Introduction
Livestock producers need to
manage animals for optimum performance and net return. Feeding cattle in
In the
Procedures
Calves born and raised at the
Modest bedding was a
minimalist approach to keeping some bedding under the calves during inclement
winter weather and generous bedding was essentially double the amount provided
in the modest bedding treatment. Straw
was added approximately weekly with longer periods between bedding when weather
allowed. Big round bales were deposited
in the pens and spread throughout the bedding area with a front end loader
equipped with a grapple fork. Calves had
access from the bedded area to feedbunks and water
fountains on concrete aprons. Data
reported represents the last four months prior to market, roughly equivalent to
December through March each year.
During the trial, calves were
observed to have variable amounts tag or manure attached to their hide
associated with bedding treatment. A
five point scoring system was developed to quantify the amount of tag on the
hide and all steers were scored prior to going to market. Three people independently scored each
steer. The scoring system was 1=no tag,
clean hide, 2=small lumps attached to the hide in limited areas of the legs and
underbelly, 3=small and large lumps attached to the hide covering larger areas
of the legs, side and underbelly, 4=small and large lumps of manure attached to
the hide in even larger areas along the hind quarter, stomach, and front
shoulder, and 5=lumps of manure attached to the hide continuously on the
underbelly and side of the animal from brisket to rear quarter.
To evaluate the effects of
bedding in lowering nitrogen losses in manure, 8-10 samples of raw manure were
collected from each pen prior to removal and analyzed. Manure from each pen was thoroughly mixed on
removal and composted for 1 to 2 months until stable and mixed again prior to a
second sampling. Comparison of analysis
of raw and composted manure will yield data from which to estimate the amount
of nitrogen volatilized as ammonia for each treatment. This data will be reported in the future.
Data were analyzed using SAS
GLM procedures with pen as the experimental unit. Normal replicated studies allot 6 to 8 steers
per pen but limited pen availability and evaluation of the practicality of
bedding larger numbers of animals led us to use more steers per pen. Granted, more replicates would increase the
confidence of the results. Years were used
as replicates as variation in winter conditions may affect need for bedding. Standard error and p values are shown in
respective tables.
Results
Feedlot performance
Dry matter intake (Table 1)
was not affected by bedding treatment (P<.05). Non-bedded steers fluctuated more in feed
intake but differences balanced out over weigh periods and multiple years
(replicates) of the study. Gains responded significantly (P<.05) in two of
the four periods and overall. Generously
bedded steers gained 3.53lb per day, modestly bedded steers gained 3.69, and
steers without bedding gained 2.83. Gain
per feed improved significantly (P=.06) in one period and tended to improve
overall for bedded steers (P=.09).
Table 1. Effect of bedding on feed intake, gain, and feed efficiency for
steers finished in
|
|
Treatment |
|
|
||
|
Item |
No bedding |
Modest bedding |
Generous bedding |
Std Err |
P value |
|
Number of head |
34 |
35 |
35 |
|
|
|
Initial wt, lb |
725 |
726 |
727 |
12.2 |
.85 |
|
Dry matter intake, lb/hd/d |
|
|
|
|
|
|
Period 1 |
20.50 |
19.91 |
20.74 |
1.41 |
.92 |
|
Period 2 |
22.84 |
21.59 |
21.64 |
1.86 |
.87 |
|
Period 3 |
22.51 |
21.86 |
22.88 |
1.45 |
.89 |
|
Period 4* |
22.11 |
23.43 |
23.41 |
1.23 |
.72 |
|
Overall |
21.99 |
21.96 |
22.16 |
1.56 |
.99 |
|
|
|
|
|
|
|
|
Avg daily gain lb** |
|
|
|
|
|
|
Period 1 |
3.16 |
3.84 |
3.81 |
.05 |
.01 |
|
Period 2 |
2.66 |
3.63 |
3.81 |
.68 |
.38 |
|
Period 3 |
2.90 |
3.67 |
3.37 |
.14 |
.03 |
|
Period 4* |
2.62 |
3.61 |
3.16 |
.65 |
.36 |
|
Overall |
2.83 |
3.69 |
3.53 |
.06 |
.01 |
|
|
|
|
|
|
|
|
Gain/feed |
|
|
|
|
|
|
Period 1 |
.155 |
.194 |
.184 |
.01 |
.14 |
|
Period 2 |
.124 |
.170 |
.178 |
.04 |
.48 |
|
Period 3 |
.130 |
.167 |
.148 |
.01 |
.06 |
|
Period 4* |
.116 |
.155 |
.035 |
.03 |
.36 |
|
Overall |
.131 |
.172 |
.161 |
.01 |
.09 |
* During year 2 in the last weigh period, calves in the “No
bedding” treatment were moved to a different pen and given bedding as they were
severely stressed by cold and wet conditions and manure tags. Compensatory gains were observed and are
included in the data set.
