Why understanding protein is critical for the growth, health and wellbeing of your animals

amino acids

Protein in all its different forms is made up of just 20 individual amino acids:

	amino acid	Essential
1	Alanine
2	Arginine
3	Asparagine
4th	Aspartic acid
5	Cysteine	Yes
6th	Glutamine
7th	Glutamic acid
8th	Glycine
9	Histidine	Yes
10	Isoleucine	Yes
11	Leucine	Yes
12th	Lysine	Yes
13	Methionine	Yes
14th	Phenylalanine	Yes
fifteen	Proline
16	Serine
17th	Threonine	Yes
18th	Tryptophan	Yes
19th	Tyrosine	Yes
20th	Valine	Yes

Some of these may be known, as EU law requires them to appear on the bag label for complete feed or vitamin / mineral premixes (lysine and methionine). Some of these are also referred to as “essential”, which means that they can only be supplied to the animal from an external source, ie food. The non-essential amino acids can be synthesized in the body, but are no less important for the biological functions of the animal.

These amino acids combine in various combinations and proportions like building blocks to form certain proteins. The protein family ‘keratin’, for example, is a structural protein that is vital for skin, hair, horns, scales, etc. and is made up of 18 amino acids, but in hair the main amino acid is cysteine, which makes up about 14% of keratin can only be about the food to be supplied. Another example would be the ‘mucin’ family of proteins, which is the main component of the mucous membrane that protects the epithelial lining of the intestine, airways and other regions and half of which is serine and / or threonine.

It can therefore be seen that “protein” is a collective term for a large number of substances in the body, which, however, are each formed from a combination of amino acids.

Protein sources for animal feed

Since 11 of the 20 amino acids are essential, they have to be included in the feed so that the animal can grow optimally and healthily.

Protein in animal feed is usually supplied by soy, but raw soy contains anti-nutritional elements that would cause harm if not processed first. Depending on the age of the digestive maturity of the animal, other proteins can also be considered – such as milk powder, specially processed soy, e.g. B. Hamlet HP300 and fish meal for young animals, through to soy meal, rapeseed and sunflower meal, beans, peas, lupins, etc. as they get older.

Each of these protein sources have different degrees of digestibility, with subsequent performance implications, but what is the process like?

Protein digestion

Whole proteins from the feed are first broken down into smaller soluble units, so-called peptides, in the stomach. These peptides are effectively an intermediate between whole proteins and amino acids. The enzyme that is crucial for this is called pepsin, a highly active protease. If the body were to produce pure pepsin, it would cause great damage to all tissues it comes in contact with, which are bound by protein-rich membranes. To overcome this, there are special cells in the stomach known as chief cells that produce a precursor called pepsinogen. Pepsinogen is converted to pepsin by the presence of hydrochloric acid, which is secreted into the stomach by parietal cells.

Young animals have a poorly established ability to secrete acid and the conversion of pepsinogen to pepsin is impaired. Hence, it is important to consider the quality and digestibility of these protein sources. From a nutritional point of view, the portfolio of specialty products available will include whey protein concentrate, which can be rich in immunoglobulins, as well as enzymatically treated soy products such as Hamlet Protein HP 300 as a substitute or supplement to fishmeal. The higher the digestibility, the higher the degree of conversion of protein to soluble peptides.

These soluble peptides leave the stomach and are then exposed in the small intestine to other powerful proteases known as trypsin, chymotrypsin carboxypeptidase. In turn, to prevent the body from digesting itself, precursors known as trypsinogen, chymotrypsinogen, and procarboxypeptidase are made from the pancreas and converted to their active form by enterokinase, which is produced by cells in the duodenum.

These enzymes then break down the soluble peptides from the stomach further into smaller units, which are then subjected to further proteases in the small intestine until they are broken down into their individual amino acids.

These amino acids are then transported through the epithelial cells of the small intestine and enter the bloodstream where they are available to be converted into what is needed by them. In many ways it is ironic that the protein-digesting enzymes described above are actually proteins in their own right and would have been formed from the amino acids that were previously part of proteins in feed.

Digestive efficiency

It is important to understand that not all of the ingested protein is digested because many proteins are resistant to digestive enzymes or are presented to an immature digestive system. This makes the choice of feed ingredients crucial for the production phase. This choice is not only driven by the optimization of the animal’s genetic potential, but economic, ecological and sustainable aspects are also the most important drivers.

A realistic proportion of food to be digested would be around 84%, ie 16% is excreted in the faeces. Of the 84% that is digested, converted to amino acids and circulated in the bloodstream, around 47% is retained in the body – like muscles, skin, hair, mucus, enzymes, immune system, etc., with the large 53% being deaminated and with the urine excreted, which corresponds to about 45% of the initial intake.

With a protein content of 16% nitrogen, any waste has an environmental impact. How can we reduce this?

Most basic would be to feed “ideal protein,” which is a protein that is 100% digestible and has the exact amino acid balance that the animal needs on a given day. To do this, one would have to estimate the exact ratio of all 20 amino acids and ensure that the 11 essential ones are supplied in exactly the right amount in the feed. The problem with this method is that most protein sources are not 100% digestible and their amino acid content is certainly not optimally balanced. Any nutritional imbalances can be corrected through the use of synthetic amino acids, but this can become prohibitively expensive and therefore economically unprofitable.

In this context, extracted soy meal (Hipro) has a raw protein content of typically around 46%, of which 89% is digestible. Extracted sunflower meal has about 36% crude protein (this can, however, vary greatly depending on the extraction process) and a digestibility of 83% and extracted rapeseed meal has a crude protein content of 33.5%, of which 76% is digestible. At the other end of the scale and only taking into account the digestibility of the protein, dry whole milk would be 95% digestible, HP 300 would be 93% and fish meal would be around 90%. This then shows the considerations in the raw material portfolio when creating diets for certain animal classes.

Undigested protein is especially important to the weaned pig as it can cause “food wash” in which the intestines attempt to empty this material by pouring water into the intestinal lumen as a rinse. Undigested protein can also be a food source for enteric pathogens like E. coli, Salmonella, Lawsonia, etc., for which we have fewer and fewer treatments. In fact, as of August 2022, the EU will no longer be able to use BP-grade zinc oxide to control E. coli, and greater attention to food composition is absolutely essential.

A unique processing technique

Given the understanding and importance of protein digestibility, Hamlet Protein developed a processing technique that uses soy and not only improves crude protein content, but also reduces any nutritionally adverse factors and increases overall digestibility. The HP 300 product was therefore specially developed for use in starter piglet feed. With 56% crude protein, it is ten percentage points higher than standard Hipro soy and with a digestibility of 92.9%, significantly less undigested protein reaches the hindgut.

HP 300 would conveniently be a partial substitute for fish meal, which, depending on the processing and drying treatment, can vary greatly in its protein content and digestibility. It also supplements other components of a starter feed, such as the milk powder, to create a diet aimed at the optimal healthy growth of the young pig.

source https://dailyhealthynews.ca/why-understanding-protein-is-critical-for-the-growth-health-and-wellbeing-of-your-animals/