BIBLIOGRAPHY ANGWAY, QUEMMY L. APRIL...
BIBLIOGRAPHY
ANGWAY, QUEMMY L. APRIL 2013. Evaluating the Meat of the Broilers Fed
with Substituted 50% Commercial Feeds with Varying Levels of Sweet Potato and Corn
Grits on the Carcass Yield and Quality of Broilers. Benguet State University, La Trinidad
Benguet.
Adviser: Ms. Myrna B. Walsiyen, MSc.
ABSTRACT
This study was conducted to find out the effect of varying levels of sweet potato
and corn grits on the carcass yield and quality of broilers. Specifically, this study aimed to
measure and compare the carcass yield of broilers fed with 50% commercial feeds with
varying levels of sweet potato and corn grits in terms of slaughter weight, carcass weight
and evaluate carcass characteristics through, organoleptic test in terms of appearance
aroma, tenderness, juiciness taste, and acceptability.
The result of statistical analysis showed that varying levels of sweet potato and
corn grits as substitute for 50% of the commercial ration did not cause any differences on
dressing percentage of broilers and quality of meat as evaluated by a taste panel. It is
therefore concluded 50% commercial ration can be substituted with varying levels of sweet
potato and corn grits.
Statistical analysis showed no significant differences in the dressing percentage
of feeds given varying levels of sweet potato and corn grits as substitute to 50% of the
commercial ration for broilers. The average dressing percentage of broilers with an average
slaughter weight of 1.56 kg. was 75.30%.
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
INTRODUCTION
Food is the most important contribution of Agricultural animals to human, that
animal contributes a greater percentage of the total food energy. For instance, animals are
more important source of protein than they are of calories. In all aspect, of animal product,
poultry meat is reach in highly-quality protein and low in total fat and saturated fat.
Furthermore, because it is mainly associated with the skin, most poultry fat can be easily
removed by removing the skin, in constant greater proportion of the fat in the red meat is
found dispersed throughout the lean, making it harder to remove. However, more concern
has being focused in poultry meat and it’s lower in cholesterol than other meat type.
Nowadays, poultry quality, which is defined by a combination of multiple factors,
has become a primary focus for producers, packers, processors, retailers and consumers.
Muscle color and texture are always the two most important factors that influence meat
quality. The cooked product appearance is significantly associated with raw meat color.
Moreover, it is suggested that lightness values could be used as an indicator of poultry
breast muscle quality for evaluating the incidence of the PSE- like (pale, soft and
exudative) condition. Meat pH, tenderness and water holding capacity are attributes of
muscle texture that have been studied most extensively.
Broiler meat is preferred not only for their soft tender quality but also its nutritive
value as excellent source of protein. The continuous effort to produce chicken meat has
stimulated further research for more suitable combination of known nutrients and new
additives to increase the efficiency, rate of growth and level of production of the animals.
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
This research aimed to produce a reference in the use of different levels of sweet
potato and corn grits in improving the carcass quality and the general health of food animals
such as broilers. Furthermore, it hopes to promote the use of natural products such as sweet
potato and corn grits in improving the carcass quality of broilers.
This study generally aimed to determine the effect of different levels of sweet
potato and corn grits on the carcass yield and quality of broiler meat. Specifically, it aimed
to determine the quality of carcass produced from broilers fed with different levels of sweet
potato and corn grits through organoleptic test and to find out the effect of different levels
of sweet potatoes and corn grits on the dressing percentage of broilers under La Trinidad,
Benguet.
The experiment used a total of 12 broilers, which was subjected to 42 days feeding
period. Meanwhile, carcass evaluation was done at the DAS laboratory in February 2011
and the organoleptic test was done four days after the evaluation.
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
REVIEW OF LITERATURE
Sweet potato is deficient in sulfur containing amino acids and tryptophan, but this
is partially compensated for by high levels of vitamin A (in a form of beta-carotene), a very
good source of vitamin C and manganese, and a good source of copper, dietary fiber,
vitamin B6, potassium and iron. Yellow and orange fleshed sweet potato are rich in
carotene (Anonymous, 2010)
Besides simple starches, sweet potatoes are rich in complex carbohydrates, dietary
fiber, beta carotene, vitamin C, and vitamin B6. Pink and yellow varieties are high in
carotene, the precursor of vitamin A. in 1992, the Center for Science in the Public Interest
compared the nutritional value of sweet potatoes to other vegetables. Considering fiber
content, complex carbohydrates, protein, vitamins A and C, iron and calcium, the sweet
potato ranked the highest in nutritional value (Anonymous, 2007).
It has attracted considerable attention over years from an experimental standpoint
because sweet potatoes given high yields of digestible carbohydrates. Sweet potatoes will
out produce most other crops in yield of digestible carbohydrates per acre. Dried sweet
potatoes are high in content of digestible starch and carotene (Perry et al., 2000).
Coma (2000) mentioned that nutrition may have a significant effect on certain
attributes of meat quality. Meat quality is a complex without single definition. Fresh meat
attributes such color, quality of fats, tenderness, juiciness and flavor are essential in order
to drive the purchase and assure consumers fidelity. In addition we must not forget the
interrelation with other elements of production process like genetic handling and slaughter.
