Wanting to explain in detail the role of molasses in cattle nutrition, we turned a series of questions to the world of science, represented in this case by Dr. Hab. Andrzej Łozicki from the Institute of Animal Sciences, SGGW.
Farmer: What role does molasses play in the nutrition of dairy and beef cattle, what nutrients does it provide?
When assessing the nutritional suitability of molasses, we can analyze its impact on the palatability of the ration or the structure of the TMR. Finally, we evaluate this feed in terms of its chemical composition and how it affects rumen metabolism and the digestibility of the entire ration.
Advantages of using molasses in cattle feeding
The most important organoleptic feature of molasses is its sweet taste, which makes it particularly eagerly consumed by animals and also increases the consumption of other feeds, which are not always characterized by good palatability.
Molasses used in doses is also a good binder, making it difficult to sort individual feed components by cattle fed in the TMR system. When adding molasses to TMR, dilute it with water, preferably in a 1:4 ratio, and then pour it over the feed.
When analyzing the nutritional value of molasses, attention should be paid to the high content of dry matter in this feed, on average about 70-80%. The main ingredient of the dry matter are sugars, mainly sucrose, whose content in molasses is on average about 60-65%. sm They are quickly fermented in the rumen and constitute a good source of energy for rumen microorganisms. The directions of fermentation of sugars from molasses are different than those of starch from cereals and do not contribute to decreases in rumen pH, and in fact, the addition of molasses may reduce the risk of ruminal acidosis. During the rumen fermentation of sugars from molasses, a significant amount of butyrate is produced, which, by positively influencing the development of the rumen papillae and mucosa, ensures better absorption of nutrients from the rumen.
The content of total protein in molasses is low and is around 12-16%. in DM The total protein of molasses consists mainly of nitrates, free amino acids (such as glutamic acid, aspartic acid, leucine, tyrosine, arginine and histidine) and nitrogenous bases (betaine, guanine, xanthine). Among these compounds, the biological role of betaine should be emphasized, which, like methionine, may contribute to reducing problems with fatty liver disease. If the dosage of molasses is too high, the product resulting from the breakdown of betaine may unfortunately give the milk a slightly fishy taste.
Molasses is low in fat-soluble vitamins. As for water-soluble vitamins, especially those from group B, molasses is characterized by a low concentration of thiamine. Molasses, especially cane molasses, contains significant amounts of biotin, which has a positive effect on fertility, production results and hoof health.
The minerals that make up the raw ash constitute approximately 10-12% of molasses. in DM Beet molasses contains particularly high potassium and sodium content, and relatively low calcium and phosphorus content. Potassium salts may constitute up to 1/3 of the ash content. The high potassium content in molasses may result in poorer utilization of other minerals (e.g. Ca, Mg) from the dose, and additionally has a laxative effect. Molasses also contains relatively much sulfur (approximately 5.6 g/kg DM). Given the high potassium content in molasses, it is important to properly balance the other ingredients.
Molasses is a good addition to summer doses
F: Have the composition and properties of molasses used in cattle feed changed over the years?
Initially, the term molasses referred to the final product obtained in the sucrose production process, after evaporation, crystallization and centrifugation of sugar beet or cane juice. Currently, several types of molasses are classified and it is generally assumed that any liquid ingredient from sugar production containing more than 43% sugars is called molasses.
Sugar mills can control the efficiency of sucrose extraction and, consequently, the sugar content of the molasses produced. Currently used sugar production technologies allow for its more effective extraction and acquisition, which means that its content in molasses is reduced and, therefore, its energy value is lower.
As for the total protein contained in molasses, it consists of non-protein nitrogenous substances (nitrates, amides, amino acids) and their content in molasses depends largely on fertilization and soil conditions. Of course, more effective sucrose acquisition and lower sugar levels in molasses result in a slight increase in the total protein content in the dry matter of molasses.
Although molasses does not contain many vitamins, their content in this feed varies greatly depending on the sugar production process and the length of the feed storage period.
F: In what feeding systems is it worth introducing molasses into the cattle diet?
Molasses, due to its specific chemical composition (high sugar content), can be an interesting element of the cattle feed, because it increases its palatability and increases feed intake, and also increases the energy value of the feed. The high content of easily fermentable sugars (mainly sucrose, as well as glucose and fructose) is a good source of energy for rumen microorganisms. This stimulates their development and translates into improved digestibility of the entire ration. Therefore, molasses will work well in rations rich in feed with high fiber content, especially those of lower quality, because by stimulating the growth of bacteria it will improve the digestibility of the fiber and thus the entire ration. Improved feed digestibility resulting from the addition of molasses and generally better palatability of the feed result in higher feed intake.
