xt7kd50fwc7w https://exploreuk.uky.edu/dips/xt7kd50fwc7w/data/mets.xml Kentucky Agricultural Experiment Station. 1969 journals 188 English Lexington : Agricultural Experiment Station, University of Kentucky Contact the Special Collections Research Center for information regarding rights and use of this collection. Kentucky Agricultural Experiment Station Progress report (Kentucky Agricultural Experiment Station) n.188 text Progress report (Kentucky Agricultural Experiment Station) n.188 1969 2014 true xt7kd50fwc7w section xt7kd50fwc7w
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PROGRAM I
I970 ANIMAL AGRICULTURE DAYS
UNIVERSITY OF KENTUCKY
JuIy I5, I970 - CoIdstream Farm, Lexington ,
9:00 - II:30 a.m. - Visit research areas on the farm .
I2:0O Noon - Barbecue lunch (Provided by BIuegrass Stockyards) .
I:00 p.m. - Address: "AnimaI Agriculture in the I970's" -
Dr. L. S. Pope, Associate Dean For Administration,
CoIIege of Agriculture, Texas A & M
Juiy I7, I97O · Western Kentucky Substation Farm, Princeton
9:00 - II:30 a.m . - Visit research areas on the Farm .
I2:0O Noon · Barbecue Iunch (Provided by FieId Packing Company
and Owensboro MiIIing Company).
I:00 p.m. - Address: "AnimaI Agriculture in the I970's" -
Dr. L. S. Pope, Associate Dean of Administration,
CoIIege oF AgricuIture, Texas A 8. M
KENTUCKY
. ANIMAL SCIENCES RESEARCH REPORTS
1970
Progress Report 188
July 1970
UNIVERSITY OF KENTUCKY
AGRICULTURAL EXPERIMENT STATION
‘ DEPARTMENT OF ANIMAL SCIENCES
CONTENTS
ANIMAL FOODS Page
Effect of Teat Dipping on the Incidence of Mastitis by Staphylococcus Aureus ........... 5
Effect of Chlordane and Heptachlor on the Growth of Staphylococcus Aureus ............ 6 _
Degradation of Organochlorine Pesticides by Bacteria .......................... 7
Feeding Phenobarbital and Activated Carbon to Accelerate Dieldrin Residue Removal
in a Contaminated Dairy Herd ....................................... 8
Microbiological Examination of Cocoa Powder ............................... 10
Effect of Antioxidants on Rancidity Development in Dry—Cured Hams ................. 10
Effects of Antemortem Injection of Papain on the Tenderness and Quality of Dry
Cured Hams ................................................... 11
Effects of Muscle Quality on Chemical and Physical Properties of Co1mtrv—Style Hams ..... 12
Lamb Tenderness as Determined by Different Methods and at Different Times After
Cooking ...................................................... 14 ~
Effect of Castration, Slaughter Weight and Testosterone Implantation on Fatty Acid
Content of Ovine Adipose Tissue ..................................... 15
Effect of Castration, Slaughter Weight and Testosterone on Lamb Carcass Composition
and Palatability ................................................. 16
Use of Liquid Nitrogen to Harden Ice Cream ................................. 18
The Thermal Diffusivity of Ice Cream at Cryoscopic Temperatures ................. 19
GENETICS—PHYSIOLOGY
Freeze vs Fire Branding as Methods of Beef Cattle Identification .................. 20
Fertility of Southdown Rams Fed a Chlorohydrin (3-Chloro-1, 2-Propanediol) .......... 20
Use of the 133Xenon Washout Method to Measure Blood Flow Rate Through the
Ram Testis .................................................... 21
Unilateral Castration and Accessory Gland Development in Ram Lambs .............. 21
Influence of the Photoperiod on Duration of Estrus, Length of the Estrous Cycle and
Ovulation Rate in Ewes ............................................ 23
Reproductive Performance of Synchronized Spring- and Fall-Bred Ewes .............. 24
Genetic, Phenotypic and Environmental Parameter Estimates for Semen Traits
Measured on Yearling Southdown Rams ................................. 25
Relationship Between Semen Quality and Ewe Fertility in Southdown Sheep ............. 26
A Study of Calving Intervals in Kentucky D. H. I.A. Herds ........................ 27
The Effect of Breeding at Various Intervals After Calving on Calving Intervals
in Dairy Cattle ................................................. 27
The Effect of Breeding at Various Intervals After Calving on the Chances for
