Splanchnic Metabolism-An Alternate Metabolic Approach for Sustainable Feeding and Nutrition of Livestock

Splanchnic Metabolism-An Alternate Metabolic Approach for Sustainable Feeding and Nutrition of Livestock

Sustainable livestock production is at the forefront of agricultural practices globally, emphasizing the need for innovative approaches to enhance efficiency, reduce environmental impact, and ensure the well-being of animals. Splanchnic metabolism, involving the metabolic processes occurring in the gastrointestinal organs, offers a unique avenue to optimize nutrient utilization in livestock. This essay explores the concept of splanchnic metabolism and its potential as an alternative metabolic approach for sustainable feeding and nutrition in livestock.

As one of the important pillar of animal husbandry sector, animal nutrition is a one of the most important tool of a livestock development in India. Although India has made a tremendous progress in cereal grains production through its most famous green revolution over the period of last sixty years after independence. The area under fodder production for animals is almost constant measuring about four percent of total land in India for the same period after independence. It is clear indication of lack or failure of planning for availability of feeds and fodder to animals for their normal health and production. Statistics regarding availability and shortage of feeds will depicts the serious challenges before animal nutritionists in coming days.

Understanding Splanchnic Metabolism

1. Definition:

• Splanchnic metabolism refers to the metabolic processes that take place in the splanchnic organs, primarily the liver and intestines. These organs play a crucial role in nutrient absorption, transformation, and distribution throughout the body.

2. Key Organs Involved:

• Liver: Primarily responsible for the metabolism of absorbed nutrients, detoxification, and synthesis of essential molecules.
• Intestines: Facilitate nutrient absorption and play a vital role in regulating nutrient availability to the rest of the body.

The Role of Splanchnic Metabolism in Sustainable Livestock Nutrition

1. Optimizing Nutrient Utilization:

• Splanchnic metabolism allows for efficient utilization of nutrients by regulating their absorption, conversion, and distribution based on the animal’s nutritional needs.

2. Energy Metabolism:

• The liver, a central hub of splanchnic metabolism, plays a crucial role in energy metabolism. It regulates glucose production, glycogen storage, and the synthesis of metabolic intermediates.

3. Protein Metabolism:

• Splanchnic organs contribute to protein metabolism by regulating amino acid absorption, protein synthesis, and the conversion of amino acids into energy or other vital molecules.

4. Lipid Metabolism:

• The liver is instrumental in lipid metabolism, including the synthesis of lipoproteins, fatty acid oxidation, and the production of ketone bodies. This metabolic flexibility is essential for adapting to different nutritional conditions.

5. Nutrient Recycling:

• Splanchnic metabolism facilitates the recycling of nutrients, such as urea and amino acids, ensuring a more efficient use of nitrogen and reducing the environmental impact of nitrogen excretion.

Implementing Splanchnic Metabolism in Livestock Feeding

1. Balanced Diets:

• Designing balanced diets that consider the specific metabolic needs of splanchnic organs can enhance nutrient utilization and reduce waste.

2. Precision Feeding:

• Precision feeding, based on the metabolic status of individual animals, allows for targeted nutrient delivery, optimizing performance and minimizing excess nutrient excretion.

3. Functional Feed Additives:

• Incorporating feed additives that support splanchnic health, such as prebiotics and probiotics, can enhance nutrient absorption and promote overall gut health.

4. Nutrigenomics:

• Utilizing nutrigenomic approaches to tailor diets based on the genetic makeup of livestock can optimize splanchnic metabolism and improve overall metabolic efficiency.

Challenges and Future Perspectives

1. Research Gaps:

• Addressing current research gaps is crucial for fully understanding the intricacies of splanchnic metabolism and its potential applications in different livestock species.

2. Integration into Current Practices:

• Integrating the principles of splanchnic metabolism into conventional feeding practices requires education, awareness, and practical guidelines for farmers and nutritionists.

3. Economic Viability:

• Assessing the economic viability of implementing splanchnic metabolism strategies is essential to ensure that sustainable practices are also economically feasible for farmers.

4. Technology Adoption:

• Embracing technological advancements, such as precision feeding technologies and real-time monitoring, can facilitate the practical implementation of splanchnic metabolism principles on farms.

Approaches to tackle feed deficiency:

1. Improve net feed availability: Ever increasing population creates competition of humans and animals for food, shrinking of land resources along with shortage of water as water tables are either showing increase in depth or vanishing at very brisk rate have imposed some limitations to increase the net feed availability.
2. Improve its utilization : 1. Outside animal body: The lot of work has been carried out to improve the unconventional feed stuffs with some promising results over the years but its field application has been proven to be limited.
3. Inside animal body: So to carry over this work one of the newest aspect of animal nutrition is Splanchnic metabolism. What is Splanchnic Metabolism? Metabolism Metabolism consists of both Anabolism and Catabolism.Anabolism is synthesis of complex substances from simple one while catabolism is synthesis of simple substances from complex ones. Splanchnic Metabolism represents an interface between diet and the animal, and it acts as the main site of regulation of nutrients that are used for maintenance, growth, lactation, reproduction, and physical activities of animals (Reynolds, 1993).

Tissues of Splanchnic Metabolism: 1. Liver 2. Portal Drained Viscera (PDV) 3. Gastrointestinal tract 4. Pancreas 5. Spleen 6. Associated omental & mesenteric fat.

Why splanchnic metabolism ?

