Because condition at calving and breeding are so important, it may at first seem silly to begin worrying about condition in the middle of July. However, it must be remembered that there are few economical ways to increase body condition once winter has arrived. So, good body condition in the winter must depend on the nutritional program the previous summer. If on July 15, the cows are in good condition and are rapidly regaining weight lost the past winter, the program can run normally. If, on the other hand, the past winter was severe and cows are still thin now, with every likelihood that they will be thin going into the next winter, thought needs to be given about the most economical method of improving condition before winter. Weaning dates can be moved up; remember calves would be young and weaning weights will be reduced. A well-planned supplementation program may offer help. When adequate standing forage is available, feeding small amounts of protein supplements during late summer and fall can efficiently increase weight and condition gain of spring calving cows (Table 1). Feeding as little as .6 lb/head/day of soybean meal, (about 1.5 lb/head, 3 times per week) during late summer increased cow weight by 25 lb. and improved condition score by .67 units. See the OSU data in table 1 below.
Table 1. Late Summer and Fall Supplementation to Increase Weight and Condition of Spring Calving Cows (source: OSU Beef Cattle Manual; 3rd Edition)
|
Trait measured |
No Supplement |
0.6 pound/day soybean meal |
|
Aug. 4 to Nov. 9 Weight change (lb) |
27 |
52 |
|
Aug. 4 to Nov. 9 Condition change |
-0.15 |
+0.52 |
A supplement level of 1 to 1.5 lbs/head/day would probably have been more desirable and provided greater weight increases. The important point is that during late summer and early fall, protein supplements can permit efficient increases in weight and condition when forage is available. If one waits until winter to try to increase cow weight, protein alone will likely not be sufficient and larger amounts of energy supplements or hay will be required. If weather conditions are very cold, it may not be economically feasible to increase condition during the winter.
The following graph shows clearly the associated effects of protein supplementation on low quality forage. In this OSU research, replacement heifers were fed low quality grass hay free choice. Without protein supplements, they were only able to consume 10 pounds of the hay per day. As the heifers were fed soybean meal in increasing amounts, the hay intake increased. Why could this happen? The microbes in the rumen are utilizing the protein to develop, grow, and multiply. The rumen microbes more quickly and more effectively digest the low quality roughage. This is in turn allows the heifers to consume more hay on a daily basis. Forage intake increases because the hay is more rapidly digested, and therefore passed through the digestive system more quickly. The amount of energy gained from each pound of roughage increased. This is determined by the % acid detergent fiber (ADF) digestibility. As a result, the total amount of digestible energy available to the heifers (Digestible Dry Matter) was greatly increased from about 4 pounds to 8 pounds per head per day.
The bottom line is: there is a "lot of bang for the buck" for the money spent on the small amount of protein supplement. With adequate quantities of standing forage available in many Oklahoma pastures, this could be an excellent summer to take advantage of positive associated effects of protein supplementation.
Glenn Selk, OSU