‘The book’ is very clear about when to cut hay – when the forage crop is just beginning to head out or make a flower. Yet we consistently suffer with overmature and low quality hay. When forage testing is mentioned, producers tend to change the subject. Inwardly, I believe they are thinking something like “I know my hay is bad. Why would I pay somebody to tell me it is bad.”
Before you stop reading – hear me out. The point is not to restate the optimum stage to cut hay, but to get you to cut earlier than last year. And to test hay!
To make the case to cut earlier, we often use Table 1 from the UK College of Ag publication ‘Quality hay production’ (AGR-62) that shows the impact that stage of harvest has on fescue hay forage quality and animal gain. I had seen it and used it for decades before realizing the insights below. These insights were ‘in the book’ but I missed them. I think you may find them compelling.
This Tennessee research compared three fescue hays cut May 3, May 14 and May 25. These dates corresponded to late boot/early head, early bloom, and early milk stage/seed forming, respectively. These hays were then fed to 500 lb. holstein heifers. Take a look at what the data shows.
- The latest cutting date, May 25, is not that late compared to most fescue cut in KY. Based only on date of cutting, this hay is better than most.
- The heifers ate more of the early cut hay, 13 lb/day compared to 11.7 and 8.6 for later cut hay.
- Early cut hay had the highest digestibility and crude protein. The drop in digestibility was small between May 3 and May 14, but much larger over the next 11-day period. Crude protein dropped about the same (about 3 %) for each 11-day delay.
- Gain per day dropped from 1.39 to 0.42 lb/day for the three hays. The earliest cut hay supported the best gains, as expected. The decline in average daily gain was about the same for each 11-day delay in cutting.
- Maturity decreased gains per day more than forage digestibility. A delay of 22 days dropped digestibility by 17% (68 to 56%). Over this same period, daily gain dropped by 70% (1.39 to 0.42 lb/day). Small changes in quality made big differences in gain.
- The highest quality hay did have the lowest yield per acre. Delaying cutting will increase yields and this may be fine for mature cows with low needs.
- Curiously, gain per acre was almost equal for each of the three hays (yield per acre divided by lb of hay per pound of gain), 132, 136, and 125 lb, respectively. If you calculate how long it would take to get that gain on each hay, you arrive at 95, 140 and 298 days respectively. Hay cut on May 25 could produce the same gain as hay cut on May 3 but it would take twice as much hay and three times as long!
- The May 3 cutting also had the added benefit of 22 extra days of forage growth compared to the May 25 hay cutting – extra growth that could further improve the argument for making an early first cutting.
Cutting hay early pays, especially for growing cattle. Small differences in maturity can make big differences in gain and your bottom line. Try to cut earlier than last year. And get your hay tested for forage quality. ~Jimmy Henning, excerpted from Farmers Pride.