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
A poultry carcass should produce highly nutritious value, flavor and texture and
eating quality of meat. As a commodity, it has to meet requirements of the costumer in
terms of bright and attractive color, characteristics of meat and appearance of the product
offered. Also, include the nutritive value, high satiety value, color and especially free from
chemical residue. Keeping the bled animal suspended by its hind legs throughout the
dressing operations greatly increased the efficiency of converting an animal into a carcass
and by products. This new system reduces the chances of microbial contamination (Paris,
1998).
According to Woolfe (1992) maize and sweet potato have comparable
metabolizable values of 14.5 to 14.8, respectively. The digestibility of sweet potato
carbohydrate fraction is reported to be above 90%. The level of starch decreases with
period of storage and instead the level of reducing sugars and total dextrins increases.
Sweet potatoes have also been reported to exhibit trypsin inhibitor activity ranging from
20 to 90%. However, trypsin inhibitor levels present in sweet potato tubers are low and
should not be a cause for concern under practical situations.
Villareal and Griggs (1982) cited that sweet potato is equal to corn in total
digestible nutrients but low in proteins. The average composition of dried sweet potato
meal is 90.2% dry matter; 4.9% protein; 0.9% fat; 3.3% fiber; 77.0% nitrogen-free extract;
4.1% minerals; 0.15% calcium and 0.14% phosphorus.
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
MATERIALS AND METHODS
Materials
The different materials that were used are as follows; 12 heads of 45 days old
broilers from a growth study that was conducted, knives, containers, weighing scale, digital
camera, record book and Ziploc bags.
Methodology
Experimental birds. The birds were fed with chick booster for the first week and
then shifted to broiler starter crumble for the next four weeks. The addition of the dried
yellow orange flesh sweet potato and corn grits to the feeds of the birds was on the 28th day
until 5th week. Broiler finisher crumble was given on the fifth week until the end of the
study.
Experimental treatments and design. 12 broilers were grouped into four treatments.
Each treatment had three replications and each bird represents one replication. The
different treatments were as follows:
To- pure commercial feeds
T1- 500g commercial feeds + 400g corn grits + 100g sweet potato
T2- 500g commercial feeds + 300g corn grits + 200g sweet potato
T3- 500g commercial feeds + 200g corn grits + 300g sweet potato
Slaughtering of Birds
Prior to dressing, the birds were fasted for 8 hours but water was provided ad
libitum. After fasting, the birds were weighed individually after which, these were
slaughtered. At slaughtering the bird was secured by holding both shanks with one hand
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
and both wings with the other hand to prevent struggling of the bird. With the help of an
assistant, sticking was done by severing the large blood vessel of the neck at the lateral side
below the mandible. After sticking, each bird was immersed into hot water for about a
minute or more after which, plucking of feathers followed. After plucking, the bird was
washed thoroughly and made it ready for evisceration.
Evisceration was done by laying the bird in dorsal recumbence. The esophagus and
wind pipe were then pulled up the base of mandible. For easy insertion of the hand, a slit
was made around the vent then down to the keel. The hand was taken inserted into the slit
in the abdominal cavity and the abdominal attachment on the entrails. After entrails were
pulled out, the liver, heart, and gizzards with proventiculus were separated. The head was
detached from the atlanto-occipital joint, which was accomplished by severing the skin,
muscle and ligaments at the said joints with a sharp knife.
Carcass Yield Evaluation
The dressed bird was placed on the pan of the weighing scale and the weight was
recorded in kilograms. The skin, carcass color and abdominal fat color were under
observation. Abdominal fats of broiler belonging to the different treatments were compared
with other.
Sensory Evaluation
From each treatment, one kilo of meat, abstained from thigh and breast was cooked
for the sensory evaluation. The meat samples were cooked separately or by treatment but
using the same kind of casserole and the same amount of water which was four cups each.
Cooking was done for 45 minutes.
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
When cooked, the meat samples were sliced into bite sizes afterwards, these were
given codes and presented to the panel of tasters. Each member of the panel tasters was
given a score or evaluation sheet for him to place his rating. Each member also was
requested to drink water rinse his mouth with water after tasting every sample to wash off
any remains of the meat previously eaten that may have affected his rating for the
succeeding meat samples.
Data Gathered
The following parameters gathered from the study:
1. Slaughter weight (kg). This was the weight of broiler before slaughter time.
2. Dressed weight (kg) . This refers to the actual weight of slaughtered bird after
plucking the feathers with head, feet, and entrails off.
3. Skin color. This was determined by comparing the skin to the yolk color fan.
4. Carcass color. This was done by observation of the carcass.
5. Color of abdominal fat. This was obtained by actual observation of the abdominal
fats and comparing it to the yolk color fan.
6. Dressing percentage (%). This was obtained by dividing the carcass weight by
the slaughter weight multiplied by 100%.
7. Meat color, tenderness, juiciness, taste, aroma and acceptability. This was
obtained through organoleptic test involving a panel of testers composed of 10 teachers, 10
students from the College of Home Economics and Technology (CHET).
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
Data Analysis
All the data gathered were tabulated and analyzed using the analysis of variance for
completely Randomized Design. Treatment means were compared using the Duncan’s
Multiple Range Test (DMRT).
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
RESULTS AND DISCUSSION
Slaughter Weight and Dressed Weight
Table 1 presents the slaughter and dressed weights of the birds in the different
treatments. Statistical analysis showed that there were no significant differences in the
slaughter weight of the birds among treatment means.
