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Animal Science Florida Agricultural
Mimeograph Series No. 62-1 Experiment Station
August, 1961 Gainesville, Florida
FURTHER OBSERVATIONS ON THE EFFECT OF PRE-SLAUGHTER
FEEDING OF SUCROSE TO SWINE-1
A. Z. Palmer, H. D. Wallace and J. W. Carpenter
The feasibility of feeding slaughter hogs a ration containing 60%
ground corn and 40% sugar during hold-over periods has been demonstrated
(Palmer et al, 1961) in terms of increased feed consumption, liver
weights, yield of the four lean cuts and improved tenderness and sweet-
ness of the livers when the feeding of that ration was compared with
the feeding of shelled corn.
The purpose of this study was to determine the palatability of
ground corn, sugar and a ration containing 70% ground corn and 30% sugar
when fed through a hold-over period of approximately 60 hours. A further
purpose was to study the effects of pre-slaughter feeding of sugar on
dressing percent, liver percent, cooler shrink, yield of the four lean
cuts and liver palatability.
Two trials were conducted in this study. In Trial 1, twenty-five
crossbred barrows and gilts from the University herd were weighed off
a previous feeding study upon reaching slaughter weight and allotted to
the hold-over feeding study according to previous treatment, weight, sex
and litter. The pigs were individually self-fed either ground corn or
sugar for the 60 hours prior to slaughter. In Trial 2, forty-one cross-
bred barrows from the University herd were weighed off a previous feed-
ing trial when reaching slaughter weight and allotted to the hold-over
feeding study according to previous treatment, weight and breeding.
The pigs were individually self-fed either ground corn or a ration
consisting of 70% ground corn and 30% sugar for the 60 hours prior to
In both trials, carcasses were dressed packer style; dressing per-
cent and liver percent were calculated on initial weight rather than
the slaughter weight obtained immediately before slaughter. This was
done to minimize the effect of "fill", as influenced by consumption
during hold-over feeding, on dressing and liver percent. Further, it
J/ The assistance of Earl Collins and Howard L. Povey, Swine Herdsman
and Meats Laboratory Manager, respectively, Mrs. Norma Bowles and
Richard Newman, Laboratory Assistants, Animal Science Department,
University of Florida is acknowledged.
2/ Palmer, Associate Animal Husbandman; Wallace, Animal Nutritionist;
and Carpenter, Assistant Animal Husbandman, Animal Science Department,
University of Florida, Gainesville.
was felt that resulting percentages would be more useful in comparing
feeding treatments in lerms of gain or loss in carcass and liver weight.
Dressing percent was calculated by the formula:
T chilled carcass wt.
Dressing percent initial live weight X 100
Liver percent was calculated by;the formula:
L hot liver wt.
Liver percent initial live wt. X 100
Percent carcass shrink during a 24 hour chill at 340 F. was calculated
by the formula:
chilled carcass wt.
Percent cooler shrink hot carcass weight X 100
The carcasses were broken-down by a standard cutting procedure
(Reciprocal Meat Conference, 1951). The combined percent of the four
lean cuts as well as individual percentages of ham, loin, picnic and
butt were calculated using the initial live.weight of each animal and
the weights of the trimmed wholesale cuts.
Liver slices were prepared 'for taste test by cooking in a covered
petri dish for 20 minutes in a 3500 F. oven. Pork loin chops were
broiled to an internal temperature of 1800F. and chilled to room
temperature; two half-inch cores were taken for Warner-Bratzler shear
determinations. The chops were tested for tenderness and juiciness and
the liver slices for tenderness and sweetness by a four-member panel;
scores were on a I to 9 hedonic scale with 5 being average and higher
values being more tender or sweeter in taste.
Loin eye area was determined by standard procedure (Kline and
Hazel, 1955) on both loins of each carcass and averaged for the values
used in this study. The data were analyzed by analysis of variance
described by Snedecor (1956).
RESULTS AND DISCUSSION
:-Trial I and 2 data are presented in Table I and 2, respectively.
In Trial I a small but consistent difference in consumption was
found between feeding treatments (P<0.01). The pigs fed the ground
corn consumed an average of 3.6 Ibs. during the 60 hour period whereas
the pigs fed sugar consumed an average of 2,1 lbs. during the same period.
In Trial 2, the pigs fed the ground corn plus sugar consumed an average
of 12,4 lbs. as compared to an average of 9.7 lbs. of ground corn con-
sumed by the other group during the same period. The higher consumption
of Trial 2.pigs fed ground corn as compared to the similar treatment in
Trial I may be noted; no explanation is offered other than that a differ-
ence in fill of the two groups going on the pre-slaughter feeding tests
might have been partly responsible.