Eventual Conception .............................................. 28
Estrus Synchronization of Swine with Aimax, PMS and HCG ...................... 29
Effect of Feeding Level at Breeding on Reproductive Performance of Swine ............ 30
Reproductive Performance of Protein-Deficient Sows ........ · ................... 30
NUTRITION
Incorporation of Radioactive Sulfur Into Rumen Microorganisms as a Measure of
Protein Synthesis ................................................ 31
Vitamin E Losses From the Digestive Tract of Steers Fed Corn Oil ................. 31
Vitamin A Turnover in the Liver of Non-Pregnant Cows ......................... 32
Influence of Corn Oil on Pre—Intestinal Disappearance of Vitamin A in Steers ........... 32
NUTRITION (continued) Page
Creep Feeding Spring Calves on Kentucky Bluegrass-Ladino Clover or Fescue-Ladino
Clover Pasture .............................................. . . . 33
Recovery of Chromic Oxide from the Gastrointestinal Tract of Heifers ............... 33
Effects of Chlormadinone Acetate (Estrostat) on Preweaning and Postweaning Growth
., Rate of Beef Heifers ............................................. 33
Nitrogen Metabolism and Water Intake of Steers .............................. 36
Plasma Nitrogen Components in the Young Calf .............................. 36
Adjustment of Steers to Differenct Supplemental Nitrogen Sources .................. 37
Supplemental Nitrogen Source and Physical Form of Shelled Corn in Corn Silage Rations
· for Finishing Steers .............................................. 37
Physical Form of Roughage and Supplemental Nitrogen Sources in Steer Finishing Rations . . 38
Soybean Meal and Urea in Steer Finishing Rations ................ ` ............ 3 9
Conditioning Steer Calves for the Feedlot ................................... 40
_ Wintering Yearling Stocker Steers with Limited Protein and Energy Supplements ........ 41
Wintering Beef Cows on Ground Ear Corn .................................. 42
Plasma Amino Acids and Energy Sources in Sheep Treated with Insulin .............. 44
Proline Supplementation of High Roughage - Urea Rations for Sheep ................. 45
Nitrogen Components in the Digestive Tract of Lambs Fed Corn Gluten Meal and Urea .... 46
” Lamb Performance on Corn Gluten Meal and Urea Supplemented Rations ............. 47
Ruminal Histamine in Wethers Fed Different Levels of Protein .................... 49
Source and Level of Nitrogen for Early—Weaned Lambs ......................... 50
» Levels of Urea in Creep Feeds for Lambs ................................. 51
Physical Forms of Corn in Creep Rations for Young Lambs ...................... 52
Effects of Weaning Age on Lamb Performance ............................... 53
Influence of Aspergillus Q Fermentation Extract on Cellulose Digestion by Sheep ..... 55
Steroid Synthesis by the Adrenals of Vitamin A-Deficient Wethers .................. 55
Excretion of Vitamin A Acid by Sheep ..................................... 56
Effect of Molybdenum and Sulfate on Copper Status of Lambs ..................... 56
" Level and Mode of Feeding Effects on Animal Performance and Certain Blood and
Rumen Metabolites ....... . .... . ............................... 57
Portal Blood Flow in a Holstein Calf Employing the Doppler Shift Technique ........... 57
Production of Gangrene in the Extremeties of Bovine Animals from Injection of
Fescue Extract ................................................. 59
· Effect of Dietary Gelatin on Hoof Development in Horses ........................ 60
Horse Blood Glucose Levels as Affected by Different Rations ..................... 61
Energy Absorption and Utilization in the Equine .............................. 61
Effect of Dietary Calcium and Phosphorus Level on Performance and Skeletal
Development of Growing-Finishing Swine ............................... 63
` Copper Stores of Pigs as Related to Dietary Additions of Copper, Molybdate,
Sulfate and Sulfide ............................................... 63
Effects of Copper, Zinc and Iron Interrelationships in Pigs ...................... 64
