What can be done if there is mold and yeast in corn silage?
javid keshtleyzeri Co.ltd
The presence of silages that are not aerobically stable is one of the most common problems on dairy farms, even in the United States. Maize silage that has not yet reached aerobic stability has characteristics such as high temperature, mold growth and unpleasant smell and mustiness that can be seen in the front parts and upper surfaces of the silage that are used on a daily basis.
Interestingly, there is little research on the negative effects of feeding poor quality silages (which are aerobically unstable). However, the decrease in feed consumption, milk production and milk fat loss from cattle farms have been reported repeatedly.
Mechanism of action of molds and yeasts in corn silage
Spending a cool growing season causes a delay in harvesting corn silage. These conditions cause the creation of a group of bacteria that are highly unfavorable for proper fermentation and food preservation in silage. As a result, fermentation will be very slow and the conditions for the growth of all types of yeasts and molds that are non-fermenting, such as: Cryptococcus, Thadotorella and Sporabulomyces, Candida and Hansenola, are prepared. This group of yeasts can use lactic acid.
The functioning of yeasts and aerobic instability (heat production due to exposure to air oxygen) in corn silage with high humidity is as follows:
1- Accumulation of a large number of yeasts in the silo
2-During slow fermentation in silage, the normal growth of yeasts continues until all oxygen is consumed.
3-During the consumption of silage, the yeasts encounter the oxygen of the air again.
4- In this case, yeast growth will be exponential.
5- Lactic acid is used.
6 - An increase in silage temperature occurs.
7 - Silage acids evaporate.
8-The acidity of silage decreases (increasing pH).
9-Mushrooms that need little oxygen to grow (makur) attack the silage.
10-Aerobic instability occurs.
How does yeast multiply?
The aerobic stability of silage decreases due to the increase in the number of yeasts.
Well-preserved edibles have less than 10,000 yeast colonies per gram (CFU/g).
At this level, the feed is aerobically stable for 120-140 hours.
If the level of yeast reaches 1 million clones per gram, the aerobic stability is reduced to 40 hours. If the number of yeasts reaches 25-50 million per gram, it indicates insufficient fermentation of food.
Since oxygen can penetrate to a depth of 60 cm in the silage being consumed, most of the time, the amount of silage harvested for animal consumption is not enough to prevent the exponential growth of molds.
The use of packaged silage in livestock feeding leads to the reduction of livestock diseases, and one of the important consequences that occurs due to the compression of fodder is the reduction of bloating resulting from the consumption of silage, and also the consumption of silage fodder causes abortion in pregnant animals. It is greatly reduced and we must note that:
"One of the main causes of abortion in livestock is consumption of green fodder".
Lactic acid, which is created as a result of silage and acid fermentation of fodder, increases the digestive and ruminal activity of animals.
Due to the recent and even earlier droughts, due to the geographical climate and weather conditions and the location of the Iranian plateau in the arid and semi-arid region, dense pastures and grasslands with diverse and palatable plants are out of the reach of animal husbandry. Is . Therefore, the main part of livestock feed is straw and stubble with a limited amount of hay.
For several years, concentrate has been added to the livestock feed basket with the help of subsidized bran advertisements, with all the descriptions that all involved are aware of, which sometimes becomes the only animal feed in the absence of even straw, and this is while the minimum consumption of dry matter for The health of the digestive system and milk production is at the limit of the natural capacity of 3% of the animal's weight. That is, if we consider the livestock to be approximately 400 or 350 kg, a dairy cow needs at least 12 kg of dry matter.
It is easy to understand with the available concentrate! And alfalfa is limited, both in terms of nutrition and in terms of economics, without its straw, it is not possible to achieve the required amount of dry matter.
Straw, except for limited consumption to provide physically effective fibers in dairy cows and filler in heifer and dry cow food (maximum consumption of 2 kg), has another role and nutritional value other than physical satiety and occupying the rumen and preventing the consumption of quality feed to increase milk production. , health and safety of the body, fertility and natural activity of the reproductive system, etc., and this is where fodder corn silage, packed with the following specifications, plays a very important and prominent role in providing dry material for livestock consumption. he does .
Packed fodder corn silage with higher nutritional value and no spoilage, with proper dry matter, no effluent loss and no loss of dry matter, proper fermentation without burning and no toxic substances and mold, the most economical choice for productivity and profitability. It is considered livestock units.
Possible reasons for the non-response of bacteria added to silage:
1- There is a high concentration of these bacteria in fodder.
