Rumen Bugs Need Ammonia
Ammonia comes to microbes in the rumen in two ways: through a breakdown of natural protein (soybean meal, cottonseed meal, etc.) or through a readily available source such as urea.
Urea Toxicity
Toxicity occurs when the ruminant animal consumes 15 grams of urea per 100-pounds of body weight in a 30-minute period. Thus, an 800-pound feedlot animal would need to consume 120 grams of urea in 30 minutes for toxicity to occur; and a 1000-pound cow would need to consume 150 grams of urea in 30 minutes for toxicity to occur.
Feedlot Urea Use
Level for Best Performance
For example: Cattle Finisher 40% Crude Protein with 26% NPN (non-protein nitrogen) fed at the rate of 1.5 pounds, per head, per day.
-
26% NPN ¸ 285% Crude Protein in urea = .09 pounds of urea per pound of CATTLE FINISHER 40%.
-
1.5 pounds CATTLE FINISHER 40% ´ .09 = .14 pounds urea/head/day.
-
.14 pounds of urea ´ 454 grams/pound = 64 grams/head/day.
Cow Urea Use -Range Cubes
Work at the Gray Summit Beef Research Center indicated 6% NPN (non-protein nitrogen) is optimal in a hand-fed product such as Forage Balancer Cube 2. At equal levels of feeding, conception rates and calf weaning weights were similar.
| Initial Weight
Cow Weight at Weaning
Cows Rebred
Calf Weaning Weight
|
20% All Natural
1020 lbs.
1001 lbs.
86.4 %
423 lbs.
|
20% with 6% NPN
1012 lbs.
996 lbs.
87.8%
429 lbs.
|
Consider, for example the urea level in Forage Balance Cube 2 which has 6% NPN (non-protein nitrogen).
-
6% ÷ 285 = .02 pounds urea/pound of Cube 2 X 454 grams/pound = 9.6 grams/pound of Forage Balancer Cube 2.
For toxicity to occur, a 1,000-pound cow would need to consume 150 grams of urea, the equivalent of eating 15.6 pounds of Cube 2 in 30 minutes.
-
(150 grams urea ÷ 9.6 grams/pound of Cube 2 = 15.6 pounds of Cube 2)
Cow Urea Use — Self-Fed Products
Cows effectively utilize higher NPN (non-protein nitrogen) levels in products such as Sup-R-Block® 2HL and Sup-R-Lix® 2HL. This is because cows consume hand-fed products in 10-30 minutes while they consume self-fed products throughout the day. In effect, they "snack" all day on self-fed products, but quickly consume their "meals" of hand-fed products.
Therefore, cows can optimally utilize higher levels of NPN when they consume the NPN slowly over a full day’s feeding period. Our research indicates exceptional performance when feeding either Cube 2, Sup-R-Block® or Sup-R-Lix®.
|
6 Research Trials
Forage Balancer Cube 2 & Sup-R-Block®
|
4 Research Trials
Forage Balancer Cube 2 & Sup-R-Lix®
|
|
Forage Balancer
Cube 2
|
Sup-R-Block®
|
Forage Balancer
Cube 2
|
Sup-R-Lix®
|
| Number of Cows |
291
|
889
|
177
|
222
|
| Initial Cow Weight (lbs) |
1063
|
1074
|
1043
|
1032
|
| Cow Weight at Weaning (lbs) |
1073
|
1078
|
1049
|
1043
|
| Conception Rate |
94.1%
|
94.5%
|
94.4%
|
97.0%
|
| Actual Calf Weaning Weight (lbs) |
567
|
563
|
554
|
549
|
| Supplement Intake (lbs/head/day) |
2.8
|
3.0
|
2.8
|
1.5
|
Dr. Danny Williams
Dr. Lee Dickerson