Comparison of Various Feed Additive Combinations for Growing—Finishing Swine ....... 64
Comparison of Two Varieties of Qpagge-2 Corn and Normal Corn for Growing Pigs ...... 65
Comparison of Qpagge-2 and Normal Corn for Finishing Swine .................... 65
NUTRITION (continued) Page
Effect of Protein Level on Performance of Finishing Gilts ....................... 66
Effects of Protein and Fat Level on Performance of Growing Pigs .................. 66
Reproductive and Progeny Performance of Protein Restricted Gilts ................. 67
Learning Ability of Offspring from Protein Restricted Gilts ...................... 68
Effect of Feeding Complex wg. Simplified Diets to Sows During Gestation and
Lactation on Reproductive Performance ................................ 68
Complex xi. Simplified Starter Diets for Baby Pigs ........................... 70
Effect of Ascorbic Acid, Fat and Cholesterol on Performance and Plasma Cholesterol
Levels of Swine ............................................... . 71
Evaluation of Some Predictors of Swine Response to Temperature and Humidity ......... 72
Effects of Iodinated Casein and Tapozole in Vitamin A Turnover ............... . . . . 72
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ANIMAL FOODS SECTION
EFFECT OF TEAT DIPPING ON THE INCIDENCE OF
. MASTITIS BY STAPHYLOCOCCUS AUREUS
W. M. Pyles and B. E. Langlois
Mastitis may be the most expensive disease of dairy cows, costing the average dairyman in Ken-
tucky an estimated $1, 270 a year owing to losses in production and cost of drugs for treatment. While
complete elimination of mastitis from a herd is probably not possible, control is very possible.
This study was made to determine if a commercial test dip solution could be used to reduce the
incidence of mastitis, especially that caused by Staphylococcus aureus.
Procedure
The universitydairy herd was divided into two groups based on breed. Diagonally opposite teats
of each cow were dipped with a commercial teat dip solution after each milking. The remaining two
teats served as controls. Milk from the two treated quarters and the two control quarters of each cow
were analyzed by the following tests: catalase test (CT), Wisconsin mastitis test (WMT), and direct
microscopic leucocyte count (DMLC) andplating on blood plates and Baird-Parker agar. A total of
1, 154 samples were analyzed between November 1967 and June 1969. Standard microbiological tests
were used to identify isolates from plates.
Results
A sample was considered mastitis positive when at least one of the screening tests gave values
greater than the following; catalase test - 29% O2, WMT - 29 mm, DMLC - 1. 5 million leucocytes/ ml.
Based on these screening test values, the samples were divided into mastitis positive and mastitis ‘
negative groups. The number of samples in each group is given in Table 1.
S Table 1. - Distribution of Samples Based on Results of
Catalase Test, Wisconsin Mastitis Test and
Direct Microscopic Count
Source Mastitis Mastitis
Samples Positive Negative
Control
quarters 180 397
Treated
quarters 159 418
Total 339 815
Of the 1, 154 samples analyzed, 815 (70. 6%) were found by screening tests to be mastitis nega-
tive. Use of the teat dip appeared to have a beneficial effect in reducing mastitis, since 46. 9% of the
mastitis positive samples were from treated quarters, while 53. 1% were from control (untreated)
quarters.
Staphylococcus aureus was found in samples classified both as mastitis positive and negative by
the screening tests. The number of samples in each group found to contain g aureus and the source of
the samples are given in Table 2. The mastitis positive group was found to contain only three more
samples containing SL aureus than the negative group. However, the number of i aureus positive
samples accounted for 55. 2% of the samples in the mastitis positive group and only 22. 6% in the mastitis
negative group. In both groups, more g aureus positive samples came from the control quarters than
from the treated quarters.
The use of a teat dip after each milking appears to be useful in controlling mastitis.
..6..