This is expected because the broilers were purposely selected to have more or less
similar weights at slaughter. This was done to eliminate the possible effect of slaughter
weight, because the broilers were almost of the same weights at slaughters, it followed that
their dresses weights were or less similar also. The overall mean slaughter weight of the
broilers used in the study was 1.56 kg and the dressed weight was 1.17 kg.
Table 1. Slaughter and dressed weights of the birds in the different treatments (kg)
TREATMENT
SLAUGHTER WEIGHT
DRESSED WEIGHT
(kg)
(kg)
Pure commercial feeds
1.553a
1.139a
500g CF + 400gCorn grits
1.557a
1.219a
+ 100g sweet potato
500g CF + 300g Corn grits
1.550a
1.196a
+ 200g sweet potato
500g CF + 200gCorn grits
1.560a
1.328a
+ 300g sweet potato
Means with the same superscript are not significantly different at 0.05 level, DMRT
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
Dressing Percentage
Statistical analysis revealed that there were no significant differences among
treatments in terms of dressing percentage. As shown in Table 2, dressing recovery from
the birds regardless of treatment was comparable. This shows that using different levels of
sweet potato and corn grits to substitute 50% of the commercial feeds given to the birds
did not affect their dressing percentage.
Color of Skin, Carcass, and Abdominal Fat
After dressing, the carcasses were displayed on the table and observed for skin
color. The skin of the carcasses was more or less of the same color of pale yellow (Fig.1).
This means that the different levels of sweet potato and corn grits did not cause any
variation in skin color of the broilers (Fig.2).
The carcasses of the broilers from the different treatments had similar color which
was pinkish-red. This means also that the different levels of sweet potato and corn grits did
not affect the carcass color of broilers (Fig.3).
The abdominal fats collected from the broilers were similarly light-yellow in color
or number one in the yolk color fan. This means that the different levels of sweet potato
and corn grits has no effect on the color of abdominal fats in broilers.
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
Table 2. Dressing percentage of the birds in the different treatments (%)
TREATMENT
DRESSING PERCENTAGE
Pure commercial feeds
73.34a
500g CF + 400gCorn grits + 100g sweet
75.80a
potato
500g CF + 300g Corn grits + 200g sweet
75.74a
potato
500g CF + 200gCorn grits + 300g sweet
76.70a
potato
Means with the same superscript are not significantly different at 0.05 level, DMRT
Figure 1. Sample color of the skin of one of the dressed broilers
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
Figure 2. Carcass color of broiler meat in the different treatments
Figure 3. Abdominal fats of broiler in the different treatments
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
Sensory Traits of the Carcass
Appearance. Table 3 shows the ratings for the appearance of the cooked meat in
the different treatments which ranged from 1.62 to 1.75 with a verbal rating of moderately
desirable. Statistical analysis revealed no significant differences between treatment means.
The results imply that corn grits and sweet potato did not produce any coloring effect to
the meat.
Aroma. Statistical analysis revealed that there were no significant differences
among treatments in terms of aroma (Table 4). The meat in all the treatments had a mean
rating of 1.72 and were all liked moderately by the panel of tasters. The result also implies
that the sweet potato and corn grits used to substitute 50% of the commercial feeds given
to the broilers did not cause special aroma to the meat of the broilers.
Table 3. Appearance of the cooked meat as rated by the panel of tasters
TREATMENT
MEAN
VERBAL RATING
Pure commercial feeds
1.62a
Moderately Desirable
500g CF + 400gCorn grits
1.75a
Moderately Desirable
+ 100g sweet potato
500g CF + 300g Corn grits
1.72a
Moderately Desirable
+ 200g sweet potato
500g CF + 200gCorn grits
1.75a
Moderately Desirable
+ 300g sweet potato
Means with the same superscript are not significantly different at 0.05 level, DMRT
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
Tenderness. For the tenderness of the meat samples, there were no significant
differences among treatment means as revealed by statistical analysis (Table 5). The
numerical rating ranges from 1.71 to 2.067 with a verbal rating of very tender. This reveals
that the tenderness of the meat samples derived from the birds in the different treatments
was more or less the same.
Juiciness. Table 6 shows the juiciness of the meat samples with a numerical rating
of 1.50 to 2.49. Statistical analysis revealed that there were no significant differences
among treatment means. This means that the meat in all the treatments were more or less
the same in juiciness. In fact, this were all rated to be moderately juicy.
Taste of the product. The numerical ratings for taste of the meat in the different
treatments are shown Table 7. Statistical analysis showed that there were no significant
differences among treatments. This implies that the corn grits and sweet potato had no
effect on the taste of the product. The meat in all the treatments were liked moderately by
the panel of tasters.
