Betaine is an amino acid derivative that serves as a methyl donor in metabolic processes. Betaine provides methyl groups (—CH3) for the synthesis of many compounds, such as creatine and carnitine, and decrease the requirement for other methyl donors, such as methionine and choline. Betaine is also an osmotically active compound that regulates water movement and electrolyte balance, providing osmotic protection for many cells, including intestinal cells and muscle fibers (Eklund et al., 2005). Betaine can be produced by chemical synthesis or as a by-product of sugarbeet processing. Betaine is commercially available as anhydrous betaine, betaine monophosphate, and betaine hydrochloride (Eklund et al., 2005).
Addition of betaine to grow-finish diets has been demonstrated to improve growth performance, carcass leanness, and pork quality (Matthews et al., 2001a,b), but the effects of betaine have been inconsistent (Sales, 2011). The mode of action of betaine have not been fully understood, but it has been suggested that betaine may have an energy-sparing effect that improves growth and protein deposition (Schrama et al., 2003) and an osmo-protectant effect that improves pork quality (Eklund et al., 2005). The osmo-protectant capacity of betaine may also improve nutrient digestibility and gut health (Eklund et al., 2005), and enhance the ability of grow-finish pigs to cope with heat stress (Mendoza et al., 2017a,b).
Addition of betaine to sow diets has been demonstrated to potentially improve reproductive performance, but there is little evidence to support consistent effects (Ramis et al., 2011; van Wettere et al., 2013). There is growing interest to supplement betaine in sow diets during summer (van Wettere et al., 2012, Cabezón et al., 2016; 2017). Betaine is believed to improve lactation feed intake, reduce wean-to-estrus interval, and enhance embryo survival during heat stress (van Wettere et al., 2012, Cabezón et al., 2016). It’s been suggested that betaine may ameliorate the effect of heat stress on sows due to an energy-sparing effect that improves energy utilization and an osmo-protectant effect that increases water retention and regulates electrolyte balance (Cabezón et al., 2016). However, the benefits of betaine supplementation on reproductive performance of sows require further research before a definitive recommendation can be made.