Table 2. — Distribution of Staphylococcus aureus in Mastitis Positive
and Mastitis Negative Samples
Mastitis
Group Positive Negative
Staph.
aureus Positive Negative Positive Negative
Control
quarters 96 84 102 295
Treated
quarters 91 68 82 336
Total 187 152 184 631
EFFECT OF CHLORDANE AND HEPTACHLOR ON
THE GROWTH OF STAPHYLOCOCCUS AUREUS A
B. E. Langlois and Kay G. Sides
Previous work has shown that growth of Staphylococcus aureus was affected by certain organo-
chlorine pesticides. This study was made to obtain more information concerning pesticide inhibition of
S; aureus—in particular, inhibition caused by heptachlor and chlordane.
Procedure
Staphylococcus aureus was grown in a broth medium containing from 5 ug to 20 ug/ ml of hepta-
chlor, chlordane, gamma chlordane and nonachlor. The heptachlor used ranged in purity from 72 to
99. 8%.
Growth was determined by standard plating methods, with analyses being made every 2 hr during
the initial 12 to 24 hr period and then daily for the duration of the incubation period.
Results
Growth of Staphylococcus aureus in broth medium was affected by 5 ug/ ml of the pesticides
studied.
Results obtained in this study are shown in Table 1. All pesticides used caused a decrease in
initial viable count, ranging from 8.3% (99% heptachlor) to 51. 1% (gamma chlordane). Length of time
that viable counts decreased ranged from 2 hr for nonachlor to 24 hr for chlordane.
No correlation was found between percent decrease in initial viable count and resulting generation
time. Staphylococcus aureus had a generation time of 31. 9 min in the control. Pesticides caused the
generation time to increase. The lengthened generation time ranged from 40. 6 min (nonachlor) to 357. 5
min (chlordane). Gamma chlordane which caused the greatest decrease in initial viable count had one of
the lowest generation times (42. 3 min).
Growth of g aureus in skimmilk was unaffected by the presence of up to 50 ug/ ml of heptachlor
or 10 ug/ml of chlordane.
-7-
Table 1. —— Effect of Pesticides on Initial Viable Count and Resulting Generation Time of
Staphylococcus aureus in Trypticase Soy Broth at 370C
Initial Minimum Viable
Viable viable count Generation
. count.l2/ count decrease timeE
. . a/
Pesticide- (Loglo) (Log1O)g7 (hr) Q? (%) (Min)
Control 5. 00 j/ 31, 9
Absolute alcohol 4. 97 j/ 34. 5
Heptachlor - 72% 4. 98 2. 88 12 42. 2 102. 0
Heptacblor — 73% 4. 96 3. 03 10 38. 9 139. 5
Heptachlor — 74% 4. 94 2. 85 12 42. 3 181.4
Heptachlor — 99% 4. 93 4. 52 4 8.3 160. 5
Heptachlor — 99. 8% 4. 96 4.33 8 12. 7 223.1
Heptachlor — .purified 4. 92 2. 50 12 49. 2 120. 0
Chlordane 5.26 3.38 24 31.7 357.5
Gamma chlordane 5. 05 2. 47 10 51. 1 42. 3
Nonachlor 4.91 4.32 2 12.0 40.6
E/ Concentration of 10 ,ug/ ml
E/Count at 0 hr
9./ Lowest count obtained during incubation
é/ Time from 0 hr to reach minimum count and to enter logarithmic growth phase
6/ Values for calculating generation time obtained only from logarithmic growth phase
E/ No decrease in viable count
DEGRADATION OF ORGANOCHLORINE PESTICHDES BY BACTERIA
B. E. Langlois, Kay G. Sides and J. A. Collins
Recent interest has been focused on the mechanisms by which microorganisms degradate organo—
chlorine pesticides to less harmful products, since many of these pesticides can persist for a long time
in the environment.
This study was made to obtain more information concerning the mechanism of pesticide degra-
dation by bacteria and to determine if degradation could occur in milk.