Table 4. Aroma of the cooked meat as rated by the panel of tasters
TREATMENT
MEAN
VERBAL RATING
Pure commercial feeds
1.717a
Like Moderately
500g CF + 400gCorn grits
1.700a
Like Moderately
+ 100g sweet potato
500g CF + 300g Corn grits
1.767a
Like Moderately
+ 200g sweet potato
500g CF + 200gCorn grits
1.683a
Like Moderately
+ 300g sweet potato
Means with the same superscript are not significantly different at 0.05 level, DMRT
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
Table 5. Tenderness of the cooked meat as rated by the panel of tasters
TREATMENT
MEAN
VERBAL RATING
Pure commercial feeds
1.867a
Very Tender
500g CF + 400gCorn grits
2.067a
Very Tender
+ 100g sweet potato
500g CF + 300g Corn grits
1.717a
Very Tender
+ 200g sweet potato
500g CF + 200gCorn grits
1.867a
Very Tender
+ 300g sweet potato
Means with the same superscript are not significantly different at 0.05 level, DMRT
Table 6. Juiciness of the cooked meat as rated by the panel of tasters
TREATMENT
MEAN
VERBAL RATING
Pure commercial feeds
2.133a
Moderately Juicy
500g CF + 400gCorn grits
2.033a
Moderately Juicy
+ 100g sweet potato
500g CF + 300g Corn grits
2.017a
Moderately Juicy
+ 200g sweet potato
500g CF + 200gCorn grits
1.867a
Moderately Juicy
+ 300g sweet potato
Means with the same superscript are not significantly different at 0.05 level, DMRT
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
Acceptability. Statistical analysis revealed that there were no significant differences
among the treatment means in terms of acceptability of the meat. This means that regardless
of what the broilers eat the tasters liked all the meat samples moderately.
Table 7. Taste of the cooked meat as rated by the panel of tasters
TREATMENT
MEAN
VERBAL RATING
Pure commercial feeds
1.950a
Like Moderately
500g CF + 400gCorn grits
1.867a
Like Moderately
+ 100g sweet potato
500g CF + 300g Corn grits
1.950a
Like Moderately
+ 200g sweet potato
500g CF + 200gCorn grits
1.700a
Like Moderately
+ 300g sweet potato
Means with the same superscript are not significantly different at 0.05 level, DMRT
Table 8.Acceptability of the cooked meat as rated by the panel of tasters
TREATMENT
MEAN
VERBAL RATING
Pure commercial feeds
2.000a
Like Moderately
500g CF + 400gCorn grits
1.817a
Like Moderately
+ 100g sweet potato
500g CF + 300g Corn grits
1.850a
Like Moderately
+ 200g sweet potato
500g CF + 200gCorn grits
2.017a
Like Moderately
+ 300g sweet potato
Means with the same superscript are not significantly different at 0.05 level, DMRT
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
SUMMARY, CONCLUSION AND RECOMMENDATION
Summary
This study was conducted to evaluate the meat of broilers fed with different levels
of sweet potato and corn grits. The carcass evaluation and the organoleptic test was done
at the Department of Animal Science Meat Laboratory on February 2011.
Specifically, the study aimed to find the effect of sweet potato and corn grits on the
meat in terms of appearance, aroma, tenderness, juiciness, taste and acceptability of the
birds. It also aimed to determine the level of sweet potato and corn grits that will give the
best carcass characteristics.
One hundred sixty day old chicks were subjected to four treatments for 45 days
namely; To- pure commercial feeds; T1- 50% commercial feeds + 40% corn grits and 10%
sweet potato; T2- 50% commercial feeds + 30% corn grits and 20% sweet potato;T3- 50%
commercial feeds + 20% corn grits and 30% sweet potato. After the feeding period, one
bird per replication from each treatment was slaughtered for carcass evaluation. The breast
and thigh muscles from the carcass were cooked in the same amount of water at the same
time and prepared for the taste testing.
Similarly, statistical analysis revealed no significant differences among treatments
in terms of appearance, aroma, tenderness, taste and acceptability of the broiler meat.
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
Conclusion
It is therefore concluded that the different levels of corn grits and sweet potato as
feed substitute to commercial feeds of corn grits and sweet potato did not cause any
variations on the carcass parameters measured in this study.
Recommendation
It is recommended that the combination of corn grits and sweet potato maybe used
as substituted for commercial feed too.
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
LITERATURE CITED
ANONYMOUS,
2010.Sweetpotatoes.Retieved
October
2010
from
http://www.whfoods.com/ genpage.php?tname=foodspicedbid=64.
ANONYMOUS.
2007.
Sweet
potatoes
Retrieved
October
2010
from
http://en.wikipedia.org/wiki/Potato%2C_sweet.
COMA, V. 2000.Feeding Guidelines for Meat and Pig Process 16. Carcass yield and
quality of cob and Hubbard Broilers Fed with varying levels of okra . P. 5.
PARIS, G. 1998. Correlation analysis between live weight and some related dressed
carcass and turkey. BS Thesis Benguet State University, La Trinidad, Benguet. P.5.
PERRY, T. W., E. CULLISON, R. S. LOWREY. 2000. Feeds and Feeding . 5th Ed. Pearson
Education AsiaPte Ltd, Singapore. P. 346.
VILLAREAL, R. L,. T. D. GRIGGS, 1982. Sweetpotato: Proceedings of the First
International Symposium. Hon Wen Printing Works. Tainan. P. 79.
WOOLFE, J. A. 1992. Sweetpoato: An Untapped Feed Resource. University Press,
Cambridge,
United
Kingdom.Retrieved
October
2010
from
http://www.Irrd.org/Irrd15/1//maph151.htm.
