Effects of feeding regiments on
meat quality
By: - ABHINAVA BANERJEE

INTRODUCTION

>>Nutrition is the powerful component of livestock production system that controls
several aspects of meat quality. Consumer oriented demands in meat quality has
motivated the meat producers to concentrate on
the nutritional aspects of the livestock rearing. The
animal feed mostly affects hygienic, sanitary &
nutritional characteristics of meat. Particularly,
various meat quality attributes that are affected by
the amount and the type of nutrients intake of the
animal shall include dressing yield, meat: bone
ratio, protein: fat ratio, fatty acid composition,
calorific value, color, physicochemical & processing properties, shelf life & sensory
attributes. In this regards, even the American Dietetic Association has endorsed beef
& lamb as functional foods. So it has been imperative to develop nutritional strategies
to produce meat more as a functional food than an ordinary source of animal protein.
The strategies for quality meat production will include genetic selection & gene
manipulation, balanced nutrition & use of approved growth promoting agents. The
meat quality can also be improved through utilization of natural antioxidants, mineral
supplements & probiotics.

PASTURE FEEDING

When animals are fed forages, growth rate is slower, animal attain slaughter weight at
later age & the carcass has less fat. The meat is leaner, darkens in color & has more
species’ specific flavor. Beta-carotene is present in
high concentrations in the fresh leaf tissues & is
responsible for the undesirable yellow color of the
fat in pasture fed beef. An undesirable grassy
flavor may results from the compounds found in
for-age. Consumption of the wild onions & garlic
can also give the undesirable flavor to the meat.
This can be decreased or eliminated by feeding
high concentrate diet up to 90 days before
slaughter. Grass feeding produces a stronger
flavored meat, preferred in UK & NEW ZEALAND;
whereas a cereal produces a milder flavored meat
that is preferred in SPAIN & USA. The difference is
generally attributed to whether the main dietary

fatty acid is alpha-linoleic, which produces a stronger flavor, or linoleic acid which
produces a mild flavor. Feeding grass or
concentrates containing linseed in the diet
increases the content of 18: 3n-3 & is longer
chain derivative eicosapentaenoic acid in beef
muscle & adipose tissue, resulting in lowering
n-6: n-3 ratio. Grass feeding also increases
docosahexaenoic acid. However, grass feeding
not only increases n-3 polyunsaturated fatty
acids and conjugated linoleic acid (CLA) (TABLE
1) but, due to its high concentration of vitamin E, color & shelf-life is also improved.
The American Dietetic Association has endorsed beef & lamb as functional food
because of the antitumor genic properties of CLA they contains.

FEEDING DIETARY
FIBRE

When diets have a high fibre & low-energy
content, carcasses are less fattened, the
skeleton is more developed & the lipid
content of the carcass is very low, but
water & protein content seems to be high.
Higher crude fibre feeding leads to lower
energy content of the meat.

FEEDING HIGH
CONCENTRATE DIET

In general, as the energy density of the diet increases, either through the use of high
quality of grains that replaces the forages or by
adding fat, the growth rate of the animals reach
slaughter weight at younger age, the resultant
carcass is heavier & higher in overall fatness &
marbling. The percentage of muscular tissue is
lower & that of fat is higher, in the animals of high
planes of nutrition than those on the power planes.
When the proteins: energy ratio is increased, the
fastest growing animals may become leaner. The meat is juicier & the fat flavors the
mask the meat flavor of the species. (TABLE1)
On high plane of nutrition, a greater proportion of
fat is synthesized from carbohydrate; & such fat has
consequently a lower iodine number. Higher plane
of nutrition increases the % of the intramuscular fat
& decreases the % of the moisture in animal.
Intensive feeding of high concentrate diets prior to
slaughter improves marbling scores & palatability rating of the meat.

FEEDING SUB-MAINTAINANCE
DIETS

In sub maintenance diets, fat is mobilized rather than deposited from muscles.
Undernutrition causes a marked increase in the water content of the muscle (83%
compared to 74% in well-nourished
animals). This is also associated with the
increase in % of intramuscular collagen &
a decrease in its salt soluble proteins, a
factor conducive to toughness. Sub-
maintenance feeding to growing broilers
from 4 to 8 weeks of age reduced yield of
breast & thigh muscle weights by 30% to
35% then those fed ad libitum.