Procedure
Strains of Bacillus cereus, Bacillus coagglans, Bacillus subtilis, Escherichia coli, Enterobaoter
aerogenes, Pseudomonas fluorescens and Staphylococcus aureus were grown in trypticase soy broth,
skimmilk and trypticase soy broth plus casein, containing up to 100 ppm of DDT, dieldrin, heptachlor
and chlordane. After growth for 1 to 4 wk, an analysis of pesticides and metabolites was made by
electron capture gas chromatography, paper chromatography and thin—layer chromatography. ’
Results
None of the bacteria studied were able to degradate any of the pesticides used in skimmilk or in
trypticase soy broth plus casein.
Dieldrin, heptachlor and chlordane were not degradated by any of the bacteria in trypticase soy
broth.
DDT was degradated by Q coli, g aerogenes, g cereus, B; coagglans and g subtilis in
trypticase soy broth. Degradation of DDT by _EL coli and E aerogenes was faster and more complete
under anerobic conditions than under aerobic conditions. Bacillus degradated DDT under aerobic
conditions and faster than any of the bacteria studied. The pathway for degradation of DDT was found
to be as follows:
..8-
DDE -——) DDT ·—-) DDD ———> DDMU -—-) DDMS
DDMS ——-)DDNU -—-) DDOH—-—t DDA -—-D DBP
FEEDING PHENOBARBITAL AND ACTIVATED CARBON TO ACCELERATE
DIELDRIN RESIDUE REMOVAL IN A CONTAMINATED DAIRY HERD
D. G. Braund, B. E.` Langlois, D. J. Connerl and E. E. Moorel
Pesticide residues in milk and dairy products represent a difficult situation for the dairy
industry. Various state and federal agencies are constantly monitoring these products to ascertain the
presence of pesticides and other adulterants. As a result of such monitoring, in March 19 69, dieldrin
was detected in cottage cheese in an adjoining state and traced to milk produced by a herd of 105 lactating ·
cows in Kentucky. Consequently, sale of this milk, amounting to approximately 4, 000 lb a day, was
prohibited.
Thus, the following study was made to determine if feeding phenobarbital and activated carbon
would accelerate removal of dieldrin residue from the above—mentioned herd.
Procedure
The presence of two bulk tanks on the farm permitted the separation of the herd in a control
group of 55 cows and a treated group of 50 cows, and the entire milk production for each group was kept
separated.
The diet for the control group consisted of pasture and concentrate of ground ear corn, protein
supplement and vitamin-mineral supplement. V
The treated group received the following in addition to the diet fed the control group: 5 g of
phenobarbital per cow per day, fed in two equal doses with the concentrate during the a. m. and p. m.
milking, and 2. 0 lb of powdered activated carbon per day mixed with corn silage and consumed at evening
feeding. The phenobarbital was fed for 24 days and the carbon for 67 days.
On the 26th day of the study carbon was given to the control group for the next 41 days and the
drug was fed for three days. ·
Milk samples were analyzed periodically for residue level by electron capture gas chroma-
tography.
Results
After one week of treatment residue level in milk from the treated group had declined 64%
compared with 36% for the control group. The results obtained are shown in Fig. 1.
About 35 days were required for the residue level in the treated group to decrease to an accepta-
ble limit or below. However, the level in the control group did not decrease below this limit until about
the 50th day. To emphasize further the importance of the treatment it must be considered that these
animals were fed phenobarbital 3 days and carbon for the last 24 days. The time undoubtedly would
have been longer if treatment had not been administered to the control group.
Removal of dieldrin residue can be accelerated by feeding phenobarbital and activated carbon.
Except under experimental conditions, however, the practice of feeding the drug to lactating dairy cows
is not permitted by the FDA. Any dairyman finding pesticide contamination of his herd should contact
his veterinarian, local health officer and FDA official before beginning treatment.
l/ Kentucky State Department of Health, Frankfort.
