PSU Herd IOFC –November 2011
by Virginia Ishler
In November we evaluated a new byproduct feed, two big research projects came to an end and the herd fat test rebounded in a positive direction. Changing the particle size of the corn grain at the end of October maintained the fat test into the beginning of November at 3.52%. Another minor change was made in the ration based on some slight indigestion problems occurring in animals around 100 days in milk. Even though the animals responded quickly to treatment, this was definitely not normal. My thought was with the corn silage starch level being so high and rapidly digestible, that was the culprit. The haylage was increased from 10 to 12 pounds of dry matter and the corn silage reduced by two pounds. This minor change apparently was enough to correct the problem. It brought the total starch level down to 25% from 27% and cows still continued to milk the same, except no more indigestion problems.
Two major changes occurred on November 7th and 8th, several research projects ended and we started feeding a commodity product based on a wet milling process. As soon as research cows were put onto the herd ration the fat test from November 9th forward averaged 3.71%.
In the real world when a farm feeds a new ingredient, usually the entire herd receives it making it difficult to know if a positive or negative response is really associated with that new ingredient. The biggest challenge with this new commodity product is its dry matter, which is 70% and the phosphorus content, which is 1.25% on a dry matter basis. The high moisture content limits the type of farms that could handle this commodity. The high phosphorus content limits how much can be fed without exceeding the animals’ requirements. For our herd, that meant limiting the inclusion level to 6% of the ration dry matter.
Utilizing the milk cow free stall barn, two groups of 60 cows were made having similar days in milk and parity. For three weeks both pens received the herd diet so average milk production and components (October’s DHIA test) could be determined. In November, pen 1 continued on the herd ration and pen 2 was fed the new ration incorporating the commodity product at five pounds/cow as-fed. For the next three weeks production was monitored and November’s DHIA test reflected the components on the new ration. Comparing components from October’s DHIA test with November’s, the fat test for pen 1 cows went from 3.50% to 3.69% and pen 2 went from 3.60% to 3.77%. So both groups showed similar improvements in fat percent and milk protein remained unchanged. Pen 1 cows’ dry matter intakes (58/59 lbs) and production (93.3/92.5 lbs) were very similar for both months. Pen 2 cows consumed similar amounts of dry matter (59/60 lbs) however they dropped 4 pounds of milk on average (89.7/85.6 lbs). A possible explanation on the cause may be shed from the TMR analyses.
TMR results for both groups came back right on for dry matter percent, NDF of 33%, starch of 25%, and phosphorus of 0.37%. The one difference was protein level. The ration was formulated for 15.5%. Pen 1 diet came back 15.6% and the pen 2 diet 14.3%. MUNs were 10 mg/dl for both groups. Since the dry matter percent and the other parameters for the pen 2 diet came back very close, it could be the protein in the new commodity ingredient was lower than what was used in the formulation program. Other universities have fed this commodity successfully up to 20% of the ration dry matter, but they do not have the same concerns about phosphorus like we do in the Chesapeake Bay Watershed and their protein levels were formulated for 16.5-17%. So as with any byproduct feed, animal performance and profitability will vary on how much is used and what else makes up the ration.
For the month of November the herd averaged 83 pounds with a 3.64% fat, 3.04% protein, 186,000 SCC and 10.1 mg/dl MUN. Feed cost/cow came down quite a bit due to improved dry matter intake efficiency. This improved feed efficiency started with the inclusion of the bunk corn silage with the very high starch level. The herd ration is still maintained with 65% forage on a dry matter basis.