FEEDING INADEQUATE PROTEIN
DIET

Although inadequacy of many nutrients is bound to have repercussion on the meat
quality, only a few are of consistent concern in practice. Protein inadequacies affect
the amount of meat more than its quality. A
failure to provide the sufficient amounts of
essential amino acids also impairs the meat
formation. Lysine is of particular concern
because of its very high proportions in
muscle proteins & its usual marginal levels in
most feeds. Such inadequacies are likely to
occur prior to marketing and results in additional carcass fat & decreased breast meat
yield. The development of glycolytic metabolism is limited & the fall of the pH during
the processing of the muscle into meat is restricted & this meat has a better water
holding capacity.

DIETARY FAT CONTENT

Fat is the main content of meat that is most affected by nutrition. When the fat is
present in the diet of animal at higher levels (more
than 9%), the dressing % is increased, carcasses are
fatter, the carcass length to circumference ratio is
reduced, & the fat content of hind leg meat is
increased, while the water & the protein content is
reduced. However, in some studies different feeding
plans & fat enriched diets do not show variation in
chemical composition of the longissimus dorsi muscle
of animals. Feeding high levels of unsaturated fats have
resulted in problems of carcass fat softness & oxidative instability of meat. Increasing
the content of n-3 PUFA improves “greasy” & “fishy” flavor in beef, whereas, color &
shelf life are reduced. Under these
situations, high levels of VIT-E are
necessary to help to stabilize the effect
of incorporating high level of long chain
PUFA into meat.

FEEDING OF FATS & OILS IN PIGS
& POULTRY

IN PIGS: -Higher oleate diet fed growing pigs was found with higher muscle & adipose
tissue oleate levels. The longissimus muscle chops were juicier & is tenderer. Attempts
to reduce the fat content of porcine carcasses
by nutritional manipulations can cause in
increase softness & loss of cohesiveness in
fatty tissue, leading to separation of sub-
cutaneous fat into layers. This undesirable
effects is due to a decrease in the size of the
fat cells & an increase in the ratio of linoleic
to stearic acids in fat. The more unsaturated
the fatty acid, the greater its propensity to
undergo peroxidation & it is well established that
feeding high levels of fish oils containing EPA & DHA
results in the fishy taints in the meat.

IN POULTRY: - A significant increase in TBA number & rancid flavor scores (TABLE 2)
for broilers fed 150g/kg full fat linseed compared
with bird fed animal diet were recorded. Raised
alpha-linoleic concentration was contributing to the
oxidative instability. Nutritional effects on flavor of
poultry meat are mainly negative & stem from
feeding excessive quantities of n-3 PUFA derived
from fish or linseed. This high susceptibility to
peroxidation results in rapid production of off-odors
& flavors that reduce shelf life of both raw &
cooked meat. Fish meal & fish oil in broiler diets should not exceed 12% & 1% weight,
respectively, if fishy taints are to be avoided.
Other factors that “taint” the meat are the use of
certain ingredients in rations.

FEEDING DIETARY
SUPPLEMENTS

Supplemental feeding of nutrients produces heavier carcass, higher dressing %, first
quality cuts, enhanced muscle proportion, slight
increase in the fat deposition & desirable
organoleptic traits. Niacin supplementation
improved ultimate pH & color score but decrease
carcass shrink & drip loss %. Dietary chromium
methionine chelate supplementation is an
alternate regimen to produce novel animal
products such as low cholesterol, high lean & low
fat meat.

FEEDING VITAMIN
SUPPLEMENTS IN THE DIET

Feeding of VITAMIN E improves color stability/freshness, tenderness, juiciness, (TABLE
3) oxidative stability & extends the shelf life of meat. VITAMIN E is not synthesized in
animal cells & must be obtained from plants through diet. Green plant tissue has high
concentration of VITAMIN E than
mature senescent tissue. Grains have
low concentration of VITAMIN E.
supplementation of VITAMIN E
@0.5g/day for 126 days doubly
increases the display life of meat from
grain finished animals. It also helps to
prevent lipid oxidation & retards
meta-myoglobin formation in meat
exposed to air, so improving quality
(TABLE 4). Retardation of browning by
VITAMIN E is linked to an inhibition of
lipid oxidation. VITAMIN C & E are the
natural anti-oxidants in meat that are

derived from diet & may contribute to color stability. Also, they are individually
effective at slowing meta-myoglobin formation,
whereas, when applied simultaneously, they
completely inhibited meta-myoglobin formation
over 7 days. An excess of dietary VITAMIN A
increases proteolytic activity of the muscle,
perhaps by increasing the permeability of the
membrane within which catheptic enzymes are
contained. Increased VITAMIN D may increase
tenderization via increased calcium levels in
muscle tissue at harvest. This increased muscle
pool then activates proteolytic enzymes that
degrade certain muscle protein.

