Page 22—foraging Around, Lancaster Farming, Saturday, February 7, 1998 (Continued from Page 21) The second easiest method is the calculation method. In thjs method we simply use "known” pounds per acre inch of grazeable forage and other “known” infomation and calculate RHD without doing field harvests. We often “rc-determine” pounds per acre inch for our forages by doing a few sample field harvests. Anyone would be wise to do so for itself. Otherwise, there are standardized figures avail able to use to cheat the system. In this case, we must measure or estimate the average inches of grazeable forage available per paddock. Let’s assume our grass is bermudagrass and bahia grass at 250 pounds per acre-inch. In this case we must know acres and stocking rate. (See Table 2.) This method is easy to use, grazier friendly and a good countercheck with the visual readings. Now, let’s do the same example us ing the measured estimates method. In this case we must hand harvest a rep resentative sample(s) from each pad dock. weigh it, tally the results and factor in the livestock need. We use a 3.1-foot square frame for the sample size (grams x 10 = lh/ac) and we cut at the recommended residue height for the forage in question. Again, I record this in my notebook or on a form. In this case, we must also know acres and stocking rate, etc. (See Table 3.) This method is good, but most gra ziers are not inclined to go to such ex tremes to gather the data. We have a form available to help determine data for methods 2 and 3. Within any of these methods we can make it complicated and factor in ad ditional expected forage production, livestock weight changes, differences in pounds per acre-inch of forage de pending on height of forage, etc. But, in practice all of that makes little dif ference in the practical use of the me thods. A one-inch rain at the right time is worlds more important. The RHD and the ebbs and flows of it are much more important than the minnute dif ference shown by adding more com plications. The average of the three methods is 27.7 (or 28). So, what does that mean? It means that there is 28 days of feed available without serious changes. A major use of RHD is to also easily measure the ebb and flow of forage supply. The ebb and flow of the RHD range does not make much sense unless we know something about what the ex pected RHD parameters need to be. For example: 1. In the green, actively growing season, there arc only 10-14 RHD needed to have forage for the herd to graze al the grass “as it grows.” More would be excess and less is often a problem indicator. 2. For summertime grazing, we need to build to have 40-60 RHD ahead of the herd by about June 15. That excess gets our herd through the summer forage slump. *Bl,76o°°* Frank Insinga, of Laceyville, PA, feeds his cows more forage now with Full Time™ Forage. Even though his herd is 270 days in milk, they are producing 80 pounds milk per day. Below is his regular corn silage ration as well as his Full Time ™ Forage ration. Feed Stuffs Normal Corn Silage Full Time™ Forage Haylage Hi-Moisture Shell Corn Protein Concentrate + Minerals & Vitamins Dry Hay Total Feed Cost/Day Feed Cost Savin Date; May 10,1997 ~ . . Forage In. Pounds Forage Available Paddock Available ~ T - Number Acres Per Ac. Per Acre PerPaHrWi. 1 20 2x250= 500 10,000 “ 20 3 750 15,000 ] 20 1 250 5,000 4 15 Trace 0 0 5 25 6 1500 37,500 6 10 5 1250 12,500 7 40 2 500 20,000 —r-Z 16 4000 40.000 Totals/ 160 3.5 875 140,000 Averages Table 2 3. For winter stockpile, we need 150-180 RHD to go through al winter no-growth times. When there is less, we can plan hay needs. There are other correlations, too. The 28 RHD means that there is more forage growing than the stock are eating. Why? Because, to graze all grass as it grows and have no reserve requires wily the 10 to 14 RHD. That is exactly what we try to do in the spring grazing of winter annual grass pastures. If our objective is to graze all grass as it grows; (1) we could add more stock or (2) cut some for hay. etc., or (3) leave the excess for later grazing. Normal Corn Sila As Fed 40 Lbs. 25 Lbs. 28 Lbs. 20 Lbs. s/Da' How can we use RHD to determine amount of hay to cut? First, we need more RHD for grazing than we are us ing. If we have 28 RHD and need only 14 RHD, then 'A of the area can be cut for hay (28 - 14/28 = 50 percent). If we have 28 RHD and need 21 RHD, then we can harvest only 'A of the ex tra forage (28 - 21/28 = 25 percent). If the RHD were only 10 to 14 or less and declining, that would indicate a forthcoming deficient forage supply and a need to adjust management. Do we de-stock some or all? Do we pro ject ahead to a sale date and get ready to sell all of the cattle? The ebb and (Turn to Page 23) Cost/Day $0.50 $0.50 $1.26 $3.98 $6.24 2.24 Full Time™ Forage Cost/Da As Fed $1.12 75 lbs. $0.50 25 Lbs. $0.68 15 Lbs. $1.45 9.75 Lbs. $0.24 3 Lbs. $3.99
Significant historical Pennsylvania newspapers