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
ANGWAY, QUEMMY L. APRIL 2013. Evaluating the Meat of the Broilers Fed
with Substituted 50% Commercial Feeds with Varying Levels of Sweet Potato and Corn
Grits on the Carcass Yield and Quality of Broilers. Benguet State University, La Trinidad
Benguet.
Adviser: Ms. Myrna B. Walsiyen, MSc.
ABSTRACT
This study was conducted to find out the effect of varying levels of sweet potato
and corn grits on the carcass yield and quality of broilers. Specifically, this study aimed to
measure and compare the carcass yield of broilers fed with 50% commercial feeds with
varying levels of sweet potato and corn grits in terms of slaughter weight, carcass weight
and evaluate carcass characteristics through, organoleptic test in terms of appearance
aroma, tenderness, juiciness taste, and acceptability.
The result of statistical analysis showed that varying levels of sweet potato and
corn grits as substitute for 50% of the commercial ration did not cause any differences on
dressing percentage of broilers and quality of meat as evaluated by a taste panel. It is
therefore concluded 50% commercial ration can be substituted with varying levels of sweet
potato and corn grits.
Statistical analysis showed no significant differences in the dressing percentage
of feeds given varying levels of sweet potato and corn grits as substitute to 50% of the
commercial ration for broilers. The average dressing percentage of broilers with an average
slaughter weight of 1.56 kg. was 75.30%.
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
INTRODUCTION
Food is the most important contribution of Agricultural animals to human, that
animal contributes a greater percentage of the total food energy. For instance, animals are
more important source of protein than they are of calories. In all aspect, of animal product,
poultry meat is reach in highly-quality protein and low in total fat and saturated fat.
Furthermore, because it is mainly associated with the skin, most poultry fat can be easily
removed by removing the skin, in constant greater proportion of the fat in the red meat is
found dispersed throughout the lean, making it harder to remove. However, more concern
has being focused in poultry meat and it’s lower in cholesterol than other meat type.
Nowadays, poultry quality, which is defined by a combination of multiple factors,
has become a primary focus for producers, packers, processors, retailers and consumers.
Muscle color and texture are always the two most important factors that influence meat
quality. The cooked product appearance is significantly associated with raw meat color.
Moreover, it is suggested that lightness values could be used as an indicator of poultry
breast muscle quality for evaluating the incidence of the PSE- like (pale, soft and
exudative) condition. Meat pH, tenderness and water holding capacity are attributes of
muscle texture that have been studied most extensively.
Broiler meat is preferred not only for their soft tender quality but also its nutritive
value as excellent source of protein. The continuous effort to produce chicken meat has
stimulated further research for more suitable combination of known nutrients and new
additives to increase the efficiency, rate of growth and level of production of the animals.
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
This research aimed to produce a reference in the use of different levels of sweet
potato and corn grits in improving the carcass quality and the general health of food animals
such as broilers. Furthermore, it hopes to promote the use of natural products such as sweet
potato and corn grits in improving the carcass quality of broilers.
This study generally aimed to determine the effect of different levels of sweet
potato and corn grits on the carcass yield and quality of broiler meat. Specifically, it aimed
to determine the quality of carcass produced from broilers fed with different levels of sweet
potato and corn grits through organoleptic test and to find out the effect of different levels
of sweet potatoes and corn grits on the dressing percentage of broilers under La Trinidad,
Benguet.
The experiment used a total of 12 broilers, which was subjected to 42 days feeding
period. Meanwhile, carcass evaluation was done at the DAS laboratory in February 2011
and the organoleptic test was done four days after the evaluation.
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
REVIEW OF LITERATURE
Sweet potato is deficient in sulfur containing amino acids and tryptophan, but this
is partially compensated for by high levels of vitamin A (in a form of beta-carotene), a very
good source of vitamin C and manganese, and a good source of copper, dietary fiber,
vitamin B6, potassium and iron. Yellow and orange fleshed sweet potato are rich in
carotene (Anonymous, 2010)
Besides simple starches, sweet potatoes are rich in complex carbohydrates, dietary
fiber, beta carotene, vitamin C, and vitamin B6. Pink and yellow varieties are high in
carotene, the precursor of vitamin A. in 1992, the Center for Science in the Public Interest
compared the nutritional value of sweet potatoes to other vegetables. Considering fiber
content, complex carbohydrates, protein, vitamins A and C, iron and calcium, the sweet
potato ranked the highest in nutritional value (Anonymous, 2007).
It has attracted considerable attention over years from an experimental standpoint
because sweet potatoes given high yields of digestible carbohydrates. Sweet potatoes will
out produce most other crops in yield of digestible carbohydrates per acre. Dried sweet
potatoes are high in content of digestible starch and carotene (Perry et al., 2000).
Coma (2000) mentioned that nutrition may have a significant effect on certain
attributes of meat quality. Meat quality is a complex without single definition. Fresh meat
attributes such color, quality of fats, tenderness, juiciness and flavor are essential in order
to drive the purchase and assure consumers fidelity. In addition we must not forget the
interrelation with other elements of production process like genetic handling and slaughter.
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
A poultry carcass should produce highly nutritious value, flavor and texture and
eating quality of meat. As a commodity, it has to meet requirements of the costumer in
terms of bright and attractive color, characteristics of meat and appearance of the product
offered. Also, include the nutritive value, high satiety value, color and especially free from
chemical residue. Keeping the bled animal suspended by its hind legs throughout the
dressing operations greatly increased the efficiency of converting an animal into a carcass
and by products. This new system reduces the chances of microbial contamination (Paris,
1998).
