By Mieke Zoon
For many decades the focus for sow farmers has been on increasing the number of total weaned piglets per sow per year. This number has been steadily rising, with more and more farmers now reaching the impressive number of 35 piglets weaned per sow per year. However, society has become more concerned about animal welfare, increasing the pressure on farmers to house gestating sows in groups, reduce lameness in sows and improve the vitality of piglets. Live weight of newborn piglets has been one of the main challenges with the increasing litter sizes and decreasing weaning age in many markets. Birthweight is seen as a very important indicator for performance in later life. Optimizing nutrition is generally accepted to be very important to meet these higher performance standards, while protecting the welfare of the sow. The approach can however be very different ranging from decreasing stress (from hunger) in gestating sows through ad libitum feeding, or stimulating fermentation in the lower gut (slow nutrient release over time), to stimulation of milk production with specific raw materials (branched chain amino acids, linoleic acid, highly digestible protein sources) or in general feed intake in lactating sows. These different approaches can be successful, but will need to be supported by optimal mineral supplementation for the best results.
Mineral supplementation
For development, growth and immunity, mineral supplementation is essential in all phases of life. For highly prolific sows the most important body functions related to minerals are described here.
Zinc
Zinc is essential to maintain healthy skin and claws. This is very important for sows, as lameness normally decreases feed intake, and therefore body condition and fertility. In addition, zinc is a critical element for many immunological processes to support general health. Finally, it is involved in carbohydrate metabolism and reproduction.
Copper
Copper is involved in many processes in the body, with the main ones being the development of bone, connective tissue and collagen, the formation of hemoglobin, acting against free radicals in the body (anti-oxidant) and supporting immunity.
Manganese
Manganese is important for the proper function of many proteins and carbohydrates, fertility, growth and development, as it is necessary for the formation of bone and joint cartilage, and neurological function. Together with zinc, fulfilling the sow’s requirement for manganese is key to prevent lameness (supports both claws and skeleton).
Iron
Iron in combination with proteins and copper forms hemoglobin, essential for oxygen supply. Iron is needed continuously to provide hemoglobin for newly produced red blood cells.
An additional challenge for the highly prolific sow is the changing mineral requirements depending on phase of production. The first phase is the development of the foetus, and replenishing the body
reserves (body condition and bone mineralization). The second phase is the growth of the foetus, followed by the parturition, and colostrum and milk production, followed by a dry period and insemination. Successfully fulfilling the mineral requirements is important for both the reproductive success and performance of the offspring. However few studies have been performed to define the mineral requirements of highly prolific sows used today, which means that many sow feeds include high amounts of minerals to fulfill requirements.
Optimizing mineral supplementation
Absorption of minerals is limited because of antagonisms and interactions with feed components. Formation of insoluble, or too big to be absorbed, complexes with other components in the feed, limit availability of minerals for the animal. In addition, some minerals compete for the same transporters and metabolic processes for absorption, which limits the availability of these minerals or vitamins for the animal. Interactions between minerals are always present and still new interactions are found, which indicates the complexity of meeting mineral requirements (figure 1). It is certain however, that simply increasing the supplementation levels is often not the solution to meet mineral requirements.
Organic trace minerals
The negative effects of interaction with feed components and competition for absorption on bioavailability can be reduced by combining the mineral with an organic ligand. Inorganic mineral forms (e.g. sulphates) are very weakly bound and are therefore free to interact. Organically bound minerals are not reactive, which will prevent complex formation. Moreover, competition for absorption can be avoided partly by absorption using the pathway(s) of the ligand.
Source: Pancosma