Selenium in Pig Nutrition and Reproduction: Boars and Semen Quality — A Review

Abstract

Selenium plays an important role in boar nutrition via participating in selenoprotein synthesis. It seems likely that selenoproteins are central for antioxidant system regulation in the body. Se-dependent enzyme glutathione peroxidase (GSH-Px) is the most studied selenoprotein in swine production. However, roles of other selenoproteins in boar semen production and maintenance of semen quality also need to be studied. Boar semen is characterised by a high proportion of easily oxidized long chain polyunsaturated fatty acids and requires an effective antioxidant defense. The requirement of swine for selenium varies depending on many environmental and other conditions and, in general, is considered to be 0.15 to 0.30 mg/kg feed. It seems likely that reproducing sows and boars are especially sensitive to Se deficiency, and meeting their requirements is an important challenge for pig nutritionists. In fact, in many countries there are legal limits as to how much Se may be included into the diet and this restricts flexibility in terms of addressing the Se needs of the developing and reproducing swine. The analysis of data of various boar trials with different Se sources indicates that in some cases when background Se levels were low, there were advantages of Se dietary supplementation. It is necessary to take into account that only an optimal Se status of animals is associated with the best antioxidant protection and could have positive effects on boar semen production and its quality. However, in many cases, background Se levels were not determined and therefore, it is difficult to judge if the basic diets were deficient in Se. It can also be suggested that, because of higher efficacy of assimilation from the diet, and possibilities of building Se reserves in the body, organic selenium in the form of selenomethionine (SeMet) provided by a range of products, including Se-Yeast and SeMet preparations is an important source of Se to better meet the needs of modern pig genotypes in commercial conditions of intensive pig production.

Organic selenium supplementation is cost-effective for increasing the number of seminal doses produced by sexually mature boars

“…It has been shown that Se from organic sources is assimilated much more efficiently compared with commonly used selenite (Mahan et al, 1999). This results in higher Se accumulation in the animal tissues, building a selenium reserve, which can be effectively used during stress conditions (Surai and Fisinin, 2015).…”

A Summary of New Findings on the Biological Effects of Selenium in Selected Animal Species—A Critical Review

“…Selenium is involved in growth and development, as well as taking part in the regulation processes related with production [ 87 , 88 , 89 , 90 , 91 , 92 , 93 , 94 , 95 , 96 , 97 , 98 , 99 , 100 , 101 , 102 , 103 ], and reproduction abilities of animals [ 104 , 105 , 106 , 107 , 108 , 109 , 110 , 111 , 112 , 113 , 114 , 115 , 116 , 117 , 118 , 119 , 120 , 121 , 122 , 123 , 124 , 125 ].…”

“…Antioxidant protection plays a key role in maintaining the integrity of the sperm membrane and their fertilizing ability [ 60 ]. Selenium involved in the antioxidant defense of the organism substantially modulates the quality of the male ejaculate [ 123 ]. In testes, several selenoproteins such as selenophosphate synthase (SPS-2) and mitochondrial capsule selenoprotein (MCSeP) were localized [ 216 , 217 ].…”

Dietary Selenium Supplementation Ameliorates Female Reproductive Efficiency in Aging Mice

“…Selenium is generally utilized in the form organic and inorganic species [10,[17][18][19]. Selenomethionine (SeMet) is the most common organic form (mainly Se-yeast) of Se present in a wide range of human and animal diets, whereas inorganic chemical forms such as, sodium selenite are usually used for supplementing animal feed [18][19][20].…”

“…Selenium is generally utilized in the form organic and inorganic species [10,[17][18][19]. Selenomethionine (SeMet) is the most common organic form (mainly Se-yeast) of Se present in a wide range of human and animal diets, whereas inorganic chemical forms such as, sodium selenite are usually used for supplementing animal feed [18][19][20]. It has been argued that the potential beneficial and/or adverse effects of Se are mainly dependent on the form being utilized; however, the total intake of Se has also been considered as an important factor in this regard [10,19].…”