Corn is the king of feed and the main source of energy in pig diets. It usually accounts for more than 60% of pig compound feed, and its quality directly affects feed quality and utilization. New corn is now coming onto the market in large quantities. How can you select high-quality new corn and prevent it from causing severe diarrhea? As everyone knows, this type of diarrhea generally does not respond to medicationTreatmentis ineffective, reduces feed conversion, slows pig growth, and lowers daily weight gain,猪病通’s licensed veterinarian Li Min shares advice on selecting new corn for pig farms, common problems when using it, and solutions.
I. How Pig Farms Should Select New Corn
The basic criteria for selecting new corn are: moldy kernels below 1%, impurities below 1%, and moisture content preferably controlled below 14%, since high-moisture corn is also prone to mold and spoilage during storage.
1, Check whether the new corn is moldy
Moldy corn generally has husks that separate very easily. Examine the germ: if there is a large black or dark gray area inside the corn germ, the corn is moldy; a small black spot at the bottom indicates good-quality corn. In terms of taste, good corn gets sweeter the more you chew it, while moldy corn tastes very bitter when chewed. In terms of fullness, moldy corn is less dense and its kernels are not plump; if you take a handful and put it in water, some kernels will float.
2, The moisture content of new corn should not be too high
For use at pig farms, the moisture content of new corn should preferably be controlled at 14%-15%. Excessive moisture in new corn can lead to mold during storage. High moisture can damage active components such as vitamins in the diet, reduce the diet's metabolizable energy and crude protein levels, and disrupt the balance among nutrients in the diet; in severe cases, it can affect pig growth.Pig diseasesVeterinarian Tong recommends the simplest way to tell: hold a large handful of corn in your hand—it should feel prickly; it should be difficult to crush a kernel with your fingers, and biting it should make your teeth vibrate.
3, Choose new corn with large, plump kernels
Corn kernels that are large and plump generally have a high starch content, a sweet taste, and good palatability. They are easy for pigs to digest and have a relatively high conversion rate, making them a high-quality feed for pigs. Avoid selecting shriveled, small-kernel corn, which tends to contain more impurities, yields less corn starch when ground, is less palatable, and has a lower utilization rate.
4 Choose naturally air-dried corn whenever possible
Naturally air-dried corn is plump and has a shiny surface. By contrast, much of the kiln-dried corn is either immature or spoiled. After drying, it generally has a more wrinkled surface, is less plump, and lacks a fresh sheen. Corn contains relatively high levels of fatty acids, so ground cornmeal can easily turn rancid.
II. What common problems arise when using new corn in pig farming?
1 New corn can easily cause diarrhea in pigs
When pigs develop diarrhea after eating new corn, many people mistakenly assume it is caused by the corn's high moisture content. In fact, excessive moisture in new corn does not cause diarrhea; it only increases pigs' feed intake and reduces their water intake, while making the feed more prone to mold and spoilage.
The main reason new corn causes diarrhea is that it contains a type of macromolecular polysaccharide that pigs do not readily absorb. It is highly viscous and is not absorbed; eating even slightly too much can cause indigestion and lead to diarrhea. Some pig farmers believe that new corn has low nutritional value and add vegetable oil to feed containing it. This has the opposite effect, making the pigs' diarrhea even more severe.
2 Feed conversion rate declines
Corn is a crop that continues to mature after harvest and has the highest resistant starch content. Its resistant starch content only decreases after storage for 5-6 weeks. In newly harvested corn that has been dried, starch denaturation increases the amylose content, making it unavailable for animals to absorb and utilize and affecting digestibility to some extent.
3, Mycotoxin contamination:
Most farmers usually believe that corn only becomes moldy during storage. In fact, when newly harvested corn is mechanically threshed, many kernels are damaged during the process. Newly harvested corn has a high respiration rate, and the presence of broken kernels increases heating and mold growth during short-term storage, reducing its feed value. Pigs can easily suffer mycotoxin poisoning after eating it.
4, Reduced feed intake:
When newly harvested corn is heavily contaminated with mold, its palatability worsens, and pigs’ feed intake decreases. This can lead to inadequate nutrient supply, reduced resistance and immunity, and the onset of disease.
III. How can this problem be addressed?
1, Extend the aging period: Dry, winnow, and sort newly harvested corn, then store it for 5-6 weeks before use. This can basically eliminate the effects of resistant starch and reduce the adverse effects of feeding newly harvested corn to pigs.
2, Use partially: Mix some newly harvested corn with aged corn,Swine diseasesConsult a licensed veterinarian about mixing old and new corn over a one-month transition period, gradually increasing the proportion of new corn to reduce the effects of resistant starch.