• Splanchnic metabolism plays major role in improving overall efficiency of animal production as, · The portal-drained viscera and the liver metabolism have a profound impact on the availability of nutrients and energy to the peripheral tissues, which is influenced by several factors, such as level of feed intake and diet composition. · PDV and liver making up only 8 to 14% of an animal’s live BW but responsible for 45 to 50% of total body O2 consumption · The ruminant gastrointestinal tract as a whole is responsible for 40% of the whole body ATP use. · splanchnic tissues are considered to contribute between 30and 50% of protein turnover in cattle, they will exert a major influence on both net and gross movements of amino acids within the animal. · Additionally, a simulation of protein turnover in growing lambs predicts that 19% of total body ATP expenditure is due to protein turnover and that 25 to 27% is due to gastrointestinal tract protein turnover.

Approaches of Splanchnic Metabolism: To improve overall efficiency of animal production, approaches are 1. Improve the efficiency of energy utilization by splanchnic organs by relating practical consequences of differences diets and animal characteristics in splanchnic heat production 2. Reduce the unnecessary losses or leak of nutrients by splanchnic tissues so as to reduce the gap between nutrients absorbed at intestinal level and exact amount available to peripheral organs for different productive purposes.

Factors affecting splanchnic energy use:

A) Chemical properties of digesta 1. VFA`SStimulate epithelial cell division in the rumen,presumably with greater effects of butyrate the ratio of Na+ to VFA in the reticulorumen affects energy use by the gut. 2. Ammonia absorption Increases hepatic energy use in ureagenesis, (Lobley et al., 1996).

B) Physical properties of digesta

Tropical grass fragments has protruding and jagged edges.“scratch factor” effect, relevant to stimulation of rumination, seem most likely via alterations of protein synthesis or turnover. Relationship between eating time and PDV heat production encompasses muscular actions for gut contractions and metabolism.

C) Feed Intake As feed intake increases up to an ad libitum level, whole-body EFF decreases along with efficiency of splanchnic metabolism. It has been noted increases in PDV and liver energy use of 0.22 and 0.16 Mcal per Mcal of increased ME intake, respectively. Seal and Reynolds (1993) different levels of restricted feed intake and observed an increase in PDV energy use of .11 Mcal per Mcal of ME intake.

D) Temperature The greater differences in digestible OM intake between a mature tropical grass and a late vegetative temperate grass hay occurred in summer than in the fall 1) High splanchnic heat production relative to absorbed energy for the tropical grass and 2) Increased energy use in respiration to dissipate summer heat.

E) Supply of Limiting Amino Acids Improves growth, feed intake, and (or) efficiency of feed usage. Such changes presumably entail direct effects on peripheral tissue metabolism. With a limiting tissue supply of one or more essential amino acid, excess amino acids are largely used for energy, accompanying high use of energy for urea synthesis and release from the liver.

F) Animal Characteristics 1. Stage of Maturity The proportion of the whole body that is the gut peaks near or somewhat earlier than at typical times of weaning and thereafter declines slowly; a similar pattern occurs for the liver, although the rate of decline is slower than that for the gut. Breeds or biological types with high milk production or growth potential generally have greater maintenance energy requirements

G) Managemental Fresh vs dried grass, which was associated with a longer time of ingestion (i.e., 75% greater).Increase energy requirement muscle and nervous tissue for standing, movement, maintaining an alert nature, and mastication (Osuji et al., 1975).

 Measurement of splanchnic mechanism

With the exception of long-chain fatty acids absorbed into lymph, using multicatheterization procedures.

1. Sampling of arterial and appropriate venous blood draining the liver and PDV Simultaneous sampling Net rates of nutrient removal or release- product of blood flow and venous-arterial difference.

2. Dual isotope method (MacRae et al., 1996)

3. An NMR-based metabolomics approach: Identification & quantification of a large number of metabolites IS a very tedious process. Based on the 1H NMR profile of plasma – potential for investigation of splanchnic metabolism is usaly done. Enhancement in spectral resolution associated with a higher magnetic field strength. Studies aiming at making the technique quantitative are needed.

4. Prediction equations Regression equations used frequently are, PDV energy use, Mcal/d = -.0194 +(.1207·DEI, Mcal/d) + (1.1173·fecal NDF excretion, kg/d) – (.2860·DEI·fecal NDF excretion) and Hepatic energy use, Mcal/d = .0014 + (.0266·DEI, Mcal/d) + (.3325·PDV energy use, Mcal/d) + (.0745·urea N hepatic net flux, mol/d) + (.0016·BW, kg).

Conclusion

An increased understanding of dietary influences on efficiency of splanchnic tissue metabolism improve the matching of dietary and animal characteristics in order to maximize splanchnic efficiency of energy use and to achieve the most efficient feed utilization and ruminant production systems. But further research is essential for better understanding of splanchnic metabolism under different feeding reigm for different categories of animals. Splanchnic metabolism presents a holistic and alternative approach to livestock nutrition, emphasizing the significance of the gastrointestinal organs in nutrient utilization and overall metabolic health. By tailoring feeding practices to optimize splanchnic metabolism, livestock producers can enhance efficiency, reduce environmental impact, and contribute to sustainable agricultural practices. As research in this field continues to advance, the integration of splanchnic metabolism principles into mainstream livestock nutrition holds great promise for a more sustainable and resilient future in animal agriculture.

Compiled  & Shared by- This paper is a compilation of groupwork provided by the

Team, LITD (Livestock Institute of Training & Development)

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 Reference-On Request.