According to Woolfe (1992) maize and sweet potato have comparable
metabolizable values of 14.5 to 14.8, respectively. The digestibility of sweet potato
carbohydrate fraction is reported to be above 90%. The level of starch decreases with
period of storage and instead the level of reducing sugars and total dextrins increases.
Sweet potatoes have also been reported to exhibit trypsin inhibitor activity ranging from
20 to 90%. However, trypsin inhibitor levels present in sweet potato tubers are low and
should not be a cause for concern under practical situations.
Villareal and Griggs (1982) cited that sweet potato is equal to corn in total
digestible nutrients but low in proteins. The average composition of dried sweet potato
meal is 90.2% dry matter; 4.9% protein; 0.9% fat; 3.3% fiber; 77.0% nitrogen-free extract;
4.1% minerals; 0.15% calcium and 0.14% phosphorus.
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
MATERIALS AND METHODS
Materials
The different materials that were used are as follows; 12 heads of 45 days old
broilers from a growth study that was conducted, knives, containers, weighing scale, digital
camera, record book and Ziploc bags.
Methodology
Experimental birds. The birds were fed with chick booster for the first week and
then shifted to broiler starter crumble for the next four weeks. The addition of the dried
yellow orange flesh sweet potato and corn grits to the feeds of the birds was on the 28th day
until 5th week. Broiler finisher crumble was given on the fifth week until the end of the
study.
Experimental treatments and design. 12 broilers were grouped into four treatments.
Each treatment had three replications and each bird represents one replication. The
different treatments were as follows:
To- pure commercial feeds
T1- 500g commercial feeds + 400g corn grits + 100g sweet potato
T2- 500g commercial feeds + 300g corn grits + 200g sweet potato
T3- 500g commercial feeds + 200g corn grits + 300g sweet potato
Slaughtering of Birds
Prior to dressing, the birds were fasted for 8 hours but water was provided ad
libitum. After fasting, the birds were weighed individually after which, these were
slaughtered. At slaughtering the bird was secured by holding both shanks with one hand
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
and both wings with the other hand to prevent struggling of the bird. With the help of an
assistant, sticking was done by severing the large blood vessel of the neck at the lateral side
below the mandible. After sticking, each bird was immersed into hot water for about a
minute or more after which, plucking of feathers followed. After plucking, the bird was
washed thoroughly and made it ready for evisceration.
Evisceration was done by laying the bird in dorsal recumbence. The esophagus and
wind pipe were then pulled up the base of mandible. For easy insertion of the hand, a slit
was made around the vent then down to the keel. The hand was taken inserted into the slit
in the abdominal cavity and the abdominal attachment on the entrails. After entrails were
pulled out, the liver, heart, and gizzards with proventiculus were separated. The head was
detached from the atlanto-occipital joint, which was accomplished by severing the skin,
muscle and ligaments at the said joints with a sharp knife.
Carcass Yield Evaluation
The dressed bird was placed on the pan of the weighing scale and the weight was
recorded in kilograms. The skin, carcass color and abdominal fat color were under
observation. Abdominal fats of broiler belonging to the different treatments were compared
with other.
Sensory Evaluation
From each treatment, one kilo of meat, abstained from thigh and breast was cooked
for the sensory evaluation. The meat samples were cooked separately or by treatment but
using the same kind of casserole and the same amount of water which was four cups each.
Cooking was done for 45 minutes.
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
When cooked, the meat samples were sliced into bite sizes afterwards, these were
given codes and presented to the panel of tasters. Each member of the panel tasters was
given a score or evaluation sheet for him to place his rating. Each member also was
requested to drink water rinse his mouth with water after tasting every sample to wash off
any remains of the meat previously eaten that may have affected his rating for the
succeeding meat samples.
Data Gathered
The following parameters gathered from the study:
1. Slaughter weight (kg). This was the weight of broiler before slaughter time.
2. Dressed weight (kg) . This refers to the actual weight of slaughtered bird after
plucking the feathers with head, feet, and entrails off.
3. Skin color. This was determined by comparing the skin to the yolk color fan.
4. Carcass color. This was done by observation of the carcass.
5. Color of abdominal fat. This was obtained by actual observation of the abdominal
fats and comparing it to the yolk color fan.
6. Dressing percentage (%). This was obtained by dividing the carcass weight by
the slaughter weight multiplied by 100%.
7. Meat color, tenderness, juiciness, taste, aroma and acceptability. This was
obtained through organoleptic test involving a panel of testers composed of 10 teachers, 10
students from the College of Home Economics and Technology (CHET).
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
Data Analysis
All the data gathered were tabulated and analyzed using the analysis of variance for
completely Randomized Design. Treatment means were compared using the Duncan’s
Multiple Range Test (DMRT).
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
RESULTS AND DISCUSSION
Slaughter Weight and Dressed Weight
Table 1 presents the slaughter and dressed weights of the birds in the different
treatments. Statistical analysis showed that there were no significant differences in the
slaughter weight of the birds among treatment means.
