%0 Journal Article %9 journal article %J Journal of Animal and Feed Sciences %@ 1230-1388 %V 18 %N 1 %D 2009 %F Strzetelski2009 %T Protected methionine as a methyl-group donor for dairy cows fed diets with different starch sources in the transition period %X Protected methionine (Smartamine™; 0, 15 or 30 g d -1 ) was supplemented to rations containing a high proportion of starch easily (barley) or slowly (maize) fermented in the rumen, fed to pre- and postpartum dairy cows to study its effect on milk yield and composition, metabolic profile and reproduction. The experiment was carried out on 24 Polish Holstein-Friesian cows, divided 21 days before expected parturition into 3 groups of 8 animals and fed individually. Protected methionine was added to the rations from day 21 before, until 21 day after parturition, but the performance of cows was controlled up to the end of week 12 of lactation. Protected methionine had no effect on milk yield and composition, metabolic profile, body weight, body condition score, or reproduction indices. Methionine supplementation increased feed intake before parturition (P<0.01) and blood glucose concentration before parturition and on day 2 after calving (P<0.03 and P<0.01, respectively). The starch source had no influence on the studied parameters. There was also no statistically significant interaction between the level of protected methionine supplementation and starch sources. These results do not support the hypothesis that feeding cows increased amounts of starch digested in the small intestine together with protected methionine can lower energy deficiency and mobilization of energy reserves as well as decrease liver lipidosis by increasing the synthesis of very-low-density lipoproteins. %A Strzetelski, J. A. %A Kowalski, Z. M. %A Kowalczyk, J. %A Borowiec, F. %A Osięgłowski, S. %A Ślusarczyk, K. %P 28-41 %R 10.22358/jafs/66364/2009 %U https://doi.org/10.22358/jafs/66364/2009