Profit Tip: Balancing Timing of Hay Harvest on Subsequent Forage Productivity
In visiting with producers, it's almost mind boggling what they are telling me their annual cow costs are. Most have indicated that their costs are above $550 per cow. If calves pounds of calf weaned of females exposed was 500 lb, breakeven calculates to be $1.10/lb. Probably still making money considering what 500 pound calves sold for last fall. It wasn't that long ago their annual cow costs were slightly less than $400 with the same weaning weight and percentage calves weaned per females exposed. The breakeven calculates to about $0.80/lb. In about 2004 profits per cow were the greatest over about the last 25 years. However, the last few years those profits have dwindled to less than 1/3 of the good years. Keeping the female grazing, harvesting her own needs, is still the most economical approach to lowering feed costs. However, in some management systems or in some areas of the United States, harvested forages are needed to feed the cow herd. Are there management practice where grazing and hay harvesting practices can be optimized?
What Determines Forage Quality and Yield
It has been said that there are three items that determine forage quality: maturity at harvest, maturity at harvest, and maturity at harvest. It is safe to say that stage of maturity of a forage is the primary factor that influences forage quality. As plants mature or advance in maturity, forage quality declines. As the plant matures, a larger portion of the plant is stem as compared to leaves. Also, as the plant matures the fiber components of the plant increases causing a decline in quality and digestibility. In addition to the fiber components that increase as the plant matures, so does the lignin content. Lignin is a cell wall component of the plant that is not digested by ruminants.
On the flip side of forage quality is forage yield. As the plant matures, more plant material is produced and more quantity of plant is available. As plants mature, forage yield goes up. So this is a balancing act for producers, to optimize forage quality and yield. If the producers maximizes quality, then forage yield is minimized. If forage yield is maximized, then forage quality suffers.
Harvesting Time on Quality and Subsequent Productivity
This experiment was conducted in the Sandhills of Nebraska. Crude protein of the grass harvested on June 1 was 11.9%, forages harvested on July 1 was 8.0% crude protein, and forages cut on August 1 was 6.4% crude protein. There are huge differences in forage yield based on first harvest date. There is about a ton (2,026 lb/acre) difference in forage yield when comparing the cutting date of June 1 to July 1. These only about half the yield (1,046 lb/acre) difference between July 1 (4,679 lb/acre) compared to August 1 (5,725 lb/acre) cutting dates. There is not much difference in yield between August 1 and August 15, in fact the data says there is a reduction in yield, but due to variation in the data, statistics says those yield numbers are not different. Early cut hay would be a good protein and energy source for females after calving when the nutrient requirements are high. The early cut hay would also be a forage that could be targeted to first-calf-females during their first lactation. If the forage source doesn't meet the requirement, then only minimal supplementation would be needed.
Interesting in this experiment, is that forage availability and forage quality was determined at a fixed time in the fall. In this cases, forage availability and crude protein were determined in September on the same locations that the different cutting dates were performed. It is interesting that in September, forages quality increased as cutting date increased. In other words, the forage in September that was on the area that was harvested on June 1 (9.10% CP) was lower in crude protein compared to the protein content in the area that was harvested on August 1 (16.53% CP). After you think about it, this makes sense, because on September, the forage cut in that area on June 1 is more mature compared to the forage first harvested on August 1 then re-cut in September.
The forage available in September is much greater when the cutting date was June 1 (3,099 lb/acre) compared to August 1 (611 lb/acre). Statistics says that September yield when first cutting date was June 15 (1,921 lb/acre) is not different than that cut on July 1 (1,669 lb/acre). In the final column of Table 1, total yield is reported which is the sum of yield at first harvest plus the forage yield in September. Total yield is not different when first harvest date was July 1 compared to August 1. However, crude protein (8.0%) content is greater in forage harvested July 1 and one could assume that energy (%TDN) content is greater in the July harvested forage compared to the crude protein (6.4%) and energy content in August 1 harvested forage.
One of the management practices that keeps the cow harvesting her needs is dormant season grazing. Forage available for dormant season grazing is 2.7 times greater when first cutting was taken as hay on July 1 compared to the forage cut as hay on August 1. Will the dormant standing forage meet the cow's nutrient needs? Maybe, maybe not as it will depend on her stage of production. If it doesn't, then a little strategic supplementation may be warranted. In addition, hay harvested in July may need little to no supplementation depending on when it is targeted to be fed. This could be a win-win situation, depending on your goals and management strategies.
Two factors that would impact forage quality and yield are precipitation and fertilization. With the recent price of nitrogen fertilizer, it's hard to pencil in the return to fertilization. Do these calculations for your area and response expected for different rates of application.
It will be important to keep costs low, especially feed cost, without negatively impacting production. The data presented suggests that there are opportunities to manipulate both hay yield and quality by changing time of first harvest. First harvest date also impacts forage quantity available for stockpiled grazing opportunities. The optimum time for first harvest will depend on management objectives and forage resource(s) for a particular ranch. These kinds of strategies can impact supplementation need and therefore supplementation costs.
High Quality Meadow Hay as a Winter Supplement for Gestating Beef Cows in the Sandhills of Nebraska. 1993 Beef Cattle Report, Page 8.
[October 2nd, 2008]
Dr. Rick Rasby, Professor of Animal Science
Animal Science, University of Nebraska - Lincoln, Lincoln, NE