This is expected because the broilers were purposely selected to have more or less
similar weights at slaughter. This was done to eliminate the possible effect of slaughter
weight, because the broilers were almost of the same weights at slaughters, it followed that
their dresses weights were or less similar also. The overall mean slaughter weight of the
broilers used in the study was 1.56 kg and the dressed weight was 1.17 kg.
Table 1. Slaughter and dressed weights of the birds in the different treatments (kg)
TREATMENT
SLAUGHTER WEIGHT
DRESSED WEIGHT
(kg)
(kg)
Pure commercial feeds
1.553a
1.139a
500g CF + 400gCorn grits
1.557a
1.219a
+ 100g sweet potato
500g CF + 300g Corn grits
1.550a
1.196a
+ 200g sweet potato
500g CF + 200gCorn grits
1.560a
1.328a
+ 300g sweet potato
Means with the same superscript are not significantly different at 0.05 level, DMRT
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
Dressing Percentage
Statistical analysis revealed that there were no significant differences among
treatments in terms of dressing percentage. As shown in Table 2, dressing recovery from
the birds regardless of treatment was comparable. This shows that using different levels of
sweet potato and corn grits to substitute 50% of the commercial feeds given to the birds
did not affect their dressing percentage.
Color of Skin, Carcass, and Abdominal Fat
After dressing, the carcasses were displayed on the table and observed for skin
color. The skin of the carcasses was more or less of the same color of pale yellow (Fig.1).
This means that the different levels of sweet potato and corn grits did not cause any
variation in skin color of the broilers (Fig.2).
The carcasses of the broilers from the different treatments had similar color which
was pinkish-red. This means also that the different levels of sweet potato and corn grits did
not affect the carcass color of broilers (Fig.3).
The abdominal fats collected from the broilers were similarly light-yellow in color
or number one in the yolk color fan. This means that the different levels of sweet potato
and corn grits has no effect on the color of abdominal fats in broilers.
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
Table 2. Dressing percentage of the birds in the different treatments (%)
TREATMENT
DRESSING PERCENTAGE
Pure commercial feeds
73.34a
500g CF + 400gCorn grits + 100g sweet
75.80a
potato
500g CF + 300g Corn grits + 200g sweet
75.74a
potato
500g CF + 200gCorn grits + 300g sweet
76.70a
potato
Means with the same superscript are not significantly different at 0.05 level, DMRT
Figure 1. Sample color of the skin of one of the dressed broilers
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
Figure 2. Carcass color of broiler meat in the different treatments
Figure 3. Abdominal fats of broiler in the different treatments
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
Sensory Traits of the Carcass
Appearance. Table 3 shows the ratings for the appearance of the cooked meat in
the different treatments which ranged from 1.62 to 1.75 with a verbal rating of moderately
desirable. Statistical analysis revealed no significant differences between treatment means.
The results imply that corn grits and sweet potato did not produce any coloring effect to
the meat.
Aroma. Statistical analysis revealed that there were no significant differences
among treatments in terms of aroma (Table 4). The meat in all the treatments had a mean
rating of 1.72 and were all liked moderately by the panel of tasters. The result also implies
that the sweet potato and corn grits used to substitute 50% of the commercial feeds given
to the broilers did not cause special aroma to the meat of the broilers.
Table 3. Appearance of the cooked meat as rated by the panel of tasters
TREATMENT
MEAN
VERBAL RATING
Pure commercial feeds
1.62a
Moderately Desirable
500g CF + 400gCorn grits
1.75a
Moderately Desirable
+ 100g sweet potato
500g CF + 300g Corn grits
1.72a
Moderately Desirable
+ 200g sweet potato
500g CF + 200gCorn grits
1.75a
Moderately Desirable
+ 300g sweet potato
Means with the same superscript are not significantly different at 0.05 level, DMRT
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
Tenderness. For the tenderness of the meat samples, there were no significant
differences among treatment means as revealed by statistical analysis (Table 5). The
numerical rating ranges from 1.71 to 2.067 with a verbal rating of very tender. This reveals
that the tenderness of the meat samples derived from the birds in the different treatments
was more or less the same.
Juiciness. Table 6 shows the juiciness of the meat samples with a numerical rating
of 1.50 to 2.49. Statistical analysis revealed that there were no significant differences
among treatment means. This means that the meat in all the treatments were more or less
the same in juiciness. In fact, this were all rated to be moderately juicy.
Taste of the product. The numerical ratings for taste of the meat in the different
treatments are shown Table 7. Statistical analysis showed that there were no significant
differences among treatments. This implies that the corn grits and sweet potato had no
effect on the taste of the product. The meat in all the treatments were liked moderately by
the panel of tasters.
