Figure 2. Daily weight gain of coccidiosis-free
(lesion group 0), subclinical ( 1) and clinically infected ( 2) groups.
Average Daily Grain (g)
100
80
60
20
0
- 20
51. 6 46. 4 55. 3
40
22. 6
- 2. 9
20 27 34 41 48 20 27 34 41 48 20 27 34 41 48 Age
Lesion 0 1 2
78.4
90.0 95.8 90.2
71.4
83.0
90.4
24.0
45.0
39. 3
Reductions in bird performance due to coccidiosis intestinal lesions are related to bird energy
metabolism.
Figure 3. Daily maintenance energy expenditure of coccidiosis-free
(lesion group 0), subclinical ( 1) and clinically infected ( 2) groups.
creating an uncertain MEn utilization.
Bird activity comprises about 18% of
MEn consumption, but is in;uenced by
management through stocking density,
lighting program, feeder and waterer
space; feed processing via pellet quality; ambient temperature; and diseases
such as coccidiosis via elevated body
temperature and malabsorption.
The sum total of the energy factors,
and how they are handled, is where the
science of nutrition becomes the art of
nutrition. For example, many companies
have seasonal adjustment (i.e. winter
vs. summer programs), carcass yield
and/or composition adjustment and rations to elevate the survivability or to
improve FCR. But, are there additional
approaches?
Maintenance Energy (Lcal/Day)
0
300
250
200
150
100
50
231
192
160
121
0
81
76
20 27 34 41 48
300
277
235
204
177
195
141
120
88
20 27 34 41 48
1
20 27 34 41 48 Age
Lesion 2
Maintenance increases in proportion to metabolic body size for the unchallenged lesion birds as
they mature.
Figure 4. Feed efficiency of coccidiosis-free (lesion group 0),
subclinical ( 1) and clinically infected ( 2) groups.
Average Daily Grain (g)
0.8
0.6
0.674 0.648
0.657 0.602
0.575 0.521
0.547 0.505
0.4
0.450
0.2
0.0
-0.2
20 27 34 41 48 20 27 34 41 48 20 27 34 41 48 Age
Lesion 0 1 2
0.260
0.408 0.424
0.297
0.157 -0.038
Feed evaluation systems
Bird maintenance needs are elevated slightly for immunity development and markedly so for coc-
cidiosis.
Today’s MEn and ECV systems
The MEn system has traditionally
been used by the poultry industry, and
poultry feeds are commonly formu-