FEEDING MINERAL
SUPPLEMENTS IN THE DIET

Feed supplemented with SELENIUM & ZINC fairly improved the acceptability &
decreased the oxidative rancidity of the cooked chicken or
meat product (TABLE 5). When the diet is high in iron, the meat
will be a very dark red & cause metallic taste when the meat is
cooked. Poor nutrition diet with inadequate levels of CALCIUM,
PHOSPHOROUS & the major VITAMINS A & D causes multi-
colored muscle meat in animals. Some muscles are dark red &
some are nearly pink in color. This causes a problem with
ground meat.

PROBIOTICS FEEDING

It is a live microbial feed supplement which improves the intestinal microbial balance
in favor if the host animal. Public disapproval & banning
of anti-biotic & growth hormones as feed additives in
certain parts of the world has renewed commercial
interest in probiotics production & its use in poultry
feeding. These are neither absorbed in the gut nor do
they reach the general circulation i.e. without any
residual effect in meat. A most widely used probiotic
bacterium is Lactobacillus acidophilus, which acts as
natural substitutes for feed anti-biotic. Dietary
yeast components, such as whole yeast & cell wall
supplementation improved tenderness & reduced
oxidation of meat. Lowest supplementation
significantly improves liver weight in broilers.

FEEDING OF β-ADRENERGIC
AGONISTS

The commonly used β-ADRENERGIC agonists include cimaterol, etc. β-ADRENERGIC
has shown enormous potential to alter the muscularity & ratio of lean to fat in meat
animals. The orders of efficacy of this drugs in livestock is CATTLE>SHEEP>TURKEY>
PIG>POULTRY. Unlike anabolic steroids hormones,
Β-ADRENERGIC are effective in all sexes to the same extent.
It also reduces the amount of fat in the body & increases
Protein accretion, so promoting muscular development. Fat
reduction is done by both fat production & fat breakdown.
Protein accretion is through reducing breakdown & favoring
normal protein turnover. Particularly, high proportion of type II, glycolytic,
Fast contracting fibres is most affected. (TABLE 6)

pH & WATER HOLDING
CAPACITY (WHC)

Carcasses from B-adrenergic agonists administered animals showed increased
glycolysis that resulted in decreased muscle glycogen that ultimately
increased the pH. The less fat cover resulted in faster cooling of carcass. The
increase in the rate of pH fall resulted in decreased WHC causing increased
drip loss in veal.

MEAT COLOR

CIMATEROL resulted in a lighter meat due to decreased WHC caused by increased
reflectance by moist surface (TABLE 7). A
significant decrease in HEAM pigment was
observed due to increased % of white
muscle fibres.

MEAT TENDERNESS

The meat obtained from these animals showed decrease in tenderness or increase in
shear force due to decrease in % of heat soluble collagen
(22-40%) & rapid maturation of connective tissues. There
was an increase in size &/or % of white muscle fibres
with larger diameters. A decreased calpain activity in the
carcasses of young bulls resulted decreased proteolysis,
which combined with changes in muscle fibres size
decreases the tenderness.

TABLES
(FOR REFERENCE TO ALL THE ABOVE WRITTEN CONTENTS…
FROM RESEARCHES…)

TABLE 1: - Carcass & meat quality characteristics of steers…
Characteristics Pasture (n=10) Concentrates (n=20)
Hot carcass weight, (kg) 225.6a
240.10b
Degree of finishing 1.5a
2.0b
Fat depth, (mm) 3.8a
6.1b
Rib eye area, (cm2
) 55.20a
62.9b
Total lipid 1.68a
3.18b
Total Conjugated Linoleic Acid 0.53b
0.25a
Saturated Fatty Acids 49.08b
47.62a
Mono-Unsaturated Fatty Acids 40.96a
46.36b
Poly-Unsaturated Fatty Acids 9.96b
6.02a
PUFA:SFA 0.20b
0.13a
n6:n3 1.44a
3.00b

