Use of protected methionine (Mepron M 85) in cattle.
The ruminal stability of Mepron M 85 and the effect of supplementation with Mepron M 85 on free methionine level of blood were studied in rumen-fistulated cows and rumen- and duodenum-fistulated growing bulls. In five rumen-fistulated cows in situ 69.5% and 64.6% of the methionine content of Mepron M 85 was found after ruminal incubation of 16 h and 24 h, respectively. Daily rations of the rumen-fistulated cows were supplemented with 15.0 g DL-methionine and 17.7 g Mepron M 85, which increased the free methionine level of blood from 13.64 mumol/L to 15.35 and 20.46 mumol/L, respectively, three hours after feeding. In the four rumen- and duodenum-fistulated growing bulls, supplementation with 15.0 g DL-methionine and 17.7 g Mepron M 85 increased the total methionine getting into the duodenum during 24 h from 14.99 g to 16.84 and 20.84 g, respectively. The influence of Mepron M 85 on milk production was studied in 35 pairs of Hungarian Fleckvieh x Holstein-Friesian cows. The animals were coupled on the basis of the number of finished lactations, milk production in the previous lactation, and the date of calving. Daily supplementation of 18.0 g Mepron M 85 increased daily milk production significantly (p < 0.05), by 1.24 litres. Milk fat content also increased significantly (from 3.10% to 3.19%, p < 0.05) in the experimental group. The supplementation did not influence milk protein content.
Schmidt
J
J
Department of Animal Nutrition, Pannon Agricultural University, Mosonmagyaróvár, Hungary. schmidt@movar.pate.hu
Sipócz
P
P
Cenkvári
E
E
Sipócz
J
J
D000821:Animal Feed; D000818:Animals; D002417:Cattle / Q000378:metabolism* / Q000502:physiology; D002852:Chromatography, Ion Exchange / Q000662:veterinary; D005260:Female; D007774:Lactation / Q000187:drug effects; D008297:Male; D008715:Methionine / Q000097:blood / Q000493:pharmacokinetics* / Q000494:pharmacology; D008892:Milk / Q000378:metabolism; D012417:Rumen / Q000378:metabolism* / Q000502:physiology
D008715:Methionine