2. The dosage should be low so that it cannot compete with the silage bacteria.
3- The conditions in the soluble carbohydrate silo - humidity and temperature respond better in wet silos.
4- Managing the supply of nutrients and covering the entire surface of the silo with these bacteria)
Corn silage quality control:
PH meter
water test (microwave)
thermometer
Appearance assessment
Examination of silage dry matter (manual method)
Pressing the water sample between the fingers and not opening it (more than 70%)
Squeezing the sample, not coming out, getting your fingers wet and not opening it (65 to 70)
Pressing the sample, no water coming out and fingers getting wet, opening slowly 60-65%)
Squeezing the sample, an example of water not coming out and fingers getting wet and opening quickly (less than 60%)
Appearance evaluation: including color, smell and taste
Corn silage pH is a good management tool to control the quality of corn silage.
The ideal pH range of corn silage is between 8.3 and 2.4, but in Iranian silos due to high humidity and activity, more bacteria inside the silage, more lactic acid production is usually less than 4. The reason for that high pH is the presence of Listeria bacteria. and cluster bacteria due to high humidity.
The reason for that is high pH, the presence of Listeria bacteria and cluster bacteria due to high humidity in the silo, the presence of dust in the silo, improper fermentation and the long duration of the silo.
Silages with a pH higher than 5.5 should be discarded and less than 5.5 should be used with caution and monitoring of ammonia levels, mycotoxins and feed additive use.
Controlling the size of corn silage pieces
Controlling the size of the pieces is important for determining the duration of mixing, livestock selection, proper fermentation of silage, and deciding on the use of silage additives.
If it is processed, the size of the corn pieces for silage is 2.5 to 3 cm, if it is not processed, it is 2 to 2.5 cm.
If the air humidity is high, and the humidity is more than 80%, the appropriate size of corn silage is 2.5 to 3 cm.
The optimal size of corn for silage in Iran is 2 to 2.5 cm.
If the duration of silage is more than 4 months and the height of the silo is 3 to 4 meters, it can be silated with 2.5 to 3 cm pieces to produce less water.
Chemical composition of silage
Dry matter (percent): 25 to 35 percent
PH: 3 to 4 in 8
Soluble carbohydrates: 80 to 100 grams
Lactate: 5 to 10 percent
Acetate: 1 to 3 percent
Propionate: less than 0.1%
Butyrate: less than 0.1%
Ethanol less than 3%
Ammonia less than 8% of protein
Ash 4 to 5 percent
Silage moisture and dryness:
One of the most important quality control factors is silage limited to 25-35% silage moisture, which has the most changes in cold and rainy seasons.
Silage moisture measurement error:
If the dry matter of corn silage has only a 3% dry matter difference, (20% compared to 23%) a 3.25 kg difference per head for each cow in a feedlot feeding 50 cows, that's a 163 kg difference. (6.5 percent) is created.
Qualitative comparison of alfalfa compared to corn silage:
- Silage with more energy
- Better palatable silage and greater uniformity
- The possibility of controlling the size of the pieces of corn silage compared to hay
- Loss of anti-nutritional compounds containing digestive fiber
- Adding stable moisture to the final corn silage feed
The effect of silo height on wastewater production
If pressure is applied to corn forage with 40% dry matter, then water is produced.
If corn fodder is silage with 30% dry matter, then water will not be produced up to 12 meters high, provided that the dry matter is increased by 1% for every three meters of height.
Each cubic meter of silage with 35% dry matter weighs 700 to 800 kg (average (750)) equivalent to 5.262 kg of dry matter.
The weight of each cubic meter of corn silage with 20% dry matter is equal to 1312 kg, which is 42% more weight.
Looking at the data in this table, we will find that the higher the humidity of the silo is over 70%, the amount of waste water produced will increase and the best and most suitable silo is the silo that has 70% humidity, in this case there is no We will not have waste water and subsequently fermentation will take place at the optimal level.
At a glance, based on the graph and its data, we will understand that the amount of dry matter of fodder corn silage has an inverse relationship with the waste water produced. That is, as much as the amount and percentage of dry matter of forage corn silage increases, the amount and percentage of waste water produced will decrease.
According to this linear diagram and the data included in it, we will find that the silo waste water will be completely exhausted after about two months, and as can be seen from the data in the table, in the first days of the silo, the waste water will be around It is 40 liters per day and over time, the waste water produced will be less and less.
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