Amino Acids

In the year 2000 I was withdrawing from daily running of a dairy farm. I thought I was old enough to avoid learning how to use a computer! I now find myself emerged in amino acid nutrition which I also thought I could let pass by.

After two years of prompting by a nutritionist friend in the USA and co-author of the most advanced amino acid optimisation program, one of my sons and I travelled to the US in February for training in this program. That was the easy part. We are now faced with the task of, ‘how do we utilize this futuristic technology in grazing based systems’?

Late last year Professor Charles Schwab, University of New Hampshire, addressed the Australian Association of Ruminant Nutrition in Melbourne on the subject of amino acid nutrition. Perhaps my most outstanding memory of Dr Chuck’s presentation was when he stopped halfway through, clapped his hands and said: “Is everybody listening! The highest producing herds in the USA have the highest milk solids and the highest fertility!!” Not a statement we can ignore. Fortunately we have Dr Chuck helping us through our dilemma.

Firstly, what are amino acids? Amino acids are fractions or types of protein. All feeds contain some mix of amino acids. The challenge is to match the amino acid profile of the ration with that of milk. Then suddenly all productivity parameters make a very positive jump.

We are all familiar with the term crude protein, and the word crude best describes it. In fact, and especially in grazing based systems, it is a useless figure. Why? Because our pastures can contain very high levels of nitrogen (CP%’s of 36%) of which only about 40% of this is ‘true protein’. A cow can utilize ‘some’ soluble protein to produce microbial protein; but our cows are well in excess of that amount. Work Dairytech Nutrition did several years ago with Milk Urea Nitrogen monitoring bore this fact out all too clearly; and the cost too, of mitigating excess rumen ammonia. We built a new product as a result of this research to eliminate high MUN readings and their legacy to health, production and fertility.

Nutritionists are constantly looking for ways to improve performance and profitability. Amino acid balancing is well documented as having that ability. Field experience in the USA has been less than successful at doing this. There are several challenges to amino acid balancing (and dairy productivity in general) that must be addressed first.

Challenge #1 – Management

We all long for the ‘silver bullet’ feed additive to fit straight into our current ration and fix all our problems. Today’s dairy rations require significant nutrients and energy to optimise the genetics our herds have. Knowing ration ingredient analysis is critical to this, especially wet feeds such as pasture and silage which can have large variations.

Grazing management, silage production and feed-out management, feed sequence to keep a healthy functionally efficient rumen, all have major impacts on productivity. Stress from poor animal handling at milking and other activities will annihilate the best nutritional strategies; let alone immunity/health. In regard to rations, the old adage: There are three rations. The one on paper; the one the cows received, and the one the cows ate!

Challenge #2 – Nutritional Status

Once all management limitations are addressed, nutritional status of the herd is next. Assessment of lean body tissue (muscle mass) as well as fat coverage needs to be considered. If prior rations have depleted lean body tissue, as with body fat, amino acids will have been mobilised to meet production demand; especially in fresh cows. Depending on the severity of this, supplementation with appropriate amino acids could take twelve weeks to replenish body reserves before production improvement is seen.

Challenge #3 – Estimating the Starting Point

This is where we stand currently. We have significant work to do to establish a baseline of current ration amino acid content. We have already invested heavily in sending common feed samples to the USA for wet chemistry analysis. This will be ongoing in regard to pasture over the growing season. We have purchased software based on the NRC model that has been proven most accurate from research into actual levels of amino acids reaching the duodenum.

Rumen health/function plays a major role in utilization of existing amino acids in feeds. The production of microbial protein, a significant supplier of amino acids to the cow, is directly proportional to rumen bacteria populations. The product developed from MUN research mentioned above, is a combination of a natural plant and yeast culture. The plant addresses excess rumen ammonia from occurring while the yeast component increased rumen bacteria populations, which essentially, become microbial protein when they pass to the lower gut for digestion.

For many of our current dairy farmers, my hope of avoiding computers, will prevail in regard to amino acid optimisation. For younger farmers and those yet to come, I assure you, amino acid optimisation will be the ‘next big thing’!

In the words of my friend and mentor, Dr Richard Ware, “Regardless, the bottom line is that amino acid balancing (as with any other supplementation) should be verified with the only expert that matters . . . . the cow! And she is never wrong.”

John Lyne is a dairy production specialist with Dairytech Nutrition

www.dairytechnutrition.com.au