TABLE 2: - Effect of dietary factors on consumer acceptability & TBA values-
of cooked dark chicken meat …
Factors studied 74 days of storage at -200
C
Acceptability score* TBA #(µg MDA/kg)
Fat source
Fish oil 4.9 86
Linseed oil 5.0 84
Animal fat 5.1 74
*Sensory scores based on 9 point scale
#Thiobarbituric acid (TBA) value
. Malonaldehyde (MDA)

TABLE 3: - Effect of VITAMIN E on taste characteristics of cooked roast beef…
Characteristics Vitamin Treatment
Vit E (E+) Control (E-) SEM
Tenderness 10.25 10.53 0.20
Saltiness 1.23 1.50 0.13
Juiciness 6.45b
7.15a
0.19
Beef flavor 8.11 8.50 0.26
Scale: 15 cm semi-structured line scale where, 0=none & 15=intense

TABLE 4: - Quality of buffalo meat pre-blended with natural antioxidants…
Treatment Day 0 Day 4 Day 8 Mean
Color scores (5 Points)
Control 4.60 2.67 1.0 2.74a
Sodium ascorbate 4.77 4.70 4.33 4.60b
Alpha-Tocopherol acetate 4.67 2.97 1.13 2.87a
SA+TA 4.70 4.60 3.90 4.39c
Met myoglobin (%)
Control 57.67 59.80 74.27 63.87a
Sodium ascorbate 52.07 53.97 60.0 55.25b
Alpha-Tocopherol acetate 55.77 58.80 68.87 60.73ac
SA+TA 54.33 55.17 60.20 50.05bc
TBARS Number (mg malonaldehyde/kg meat)
Control 0.355 0.663 1.313 0.733a
Sodium ascorbate 0.276 0.313 0.551 0.367b
Alpha-Tocopherol acetate 0.310 0.440 0.709 0.469b
SA+TA 0.291 0.318 0.705 0.420b

TABLE 5: - Effect of dietary factors on consumer acceptability & TBA values-
of cooked dark chicken meat…
Factors studied 74 days of storage at -200
c
Acceptability score* TBA#(µg MDA/kg)
Zn supplementation
0 mg/kg 4.9 93
600 mg/kg 5.1 71
Se supplementation
0 mg/kg 5.0 91
Selenite, 1.2 mg/kg 5.2 73
Se yeast, 0.20 mg/kg 4.8 83
*Sensory scores based on 9 point scale
#Thiobarbituric acid (TBA) value
. Malonaldehyde (MDA)

TABLE 6: - Effect of Oral administration of β-adrenergic Agonists…
Animal Weight
gain (%)
Feed
Consumption (%)
Feed/Gain
(%)
Muscle
(%)
Fat (%)
Cattle +10 -5 +15 +10 -30
Chicken +2 - +2 +2 -7
Pigs +4 -5 -5 +4 -8
Sheep +15 +2 +15 +25 -25

TABLE 7: - Effect of Cimaterol on Meat Quality of LD Muscle…
Treatments Control Cimaterol
Glycogen 93 75.5
Protein 22.5 23.3
Intramuscular fat 0.86 0.58
Soluble collagen 23.9 24.2
Shear force 5.8 17.7
Meat Color
Lightness 40.6 42.4
Hue 31 33.2
Saturation 21.2 19.9

ARTICLES BY WHICH THE INFORMATIONS
ARE TAKEN…..
1)https://drive.google.com/file/d/1UFHVW5VoggFpYzfPRUPEstqLX50m4qJ
G/view?usp=drivesdk
2)https://drive.google.com/file/d/1UG5UR4UI80Us6j_qqo_Y92JRuqqG27b
M/view?usp=drivesdk

RESOURCES…
1) https://www.slideshare.net/drpksinghbvc/feeding-management-of-poultry
2) https://www.slideshare.net/drshama65/diet-and-nutritionnewppt
3) https://core.ac.uk/download/pdf/14423473.pdf
4) https://onlinelibrary.wiley.com/doi/10.1002/fsn3.1494
5) http://hrcak.srce.hr/file/80152
6) https://www.researchgate.net/publication/340628504_Effect_of_feeding_regi
men_on_meat_quality_MyHC_isoforms_AMPK_and_PGC-
1a_genes_expression_in_the_biceps_femoris_muscle_of_Mongolia_sheep
7) https://naldc.nal.usda.gov/download/34597/PDF