ARTICLE FEED & ADDITIVE MAGAZINE December 2022 51 tabolism. It is described that betaine reduced saturated fatty acids (SFA) and enhanced poly-unsaturated fatty acids (PUFA) contents in poultry (Yang et al., 2022), lamb (Dong et al., 2020) and pigs (Zhong et al., 2021). In this last study, also a slightly altered free amino acid profile in serum and muscle was observed. Regarding sensory quality of meat, there are several important parameters: Drip loss/Water loss, water holding capacity (WHC), cooking loss, shear force, pH, and meat color measurements including L* (lightness), a* (redness) and b* (yellowness) values. Via the osmoregulatory role of betaine, reduced drip loss by increasing the water retention of the muscle tissues can be expected. In a small-scale broiler study, a numerical increase in moisture content in breast muscle from 74.43% in the control group to 76.01% for the betaine supplemented group (1g/ kg) was mentioned (Alirezaei et al., 2012). A significant reduction in drip loss from 3.43% to 1.15% was observed in another study in heat challenged birds, as shown in figure 1 (Shakeri et al., 2019). Still, some studies did not find an effect of dietary betaine on water holding capacity of meat (Park and Kim, 2019; Al-Abdullatif et al., 2021). This indicates the multifactorial impacts on sensory meat quality, which might be influenced amongst others by genotype, age and sex, environmental conditions, exercise, transport, time after slaughter... Differences between the different muscles can also exist. Dong et al. (2019) found for example a decreased water loss in shoulder muscle of lambs supplemented with betaine, while in the gluteus muscle this effect was not visible. Another reported effect of betaine is the slower decrease in pH of meat, which suggests lower lactic acid accumulation (Matthews et al., 2001). After slaughter, oxygen in the muscle tissues is gradually exhausted and cells switch from oxidative phosphorylation for the generation of ATP to glycolysis. When anaerobic glycolysis begins, there is production of lactic acid and a rapid fall in pH. A low pH value and a rapid further decrease in pH after slaughter (due to accu-
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