PSU Herd IOFC – August 2011
by Virginia Ishler
There have been some interesting dynamics in August coming off of July’s record temperatures. This time of year we are usually in between a lot of late lactation animals and fresh cows. This month we had 33 animals freshening with 36% being first calf heifers. Forty animals are in the low group, 54 cows are on various research projects, which leave 73 animals at about 115 days in milk. Production remained steady but components suffered. The beginning of the month fat test was 3.30% and was consistent even after adjusting the ration protein to 16.5%. In the past as soon as the protein was increased an immediate response in both fat and protein occurred. This did not happen. The TMR was sent out for analysis and came back 16.3% protein, 35% NDF and 23% starch. This matched very closely to what was formulated.
The high and 2-year old groups have remained on a 65%-forage based diet for the entire summer. Reviewing the dry matter intakes for August, it was striking the difference in intakes for the first half of the month compared to the second half. Even though the ration was the same for the entire month the high group and 2 year olds showed a difference of 6-10 pounds in dry matter intakes. When examining intakes along with components there was a correlation. From August 1-16 milk fat averaged 3.30% and milk protein 2.95%. From August 16-31 milk fat averaged 3.41% and milk protein 3.02%. It appears the cows needed time to adjust coming off July’s heat. It also shows that sometimes there are outside stressors that may impact components and may not necessarily correlate to the amount of fiber or starch consumed. Even at the lowest intakes at the beginning of the month, cows were consuming 17-21 pounds of NDF and 11 to 14 pounds of starch.
Using BMR corn silage during the latter part of the summer has paid off, so far. Last year we ran out of BMR the end of July. Considering last summer was relatively mild, the herd dropped 28,000 pounds in August 2010 with 6 additional cows compared to July. This summer, coming off July’s sweltering heat and humidity, we shipped 55,000 pounds more milk in August with eleven additional cows (compared to July). In a perfect world it would be ideal if we could store enough BMR to feed for the entire summer. However, research requirements and storage limitations do not allow for this. Our strategy to prolong BMR usage is to feed it only to the groups that benefit the most, fresh and early lactation cows.
Our feed costs went up this month compared to July due to some increases in commodity prices as well as cows coming up in dry matter intake. Keeping the late lactation cows on a low group diet has really helped control feed costs and has kept body condition in check. The fresh cows have remained in the free stall barn with the fans and sprinklers, which have really allowed cows to start off extremely well. Income over feed costs remained the same as July, $10.76/cow. For the month of August the herd averaged 75.6 lbs. with a 3.35% fat, 2.98% protein, 243,000 SCC and MUN of 7.7 mg/dl.
More information about the Penn State Dairy herd’s IOFC can be found here http://www.das.psu.edu/dairy-alliance/resources/income-over-feed-cost-tool