Molasses in young pigs' diets

Dr Ioannis Mavromichalis
Can molasses, beet or cane, be used in diets for young pigs? Is it a sweetener, an energy source, or a lactose replacement? In times of high-lactose prices, non-traditional alternatives always resurface with renewed interest and even more questions! So, let me explain…

Can molasses, beet or cane, be used in diets for young pigs? Is it a sweetener, an energy source, or a lactose replacement? In times of high-lactose prices, non-traditional alternatives always resurface with renewed interest and even more questions! So, let me explain…
Molasses is rarely used in piglet diets, mostly as a pelleting aid and perhaps as a sweetener. Molasses, after all, contains around 50% simple sugars (sucrose, glucose, and fructose). But, molasses also contains relatively high levels of potassium (around 4%), which have been blamed for increasing incidences of diarrhea in weaned pigs. Nevertheless, such claims are not supported by scientific literature and any such scours are more likely to occur from an overload of sucrose!
The high concentration of simple sugars in molasses definitely makes it a good candidate for lactose.
• But, can piglets really use molasses instead of lactose?
• Isn't sucrose toxic for young pigs?
Yes, that is correct; sucrose is toxic for pigs, but only during the first week of their life. After that, they can metabolize sucrose normally. Actually, as early as the 1950s, it was discovered that sucrose, and its components - glucose and fructose - can replace effectively all lactose in diets for young pigs. And molasses is just that, a viscous liquid solution of sucrose, and free glucose and fructose. So, let's see finally if molasses can replace lactose in practical diets!
Trials conducted
In a series of trials we conducted some time ago (time flies fast!) at Kansas State University, we replaced pure crystalline lactose with molasses and sucrose in practical diets for early weaned piglets. Not surprisingly, piglets did not scour, not even when molasses was included at 20% of the diet! Not only that, but piglets on diets with molasses actually grew faster than piglets on lactose or sucrose. Whether this was an effect of taste or because of higher energy availability (fructose is being absorbed from a channel parallel to that of glucose) is unknown. What was clear is the fact that piglets thrived on diets with very high levels of molasses.
Practical tips
Since then, I have often created diets with high levels of molasses, so here are some practical tips.
• First, it is best to use a high quality molasses . It always pays as this policy avoids unexpected surprises regarding molasses consistency and viscosity!
• Second, make sure such high levels of molasses can be physically mixed in at the feed plant you're using for your piglet diets.
• Third, when pelleting diets with molasses , always lower the pelleting temperature (less steam) as pellets burn quite easily (Maillard reaction).
• Fourth, if scours do occur with high-molasses diets, check the electrolyte balance and consider adding extra fiber.
• Fifth, and final comment, don't start using high levels of molasses immediately - experiment with 5-10% levels using your locally available source of molasses and existing diets!
For those wanting some more in-depth reading on the topic, here's the link to our trials:


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    noni ward

    I have been using molasses now for some time in weaner diets and I find the weaners blossom on this diet.

    what i would like to know is what honey will do to the pig

    Will it increase the weight of the pig at a greater weight or will it advance at the same rate as the molasses?

    Honey is readity available and easily usable, and this is also so with molasses. Also the use of glucose which is also readily available for the same reason in weaner diets could be an option to gain weight quicker.

    I would be interested in as answer to some of these ideas and questions

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    It is very intresting topic.Could you tell me the quality standard of Molasses?
    thank you

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    ogbechie H.O

    since it contain energy and other micro nutrients. i agreed to the usage,but i need to practicalise it since not yet known to us in Nigeria, we need more informations inorder to educate farmers on the useage.thanks

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    can molasses be added to the weaner feed?

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    Isaiah Tumwesigye, Kisoro Uganda

    I have picked interest in using molasses for pigs but here in Uganda it is used to make local spirits known as Waragi. cant it have an alcoholic impact on pigs as it happens when by product of breweries? i would be interested in the answer before i start using.

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    I want to give 20% of molasses to my 4 months pigs in their feed.any danger in that amount?I can get this easily in Kenya.

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    kazu tamaki

    Dear Dr.Yanni,
    It is very intresting topic.
    How is it in comparison of molasses and glucose? If there is a standard of good molasses, please let me know. Thank you.

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    Franz Waxenecker

    Not scouring of the piglets in these trials is not that surprising after these diets contained 2,6 resp. 3,9 kg ZnO per ton of feed. What would you exptect in ZnO-free diets? best regards

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    Ioannis Mavromichalis

    • Honey and glucose are also simple sugars and nutritionaly, they should behave like lactose giving comparable performance.

    • Quality in molasses is usually measured in terms of concentration of inverted sugars, total sugars, and of course, non-protein nitrogen, which should be minimal. Ash content should also be minimal.

    • Raw, unfermented molasses, has no alcoholic effect on pigs. I don’t know about how molasses fermenation by-products behave on this aspect, but it should depend on residual alcohol content.

    • In our trials, we used up to 20% molasses without adverse effects. But, do pay attention to the precautions described above before using such high levels of molassses.

    • Molasses contains free glucose, free fructose, and sucrose. So, all these compunds should behave the same, from a nutritional point of view. Molasses, also contains other nutrients/substances that require special attention, as described above.

    • The perceived ‘scour’ effect of molasses is nutritional (secretory diarrhea) and not pathogenic. Unless there are secondary pathogenic complications, diets without antimicrobial agents should be (or not) equally prone to secretory diarrhea as diets with such agents.

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    paul luyimbazi

    nice and eye opener. can i feed my pigs on left over soda? i work in pepsi soda depot and there is a lot of left over soda in bottles, i have collected over 1000 litres

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