Characteristics of modern mineral feeds for fattening pigs, sows and piglets

Optimal body condition for parturition and for subsequent milk production is important in sows. The pregnant sow must also receive sufficient nutrients for the embryonic growth of the piglets through the feed. The better the supply, the more consistent and higher the average weight of the piglets in the litter. To ensure this, mineral feeds for pregnant sows must have a balanced supply of amino acids. In the low-bearing phase (days 1-84 of gestation), the feeding recommendation is 14.6 g of lysine, and in the high-bearing phase (days 85-115), 20.4 g per animal per day.

However, sow farmers should also ensure a moderate calcium and phosphorus supply with the help of the gestation mineral. Too high a calcium content and a calcium/phosphorus ratio above 2:1 reduce the utilization of phosphorus and magnesium as well as a number of trace elements. On the other hand, an excessively high phosphorus supply and a narrow calcium/phosphorus ratio leads to demineralization of the bones. The supply recommendations for pregnant sows are 6.0 g calcium and 4.5 g phosphorus per kilogram of feed. An adequate supply of vitamins keeps the animals' metabolism and immune system stable. Vitamin E in particular can help prevent fetal death in the early stages of pregnancy. The German Agricultural Society (DLG) and the Society for Nutritional Physiology (GfE) recommend at least 15 International Units (I. E.) of vitamin E per kg of feed for a supply that meets requirements. However, the levels in common mineral feeds are usually much higher to take advantage of the antioxidant effect of vitamin E.  Vitamin E protects cells from the influence of free radicals and thus prevents their harmful effect on the organism.

After farrowing, sows need to get back to eating quickly. Only in this way are they able to produce sufficient milk to supply their piglets and quickly regain their strength after the strenuous birth. Mineral feeds for sows in the suckling phase should therefore contain a safety supplement to meet the increased requirements resulting from high milk production, strong growth of the piglets and natural fluctuations in the ingredients of the basic feeds. Highly available calcium sources (e.g. calcium formate) are also used in high-quality sow mineral feeds. In this way, the body's own mobilization of the mineral from the bones can be kept to a minimum and the sow has sufficient calcium available for milk production.

The use of L-carnitine is also useful in the suckling phase. The vitamin-like substance transports fatty acids to the site of processing and thus promotes more effective energy utilization. As a result, milk yield increases, which promotes rapid piglet gain. The sows must not over-seed during lactation, which is why the use of synthetic amino acids is mandatory for muscle maintenance and milk production.

On-farm feeds are usually used for the first time after weaning of the piglets. Weaning and the - in most cases associated - new housing means stress for the young animals. Stress in turn reduces growth, leads to immunosuppression and ultimately increases susceptibility to diseases (e.g. diarrhea). To cope with the changeover, a piglet supplement is used after weaning (30-50% of the total piglet ration), which contains milk components and other highly digestible components (e.g. digested cereals).

From about twelve kg live weight, piglets also receive a ration consisting of various basic feed components and a mineral feed. The piglet mineral feed not only provides all the essential components for a balanced ration, it also safeguards this by adding acid. Piglets are not yet able to produce sufficient gastric acid, which serves to acidify the feed slurry and activate protein digestion. Various acids such as formic, lactic or fumaric acid or their salts are used in the ration. Other safety components in mineral feeds include probiotics, which positively influence the microflora in the small intestine and thus reduce pathogen attachment to the intestinal wall.

In addition, additives such as phytases and NSP enzymes are indispensable in modern mineral feeds for piglets. In order to increase the digestibility of the feed with the help of these enzymes, legal minimum dosages must be observed. NSP enzymes in particular reduce the viscosity of the feed slurry in the intestine by digesting non-starch polysaccharides - of which the animals are otherwise incapable. The resulting "more fluid" intestinal contents improve the overall utilization of the nutrients in the feed, as the enzymes are thus better able to reach their site of action.

In the feeding of fattening pigs, the focus is on growth and a high meat content. Mineral feeds can support this and ensure that the ration is adequately supplied with amino acids. At the same time, the protein content of the total ration can be reduced and nutrient management improved. The phytases contained in mineral feeds optimize phosphorus utilization and thus reduce the animals' P excretion. As a result, animals excrete less excess nitrogen unused. NSP enzymes also ensure (as in piglets) better digestibility of nutrients and higher energetic utilization of feed components.

Fattening pigs also need sufficient calcium for stable bone growth and skeletal development that keeps pace with meat gain. The calcium required for this must be supplied to them in sufficient quantities via a mineral feed. The recommendations are 7.0 g of calcium per kg of feed for pre-fattening, 6.0 g for mid-fattening and 5.5 g for finishing.