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ANIMAL FEED NUTRITION- the production of agricultural bioproducts

Introduction-

When we talk about the agricultural industry, livestock plays a key role in food and economic security. They provide services for households, such as draughting and manure for fuel and fertilizer as the most valuable agricultural products on earth. Increasing livestock production can improve incomes (and livelihoods) for millions of farmers.

But it is also true that rearing animals comes with a lot of problems. Feeding and watering animals is a big concern in India as well as globally. Added to that, the land area taken up to grow crops that are then fed to farmed animals is enormous, and a leading driver of deforestation. Malnourished livestock is far less productive, not to mention sad and unhealthy. Animal food must be nutritious, and have high-quality protein content, with lots and lots of nutrients and vitamins. But getting them the high-quality feed, they need to thrive costs money and prices are soaring especially right now.


To overcome less production and feeding costs, farmers often use antibiotics/ hormonal doses in abundance to improve the productivity of herds. This practice adds to anti-microbial resistance – meaning there will be no treatable effects on animals when they suffer illness. This resistance renders important medicines ineffective leading to high exposure to infections and killings hundreds and thousands of livestock. Many of our front-line antibiotics no longer work against a range of illnesses that were once very treatable, from salmonella to gonorrhea. An estimated 1.2 million people died worldwide in 2019 from antibiotic-resistant infections.

The solution to this problem is giving them good food but this way of feeding animals isn’t fit for purpose. Modern solutions are currently going through roof. A range of new feedstocks like algae, oils, and mushrooms, feed additives like vitamins, minerals, supplements, alternative proteins, and even cultured meat is a success.

There are sustainable alternatives that require fewer resources, are even more nutritious, and tackle the issue of waste. Check some of them out below.

Modern fermentation technology-

  • Microbial proteins- Instead of growing plants and rearing animals to create protein as a feed ingredient, microbial proteins are grown using bacteria, fungi, yeast, and algae. In short microbial proteins are a replacement for plant proteins. The very first idea to create microbial proteins was established in the 1970s. As the main source of protein production is nitrogen, oxygen, and carbon, scientists used methanol as a substrate at that time. Eventually, the prices of oil increased, and from an economic point of view, fermentation did not proceed to production at a large scale. Modern fermentation technology and increasing feed ingredient prices, combined with an improved understanding of the environmental impact of waste nitrogen have now made feed manufacturers look again at opportunities that microbial protein production could bring.



  • Nowadays, biotechnology and biochemical transformations have taken new heights. Scientists have designed a biochemical transformation process that turns carbon dioxide (CO2) into a protein-rich powder for animals to eat. The process converts carbon dioxide into a powder, called Proton, which has around 70% protein content. This is much higher than natural soy, which has around 40%. The carbon dioxide is put into a fermentation tank as a gas, with hydrogen added to serve as an energy source. After the cellular process is complete, the protein is then dried into a powder to be used as an ingredient in sustainable animal feed. Microbial proteins produced with carbon dioxide and other gas feedstocks could replace between 175 million and 307 million tons of crop-based animal feed annually, or 10 to 19 percent of conventional crop-based animal feed protein demand.

  • Single-cell protein production- Microorganisms like algae, fungi, yeast, and bacteria have very high protein content in their biomass. These microbes can be grown using inexpensive substrates like agricultural waste viz. wood shavings, sugarcane molasses, sawdust, corn cobs, etc., and even human and animal waste. The obtained extract is then taken and transferred to a pre-sterilized conical flask, autoclaved at a standard temperature of 121 °C, with a pressure of 15 psi for a time of 15 minutes. After autoclaving, the sterilized sugar cane extract is aseptically transferred into pre-sterilized Petri-plates. Then upon cooling, in aseptic conditions, the Petri plates containing sugar cane extract are inoculated with common filamentous fungi i.e., Aspergillus Niger. These Petri plates are then incubated at 28 °C for 7 days. After the growth of fungal biomass, the mycelia are transferred on a filter paper (Whatman filter paper) and washed with distilled water if any. The filter papers containing the mycelia were dried at 90 °C for 24 hrs to get moisture-free fungal content.