Table 4. Aroma of the cooked meat as rated by the panel of tasters
TREATMENT
MEAN
VERBAL RATING
Pure commercial feeds
1.717a
Like Moderately
500g CF + 400gCorn grits
1.700a
Like Moderately
+ 100g sweet potato
500g CF + 300g Corn grits
1.767a
Like Moderately
+ 200g sweet potato
500g CF + 200gCorn grits
1.683a
Like Moderately
+ 300g sweet potato
Means with the same superscript are not significantly different at 0.05 level, DMRT
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
Table 5. Tenderness of the cooked meat as rated by the panel of tasters
TREATMENT
MEAN
VERBAL RATING
Pure commercial feeds
1.867a
Very Tender
500g CF + 400gCorn grits
2.067a
Very Tender
+ 100g sweet potato
500g CF + 300g Corn grits
1.717a
Very Tender
+ 200g sweet potato
500g CF + 200gCorn grits
1.867a
Very Tender
+ 300g sweet potato
Means with the same superscript are not significantly different at 0.05 level, DMRT
Table 6. Juiciness of the cooked meat as rated by the panel of tasters
TREATMENT
MEAN
VERBAL RATING
Pure commercial feeds
2.133a
Moderately Juicy
500g CF + 400gCorn grits
2.033a
Moderately Juicy
+ 100g sweet potato
500g CF + 300g Corn grits
2.017a
Moderately Juicy
+ 200g sweet potato
500g CF + 200gCorn grits
1.867a
Moderately Juicy
+ 300g sweet potato
Means with the same superscript are not significantly different at 0.05 level, DMRT
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
Acceptability. Statistical analysis revealed that there were no significant differences
among the treatment means in terms of acceptability of the meat. This means that regardless
of what the broilers eat the tasters liked all the meat samples moderately.
Table 7. Taste of the cooked meat as rated by the panel of tasters
TREATMENT
MEAN
VERBAL RATING
Pure commercial feeds
1.950a
Like Moderately
500g CF + 400gCorn grits
1.867a
Like Moderately
+ 100g sweet potato
500g CF + 300g Corn grits
1.950a
Like Moderately
+ 200g sweet potato
500g CF + 200gCorn grits
1.700a
Like Moderately
+ 300g sweet potato
Means with the same superscript are not significantly different at 0.05 level, DMRT
Table 8.Acceptability of the cooked meat as rated by the panel of tasters
TREATMENT
MEAN
VERBAL RATING
Pure commercial feeds
2.000a
Like Moderately
500g CF + 400gCorn grits
1.817a
Like Moderately
+ 100g sweet potato
500g CF + 300g Corn grits
1.850a
Like Moderately
+ 200g sweet potato
500g CF + 200gCorn grits
2.017a
Like Moderately
+ 300g sweet potato
Means with the same superscript are not significantly different at 0.05 level, DMRT
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
SUMMARY, CONCLUSION AND RECOMMENDATION
Summary
This study was conducted to evaluate the meat of broilers fed with different levels
of sweet potato and corn grits. The carcass evaluation and the organoleptic test was done
at the Department of Animal Science Meat Laboratory on February 2011.
Specifically, the study aimed to find the effect of sweet potato and corn grits on the
meat in terms of appearance, aroma, tenderness, juiciness, taste and acceptability of the
birds. It also aimed to determine the level of sweet potato and corn grits that will give the
best carcass characteristics.
One hundred sixty day old chicks were subjected to four treatments for 45 days
namely; To- pure commercial feeds; T1- 50% commercial feeds + 40% corn grits and 10%
sweet potato; T2- 50% commercial feeds + 30% corn grits and 20% sweet potato;T3- 50%
commercial feeds + 20% corn grits and 30% sweet potato. After the feeding period, one
bird per replication from each treatment was slaughtered for carcass evaluation. The breast
and thigh muscles from the carcass were cooked in the same amount of water at the same
time and prepared for the taste testing.
Similarly, statistical analysis revealed no significant differences among treatments
in terms of appearance, aroma, tenderness, taste and acceptability of the broiler meat.
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
Conclusion
It is therefore concluded that the different levels of corn grits and sweet potato as
feed substitute to commercial feeds of corn grits and sweet potato did not cause any
variations on the carcass parameters measured in this study.
Recommendation
It is recommended that the combination of corn grits and sweet potato maybe used
as substituted for commercial feed too.
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013
LITERATURE CITED
ANONYMOUS,
2010.Sweetpotatoes.Retieved
October
2010
from
http://www.whfoods.com/ genpage.php?tname=foodspicedbid=64.
ANONYMOUS.
2007.
Sweet
potatoes
Retrieved
October
2010
from
http://en.wikipedia.org/wiki/Potato%2C_sweet.
COMA, V. 2000.Feeding Guidelines for Meat and Pig Process 16. Carcass yield and
quality of cob and Hubbard Broilers Fed with varying levels of okra . P. 5.
PARIS, G. 1998. Correlation analysis between live weight and some related dressed
carcass and turkey. BS Thesis Benguet State University, La Trinidad, Benguet. P.5.
PERRY, T. W., E. CULLISON, R. S. LOWREY. 2000. Feeds and Feeding . 5th Ed. Pearson
Education AsiaPte Ltd, Singapore. P. 346.
VILLAREAL, R. L,. T. D. GRIGGS, 1982. Sweetpotato: Proceedings of the First
International Symposium. Hon Wen Printing Works. Tainan. P. 79.
WOOLFE, J. A. 1992. Sweetpoato: An Untapped Feed Resource. University Press,
Cambridge,
United
Kingdom.Retrieved
October
2010
from
http://www.Irrd.org/Irrd15/1//maph151.htm.
Evaluating the Meat of the Broilers Fed with Substituted 50% Commercial Feeds with
Varying Levels of Sweet Potato and Corn Grits on the Carcass Yield and Quality of Broilers
ANGWAY, QUEMMY L. APRIL 2013