Molasses, as a good source of energy quickly available to microorganisms, also worked well in feed rations with a high proportion of protein that is quickly degraded in the rumen – pasture feeding, feeding large amounts of grass or alfalfa silage, introducing urea into the rations. Thanks to the energy quickly released from molasses, bacteria make good use of the ammonia produced from protein breakdown in the rumen. This results in better utilization of the protein in the ration, increases the production of protein by microorganisms, reduces the concentration of ammonia in the rumen fluid and, consequently, reduces the concentration of urea in blood and milk.
Due to the high potassium content, molasses is a good addition to doses in the summer, when animals, experiencing high temperatures, sweat and lose some amounts of this ingredient through sweat. The introduction of molasses may improve the intake of dry matter of the dose, which decreases during hot weather, and supplements potassium. Please remember to provide mineral licks with other minerals.
In what food doses does molasses work best?
F: What dosages of molasses are optimal for feeding ruminants and are there any age restrictions (calves) for feeding this product?
The share of molasses in the ration depends on the group of animals to which it will be fed and on the composition of the entire ration.
- In the case of dairy cows, when using doses rich in high-energy feeds – corn silage, concentrates – it is recommended that the share of molasses does not exceed 10-15%. taking the dry weight of the dose.
- In doses with a high share of fibrous roughage (grass and alfalfa silage, hay, straw) and a smaller share of concentrated feed, it is estimated that the share of molasses in the dose may increase to 15-20%. dry weight of the dose.
- However, the most often recommended dose during lactation is up to 1-2 kg/day. There are also studies indicating the positive effects of using higher doses – up to 2-3 kg/day. However, it is not recommended to use large doses of molasses – about 5-6 kg/day, because with increased butyric fermentation stimulated by molasses, the risk of dietary ketosis increases.
Molasses may be an interesting element of the diet for dry cows, especially in the first dry period, when fed with large amounts of fibrous feed. It should be limited or eliminated from doses during the pre-calving period. Due to the high potassium content, it may disturb Ca metabolism and increase the risk of hypocalcemia. The recommended amount of molasses in doses for dry cows is up to 1 kg/day. When using molasses before the entire dry period, it is advisable to determine the cation-anion balance (DCAD) in the doses for cows before calving and possibly introduce anionic salts into the dose. Molasses can even be a good carrier for salts that are unpalatable, and they will be more willingly consumed with molasses.
Molasses can also be a good component of rations for beef cattle, in which its share can be up to 20%. dry weight of the dose.
- In the case of beef cattle weighing up to 200 kg, this may amount to up to 0.5 kg of molasses per day.
- Older animals with higher body weights may receive up to 1-2 kg/day.
There are also known studies with a higher share of molasses in doses, without a negative impact on the growth of animals. It should be remembered here that, as in the case of dairy cows, a higher proportion of molasses is more advisable when feeding rations with a high proportion of grass silage. Molasses will also work well in doses with the addition of urea.
- Molasses should not be fed to calves during the milking period.
- It can be administered to older calves in an amount of up to 0.5 kg/day, similarly to breeding heifers.
It can often be an ingredient of granules, used as a bonding component and improving the palatability of feed.
When introducing molasses into food rations, remember that due to the high content of sugars and potassium in molasses, it should be done gradually over a period of several days. It is also important to provide animals with access to licks or mineral mixtures to maintain the appropriate proportions of minerals – Na, Mg, Ca.
F: To what extent can the use of molasses in cattle feed translate into the achieved production results (body weight gain, milk production)?
It is difficult to clearly indicate what effects, such as increased milk production or increased body weight gain, can be expected after introducing molasses into the diets of dairy cows or fattening animals. It is easier to describe in more general terms the benefits of molasses in doses.
The introduction of molasses into the diet supports the prevention of metabolic diseases
This feed, used in appropriate doses, increases the intake of dry matter of the feed and the availability of energy and digestible protein from the feed. In the case of dairy cows, this translates into an increase in milk production and improvement of its composition, as well as extending the durability of the lactation curve. Research and practice indicate that due to a different direction of fermentation than in the case of feeds rich in starch, replacing some of them with molasses reduces the risk of ruminal acidosis and damage to the rumen mucosa. At the beginning of lactation, better palatability and digestibility of the dose stimulates feed intake, and consequently reduces body weight loss and the incidence of ketosis and has a positive effect on reproductive results.
In the case of beef cattle, the use of molasses from the beginning of fattening increases the attractiveness of the dose at the beginning of fattening. Better digestibility of the doses and the use of protein from them, which is especially important in the case of doses with urea, influences the increase in daily growth and improved feed conversion rates. Importantly, there are no significant changes in carcass quality (color, marbling, meat tenderness).
