The Potential Effect of Dietary Tannins on Enteric Methane Emission and Ruminant Production, as an Alternative to Antibiotic Feed Additives – A Review

Effect of Jackfruit Leaf Extract (Artocarpus heterophyllus) on Sitophilus oryzae Mortality and Rice Quality

Sitophilus oryzae is an insect pest known for its destructive impact on rice crops. Chemical pesticides continue to be employed for the prevention of Sitophilus oryzae. The aforementioned phenomenon exerts adverse effects, notably in the form of human intoxication. Hence, one alternate approach to address the issue involves utilizing a preparation derived from the leaves of the jackfruit tree. The leaves of the jackfruit tree are known to possess many bioactive compounds such as flavonoids, saponins, and tannins, which have insecticidal properties. Hence, the objectives of this study are to investigate the impact of jackfruit leaf extract on the mortality rate of rice insects and to evaluate the quality of rice. The study was carried out in the Biology Laboratory of the Faculty of Education and Teacher Training at the Tadulako University. The study employed a research strategy known as a completely randomized design (CRD), which included five treatments. Each treatment was repeated in four biological and ten technical replicates. The treatments were as follows: treatment A served as the control and involved the use of Bestrin forte, treatment B involved the application of a 10% jackfruit leaf extract, treatment C involved the application of a 20% jackfruit leaf extract, treatment D involved the application of a 30% jackfruit leaf extract, and treatment E involved the application of a 40% jackfruit leaf extract. Every treatment was administered through spraying to all ten insects and that was repeated four times. The data collected were subjected to analysis using analysis of variance (ANOVA) and supported by the SPSS-25 software. The findings of the study indicated that the application of jackfruit leaf extract (Artocarpus heterophyllus) at specific time intervals (20th, 40th, and 60th minutes) resulted in a noteworthy impact on the death rate of rice beetles. Furthermore, the extracts successfully preserved the olfactory attributes of the rice, ensuring its quality. Nevertheless, their ability to uphold the standard of the rice in relation to its color and flavor was inadequate. The efficacy of the jackfruit leaf extract in eradicating rice bugs was found to be highest when applied at a concentration of 40%.

Alternatives to the Use of Antibiotics in Animal Production

There is a growing demand for livestock products and by-products due to an increase in the human population globally. Farmers utilize feed additives and antibiotics to enhance growth and alleviate diseases to meet this increasing demand for meat and meat products. Although antibiotic use as growth promoters (AGPs) in the livestock industry has brought about a positive increase in production, the industry has also been negatively affected by the development of bacteria resistant to antibiotics and the presence of chemical residues in meat and excreta. Due to this, concerns have risen as this poses a health risk. Resistant bacteria can be transmitted to humans by consuming meat from antibiotic-fed animals or environmental spread from animal wastes. Therefore, action is required to curb this issue because it is estimated that the annual losses in GDP and death toll globally could increase because of the continuous use of antibiotics in livestock production. Hence, this review aims to examine natural alternatives that have the potential to replace antibiotics for food safety, health, and environmental reasons. These could bring a satisfactory impact on nutrient absorption for growth together with health-stimulating virtues.

Tannin in Ruminant Nutrition: Review

Tannins are polyphenols characterized by different molecular weights that plants are able to synthetize during their secondary metabolism. Macromolecules (proteins, structural carbohydrates and starch) can link tannins and their digestion can decrease. Tannins can be classified into two groups: hydrolysable tannins and condensed tannins. Tannins are polyphenols, which can directly or indirectly affect intake and digestion. Their ability to bind molecules and form complexes depends on the structure of polyphenols and on the macromolecule involved. Tannins have long been known to be an "anti-nutritional agent" in monogastric and poultry animals. Using good tannins' proper application protocols helped the researchers observe positive effects on the intestinal microbial ecosystem, gut health, and animal production. Plant tannins are used as an alternative to in-feed antibiotics, and many factors have been described by researchers which contribute to the variability in their efficiencies. The objective of this study was to review the literature about tannins, their effects and use in ruminant nutrition.

Phytogenic Additives Can Modulate Rumen Microbiome to Mediate Fermentation Kinetics and Methanogenesis Through Exploiting Diet-Microbe Interaction

Ruminants inhabit the consortia of gut microbes that play a critical functional role in their maintenance and nourishment by enabling them to use cellulosic and non-cellulosic feed material. These gut microbes perform major physiological activities, including digestion and metabolism of dietary components, to derive energy to meet major protein (65-85%) and energy (ca 80%) requirements of the host. Owing to their contribution to digestive physiology, rumen microbes are considered one of the crucial factors affecting feed conversion efficiency in ruminants. Any change in the rumen microbiome has an imperative effect on animal physiology. Ruminal microbes are fundamentally anaerobic and produce various compounds during rumen fermentation, which are directly used by the host or other microbes. Methane (CH4) is produced by methanogens through utilizing metabolic hydrogen during rumen fermentation. Maximizing the flow of metabolic hydrogen in the rumen away from CH4 and toward volatile fatty acids (VFA) would increase the efficiency of ruminant production and decrease its environmental impact. Understanding of microbial diversity and rumen dynamics is not only crucial for the optimization of host efficiency but also required to mediate emission of greenhouse gases (GHGs) from ruminants. There are various strategies to modulate the rumen microbiome, mainly including dietary interventions and the use of different feed additives. Phytogenic feed additives, mainly plant secondary compounds, have been shown to modulate rumen microflora and change rumen fermentation dynamics leading to enhanced animal performance. Many in vitro and in vivo studies aimed to evaluate the use of plant secondary metabolites in ruminants have been conducted using different plants or their extract or essential oils. This review specifically aims to provide insights into dietary interactions of rumen microbes and their subsequent consequences on rumen fermentation. Moreover, a comprehensive overview of the modulation of rumen microbiome by using phytogenic compounds (essential oils, saponins, and tannins) for manipulating rumen dynamics to mediate CH4 emanation from livestock is presented. We have also discussed the pros and cons of each strategy along with future prospective of dietary modulation of rumen microbiome to improve the performance of ruminants while decreasing GHG emissions.