TMR Analysis - Comparing Formulated to Actual

New corn silage and candy product pose challenges to ration balancing.
TMR Analysis - Comparing Formulated to Actual - Articles


Penn State Dairy Cows

November was less eventful than October however it did bring some interesting developments. The herd has continued on the candy product. The milk fat and protein have maintained at their high levels consistently. These levels were confirmed on DHIA. The one thing that has changed is the MUNs. They are trending a bit higher than what we have observed in the past (7-9 mg/dl). Both the total mixed ration (TMR) and corn silage from a new Ag Bag were sent out for analyses to confirm carbohydrate and protein levels.

This fall has been challenging since the corn silage fermented for a few weeks instead of a few months before feeding. I wanted to check the 7-hour starch digestibility on both the upright and the new Ag Bag. Both sources had a fermentation period ranging from 4 to 6 weeks. The silages tested almost identically with 44% starch and a 7-hour digestibility of 68%. From discussions with researchers, the starch digestibility was pretty good. Work being conducted at the Miner Institute has shown upwards of 80%+ on corn silage that has fermented for several months. I plan on tracking this number more closely, especially since I have observed responses by changing the particle size of the corn grain during various times of the year. This is probably related to the level of starch and its digestibility in the corn silage.

One of the goals of checking the TMR analysis was to make sure the carbohydrate status along with the protein levels were close to formulated. Table 1 shows the comparison between the formulated ration and the TMR analysis.

Table 1
Dry matter, %50.851.2
Crude protein, %1515.2
NDF, %31.330.6
Starch, %26.925.3
Sugar, %7.8
Calcium, %0.770.78
Phosphorus, %0.340.35
Magnesium, %0.310.33

Everything in the TMR analysis appeared to be right on target. The starch was a bit lower than expected and I included sugar to get a feel for what the candy product might be contributing. The dry matter intakes in the herd are fairly consistent and the feed efficiency has improved since starting on the candy product. The fresh cows also appear to be starting out much better. With the really high components the energy corrected milk of the herd is very good and is higher than last November; however I am not satisfied with the milk production as we are down about two pounds on average.

Forage inventory is still an issue, especially with the hay-crop forage. We have had to reduce the level of haylage back to 6 pounds of dry matter per cow per day. Unfortunately we still have some of the early corn silage to feed. It has been fed at a low inclusion level because of the poor herd performance observed when it was fed at higher levels. Hopefully it will be out of the picture for December. For the month of November the herd averaged 81.0 pounds with a 3.88 % fat, 3.31 % protein, 172,000 SCC and 10.35 mg/dl MUN.

IOFC Results

Month and YearNo Risk Mgt Gross Milk Price/cwtW/ Risk Mgt Gross Milk Price/cwtMilk income/cowFeed cost/cowIOFCAverage milk lbsLow BenchmarkHigh benchmark

IOFC Graph