  • In the case of large scale, the same process occurs in fermenters or bioreactors and processes essentially begin the same way. Scaling up can lower the costs of goods as it involves a higher number of cells but can also increase the difficulty and control when working with such a vast number of cells. The cultures are inoculated into the sterilized substrate present in the reactor for 2-3 days. After harvesting culture, the mycelia are transferred and filtered. Filtered biomass is then dried to get dry protein powder. The following image will show dry weight according to the species used in fermentation processes.



  • Probiotics like Cylactin, which contains the bacteria Enterococcus faecium, have a dual benefit of improving weight gain while also cultivating natural defenses to common gut pathogens, and preventing illnesses such as diarrhea in animals. The efficacy of such probiotic treatments is backed up by several studies, which cite improvements in growth and the quality of meat, milk, and eggs in farm animals from turkeys and chickens to sheep, goats, cattle, horses, and fish. They could even help control Salmonella infections as well.

Amerging role in animal feed-

By 2050, microbial protein grown in vats and tanks will become a basic raw material for animal feed. Amerging vision is to develop novel feed ingredients from natural bioresources. To find sustainable and nutritious solutions to keeping animals healthy and productive. While the use of microbial proteins grown in tanks may seem a more complicated method of animal feed raw material production, it may be a necessary solution given the impact that livestock farming has on the planet’s atmosphere.


Production patterns and actions-

The main premise behind bioreactors is to increase the percentage of nutrients present in the growth medium that is eventually converted into cells. The protein production takes place in fully controlled, enclosed, and automated bioreactors like those widely used in the fermentation processes by the other industries to produce favorable products. The microbes convert nitrogen into cellular protein with an unmatched efficiency of close to 100%. The researchers believe that modern reactor systems are now so efficient that as much as 10–43% ends up as consumable protein, compared to only 4–14% for agriculturally based protein production. All ingredients are fed into a reactor system that enables the highly efficient production and harvesting of the protein.

Most common used culture in protein production-

  • Yeast

  • Oleaginous yeast

  • Filamentous yeast

  • Microalgae

  • Bacteria

Most common used Biomass in protein production-

  • Forest by-products

  • Seaweed

  • Organic waste

  • Gas based substrates

Most common used Bioreactors in the production of animal feed-

  • Solid state fermenter

  • Trickle bed reactor

  • Perfusion tank reactor

  • CSTRs and repeated fed-batch reactors

Stirred tank bioreactors are common bioreactor that is utilized for their scalability but has high shear stress during mixing. It all starts with a small number of cells cultivated with a high cell density in a perfusion bioreactor. Fluidized bed reactors or trickle bed reactors are also used for high-density cultures. Mechanical mixing is unnecessary minimizing factors like mechanical agitation, but these bioreactors haven’t been tested at scale.

Whereas perfusion bioreactor is a certain type of bioreactor that involves the exchanging of cell growth media while retaining cells. Thus, perfusion bioreactors allow for high cell density, which is why it is often used in the cellular agriculture process. Overall these points the most important feature of a reactor is to monitor the system wisely. There are three different types of monitoring systems currently used in cell culturing bioreactors: offline, in-line, and online.




Offline monitoring is a manual operation of removing samples from bioreactors and processing them. Offline methods often take a lot of time and do not allow for real-time testing of the cells within the bioreactor. In-line monitoring is when samples are removed from the bioreactor and monitoring like the measurement of characteristics like pH, dissolved oxygen, and temperature is performed. Thus, more automated systems of monitoring (online) need to be developed within bioreactors (which are generally customized) to boost the culture process and provide desirable conditions for cell growth.


Still, up to this date, there is a need for the right piece of the reactor which can solve all the current problems that occur in culturing and scale-up procedures. In the hope of new technologies and future food, let's end this blog and try building new designs.

References:

https://hiralchavre.medium.com/bioreactors-cultivating-the-future-of-food-d377fd472355

http://ijpsr.com/bft-article/production-of-single-cell-protein-from-sugarcane-using-fungi/?view=fulltext

https://www.agchemigroup.eu/en/blog/post/microbial-protein-bacteria-feed-raw-material-future



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