Nutritional technical strategies for suckling piglets in late autumn & winter season

The temperature difference between day and night in autumn and winter can reach more than 10 ℃, which will lead to a leap increase of diarrhea in suckling piglet. The diarrhea rate of the whole group even exceeds 30%; the mortality rate of piglets during lactation and nursery period reaches 20-30%, and the growth rate decreases by 30%. The FCR of the whole group increases and even turn into cad pig. Antibiotics Growth Promoter was completely banned in feed in July 2020. When the intestines of suckling piglets lost the protection of AGP, the diarrhea, survival rate and growth rate cannot be ensured in Autumn and Winter season. Feed companies may face many problems such as increased complaints, market instability, and service pressure.

After successfully solving the first stage challenges of the AGP-free, are you ready for the second stage? Here we sorted out the influencing factors and solutions of piglet diarrhea in autumn and winter, hoping to provide assistance that can help to successfully pass the second stage.

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1. Influencing factors of diarrhea in suckling piglets in autumn and winter

1.1 Physiological factors (internal factors)

-Small stomach volume and insufficient gastric acid secretion

The stomach volume of newborn piglets is 30-40mL, pH value 5-6 and will drop to 4 a few hours after drinking colostrum; the stomach volume of weaned piglets is 100-150mL, and the pH maintained around 4; the stomach volume of adult pigs is 8L, and the pH is 2-3.It can be seen from these data that suckling piglets have a small stomach volume and insufficient gastric acid secretion, which directly leads to weak digestibility in protein and the gastric acid can hardly play a bactericidal function.

-Imperfect intestine development

The length of the small intestine for the newborn piglets is only 3.5m, and that of adult pigs is 20m. It shows that the intestinal development of suckling pigs is not well-developed, the digestion, absorption capacity and barrier function are weak.

-Low digestive enzyme activity

The lipase and amylase activities of suckling pigs gradually increase after birth, and the pepsin activity only starts to increase after 2 weeks of birth, and the trypsin activity has been in a low activity state. It shows that suckling piglets have weak digestion ability of various nutrients, especially inadequate digestion of protein. Undigested and absorbed protein enters the hindgut to ferment, increasing the risk of diarrhea.

Figure: Changes in digestive function (digestive enzyme activity) of piglets before and after weaning

1.2 Stress factors (external factors)

-Management stress

In actual production, in order to improve the efficiency of pig farming, forced weaning is an inevitable management measure.Weaning will bring a series of stress, like change of feed，transition of houses and psychological stress. These stresses lead to the destruction of intestinal structure and function.

A. After weaning, an "empty period" condition occurs in the intestine, which leads to a decrease in the tight junctions between intestinal epithelial cells, an increase in intestinal permeability, and an intensified inflammatory response. Thus, the small intestine villi grows shorter and even fall off, the villi surface changes from a high-density digital to a ligule form, and the crypts are deepened. As a result, the digestion and absorption area is reduced, and the absorption and digestion capacity is further decreased.

B. When the structure of the intestine is destroyed, the intestine cannot perform its digestion, absorption and barrier protection functions as before, resulting in abnormal conditions such as diarrhea, decreased feed intake, slow growth, and high FCR in production. Part of the herds can recover in 2 to 3 weeks, and the rest herds may not be able to recover for a long time, and even becoming susceptible and cad pigs.

-Environmental stress

In autumn and winter, the temperature difference between day and night could be more than 10 ℃, and the changes also goes to temperature, humidity, and air quality in the pen, which will have following four adverse effects:

A. The large temperature difference leads to a stress response in piglets

Oxygen free radicals are heavy produced in the body, which will damage the structure of the intestine and increase the risk of diarrhea.

B. The cold concrete floor or the air leaking floor causes the piglet's belly to catch cold

Speed up gastrointestinal peristalsis to cramps, increasing the chance of diarrhea.

C. The increase of pathogenic bacteria and toxic and harmful gases damages the health of piglets

Insufficient ventilation while maintaining heat preservation will cause the following two harms:

Increase in humidity and possibility of feed mildew and the growth of bacteria in the pen, which may increase the risk of diarrhea (diarrhea reaches 60% when the humidity exceeds 70%).

The increase in the concentration of ammonia, hydrogen sulfide, and carbon dioxide, which stimulates the respiratory tract of pigs, increases the chance of asthma and coughing, makes the pigs in a sub-healthy state and reduces production performance.

D. Indigestion caused by increasing feed intake to maintain body temperature

If the protein digestibility of the feed is low and the content of anti-nutritional factors is high, it will further increase the risk of intestinal structure destruction and break the balance of flora, thereby increasing the rate of diarrhea.

In order to adapt to the physiological characteristics of digestive track in suckling piglets, to deal with the adverse effects of weaning and environmental stress in autumn and winter, feeding management and nutrition control measures must keep up.

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2 Anti-diarrhea solutions for suckling piglets in autumn and winter

2.1 Strengthen management and reduce stress

A. Temperature: heat preservation in the pen, adjust the room temperature to constant at 25-28℃, increasing pad thickness and heating the floor to reduce the temperature difference on the ground

B. Humidity: proper ventilation and heating to control the humidity in the house below 65%

C. Sanitation: Proper ventilation, reduce the concentration of harmful gases in the house, clean up the remaining materials in time, and disinfect regularly

2.2 Nutrition regulation and intestinal health

When designing feed formulations, a reasonable nutrient level, nutrients supply structure, raw material source of nutrients, proper use of feed additives should be carefully considered to adapt to the intestinal physiology of suckling piglets and respond to various stresses to reduce the risk of diarrhea.

