Silage is a fermented product that is obtained from keeping fodder with high humidity in anaerobic and acidic conditions, and it is one of the materials for animal feed, which is widely used in animal feeding due to its cheapness.
Why is silage good?
Corn silage, alfalfa, sugar beet, tomato plant, barley, potato are common examples in this industry. No matter what season it is, using silage can ensure that dairy cows have adequate food on farms. Forage packed by silage method can be kept completely healthy for more than one year. On the other hand, special environmental conditions are not required for their safe storage and it is very easy to put them under different temperature conditions.
What are the main advantages of fodder silage?
• Ensuring regular food supply for livestock and poultry
• Ensuring the supply of fodder of the same quality for livestock during different seasons
• Can be used in all seasons
• The possibility of silage production in any weather conditions
• Preventing wastage of surplus green and fresh fodder
• Elimination of parasitic diseases during the silage process
• Increasing the production of green fodder by improving the harvesting process
Managing the production of healthy and clean silage in order to modernize the safety of animal feed makes it inevitable to identify the risks in the food chain. Reducing these risks is possible with a clear plan and ensuring that the animal feed purchased from factories is clean and healthy. 50% of clean and healthy livestock feed is related to purchased feed that is given to livestock and another 50% is related to fermented grains and fodder.
Clearly, farm-grown foods pose no significant risk to the human food chain. Except for aflatoxin, which is highly carcinogenic and is found in milk, by limiting the bacterial and fungal population in grain and fodder grown in the field, it is possible to ensure the health of animal feed.
A successful fermentation can combat mold and pathogenic bacteria brought in from the farm.
As already mentioned, harmful bacteria such as( Clostridium spp, Listeria spp, E.Coli spp and Salmonella spp )and harmful molds such as (Aspergillus spp or Fusarium spp )exist in the soil. If there is a lot of livestock or fodder, or if the dairy animal is under stress and its immune system is at risk, these pathogenic species will be a problem for the health of the animal. Both mycotoxins and childbirth are stressful and suppress the immune system. Factors Pathogens can cause health problems and even lead to death when the immune system is weakened and the cow is under stress.
According to research from the German University of Bonn on healthy silage production management, biogenic amines and alcohols suppress feed intake. In some situations where fermentation is insufficient, the animal feed never reaches the stable stage and even gradually deteriorates. One of these cases is when the legume is ensiled at a humidity of 65% or higher. If these conditions are unavoidable, the feed should only be fermented for a few weeks and consumed sooner because the quality of the feed deteriorates over time when the negative bacteria prevail.
Higher mineral content in forage also prolongs fermentation time. Even when the amount of sugar is sufficient to produce lactic acid that causes bacteria to grow, the high amount of minerals such as calcium, potassium and magnesium makes it difficult to lower the pH. Soil minerals are readily absorbed by most plants (depending on soil pH and other factors).
Management of harmful and beneficial bacteria in silage production
Beneficial bacteria (lactic acid producers) grow in the feed and acidify the forage. This should happen a few days after filling the silo. On the other hand, rain on forage or low quality of forage, soil pollution, high moisture content, or high mineral content make forage more difficult to acidify. Whenever the forage pH is above 4.5 or 5, harmful bacteria will grow.
Beneficial bacteria need food to grow. Rainfed or poor quality forage is more difficult to maintain as the feed loses important compounds such as sugar (fuel) and lactic acid producing bacteria. Keeping grass with very high humidity (more than 65%) and ensiled leguminous fodder is also difficult. Under prolonged fermentation conditions, clostridia and other negative organisms can contaminate feed by breaking down protein into biogenic amines and other alcohols. These compounds, which have a pungent smell, are problematic for the health of cows during the transition period and have a negative effect on the liver.
In order to manage silage production, it should be known that higher mineral content in forage also prolongs the fermentation time. Even when the amount of sugar is sufficient to produce lactic acid that causes bacteria to grow, the high amount of minerals such as calcium, potassium and magnesium makes it difficult to lower the pH.
Legumes and grasses absorb minerals well and increase the mineral content of fodder and as a result, fermentation of fodder is more difficult. This happens because of the buffering capacity. The buffering capacity of feeds with high potassium content makes the negative DCAD balance less effective in pre-calving cattle diets.
Contamination with soil, from the farm or silage, provides problems for feed. Soil minerals provide more buffering capacity for forage and also soil is a habitat for fungi and bacteria and potentially increases the pollution load. If the ash content of corn silage is more than 5% or the ash content of legume and grass silage is more than 12%, its source should be checked. During the drought period, due to the fact that there is more wind and dust, rain with floods, etc., the ash content can be higher.
Oxygen release to prevent wild yeast growth
It is necessary to exhaust the air from the silo to prevent overgrowth of mold and wild yeast because wild yeast and fungus need oxygen to grow. Improper compaction, very dry forage, or holes in the bag or cover layer mean that there is more oxygen and the fungus will grow even when the pH is low.
The presence of wild yeast is particularly problematic because they use sugars and fermentable acids as fuel. This creates two health problems related to animal feed:
• Less sugar (energy) available for dairy cattle
• Lower stability of animal feed due to the increase in silage pH
In addition, yeast produces ethanol and other alcohols and causes the loss of animal feed energy. According to research, wild yeast can also interfere with rumen function. Yeast and mold cause feed health problems because the low sugar and high pH of the forage leads to the bacterial problems mentioned above.