Rumen-Protected Methionine Fed to Dairy Cows: Bioavailability and Effects on Plasma Amino Acid Pattern and Plasma Metabolite and Insulin Concentrations

• Published in: Journal of dairy science 1999-09, Vol.82 (9), p.1991-1998
• Main Authors: Blum, J.W., Bruckmaier, R.M., Jans, F.
• Format: Article
• Language: English
• Subjects: amino acids; Amino Acids - blood; Animal productions; Animals; bioavailability; Biological and medical sciences; Biological Availability; blood glucose; blood lipids; blood plasma; Cattle - blood; dairy cows; Diet; Dietary Proteins - administration & dosage; dosage; Energy Intake; fatty acids; Fatty Acids, Nonesterified - blood; Female; Fundamental and applied biological sciences. Psychology; insulin; Insulin - blood; lactose; Lactose - analysis; Lysine - administration & dosage; Metabolisms and neurohumoral controls; methionine; Methionine - administration & dosage; Methionine - pharmacology; Milk - chemistry; milk fat percentage; milk protein percentage; milk yield; Minerals - administration & dosage; Nitrogen metabolism. Proteins. Glycoproteins. Nucleic acids. Collagen; plasma amino acids; protective coatings; Rumen - metabolism; Silage; somatic cell count; Terrestrial animal productions; urea; Urea - analysis; Vertebrates; Vertebrates: anatomy and physiology, studies on body, several organs or systems; Zea mays
• ISSN: 0022-0302; 1525-3198
• DOI: 10.3168/jds.S0022-0302(99)75435-4

An experiment was performed to compare the bioavailability of D,L-methionine (Met) of two rumen (polymer and fat)-protected Met forms (Smartamineltrade;; Rhoône-Poulenc, Animal Nutrition, Antony, France and Mepron®; Degussa AG, Hanau, Germany, respectively) fed once daily (at 0730h) in amounts of 50g per cow for 5 d. Six dairy cows were used in the crossover design. Blood samples were obtained from jugular veins 3 d before and 5 d after the start of Met supplementation at 1000, 1400, and 1800h, and the three blood samples were pooled for analyses. Smartamine Mltrade; feeding caused elevations of sulfur-containing amino acids (Met, Cys, and taurine) and reductions of Val and Ile and the total of branched-chain amino acids (Val + Leu + Ile). Mepron M85® feeding caused only a rise of Met concentrations. Concentrations of Met, taurine, and Gln were higher when Smartamine Mltrade; than when Mepron M85®; was fed. Concentrations of nonesterified fatty acids were reduced, and those of insulin were increased only by Mepron M85®; feeding. Milk urea concentrations were lower in cows fed Mepron M85®; than in controls, but milk yields; concentrations of fat, protein, and lactose; and somatic cell counts did not significantly change during the experiment and were not different between groups. Food intake, body weight, and body condition scores were not affected. In conclusion, only Mepron M85®; supplementation influenced nonesterified fatty acids and insulin concentrations. However, the bioavailability of Met from Smartamine Mltrade; was greater than of Mepron M85®; and effects on other plasma-free amino acids were more marked. Whether less Met in the form of Smartamine Mltrade; as Mepron M85®;is needed to have the same effects on milk yield and composition needs to be investigated with doses used in practice.