. -9-
3.0
h \
‘ \
\
\
\ - — - Treated Group
2-0 ° Control Group
Q, \
O)
R; ‘
E \
;~<
§ ,
.$
5
1 E l
Q \
s
F 1.0 \
\\ A
\
\ B
N; Y
x
\
`\
\ ` ·
—* _; -¤ an 1 ; —
k
Y 0 10 20 30 40 50 60 /3:1
Days
Fig. l . Effect of feeding phenobarbital and activated carbon on dieldrin residue levels in herd
milk. A. Feeding carbon to control group begun; drug fed for 3 days only. B. Drug
feeding to treated group stopped.
i
-10-
MICROBIOLOGICAL EXAMINATION OF COCOA POWDER
D. A. Gabis, B. E. Langlois and A. W. Rudnick
Little information is available concerning the microbiology of cocoa powders used in the manu- ,
facture of chocolate milk. Previous work in our laboratory found that shelf-life of chocolate milk was
significantly less than that of other milk products studied.
This study was made to determine the types and numbers of bacteria in cocoa powder and to ,
classify them using numerical taxonomy.
Procedure
From 10 different manufacturers, 36 cocoa powders were obtained and examined. Both total
aerobic counts and coliform counts were obtained by plating representative portions of the samples and
counting colonies formed at 320C after 48 and M hr, respectively.
Isolates were obtained from total aerobic count plates for use in identifying the species making
up the microflora of cocoa powder.
Tests for identification were run on the isolates, and the results were coded and placed on IBM ·
data cards. The isolates were compared with known species, and the isolates having the greatest
similarity to those of known species were classified as being the same species. A
Results
No coliform bacteria were found in the samples.
Total aerobic counts ranged from 100 to 27, 000/g. Thirty—one samples (86.1%) had counts of
less than 9, 300/g. Of these 12 (39%) had counts less than 1, 500/g. Based on the amount of cocoa
powder added to make 100 gal of chocolate milk and the number of bacteria found, the theoretical number
of aerobic bacteria added by cocoa powder would range from 6. 8 x 105 to 1. 3 x 108. This amounts to j
the addition of 2 to 324 bacteria per ml or 1, 700 to 326, 663 per qt of chocolate milk.
Bacillus and Micrococcus were the only genera comprising the microflora of the samples. All
samples contained bacilli, but only none contained micrococci.
Of the 519 isolates identified, only 10 were of the genus Micrococcus, while the rest were .of the
genus Bacillus. Micrococcus freudenreichii comprised one—half of the micrococci species, with M; luteus,
lvl; colpogenes and M agilis comprising the rest.
Bacillus licheniformis comprised 45% of the total bacilli population, with g cereus, B; mega-
terium and Q subtilis comprising an additional 40%. In all, 20 species of bacilli were identified.
EFFECT OF ANTIOXIDANTS ON RANCH)ITY DEVELOPMENT IN
DRY-CURED HAMS
Everett C. Lail, Jr., James D. Kemp and J. D. Fox
The use of antioxidants to retard oxidative deterioration in foods has increased tremendously in
the last few days. Only a very small amount of work, however, has been reported concerning their use
on dry-cured pork products. This research was designed to determine the effects of two food grade
antioxidants, Butylated Hydroxyanisole (BHA) and Tenox 7 (a mixture of BHA, Propyl Gallate and citric
acid in a propylene glycol and glyceryl mono-oleate base), on the rancidity development in dry-cured
aged hams.
Forty-eight freshly skinned hams were dry-cured 2 days per 0.45 kg of fresh weight and then
placed in salt equalization for one month. Half (24) were smoked and half (24) were not smoked. Eight _
hams in each group were then treated with BHA, 8 with Tenox 7, and 8 served as controls. External fat
samples were removed prior to antioxidant application. Subsequent to antioxidant application fat samples
-11-
were taken at 2, 4 and 6 month's aging. Characteristics of the external fat were determined by iodine
numbers, peroxide numbers, free fatty acid values and TBA values.
