feed + Rumizyme powder @ 7.5 mg/g substrate). The concentration of each herbal product was selected on the basis of their in vitro results. Animals were housed in well ventilated, hygienic and protected sheds and were allowed to acclimatize for a period of 10 days prior to experimental feeding. The animals were given prophylactic doses of Fenzole as anthelmintic. The complete feed was prepared with wheat straw as basal roughage source and concentrate in ratio of 60: 40. The animals were given measured quantity of experimental feed and ad lib water every morning.
        
At the end of feeding trial of 28 rumen liquor sample were collected from each animal at 0, 2, 4, 6, 8, 12 and 18 h post feeding with the help of Ryle’s tube introduced through the wooden mouth gag in the rumen against a negative pressure created by the suction pump.
        
Rumen fluid pH was determined immediately after collection using portable digital pH meter (pen type) at the site of collection. After pH determination one ml of saturated HgCl₂ solution was added to each collected sample to kill the microbes and to stop metabolic activity. Rumen liquor was strained through four layers of muslin cloth and referred as strained rumen liquor (SRL). The strained rumen liquor (SRL) was brought to the laboratory in a pre-warmed (39°C) thermos flask and stored in refrigerator. Total volatile fatty acids (TVFA) were determined according to the method of Barnett and Reid (1957) using Markham still distillation apparatus. Total protozoal count of the SRL was done by the method of Moir and Somers (1956) adopted by Purser and Moir (1959) using Sedgewick Rafter Cell (50 × 20 × 1 mm) in 10 × 10 magnification. Rumen ammonia nitrogen in SRL was estimated by Conway’s micro diffusion method (1957) using Conway diffusion cell. Total nitrogen was estimated by Kjeldahl method. 5 ml of rumen liquor was precipitated with 5 ml of 20 per cent trichloroacetic acid and kept overnight in refrigerated condition. Next day after centrifugation at 2000 rpm for 10 minutes, the whole supernatant was transferred in Kjeldahl’s digestion tube and nitrogen was estimated. The value thus obtained is reported as non protein nitrogen (NPN) and the difference of above two is reported as TCA precipitable nitrogen. The data obtained in the experiment were analyzed using statistical procedures as suggested by Snedecor and Cochran (1994). Significance of mean differences was tested by Duncan’s New Multiple Range Test (DNMRT) as modified by Kramer (1957).

TVFA  
Ruminal pH was unaffected by the dietary herbal product supplementation (Table 2). Table 2 showed significant higher values of TVFA concentration were recorded in Himalayan Batisa (T₂) (86.57 mEq/l) and Ruchamax (T₄) (85.65 mEq/l) followed by Appetonic Vet powder (T₃) (83.66 mEq/l) and Rumizyme powder (T₅) (83.57 mEq/l) added groups. The results were in consensus with Singh et al., (1992) and Bhatt and Singh (2009) who reported an increase in the TVFA concentration in the strained rumen liquor of animals feeding with different herbal products viz., Himalayan Batisa, Haryana Batisa, Digestovet, Rumbion bolus, Ruchamax and Payapro. The findings were also in agreement with Sardar et al., (1997), Manjunatha (1998), Pankaj et al., (2008), Ahirwar et al., (2009) which might be due to regeneration of VFA producing bacteria by adding polyherbal formulations in the diet.
 

 
Total protozoal count
 
Effect of herbal products supplementation on total protozoal count revealed that supplementation decreased (p<0.05) total number of protozoa in rumen with non significant differences among supplemented groups. Rejil et al., (2008) and Amanullah et al., (2009) also observed decrease in rumen protozoal number in cattle on feeding Fenugreek seed and Sapindus mukorrossi, Camelia sinensis and Acacia concinna as feed additive. Ando et al., (2003) also found decrease in rumen protozoal numbers in steers fed peppermint as additives.
 
Ammonia nitrogen
 
The concentration of ammonia nitrogen in herbal product supplemented group decreased significantly as compared to control group and indicated reduction in concentration of ammonia nitrogen in rumen liquor on herbal product supplementation (Table 2) with maximum in Himalayan Batisa (T₂) followed by T₄, T₃ and T₅ treatment groups. The reduced level of ammonia nitrogen of herbal product supplementation may not be associated with decreased dietary protein degradation or deamination but appears to be related with increased uptake and assimilation of ammonia nitrogen by rumen microbes due to stimulation of bacterial growth by herbs. Ando et al., (2003) and Manjunatha (1998) also observed non-significant rise in ammonia nitrogen on feeding herb as bio stimulator which might be due to faster rate of ammonia metabolism and conversion into microbial proteins. Similarly, Hosoda et al., (2006) also reported that clove feeding to Holstein Steers as feed supplement tended (P<0.01) to decrease the ammonia nitrogen concentration compared with those in the control group. Likewise, Bhatt and Singh (2009) also found a decrease in concentration of rumen ammonia nitrogen in Ruchamax and Payapro herbal products supplemented group of cattle.
 
Total rumen nitrogen
 
The concentration of total rumen nitrogen obtained for animals fed on various herbal product supplemented and un-supplemented complete feed irrespective of time of sampling were higher values in herbal products supplemented groups as compared to control group (Table 2). Among supplemented groups T₂ showed significantly highest concentration of ruminal nitrogen and T₅ showed lowest concentration.
 
TCA-precipitable nitrogen  
 
Table 2 showed that TCA-precipitable nitrogen concentration was significantly higher in herbal products supplemented groups. This might be due to increased utilization of ammonia nitrogen by rumen microbes for microbial protein synthesis. Bhatt and Singh (2009) also observed an increase in the concentration of TCA precipitable nitrogen in animals feeding with Ruchamax and Payapro.
 
Non protein nitrogen
 
 A non significant effect in non protein nitrogen concentration on supplementation of herbal products was shown in Table 2. Rani et al., (2006) also reported similar findings of no effect on non protein nitrogen concentration on supplementation of herb.

Based on the results of present study, it may be concluded that supplementation of herbal products viz., Himalayan Batisa, Appetonic Vet powder, Ruchamax and Rumizyme powder as a feed additive have beneficial effect on rumen fermentation pattern of goat. It is revealed that supplementation of herbal products can also be used as a part of strategy to be adopted to improve productivity of goats in arid and semi-arid region and to have lucrative goat farming.