**Actual weight gains may be lower than reported due to
higher levels of manure tags on the steers in the no bedding treatment.
Animal Tag
The least amount of tag was
attached to the generously bedding animals (1.58 tag score), more tag on the
modestly bedded animals (2.64 tag score), and much more (3.75 tag score)
associated with no bedding. The excessive tag on the non-bedding calves added
to their discomfort by reducing any protection dry hair on a clean hide
provided. Calves in this group were
observed to be stiff and slow to get up.
Individual steer weights used for calculating average daily gains
included manure tags attached to the hide which may have inflated gains
slightly.
Clean steers in bedded pens gained faster. No
bedding steers carry significant manure tag.
Carcass Quality
Most carcass quality traits
(Table 2) were also positively affected by bedding (P<.05). Final weight was greater for both bedded
treatments at 1182 and 1172 lbs vs. 1121 for steers with no bedding. Carcass weight and dressing percent improved
with bedding, again affected by the weight of manure tags on the non-bedded
calves. Marbling scores, the indicator
for carcass quality grade, improved with bedding as did the percent of
carcasses grading choice. Twenty three
percent of carcasses from steers without bedding
graded choice, vs. 45% and 63% for bedded steers. Rib eye area tended to increase (P=.06) with
bedding from 11.47 square inches to 12.09, and 11.99 respectively for normal
and extra bedding. Yield grade, fat
thickness over the 12th rib, and internal fat (kidney, pelvic, heart
fat, KPH) were not affected by bedding.
Steers with no bedding may have improved in carcass quality with another
50 pounds of gain which would have taken several more days on feed.
Table
2. Effect of bedding on carcass quality for steers finished in
|
|
Treatment |
|
|
||
|
Item |
No bedding |
Modest bedding |
Generous bedding |
Std Err |
P value |
|
|
|
|
|
|
|
|
Final weight, lb |
1121 |
1182 |
1172 |
18.41 |
.02 |
|
Carcass wt, lb |
674 |
715 |
721 |
12.86 |
.02 |
|
Dressing percent |
61.95 |
62.33 |
63.43 |
.38 |
.02 |
|
Marbling score* |
361 |
392 |
415 |
10.89 |
.01 |
|
Percent Choice |
23 |
45 |
63 |
- |
- |
|
Yield grade** |
2.98 |
3.03 |
3.09 |
.07 |
.30 |
|
Fat thickness, inches*** |
.39 |
.43 |
.46 |
.03 |
.13 |
|
Rib eye area, square in. |
11.47 |
12.09 |
11.99 |
.25 |
.06 |
|
KPH, % |
2.43 |
2.51 |
2.43 |
.05 |
.14 |
* Marbling score is numeric value based on dispersion of fat
inside ribeye muscle, 300-399 = select, 400-499=low
choice. Higher scores = more marbling
and higher carcass value
** Yield grade is a measure of fat to lean ratio, 1=lean,
5=fat.
*** Measured over 12 rib
Economics of Bedding
The amount of bedding varied
with year as indicated in Table 3. Size
of pens, number of animals, method of bedding (shredder, whole bales etc),
bedding material (straw, stover, soybean
residue), precipitation, southern exposure, temperature and other factors may
affect amount of bedding. In this study modestly bedded steers were charged
$5.77 per head and generously bedded steers $10.15. A modest amount of bedding was provided to
the steers in the non-bedded treatment during the last feeding period in year 2
in an effort to alleviate severe stress and improve the hide condition prior to
market.
Table 3.
Bedding use and cost per head for finishing steers in
|
|
Treatment |
|||||
|
Item |
No bedding |
Modest bedding |
Generous bedding |
|||
|
Year |
1 |
2 |
1 |
2 |
1 |
2 |
|
Pounds
per head for feeding period |
0 |
150 |
204 |
565 |
407 |
941 |
|
Bedding cost per head @
$30/ton |
0 |
|||||