The results of the iodine numbers indicated the fat was firm. During aging iodine numbers
increased during the first 2 months and then decreased during the remaining aging period. There were
no significant differences in iodine numbers due to antioxidant treatments. However, the smoked hams
had a significantly (P <. 01) larger iodine number than did the unsmoked hams. The effect of anti-
. oxidants on peroxide numbers was significantly (P < . 01) lower in the antioxidant—treated hams in the
unsmoked group, whereas in the smoked group there were no significant differences. Free fatty acid
content increased with age (P < . 01) in both the smoked and non—smoked groups but at a slower rate in
the antioxidant treated hams. The non-smoked hams had a significantly (P <. O1) lower FFA value than
the smoked hams. The antioxidant treatments resulted in significantly (P < . 01) lower TBA values in
both smoked and non-smoked groups. Smoking significantly (P <. 01) reduced the TBA values.
From the results of this study, it is evident that both antioxidant treatment and smoking of dry-
cured aged hams retarded rancidity development.
EFFECTS OF ANTEMORTEM INJECTION OF PAPAIN ON THE TENDERNESS
AND QUALITY OF DRY-CURED HAMS
J. Bruce Smalling, James D. Kemp, and J. D. Fox
The dry-cured or country style ham is a savorecl meat item in Kentucky and other southeastern
states. One of the major problems in its processing is ;he produ ction of a uniformly tender product.
The use of papain, administered antemortem, has proven successful in the production of
tenderized beef. This study was initiated to investigate the use of antemortem—injected papain in the
production of tenderized dry cured hams.
Thirty-nine Hampshire and Yorkshire pigs, averaging approximately 95 kg, were randomly .
assigned to three treatment groups. Those in treatments I and II were injected with 0.33 and 0. 44 cc
of a papain enzyme solution, containing 60 mg papain per ml, per kg liveweight respectively. Treatment
III was a control. The injection levels were determined on the basis of a preliminary trial using 0. 22,
0.33, 0.44 and 0. 55 cc of solution per kg of liveweight. The 0. 22 and 0.55 cc levels were eliminated as
they produced negligible change and overtenderness respectively.
The enzyme was injected into the vena cava 30 minutes prior to slaughter. Hams were dry—cured,
using 8 kg of curing mixture per 100 kg of hams and held for 2 days per 0.45 of average weight. After
curing, the hams were salt equalized 30 days, cold smoked and aged 12 weeks at 18OC and 65% relative
‘ humidity. The fresh picnic and loin from each hog were used for shear tests to ascertain the effective-
ness of the enzyme.
At the completion of aging, the hams were out and subjectively rated for color, firmness, aged
aroma and general appearance. Slices were taken and subjected_to sensory evaluations for flavor,
saltiness, tenderness and overall satisfaction. Other center cut slices were subjected to shear tests on
the biceps femoris, semimembranosus and semitendinosus muscles, using a Warner-Bratzler shear ,
device.
Papain application did not significantly affect the change in ham weights during curing, salt
V equalization or aging. Post-aging quality appraisal scores were independent of treatment effects. The
majority of the hams scored red in color, slightly soft to soft in firmness, moderately aged in aroma,
and excellent to good in general appearance. Eight hams were noted as being noticeably mushy. Four
hams had an unusual aroma. Histological and biochemical analysis of proteolytic activity during the
12—week aging period suggested that the softness encountered was not due to the activation of papain.
Taste panel scores favored the control hams for flavor, saltiness and overall satisfaction.
Tenderness scores were higher, though not significantly for the treated hams. Shear tests on the fresh
picnic and loin showed that the papain was effective when injected antemortem, Ham shear values were
also significantly (P < . 01) affected by the papain. Muscle quality appraisal scores were independent of
treatment effects. The majority of the scores for firmness interacted with the papain to produce varied
-12-
tenderness between each muscle of the ham. Within the treated groups, the decreasing order of tender-
ness of the muscles tested was biceps femoris, semimembranosus and semitendinosus. Nested analysis
of variance gave evidence that more variation in shear values was obtained from the muscle than the
shear itself. Generally, it was concluded that the papain-treated hams were significantly more tender
than the untreated, but this degree of tenderness was considered objectionable because of the somewhat
mushy texture. Correlation analysis suggested that overall satisfaction and flavor were influenced by
tenderness as determined organoleptically.
