PSU Herd IOFC – June 2012 “Making Corn Silage Last”
by Virginia Ishler
June was filled with a lot of ration adjustments. There was the addition of new hay-crop forage into the diets. Corn silage inventory was still a very big concern as the bagged conventional silage ended and the BMR corn silage began. We struggled to keep fat test above 3.50% and there was the heat wave starting the third week of the month.
At the beginning of June I increased the concentrate dry matter to 40%. We had been at 35% and then 38% but the concern about having enough corn silage until the fall is still lingering. We incorporated first cut alfalfa haylage into the ration going 50/50 with the 2011 haylage. The first cutting tested very well and was comparable to the material we had been feeding, at least on paper. However, right after the inclusion of the first cutting, fat test dropped from 3.60% to 3.35%. Cows were still holding at 88-89 pounds. Just as I was considering making an adjustment, the bagged corn silage was almost gone. It lasted only 4 weeks. I had hoped the bag would get us to the beginning of July but as it turned out we had to start BMR corn silage on June 22nd.
Looking back, starting the BMR when we did was advantageous because it timed with the heat wave and for the cows was a benefit in keeping them milking. However, now more than ever was I concerned about keeping the BMR corn silage viable well into August. For this summer I changed my approach completely on feeding the cows. Typically the cows would get 29-30 pounds of BMR corn silage dry matter and 6 pounds of haylage dry matter. If I fed this level of corn silage it would not last much past July. The other concern was we had only one bag of alfalfa haylage and that needed to last until second cut was ensiled (especially to accommodate research projects), so the decision was made to incorporate grass silage. For the last part of the month cows were started on BMR corn silage at 22 pounds dry matter and 7 pounds grass and 6.5 pounds alfalfa dry matter. It should be noted that the grass silage tested 65% neutral detergent fiber and 10% protein. Because of the high fiber content in the grass silage, all the cottonseed hulls were removed from the ration. To help improve the fat test we switched from all coarse corn to 50/50 coarse/ground. So the big question was – how will cows respond to this diet?
To continue with the rest of the story, the BMR corn silage was very wet (30% dry matter) compared to the bag corn silage which was 43% dry matter. The ration change with BMR started on Friday June 22nd. When I went to the barns on Monday I noticed the cows had dropped below 80 pounds, which seemed extreme. I updated the dry matters on all feeds and checked the amounts of TMR being fed to the groups. Even though the feeder was increasing the amounts of TMR each day, it was not enough and there were zero refusals. When I checked the cows at 1:30 in the afternoon I observed how little feed was left and I knew they would have it cleaned up well before the next day. I calculated that a pen of cows getting 7800 pounds as-fed should really be getting 8400 pounds. At the Penn State Dairy, cows are fed in the morning and the crew working the p.m. shift never has to feed. So credit to our afternoon employees and assistant manager, they were able to mix and feed several hundred additional pounds of TMR to the cows that day. A message was left for the feeder so he would know how much to mix for each pen the following morning. Cows bounced back on production immediately. Also, the ration change boosted fat test back to 3.60%. For the last 2 weeks in June the cows averaged 83 pounds.
In previous articles about the dairy farm I have written about the impact of the simple change of corn grain particle size on components and production. The following video illustrates the difference between the coarse and fine particle size of the corn grain fed to the Penn State dairy cows.
For the month of June the herd averaged 86 pounds with a 3.53 % fat, 2.98 % protein, 246,000 SCC and 7.8 mg/dl MUN. Milk price took a major down turn this month and with the continued high feed costs resulted in a low IOFC.
For more information visit http://extension.psu.edu/animals/dairy/business-management/income-over-feed-cost