3. Before using new corn, screening and winnowing can effectively reduce the amount of broken kernels and impurities in the corn. A mold inhibitor can be added to the feed to reduce mycotoxin contamination and thereby lessen harm to pigs; palatability can also be improved.
4. Feed made with new corn has a higher moisture content and should not be stored for long. It is best to prepare it just before feeding.
I. How Pig Farms Should Select New Corn
The basic criteria for selecting new corn are: moldy kernels below 1%, impurities below 1%, and moisture content preferably controlled below 14%, since high-moisture corn is also prone to mold and spoilage during storage.
1, Check whether the new corn is moldy
Moldy corn generally has husks that separate very easily. Examine the germ: if there is a large black or dark gray area inside the corn germ, the corn is moldy; a small black spot at the bottom indicates good-quality corn. In terms of taste, good corn gets sweeter the more you chew it, while moldy corn tastes very bitter when chewed. In terms of fullness, moldy corn is less dense and its kernels are not plump; if you take a handful and put it in water, some kernels will float.
2, The moisture content of new corn should not be too high
For use at pig farms, the moisture content of new corn should preferably be controlled at 14%-15%. Excessive moisture in new corn can lead to mold during storage. High moisture can damage active components such as vitamins in the diet, reduce the diet's metabolizable energy and crude protein levels, and disrupt the balance among nutrients in the diet; in severe cases, it can affect pig growth.Pig diseasesVeterinarian Tong recommends the simplest way to tell: hold a large handful of corn in your hand—it should feel prickly; it should be difficult to crush a kernel with your fingers, and biting it should make your teeth vibrate.
3, Choose new corn with large, plump kernels
Corn kernels that are large and plump generally have a high starch content, a sweet taste, and good palatability. They are easy for pigs to digest and have a relatively high conversion rate, making them a high-quality feed for pigs. Avoid selecting shriveled, small-kernel corn, which tends to contain more impurities, yields less corn starch when ground, is less palatable, and has a lower utilization rate.
4 Choose naturally air-dried corn whenever possible
Naturally air-dried corn is plump and has a shiny surface. By contrast, much of the kiln-dried corn is either immature or spoiled. After drying, it generally has a more wrinkled surface, is less plump, and lacks a fresh sheen. Corn contains relatively high levels of fatty acids, so ground cornmeal can easily turn rancid.
II. What common problems arise when using new corn in pig farming?
1 New corn can easily cause diarrhea in pigs
When pigs develop diarrhea after eating new corn, many people mistakenly assume it is caused by the corn's high moisture content. In fact, excessive moisture in new corn does not cause diarrhea; it only increases pigs' feed intake and reduces their water intake, while making the feed more prone to mold and spoilage.
The main reason new corn causes diarrhea is that it contains a type of macromolecular polysaccharide that pigs do not readily absorb. It is highly viscous and is not absorbed; eating even slightly too much can cause indigestion and lead to diarrhea. Some pig farmers believe that new corn has low nutritional value and add vegetable oil to feed containing it. This has the opposite effect, making the pigs' diarrhea even more severe.
2 Feed conversion rate declines
Corn is a crop that continues to mature after harvest and has the highest resistant starch content. Its resistant starch content only decreases after storage for 5-6 weeks. In newly harvested corn that has been dried, starch denaturation increases the amylose content, making it unavailable for animals to absorb and utilize and affecting digestibility to some extent.
3, Mycotoxin contamination:
Most farmers usually believe that corn only becomes moldy during storage. In fact, when newly harvested corn is mechanically threshed, many kernels are damaged during the process. Newly harvested corn has a high respiration rate, and the presence of broken kernels increases heating and mold growth during short-term storage, reducing its feed value. Pigs can easily suffer mycotoxin poisoning after eating it.
4, Reduced feed intake:
When newly harvested corn is heavily contaminated with mold, its palatability worsens, and pigs’ feed intake decreases. This can lead to inadequate nutrient supply, reduced resistance and immunity, and the onset of disease.
III. How can this problem be addressed?
1, Extend the aging period: Dry, winnow, and sort newly harvested corn, then store it for 5-6 weeks before use. This can basically eliminate the effects of resistant starch and reduce the adverse effects of feeding newly harvested corn to pigs.
2, Use partially: Mix some newly harvested corn with aged corn,Swine diseasesConsult a licensed veterinarian about mixing old and new corn over a one-month transition period, gradually increasing the proportion of new corn to reduce the effects of resistant starch.
3. Before using new corn, screening and winnowing can effectively reduce the amount of broken kernels and impurities in the corn. A mold inhibitor can be added to the feed to reduce mycotoxin contamination and thereby lessen harm to pigs; palatability can also be improved.
4. Feed made with new corn has a higher moisture content and should not be stored for long. It is best to prepare it just before feeding.