Page 117 - Calculating Agriculture Cover 20191124 STUDENT - A

CH 11 Calculating Agriculture 11-5

Step 5: What is the calving % to market?

Solution:
(e) Calving % to Market = pregnancy percent x calving rate x weaning percent x 100%
Calving % to Market = 87.67% x 97.72% x 99.22% x 100%
= 0.8767 x 0.9772 x 0.9922 x 100% change %rates to decimal
= 0.8567 x 0.9922 x 100%
= 0.8500 x 100%
(e) Calving % to Market = 85.00 % 11

The effective calving rage is 85% for the 300 head of cows. Which is to state that 85 calves for every
100 cows make it to market. As this herd consists of 300 cows then ( 300 x 0.85 =) 255 calves went to
market. In our example, 300 cows were exposed to a bull and 255 cows weaned a calf. Calf Crop Percent is
((255 calves weaned/300 cows exposed to the bull) x 100 = ) 85%. Records indicate 37 cows had no
record of calving, 6 calves lost at calving, and 2 calves were lost between calving and weaning. It is
assumed the 37 head did not get pregnant during the breeding season because there was no record that they
aborted.

Weaning Weight: Cattle

Cattle adjusted 205 day weight. The weaning weight of offspring is an important measure of the
dam's productivity. If weaning weights are to be useful, they must adjust the offspring’s weight to a
comparable age. Calves are usually adjusted to 205 days of age; pigs are adjusted to 25 days. The sex of the
offspring and age of the dam also influence offspring weight.

The following formula can be used for correcting calves' weight to a 205-day basis:

weaning wt. − birth wt. Dams Age
(1) Adjusted 205-day wt. = ——————–———— x 205) + birth wt. + Weaning wt
age in days Adjustment

If birth weight is not available, an estimate of 65 pounds can be used for heifers
and 70 pounds for bulls.

(2) Adjustment for age of cow is made by the following factors:

Table 11.3 Dams Age Weaning Wt. Adjustment
Age of Dam in Amount to Add to
Years at Calving Weaning Wt. (lbs.)
2............................................................................ 60
3............................................................................ 40
4............................................................................ 20
5 − 8 ........................................................................... 0
9 ............................................................................ 10
10........................................................................... 25
11........................................................................... 35
12........................................................................... 50

(3) Adjusted factors for sex are used to adjust to a steer equivalent by:
Adding 25 lbs. to the heifer calf weight.
Subtracting 25 lbs. from the bull calf wt.

INSTRUCTOR Copyrighted Material