What does normal pig manure look like? In the complex conditions of pig farming, farmers seem to have forgotten. Nowadays, most farmers believe that as long as sows are not constipated, piglets do not have diarrhea, and the manure of grown pigs is black, it is normal. This is not actually the case.
I. Believing that black manure is good
Black manure in meat pigs may be related to intestinal disease. “Red skin, shiny coat, and black manure”—this is the biggest misconception based on appearance on large-scale farms. Whether manure is black has no necessary connection with the quality of the feed. Farmers’ belief that black pig manure means the feed is highly digestible is related to the fact that, in the past, rural pig farming relied mainly on sweet potato vines, vegetable tops, vegetable trimmings, and wild vegetables as feed. These green feeds are rich in chlorophyll and other substances, so pig manure naturally appears black. When a pig has a minor ailment, its feed intake drops, and pig farmers often “improve” its nutrition at that point by giving it more gruel and rice bran. The manure then becomes lighter or somewhat yellowish. Over time, this has led to the mistaken notion that black manure indicates high digestibility, while lighter-colored manure indicates low digestibility. In fact, feed digestibility and absorption are not measured by manure color, but by feed conversion and the feed-to-meat ratio.
II. High copper—black feces
Complete feed contains no green forage ingredients, so pig feces are not very black. However, to cater to customers’ preference for “black feces,” feed manufacturers often add substances that produce this effect. The most commonly used is copper sulfate (CuSO4·5H2O). It is reported that copper sulfate has some growth-promoting effect on piglets (similar to antibiotics), but has little effect on medium and large pigs. Adding high levels of copper to feed for medium and large pigs also causes copper residues to accumulate in pig liver and meat, affecting human health. Therefore, national feed standards stipulate that high copper may be used in piglet feed, but the amount must not exceed 250 milligrams/kg.
III. Identifying disease by feces
1, intestinal diseases
Sometimes black pig feces are not a good sign and may be associated with intestinal inflammation. “When early ulcers develop in the pig’s gastrointestinal tract, feed intake usually does not decrease, but the feces tend to be darker.” In the later stages of classical swine fever, button-shaped necrosis may occur in the gastrointestinal tract, and the pig’s feces may appear black to varying degrees.
2, incomplete digestion
If visible feed particles can be seen in a pig’s feces, this indicates that its digestive conversion rate is not good. Normal feces should be earthy yellow and banana-shaped. Feces that are too hard indicate that the animal is dehydrated or that intestinal motility is too low; some crude fiber can be added to the feed to aid digestion. Feed pigs some grass or sweet potato vines. Based on practical experience, feeding green fodder in summer is especially beneficial for digestion, but the problem is that the stems of sweet potato vines often clog slatted floors.
3, constipation in sows is normal
Constipation in sows is a symptom rather than a disease. Mild cases may cause loss of appetite, insufficient nutrient intake, lack of milk after farrowing, and the birth of weak piglets. If not addressed promptly, it may develop into a pathological condition. Severely constipated sows may also experience impaired digestive and absorptive function.
There are many sow health products, mainly aimed at regulating the gastrointestinal tract, improving reproductive capacity, and detoxification. Common products on the market include microbial preparations, probiotics, and Chinese herbal medicines. To prevent constipation in sows, many pig farms have increased the proportion of bran in feed. However, constipation in sows is not caused by insufficient bran. On the contrary, increasing the amount of bran without considering other factors can reduce sows’ energy intake and intensify heat stress in summer. In severe cases, sows may also fail to come into heat after farrowing.
4, piglet yellow and white scours
Yellow scours mainly occur in suckling piglets around 3 days old, while white scours mainly occur in piglets aged 10-20 days. The feces are initially thick and paste-like, then become loose and develop into yellow watery diarrhea. Loose feces often gush from the anus, and piglets rapidly lose weight, become dehydrated, and die from exhaustion. White scours are characterized by the passage of milky-white or grayish-white, thin, paste-like feces. The feces contain bubbles and have a distinctive foul odor. If the condition persists for several days, the piglets’ coats become dull, their conjunctivae turn pale, and they become cold-sensitive; they may later become runts.
Products for treating white and yellow diarrhea in piglets include antibiotics and egg yolk antibodies, as well as microecological preparations, enzyme preparations, acidifiers, and others that have become popular in recent years.
5, weaning diarrhea
Another type of loose stool is diarrhea in piglets caused by weaning stress around the time of weaning. This diarrhea usually has no odor. Farmers typically add some electrolytes and multivitamins to piglets around weaning to help them cope with stress. Some electrolyte products contain glucose and vitamins, while others have added amino acids. There is a wider range of antibiotics used for treatment; commonly used drugs include neomycin, colistin, amikacin, ceftiofur, enrofloxacin, florfenicol, and others. The drugs used, methods of administration, and treatment courses vary from farm to farm. Although the drugs may be commonly used, resistance rates also vary, which is related to the pig farm’s medication practices and the duration of use.