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Better Pork
February 2017
35
NUTRITION
were from the same corn source and
had identical particle sizes, it is pos-
sible that the pelleting process may
have negatively impacted the particle
size of the diet. Achieving a finer
grind would explain why stomach
morphology scores worsened when
pigs were fed pellets.
The researchers suggested that an
increase in fluidity of the stomach
contents could have led to increased
incidences of ulceration. References
in the literature show that the pH of
the stomach is more consistent in
all four regions when pigs are fed a
pelleted diet compared with a coarse
meal diet. These findings could indi-
cate that the level of fluidity creates
an environment where there is in-
creased mixing of stomach contents
when a pelleted diet is fed.
The researchers also performed
an economic analysis of the research
outcomes (data not shown). For the
purposes of this analysis, pig remov-
als during the trial were considered
mortalities. The economic picture
showed that feeding a meal diet
throughout the experiment signifi-
cantly increased feed cost ($/lb gain)
compared to all other treatments.
There were no significant dif-
ferences in income over feed cost
(IOFC; calculated as total revenue/
pig minus feed cost/pig). However,
there were numerical differences
suggesting that rotating between pel-
lets and meal diets improved IOFC
by $1 to $2 above feeding a meal diet
throughout the finishing period.
In conclusion, these results sug-
gest that rotating between a meal
diet and a pelleted diet during the
finishing period can have an impact
on pig health. This feeding approach
can decrease the incidence of stom-
ach ulcers, while still realizing some
of the feed efficiency benefits of
pelleting. Alternating between pel-
lets and a meal diet also appeared to
maximize economic returns.
BP
Janice Murphy lives in P.E.I. She is a
graduate of the University of Guelph
with a MSc in swine nutrition and has
worked in both the private and public
sectors.
The effect of pellet feeding on finishing pig growth performance, carcass characteristics and stomach
morphology
Period
Diet form fed during period
Day 0 to 70
Meal
Pellet
Meal
Pellet
Rotated
1
Rotated
2
Day 70 to 118
Meal
Pellet
Pellet
Meal
Rotated
Rotated
BW, kg
Day 0
31.5
31.6
31.4
31.4
31.6
31.5
Final weight
135.6
136.6
136.0
134.0
135.3
136.2
Day 0 to 118
Average daily gain, kg
0.96
0.97
0.96
0.96
0.96
0.97
Average daily feed intake, kg
2.36
a
2.26
b
2.30
bc
2.28
bc
2.30
b
2.29
bc
Gain: Feed
0.407
c
0.430
a
0.421
b
0.422
b
0.420
b
0.423
b
Pigs removed/pen
0.50
b
1.92
a
1.06
b
0.93
b
0.85
b
0.92
b
Keratinization score
2.3
2.4
2.2
2.1
2.8
2.1
Ulceration score
1.5
2.0
2.2
1.6
1.8
1.6
Ulcer index
3
5.25
ab
6.72
a
6.72
a
4.61
b
6.15
ab
5.32
ab
Carcass characteristics
Hot carcass weight, kg
97.9
99.2
98.6
97.9
98.4
98.9
Yield, %
74.8
75.2
74.7
74.8
75.3
75.6
Backfat, mm
16.7
17.1
16.8
16.5
16.8
16.8
Loin depth, mm
72.8
73.8
73.9
73.4
73.7
73.9
Lean, %
56.3
56.2
56.2
56.5
56.5
56.3
a–c Superscripts within a row are different (P < 0.05).
1 Meal and pellet were rotated every two weeks starting with meal and ending with pellet. Pigs were fed a meal diet for 10 days prior to collecting stomach morphology scores.
2 Meal and pellet were rotated every two weeks starting with pellet and ending with meal. Pigs were fed a pelleted diet for 10 days prior to collecting stomach morphology scores.
3 An index of stomach morphology was developed by adding a pig’s ulcer and keratinization score. An additional score of four was added to each pig that had an ulceration score greater than one.
Sources: J.A. De Jong, J.M. DeRouchey, M.D. Tokach, S.S. Dritz, R.D. Goodband, J.C. Woodworth, and M.W. Allerson. 2016. “Evaluating pellet and meal feeding regimens on finishing pig performance, stomach
morphology, and carcass characteristics.” J Anim Sci 94(11):4781-4788; and JA De Jong, JM DeRouchey, MD Tokach, SS Dritz, RD Goodband, and MW Allerson. 2015. “Evaluating pellet and meal feeding regimens on
finishing pig performance, stomach morphology, carcass characteristics, and economics.” Kansas Agricultural Experiment Station Research Reports 1(7): Article 18.