To boil it all down to something very simple, the most common cause of soil and plant health problems comes from a lack of oxygen in the soil. This means the essential aerobic, air breathing soil microbes can’t exist in enough numbers to create enough soil electrical conductivity to allow plant growth. Calcium and phosphorus can’t be taken up into the plants to allow sufficient photosynthesis to occur to produce a healthy nutritious plant. The electrical conductivity of the soil can be somewhat induced through the application of conventional fertilisers. However, there is a problem. Many of these fertiliser salts (urea for example) will cause the structure of the soil to alter over time so that in essence, it becomes further compacted and anaerobic meaning that while plants will grow, they lack quality and nutrition beneficial to the animals it’s feeding.

In the absence of available calcium and phosphorus, plants will ‘fill up’ on potassium, an electrolyte mineral that holds on to a lot of water, thus diluting soluble sugars and not providing sustenance for the animal. This also leaves the plant very vulnerable to diseases and insect attack meaning not only increase pest management costs, but also can be life-threatening to stock if used as a forage or feed.

When we feed animals low sugar, low mineralised feed with a high water content and relatively high protein content, we are feeding an imbalanced diet. Ruminant animals may consume plant material, but this is not what they live on, the microbes in their rumen do; and the cow or sheep lives on the dead digested microbes that wash further down the gut. What happens in the rumen when feed low in sugar, high in protein and also lacking fibre, is the start of the animal health issues we see.

Rumen microbiological flora are similar to those in the soil in that they need a carbohydrate/sugar source for energy to live and a protein source to build muscle. When the protein to carbohydrate ratio is out of balance the rumen biology will turn some of the excess protein into energy to compensate. This is not only inefficient but produces ammonia gas and PH change within the rumen (called sub clinical rumen acidosis). This causes a burning effect to the rumen wall allowing bacteria to enter the blood stream. When this happens some of these bacteria can become trapped in tiny blood vessels as they’re carried around the body. The most common symptom can be acute lameness as these bacteria block the little arteries in the toes. Even when the animal seems to recover from the immediate pain, blood clot damage can result in further infection and a second more-long lasting lameness event.

At the same time the bacteria that cause the blood clots in the feet can also become trapped in the tiny vessels of the liver, some growing to develop into abscesses which can further develop into more serious consequences for the animal later on. This is often reflected in a high incidence of peritonitis reported in cull animals sent to slaughter facilities. The ammonia gas in the rumen also gets into the blood stream but can’t be directly excreted and first has to enter the liver where it is turned into urea, returned to the blood stream and then excreted via the urine and also in the milk of a lactating cow. In New Zealand we measure this as MUN – Milk Urea Nitrogen. This process uses up energy that the animal could have otherwise used to grow. But the worst consequence can be the embryonic death that can occur as a result of fluctuating blood PH.

“I have been involved in and helped pioneer the early diagnosis of dairy cow pregnancies at five weeks post mating. During the course of thousands of cows tested over many years being confirmed pregnant I observed large numbers of cows subsequently being diagnosed empty some months later when I knew they had been pregnant earlier. I also observed at the time of the early test that a number of cows had dead embryos still palpable. Over some years of observation, I was able to relate this phenomenon to when I also observed the cows to be very loose in their faeces and I came to relate this to the subclinical rumen acidosis they were currently suffering. Milk production was also seen to suffer. In New Zealand some experts say this doesn’t happen in New Zealand and it is a phenomime only seen overseas and that our cows are different and high MUN levels are not bad, encouraged even. They are in my experience, completely wrong.” Allan Piercy, rural vet.

At Agraforum, we believe the majority of the animal health and production failures we observe are directly related to the unhealthy state of the soil on many of our farms as well as the inappropriate use of some supplementary feeds and the over use of manufactured nitrogen fertiliser.

But it doesn’t have to be this way and by applying the scientific knowledge of how soil should be working and using only products that improve soil health, we can produce better quality feed that is a balanced diet for the rumen microbes that feed our grazing animals.