Impact of Dietary Phytogenic Composite Feed Additives on Immune Response, Antioxidant Status, Methane Production, Growth Performance and Nutrient Utilization of Buffalo (Bubalus bubalis) Calves

Abstract

The focus on the bioactive effects of plants concerns mainly ruminal microflora for the modulation of rumen fermentation with very little emphasis placed on their consequences on health parameters, including antioxidative and immune stimulating effects. The aim of the present study was to examine the effects of supplementing phytogenic feed additives composed of a mixture of eucalyptus (Eucalyptus citriodora) and poplar (Populus deltoides) leaf-meal (EPLM) on immune response, antioxidant status, metabolic profile, enteric methane production, growth performance, and nutrient utilization in buffalo (Bubalus bubalis) calves. In vitro studies with graded doses of EPLM extract revealed a reduction in total gas and methane production with an increased proportion of propionate without affecting feed degradability. In the in vivo experimentation, eighteen female buffalo calves (10–14 months old, avg. body weight 131.68 ± 7.50 kg) were divided into three groups (CONT, EPLM-1, and EPLM-2) of six each in a completely randomized design. Treatment groups were supplemented with a blend (1:1) of dry grounded eucalyptus (Eucalyptus citriodora) and poplar (Populus deltoids) leaves (50 g, EPLM-1; 150 g, EPLM-2). Feed intake and growth rate of buffalo calves fed on different feeding regimens did not differ (p > 0.05). Haemato-biochemical parameters reveal no variations (p > 0.05) among groups, irrespective of period of collection, except the concentration of blood urea, which was decreased (p < 0.05) in both treatment groups as compared to the control. The levels of reduced glutathione (GSH), catalase (CAT), and superoxide dismutase (SOD) increased (p < 0.05) in EPLM supplemented animals as compared to CONT. The extent of lipid peroxidation (LPO) was reduced (p < 0.05) with increased level of EPLM in the diet. The total thiol group (T-SH) was also increased with the supplementation of leaves in the diet. The mean absolute values for skin thickness following the intra-dermal injection of PHA-P were increased (p < 0.05) in all the supplemented animals relative to CONT. However, there was no significant difference among the calves fed graded levels of these feed additives in the diet. The Ab titer against Pasteurella multocida vaccine was higher (p < 0.05) on both day 45 and 90 in both treatments, irrespective of the level of additive supplemented. The enteric methane production was reduced in EPLM supplemented buffaloes; however, digestibility of all the nutrients remained comparable (p > 0.05) among the animals. It may be concluded that blends of eucalyptus (Eucalyptus citriodora) and poplar (Populus deltoides) leaf-meal (50 g/h/d) containing 3.19 g, 2.30 g, and 0.71 g of total phenolics, tannin phenolics, and condensed tannins, respectively, can be used as the phytogenic feed additive for improving antioxidant status and immunity of buffalo calves, and mitigating enteric methane production without affecting performance and nutrient utilization.

Effect of Oregano (Lippia graveolens) Essential Oil as a Phytogenic Feed Additive on Productive Performance, Ruminal Fermentation, and Antioxidant Activity in Lamb Meat

“…However, there are currently restrictions in many countries on the use of antibiotics as additives, given their risk to public health, which has made it necessary to search for safe alternatives for the consumer [3]. Phytogenic additives, mainly plant extracts (essential oils, oleoresins, and flavonoids), are used as alternatives to antibiotics because they might maintain a healthy gut environment, modulate the microbiota, and sustain rumen fermentation dynamics; they also have antioxidant properties that increase animal production and contribute to the consumer's demand for healthier foods of animal origin [4,5]. Essential oils contain bioactive compounds, mainly terpenoids and phenylpropanoids, which favor the functioning of the digestive system, reduce the growth of pathogenic bacteria, and diminish the oxidation of lipids [6].…”

Antimicrobial Screening and Fungicidal Properties of Eucalýptus globulus Ultrasonic Extracts

“…Rosmarinic acid exhibits antioxidant, antiviral, antibacterial, and antitumor activities [ 45 ]. Some studies have shown that rosmarinic acid has a light protective factor against UV radiation [ 46 ]. Analyzing the obtained data for samples after extraction without US treatment, it can be concluded that extraction for 20 and 25 min will be the most effective.…”

“…Eucalyptus extracts are widely used for the production of phytogenic feed additives [ 46 ]. The natural eucalyptus oils included in the feed additive improve the functioning of the respiratory organs of animals and birds, facilitate breathing, have an antispasmodic, expectorant, anti-inflammatory, vasoconstrictive, analgesic effect, stimulate water and feed intake, improve metabolism and reduce the negative effect of heat stress, have adaptogenic effect under unfavorable environmental conditions and under conditions of extreme stress, reduce the number of post-vaccination complications, and have a moderate antibacterial effect [ 46 ]. The period of extraction with ultrasonic treatment of medicinal plant materials should not exceed 25 min to produce an effective phytogenic feed additive based on E. globúlus (the yield of useful active substances was the highest with strong antiseptic properties).…”

Advances in the Application of Phytogenic Extracts as Antioxidants and Their Potential Mechanisms in Ruminants

“…A large number of studies have been conducted to evaluate the effects of plant extracts on the growth performance, feed efficiency, and antioxidant capabilities of cattle ( Table 2 ). Dietary supplementation with a composite feed additive consisting of a blend (1:1) of eucalyptus ( Eucalyptus citriodora ) and poplar ( Populus deltoids ) leaves containing total phenolics, tannin phenolics, and condensed tannins at two different dose levels (50 g and 150 g/h/d) did not affect growth performance or nutrient digestibility, but it did improve antioxidant status and immunity, and it reduced methane production in buffalo calves compared to a control group [ 84 ]. Regarding the improved immunity of the animals, the authors explained that the probiotic effects of the combined supplementation of both extracts containing essential oils and tannins could indirectly enhance the immune system by inhibiting hyper-ammonia-producing and proteolytic bacteria with the stimulation of Bifidobacterium and Lactobacillus .…”