The effect of protected lysine and methionine on milk yield and its composition in lactating dairy cows fed grass silage-based rations

Abstract

Five multiparous Polish Red-and-White cows, weeks 8-12 of lactation, in a 5 x 5 Latin square treatment were fed a total mixed ration with grass silage and concentrates (58 and 42% DM). The five treatments were dietary supplements of protected L-lysine and DL-methionine (Smartamine™ ML) and DL-methionine (Smartamine™M) fed in the following amounts: I: 0 g/d + 0 g/d; II: 35 g/d + 0 g/d; III: 35 g/d + 10 g/d; IV: 35 g/d + 20 g/d; and V: 35 g/d + 30 g/d. The corresponding intestinal concentrations of lysine and methionine (% PDI) were: I: 6.89 and 1.88; II: 7.37 and 2.05; III: 7.32 and 2.29; IV: 7.31 and 2.54; V: 7.28 and 2.78, respectively. The DMI and milk yield were similar among treatments. In contrast, milk protein content was significantly increased (P<0.05) over the II treatment and then varied little. Milk fat content and yield varied inconsistently. Plasma metabolites such as glucose and (3-hydroxybutyrate were not affected and fell within physiological limits.Plasma free amino acids responded to the treatments, particularly lysine (PO.05) and methionine (P<0.001), producing a pattern of responses similar to that described for milk protein. Significant increases in milk protein content in the second treatment (Smartamine™ ML, 35 g/d) as resulting from improved postruminal supply of lysine (equal to needs), confirm the validity of the assumed requirement for this amino acid (i.e. 7.3% PDI). These increases could have also been due to a higher supply of limiting methionine. However, further improvements in intestinal supply of methionine, gradually meeting the assumed requirement (i.e. 2.5% PDI), had no effect on milk protein content. This lack of responses to methionine (treatments III-V), could have resulted either from a higher postruminal supply of this amino acid than that predicted or from a lower methionine requirement than that assumed.

Effects of Dietary Supplements of Folic Acid and Rumen-Protected Methionine on Lactational Performance and Folate Metabolism of Dairy Cows

“…Ingestion of RPM increased serum concentrations of methionine in a range similar to those reported in the literature (Aldrich et al, 1993;Overton et al, 1996;Pacheco-Rios et al, 1997;Rulquin and Delaby, 1997a, b;Robinson et al, 1998;Pisulewski and Kowalski, 1999;Vanhatalo et al, 1999;Krober et al, 2000;Pisulewski et al, 2002). Serum concentrations of homocysteine were also higher in cows fed RPM.…”

“…The absence of response in milk production and DMI to supplementation with RPM is similar to those frequently reported in the literature. In a nonexhaustive review of the literature between 1993 and 2003, only 1 (Vanhatalo et al, 1999) effect of RPM fed to dairy cows reported an increase in milk production, and none described an effect on DMI (Aldrich et al, 1993;Guinard and Rulquin, 1995;Jurjanz et al, 1996;Overton et al, 1996;Armentano et al, 1997;Chilliard and Doreau, 1997;Pacheco-Rios et al, 1997Rulquin and Delaby, 1997a, b;Robinson et al, 1998;Blum et al, 1999;Pisulewski and Kowalski, 1999;Vanhatalo et al, 1999;Krober et al, 2000;Berthiaume et al, 2001;Younge et al, 2001;Pisulewski et al, 2002;Kowalski et al, 2003;Leonardi et al, 2003;Misciattelli et al, 2003;Noftsger and St-Pierre, 2003). The major effect of RPM supplements is an increase in milk protein concentration and yield (Guinard and Rulquin, 1995;Jurjanz et al, 1996;Armentano et al, 1997;Chilliard and Doreau, 1997;Pacheco-Rios et al, 1997Rulquin and Delaby, 1997b a, b;Krober et al, 2000;Kowalski et al, 2003;Leonardi et al, 2003;Misciattelli et al, 2003;Noftsger and St-Pierre, 2003).…”

Supplementation of mixed roughage-based diet with rumen protected methionine for lactating goats

“…However, in our experiments we did not observe a significant increase of the above parameters, contrary to studies in which grass silage or maize silage-based diets were post-ruminally supplemented with Met (Pisulewski et al, 1996;Rulquin and Delaby, 1997) or when protected Met and Lys were added to a maize-based diet (Armentano et al, 1993). Similarly to our experiment, also Overton et al (1998) and Pisulewski and Kowalski (1999) did not find a significant increase in milk protein yield as well as protein and casein content in milk.…”

Effect of rumen-protected methionine on feed intake, milk production, true milk protein concentration, and true milk protein yield, and the factors that influence these effects: A meta-analysis

“…For these studies, only a single comparison was made for the longest observational period because the diets did not change. Some studies tested multiple levels of RPM against a single control diet (Pappas et al, 1984a,b;Pisulewski and Kowalski, 1999a;Soder and Holden, 1999;Samuelson et al, 2001, study 1;Lara et al, 2006;Benefield et al, 2009) and were counted as 4, 4, 4, 2, 3, 2, 3, and 2 comparisons, respectively. In all studies, it was assumed that milk protein was reported as milk CP unless it was expressly noted as true milk protein (TMP).…”