The first supplementation study we did with stockpiled tall fescue has now been almost 25 years ago, but that work continues to impact how I manage on our home farm. We developed Angus cross heifers on stockpiled Kentucky-31 tall fescue with or without a supplement of 2 lbs of whole cottonseed. We had earlier done work with whole cottonseed in total mixed rations that suggested a limit of 15% of the diet or 0.33% of body weight, so that is what we used in this trial. The question was “Can this limited amount of whole cottonseed improve performance enough to make it work the effort to supplement”.
The two year study was conducted in Raleigh at the current location of the E. Carrol Joyner Beef Education Unit. We ran 600 lb heifers for 84 days, starting in early December and finishing in early March. There was a considerable difference in the forage each year. The first year we had mostly tall fescue that remained very green throughout the winter. Crude protein ran between 15 and 20%, which seems high, but is characteristic of what we see on old pastures that are mostly tall fescue. During the second year we had a lot of early autumn rain, and that resulted in a lot of warm season grasses in the sward, both bermudagrass and crabgrass. As a result, crude protein was lower, about 12%, and energy was also considerably lower than the first year.
We learned a lot from this early experiment, including the observation later confirmed with additional research that, despite very high nutritive value, intake and performance of heifers frontal grazing tall fescue is less than usually considered necessary for good heifer development. The whole cottonseed gave us a boost in performance in each year, with a bigger increase in the second year. Based on the blood urea nitrogen levels in the heifers (an indicator of protein status in forage-fed cattle) we attributed the modest 0.25 lb/day increase in year one as an energy response which would be similar to what we would see with any energy source like corn or soybean hulls. In the second year we saw more of a boost, closer to 0.5 lb/day which was more characteristic of a protein and energy supplement.
One thing about whole cottonseed is that it has both a high level of energy and protein, making it an all-purpose supplement that can help overcome deficiencies of each. Another benefit of the whole cottonseed is that it is easy to feed in a frontal grazing system by placing it on sod under the temporary hot wire. Because of it’s consistency, the cottonseed piles up well on top of the sod, so that the animals eat nearly every seed. This is also beneficial because there is no mess around feeders, and the behavior of the cattle is that they meet you at the grazing front each day to get their supplement.
Twenty five years later, I continue to routinely use whole cottonseed as the primary supplement for developing heifers and grazing beef steers. We know that stockpiled fescue, whether it is toxic KY-31 or novel endophyte, will only give us about 1 lb/day average daily gain for growing cattle. Average daily gain needs to be a little higher than that for good reproduction and beef quality. We later showed that protein tubs or a byproduct-based concentrate give a similar response, but because of the price and handling characteristics, whole cottonseed is still my first choice at home. If you are in the south, have a tall fescue-based system, and have access to whole cottonseed, consider giving it a try. If you are interested in the detailed report of our study, it is published here.
~ Dr. Matt Poore
The Alliance for Grassland Renewal is a national organization focused on enhancing the appropriate adoption of novel endophyte tall fescue technology through education, incentives, self-regulation and promotion. For more resources or to learn more about the Alliance for Grassland Renewal, go to www.grasslandrenewal.org