Mineral element nutrition

Mineral elements are an irreplaceable nutrient in the normal physiology and production of animals. Current research indicates that approximately 45 mineral elements have been detected in animal tissues. Animal nutrition is usually divided into constant and trace mineral elements according to its content in animals; the content of more than 0.01% of the main elements, including calcium, phosphorus, magnesium, sulfur, sodium, potassium, chlorine, etc.; Less than 0.01% is called trace element, and iron, copper, manganese, zinc, selenium, iodine, cobalt, molybdenum, fluorine, tin, nickel, silicon, arsenic, chromium, vanadium, niobium and the like are closely related to animal nutrition. With the advancement of technology, mineral elements have also appeared in new forms of addition, such as organic trace elements. This field has gradually become a hot spot in the study of mineral elements.

1 Classification of mineral elements

Mineral elements can be divided into the following two categories according to different sources. Mineral elements in the feed (such as sodium, potassium, chlorine, calcium, phosphorus and sulfur, etc.) and exogenous mineral elements. Exogenous mineral elements can be further divided into inorganic mineral elements (such as sodium, potassium, chlorine, calcium, phosphorus, magnesium, iron, zinc, copper, selenium, etc.), organic acid salts (such as acetate, citrate, Fumarate, gluconate, etc.) and organic trace elements (such as metal amino acid complexes, metal (specific AA) complexes, metal AA chelate compounds, metal polysaccharide complexes, metal protein salts, etc.).

2 Methods for the detection of mineral elements

2.1 Methods for the detection of inorganic mineral elements

GB/T 13885-2003 Determination of calcium, copper, iron, magnesium, manganese, potassium, sodium and zinc in feeds;

GB/T 6439-2007 Method for determination of chlorine content in feed;

GB/T 6437-2002 Determination method of phosphorus content in feed;

GB/T 17776-1999 Determination of sulfur in feeds - Magnesium nitrate method;

GB/T 13882-1992 Method for determination of iodine in feed;

GB/T 17777-1999 Determination of molybdenum in feeds - Spectrophotometric method;

GB/T 13883-1992 Determination method of selenium in feed.

2.2 Determination method of organic trace elements

Spectrophotometry and potentiometry.

GB/T 21996-2008 Determination method of feed additive glycine iron complex;

GB/T 13080.2-2005 Determination of the chelation rate of feed additive methionine iron (copper, manganese, zinc) by gel filtration chromatography.

3 Contents of mineral elements in raw materials and exogenous additives

The content of mineral elements in raw materials is shown in Table 1. The content of mineral elements in exogenous additives is shown in Table 2.

Table 1 Content of mineral elements in raw materials (g/kg)

Table 2 Contents of mineral elements in exogenous additives

4 Effects of mineral elements on pigs

4.1 Inorganic mineral elements

Kline et al. (1972) studied the effects of different ratios of Cu, Fe and Zn on the performance of weaned piglets. The results showed that the optimum ratio was: Zn:Fe:Cu = 0.55:1.05:1.31. Yin Haicheng (2002) studied the effects of different levels of copper, zinc and iron on the performance and hemoglobin levels of piglets. The best ratio of the three was 1:1.45:1. Dove and Haydon (1991) found that adding 250 ppm Cu to the diet significantly increased piglet daily gain and feed intake, while iron addition had no effect on both. He Wanling et al (2004) reported that dietary copper 250 mg/kg, iron 38 mg/kg, and zinc 138 mg/kg had the best effect on improving piglet performance, and fecal copper excretion increased with dietary copper levels. The number of iron and zinc excretions increased slowly and steadily.

4.2 Organic trace elements

Yu Deqian et al (2005) found that the addition of organic forms of Cu, Fe, Zn, the effect is better than the inorganic form, and the residue in the feces is reduced by 30%. Zhang Chun et al (2005) studied the effects of different ratios of Zn-AAC and ZnSO4 on growth performance and blood parameters of weaned piglets, and found that 60% organic zinc and 40% inorganic zinc were the best ratio. Xia Zhongsheng et al. (2007) reported that the suitable ratio of trace element chelates to inorganic elements is 25%. Peters and Mahan (2008) studied the effects of organic and inorganic trace elements on the reproductive performance of sows. The results showed that the addition of organic trace elements could improve the reproductive performance of sows.

4.3 Electrolyte balance

Dietary electrolyte balance plays an important role in pig health. Haydon (1990) found that when the deb value was 250 meq/kg, the end-digestibility and total digestibility of the growing pig small intestine increased. Tang Xiangfang et al. (2007) investigated the acidity and electrolyte balance of the typical typical piglet diets in China. It was found that domestic piglets were about 132-188, and the optimal addition amount was 200-300 meq/kg. Dove (1994) studied the effects of different nutrient levels and acid-base balance on sow litter size and piglet weight, and found that the recommended deb value for sows was 250. However, De Rouchey (2003) found that the sow diet deb was less than 185, which was better for the mother and the fetus, and the piglet survival rate was higher after 10 days.

5 Research direction

The study of mineral elemental nutrition has been studied for many years, and the recommended amount is available in the breeding standards of each version. However, with the advancement of technology and research, it is found that organic trace elements, electrolyte balance and sulfur have an important role in pig performance and health, and are a new aspect of mineral element nutrition research. These aspects should be included in the creation of a new database.