A. Reasonable nutrient levels: decrease protein level, increase energy level and the ratio of amino acids

B. Optimize nutrient structure: the energy supply structure is realized through the combination of monosaccharides, disaccharides, starch, and fat; the protein supply structure is realized through a pyramid model with amino acid, peptides, and protein

C. Accurate selection of nutrient source: the high total amount of absorbable nutrients provided by the nutrient source; the toxic and harmful components in the nutrient source (mycotoxin in energy raw materials, histamine in fish meal, antigen in soybean proteins, and oxidation products in oil and oil raw materials, etc.)

D. Reasonable combination of functional additives: use flavors, sweeteners, etc. to increase feed intake; use acidifiers, enzyme preparations, etc. to improve digestion. use butyric acid, which is beneficial to intestinal cell proliferation and differentiation, zinc oxide, which enhance tight junction between the cells, plant essential oils, which have anti-oxidation and anti-inflammatory functions, and small molecule active peptides, which have the above three effects to promote repair after intestinal injury; use acid preparations, antibacterial peptides, etc. for antibacterium and sterilization.

It can be seen that protein is in a very important role in the nutrition regulation measures for controlling suckling piglet diarrhea in autumn and winter! Good protein nutrition can effectively help intestinal health (promote intestine development, reduce intestine damage, promote repair after intestine damage, etc.). Well, how to design a good protein nutrition? Let's see the measures recommended from Mytech company.

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3 Protein nutrition strategy for anti-diarrhea of suckling piglets in autumn and winter

3.1 Protein level (high energy and low protein)

There is a large temperature difference during the alternating seasons, and the indigestion of protein by suckling piglets is a key factor that causing diarrhea. Usually low protein diet is our first choice. Generally, the protein level of suckling pig feed is 3% less than that of animal’s needs. Therefore, the high digestion, absorption and deposition efficiency of protein must be ensured in order to achieve growth potential. At the same time, when the temperature decreases, the suckling piglets will keep warm by increasing the basal metabolism and heat production, thus the energy value of the feed needs to be improved. Below are the net energy, protein levels, and amino acid ratios recommendation for your reference.

3.2 Protein supply structure (pyramid supply model)

After the determination of dietary protein, we need to consider what protein raw material to be choosed, how much shall we use, whether the cost is optimized and if there’s any basis for judgment that can give answers to all the questions above?

The primary basis is the protein supply structure. In order to match the physiological characteristics of suckling piglets, a pyramid supply model that contains complete protein, small molecule peptides, and amino acids is indispensable.

3.3 Selection principle of nutrition source ("three high and one low")

What protein source should be selected to meet the requirements of protein level and supply structure? We propose the "three high and one low" principle for protein source selection.

-High nutritional value (total absorbable and deposited protein = protein * apparent ileal digestibility (AID) * deposition rate)

A. Protein content, excluding non-protein nitrogen, should be in high amount

B. Apparent ileal digestibility (AID) should be high

Different protein raw materials have different AID at different weight stages (see the Analysis & Protein Composition Characteristics In Vivo Digestibility Of Different Raw Materials for details). The AID of the entire diet at different stages should match the capacity of the suckling piglets at this stage.

AID of feed for piglets of about 6kg is 70%. (Yun et al. 2005)

AID of feed for piglets of about 10kg is 75%. (Blasco et al. 2005)

AID of feed for piglets of about 25kg is 85%. (Zhang et al. 2013)

C. High deposition rate (high content of small molecule peptides)

The deposition efficiency of small molecule peptides (2-3 peptides) is 1.5 times of amino acids (Le Guowei et al. 1998)

The diet provides 7g/d of weight gain for every 1g of small molecule peptides in the diet (that is a 4.8g/d of weight gain from every 1g of absorbable protein).

- High health care value

A. Low anti-nutrient content (reduce damage to the intestinal structure of suckling piglets)

Usually, there are six types of anti-nutritional factors mentioned in the feed for suckling pigs (see the Limit Requirements Of The Six Types Of Anti-Nutritional Factors In Suckling Pig Feed for details). A large number of studies have found that suckling piglets are particularly sensitive to two types of anti-nutritional factors.

β-Conglycinin (high contents in soy proteins): the total amount of β-conglycinin in the feed of 10-40d piglets should be less than 1%.

Histamine (high content in animal protein): the total amount of histamine in the feed of 28-60d piglets should be less than 5mg/kg.

B. High content of functional components (that help on the development of the intestine of suckling piglets and repair after injury)

It is beneficial to the proliferation, differentiation and structural integrity of intestinal epithelial cells: small molecular peptides (2-3 peptides), functional amino acids, etc

It is beneficial to enhance the tight junction between intestinal epithelial cells: small molecular active peptide (2-6 peptide), zinc oxide and etc.

It is beneficial to reduce intestinal inflammation: immunoglobulins and glycoproteins, small molecule active peptides (2-6 peptides), etc.

It is beneficial to enhance antioxidant capacity: small molecule bioactive peptides (2-6 peptides), taurine, etc.

- Low risk

A. The impact on formulation costs

B. Stability of quality (finished product and after days of storage), stability of supply and price sup and price

- High benefit

A. No biosecurity risks

B. Feeding effect on pigs: consider diarrhea rate of piglets, body weight after nursery, FCR, etc.

Analysis of the quality status of commonly used protein sources in suckling pig feed from nutritional value, health care value, risky factors