Studies of the Effect of Supplementing Protected Methionine (HMM-Ca) to Dairy Cows on Milk Yield and Fertility

Abstract

A trial with 90 cows was conducted to examine the effect of supplementing 30 g N-hydroxymethyl-DL-methionine-calcium (HMM-Ca) from 14 days pre calving till 100 days in lactation on the performance and some physiological traits. Cows were kept on four energy levels by feeding different amounts of concentrate. At each energy level, half of the cows were given a methionine supplement. Forage consisted of 1/3 corn- and/or beet pulp silage and 2/3 grass silage ad libitum. The amount of daily milk yield differed not significantly from 31.5 kg for the supplement group to 30.6 kg for the control group. No interaction between the methionine supplementation and energy level could be detected. Mean methionine content in blood plasma differed from 22.7 mmol/l for the supplement group to 16.8 mmol/l for the control group. GOT, tau-GT, bilirubin and urea in blood serum and milk urea content did not indicate a positive effect of the methionine supplementation on the metabolism. Conception rate differed slightly from 87% in the supplement group to 73% in the control group.

266 Evaluation of peri-partum supplementation of methionine hydroxy analog on cow-calf performance.

“…No differences in FTAI or total breeding season pregnancy rates were observed in the current study in agreement with the MFP study conducted by Clements et al (2017) for both AI-pregnancy determination (51 vs. 47%, respectively) and breeding season pregnancy determination (74 vs. 77%, respectively). When Spiekers and Pfeffer (1990) supplemented dairy cows with N-hydroxymethyl-DL-methionine-Ca, conception was higher compared to controls (87 vs. 73%). In the same study there was no difference in…”

“…Very few studies have been designed to test for effects of RPMet supplementation on reproductive efficiency and often those that have measured reproductive variables are not adequately powered, especially on binomial pregnancy data. Spiekers and Pfeffer (1990) randomly assigned Holstein cows to 1 of 4 dietary energy levels supplemented with or without a hydroxy analog calcium salt and saw pregnancy rates of 87% in the supplement group and 73% in the control group; however, the difference was not significant nor were any of the changes in regards to milk parameters. Numerical reductions in days to first estrus, open days, and services per conception were observed in the study by Ardalan et al (2009); however, statistical power was far too weak to see significant differences.…”

Methionine Requirements for the Preimplantation Bovine Embryo

“…It may be possible, however, to improve embryo survival by increasing methionine concentration above these concentrations. Feeding a rumen-protected methionine supplement to lactating dairy cows, which can increase circulating concentrations of methionine from 22-78% [15][16][17], tended to increase fertility [18,19].…”