In Trial I, differences in backfat thickness were found between
feeding treatments as well as between barrows and gilts within each
treatment; these differences should not be attributed to pre-slaughter
feeding treatments but are pointed out since the differences are suf-
ficient to account largely for the differences in yields of the four
lean cuts from the carcasses. It is generally known that carcasses with
thicker backfat do not cut out as high a percentage of the four lean
cuts as do carcasses with less backfat covering; carcass weight being
constant, gilt carcasses usually yield more ham, loin, picnic and butt
due to a thinner cover of backfat.
In Trial 1, the barrows fed sugar had larger livers than the barrows
fed ground corn; no difference in liver weight was found between the gilts
on the two treatments. In Trial 2, the pigs fed ground corn plus sugar
had slightly larger livers than the pigs fed ground corn.
Differences in dressing percent and cooler shrink were not signi-
ficant in either Trial I or Trial 2.
Liver palatability was not affected by feeding treatment in either
Trial I or Trial 2.
Differences in yields of ham, loin, picnic and butt were not found
when comparing feeding treatments. However, in Trial I the gilt carcasses
cut out higher percentages of the four lean cuts and had larger loin
Kline, E. A. and L. N. Hazels 1955. Loin area at tenth and last rib
as related to leanness of pork carcasses. J. Animal Sci. 14:659.
Palmer, A. Z., H. D. Wallace and J. W. Carpenter. 1961. The effect of
pre-slaughter feeding of sucrose to swine on slaughter, carcass and
quality characteristics. Ani. Husb. and Nutr. Mimeo Series No.
61-6. Fla. Agric. Expt. Sta., Gainesville.
Reciprocal Meat Conference, Proceedings of the Fourth Annual. 1951.
Snedecor, G. W. 1956. Statistical Methods (5th Ed.) The Iowa State
College Press, Ames, Iowa.
TABLE 1. A COMPARISON OF THE EFFECTS OF PRE-SLAUGHTER FEEDING OF GROUND CORN AND SUGAR.--TRIAL I
Fed Ground Corn -Fed Sugar
Item o0 Combined o* .0 Combined
No. Animals 6 6 12 7 6 13
Av. Initial wt., Ibs. 213.3 215.8 214.6 213.7 214.8 214.2
Av. Final wt., Ibs. 207.7 212.8 209.9 205.6 210.8 208.0
Av. Feed Consumption, Ibs. 3.4 3.9 3.6 1.2 2.6 2.1
Av. Backfat, in. 1.65 1.42 1.50 1.55 1.27 1.32
Av. Liver percent/ 1.57 1.84 1.71 1.94 1.84 1.89
Av. Dressing percent/ 70.9 70.9 70.9 69.9 70.6 70.2
Av. Cooler shrink, percent 2.17 1.87 2.02 2.17 2.68 2.18
Tenderness, av. 5.38 4.88 5.13 5.04 4.96 5.00
Sweetness, av. 5.75 5.42 5.58 5.61 5.21 5.42
Four Lean Cuts.A
Ham, percent 13.09 14.04 13.56 13.01 14.03 13.48
Loin, percent 10.19 11.05 10.62 10.36 11.16 10.73
Picnic, percent 6.45 6.98 6.71 6.44 7.10 6.75
Butt, percent 4.41 4.71 4.56 4.47 4.63 4.54
Combined Four Lean Cuts, percent 34.14 36.77 35.46 34.29 36.92 35.50
Loin Eye Area, av., sq. in 3.95 4.73 4.34 3.62 4.72 4.12
a/ Percentages based on initial weight.
TABLE 2. A COMPARISON OF THE EFFECTS OF PRE-SLAUGHTER FEEDING
OF GROUND CORN AND GROUND CORN PLUS SUGAR.--TRIAL 2
Item Fed Ground Corn Fed Ground Corn Plus Sugar
No. Animals 21 20
Av. Initial wt., Ibs. 213.7 213.5
Av. Final wt., lbs. 212.4 214,4
Av. Feed Consumption, Ib$. 9.7 12.4
Av. Backfat, in. 1.55 1.55
Av. Liver percent?-' 1.52 1.83
Av. Dressing percent/ 72.9 73.5
Av. Cooler shrink, percent 2.19 2.28
Tenderness, a/. 6.14 6.46
Sweetness, av. 6.01 6.04
Four Lean Cutsa/
Ham, percent 13.54 13.44
Loin, percent 10.44 10.30
Picnic, percent 6.45 6.23
Butt, percent 4.28 4.17
Combined four lean cuts,
percent 34.71 34.14
Loin Eye area, av., sq. in. 3.86 3.70
,/ Percentages based on initial weight.