Effects of dietary methionine supplementation from different sources on growth performance and meat quality of barrows and gilts

Methionine is indispensable for growth and meat formation in pigs. However, it is still unclear that increasing dietary sulphur-containing amino acid (SAA) levels using different methionine sources affects the growth performance and meat quality of barrows and gilts. To investigate this, 144 pigs (half barrows and half gilts) were fed the control (100% SAA, CON), DL-Methionine (125% SAA, DL-Met)-supplemented, or OH-Methionine (125% SAA, OH-Met)-supplemented diets during the 11-110 kg period. The results showed that plasma methionine levels varied among treatments during the experimental phase, with increased plasma methionine levels observed following increased SAA consumption during the 25-45 kg period. In contrast, pigs fed the DL-Met diet had lower plasma methionine levels than those fed the CON diet (95-110 kg). Additionally, gilts fed the DL-Met or OH-Met diets showed decreased drip loss in longissimus lumborum muscle (LM) compared to CON-fed gilts. OH-Met-fed gilts had higher pH45min values than those fed the CON or DL-Met diets, whereas OH-Met-fed barrows had higher L45min values than those fed the CON or DL-Met diets. Moreover, increased consumption of SAA, regardless of the methionine source, tended to decrease the shear force of the LM in pigs. In conclusion, this study indicates that increasing dietary levels of SAA (+25%) appeared to improve the meat quality of gilts by decreasing drip loss and increasing meat tenderness.