EFFECTS OF MUSCLE QUALITY ON CHEMICAL AND PHYSICAL
PROPERTIES OF COUNTRY-STYLE HAMS
W. R. Henning, W. G. Moody, J. D. Fox and James D. Kemp
Much interest has been shown recently by packers concerning the economic loss from excessive
shrinkage of pale, soft, exudative (PSE) pork. This study was conducted to compare selected physical,
chemical and histological characteristics between extremely low quality and normal hams during curing
and aging.
Approximately 200 pork carcasses were screened for pH values of the gluteus medius muscle 1 '
hr post-mortem. Those having a low pH were thought to be susceptible to PSE development, and those .
with a high pH were expected to be normal. When the carcasses were cut 24 hr post—mortem, the hams
from 16 carcasses were visually selected for extreme PSE condition (Wisconsin quality score of 1) and i
16 carcasses were selected as high quality (Wisconsin quality scores of 3 or 4). At approximately 40 hr
post—mortem the pH values were again checked. At both 1 hr and 40 hr the pH values were significantly
(P ( . 01) lower for the PSE hams.
After the hams were removed from the carcass, fresh samples were obtained from the biceps
femoris of the right hams and analyzed for moisture, ether extract and total pigment. No differences
were found in percentage of moisture or ether extract, but the low quality hams contained significantly
(P <. O1) less total pigment than the normal hams.
All hams were cured, held for salt equalization, smoked and aged for 4 months, using standard
University of Kentucky procedures.
The biceps femoris of each right ham was sampled for chemical analysis and histological exami-
nation fresh, after salt equalization and after aging. Again, no differences were shown in moisture or
ether extract but the water—binding capacity of the muscle was significantly (P < .01) lower for the low
quality hams at all sampling times as shown in Table 1.
Results of the measurements of the histological sections of the biceps femoris stained with a x
succinic dehydrogenose stain are shown in Table 2. No statistically significant difference was shown in
fiber size between groups, but the low quality hams showed a significantly (P <. 01) higher white fiber
to red fiber ratio.
The left hams were used for determination of relative weight loss and palatability. The shrinkage
data are shown in Table 3. The low quality hams shrank significantly (P <. 01) more at all stages
throughout curing, salt equalization andaging. A trained sensory evaluation panel was unable to detect
differences between the two groups and there was no difference in tenderness measured by a Warner-
Bratzler shear device.
It is apparent from this study that much consideration should be given to the quality of pork,
especially when processing by country—style curing methods.
. -13-
Table 1.- Physical and Chemical Variables
Variable Normal; PSEE
_ Initial pH S/ 6.42 6. 08
Final pH£/ 6.02 5. 56
Expressible juices9/
fresl&/ 55. 2 65. 2
` after salt eq.-Q/ 27. 8 33. 2
after aging.‘l/ 22. 7 28. 4
Moisture, %
fresh 74. 8 74. 9
after salt eq. 66. 6 66. 9
after aging 61. 8 60.4
Ether extract, %
fresh 3. 62 3. 17
after salt eq. 3. 79 3.49
after aging 4. 63 4.41
Myoglobin, mg/g 9. 90 4. 36
[
2/ Muscles uniformly grayish pink, moderately
firm and dry
E/ Extremely pale, soft, exudative muscles
equivalentto quality score 1 based on Wisconsin
quality index.
Q/ A relative measure of water binding capacity
expressed as cm2 of expressible juice on No. 2
filter paper when 2 g sample was subjected to .
22. 5 kg pressure for 5 min.
Q/P < . 05
A 2/1¤ < . O1
Table 2. — Histological Measurements
Variable Normal PSE
White to red ratioE/ 1. 47 2. O2
White fiber diameter, p 91. 9 85. 3
Red fiber diameter, ju 59. 6 59. 7
E/P < . O1
Table 3. — % Shrinkage During Curing
Time Measured Normal PSE
After curingiaj 4. 72 7. 70
After salt eq.E/ 14. 81 18.47
After smokin/gE/ 16.07 19. 72
After aging? 25. 36 30. 25
2/P <. Ol
-14- I A
LAMB TENDER