Dealing with Bird Damage and Bagged Silage

Crows are not dumb birds. They can cause a lot of damage to forages stored in Ag bags.
Dealing with Bird Damage and Bagged Silage - Articles


Penn State Dairy Cows

Those darn birds! That is too nice a statement considering all the headaches they cause. We transitioned to a new Ag Bag the end of February and were feeding it 100% the beginning of March. However, the birds had done a lot of damage and it was reflected in the bulk tank.

Ag Bags are a good way to increase forage inventory when permanent structures are not adequate for feeding heavy forage based rations or the herd size has increased over the years. At Penn State we usually fill 12 to 15 bags per year. About seven bags get committed to corn silage with the other bags going to grass or alfalfa haylage. It amazes me how crows have an innate sense on which bags have corn silage in them. The assistant manager and the full time employees do check the bags on a regular basis and if they notice any holes, they get taped. The challenge is crows are not dumb birds. They tend to come in all at once, right at dusk when the p.m. crew is milking and there is very little activity. This may happen only once or twice, but that is all it takes to do significant damage.

Ag Bag without a green cover.

With this particular bag, we did not have a green cover, which are somewhat effective at keeping the birds from poking too many holes.

Bunker Silo with a green cover to reduce bird damage.

The employees caught the damage on this bag right away but there were so many holes that taping did not seem a very effective solution. The decision was made to cover the bag with plastic and secure it the best they could. Then Mother Nature played her hand with a major wind storm blowing the plastic off. With the snow covering and freezing to the plastic it could not be used to recover the bag. This happened right before we would start feeding from the bag.

The challenge is when the bags get compromised and air infiltrates the silage resulting in spoilage. The full time employees are excellent in removing the spoiled material when mixing feed, but in today's environment, we can't afford all that storage loss. I knew from the start that the silage quality was not the best. It had a very stale smell and for the first two weeks the cows were not milking as expected. We opened another Ag Bag and fed 50/50 from each. Cows bounced back on production. Towards the end of the month we finished the compromised bag and started feeding from the other bag. This silage had a great smell and I expected cows to perform even better when feeding it as the sole source of silage.

On Monday March 25th when I checked on the cows I was surprised the herd was coming down on milk when they should be going up. This was the peak of the BST cycle. I met with the management team to investigate why this was occurring. My first question was who had been feeding. When I heard who it was I immediately checked feed amounts. However, the cows were being fed with some refusals and the cows were backing down on feed. Next I checked TMR Tracker to make sure all the ingredients were going into the mix and at the proper amounts, which they were. In our brain storming we realized we got a new load of candy product that coincided with the herd dropping in milk. This product has been extremely consistent so I was surprised that this might be the culprit. We sent a sample to the lab for analyses however too much time would elapse until results came back. The decision was made to switch back to 100% fine ground corn, assuming the corn silage quality may not be the best. The one disadvantage of feeding from the Ag Bag is it lasts about four weeks and does not lend itself for sending a sample for analyses.

The cows quickly responded to the all fine ground corn. The candy product analysis came back identical to what I had used in the ration formulation. However, since we missed the window of the BST cycle when cows should have been peaking, the herd was increasing in milk production as they were getting to the low end of the cycle. The cows also responded with a slight boost in milk fat and milk protein. This illustrates how grain particle size can have a significant impact on animal performance and if you are not monitoring the cows and knowing what is normal and not normal, there can be a lot of missed opportunities. For the month of March the herd averaged 83.0 pounds with a 3.82 % fat, 3.26 % protein, 175,000 SCC and 10.3 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