Chromium_Animal_Nutrition.pptx

› Introduction
› Chromium in Metabolism
› Chromium in Stress
› Chromium in Poultry
› Chromium in Livestock

› Interest in chromium as an essential nutrient for livestock in manipulating growth
performance and improving carcass composition has been reported as early in the
1960s.
› At this time, chromium was first reported as an essential mineral in rats and was
demonstrated as an essential mineral for humans.
› In humans, the major focus of chromium research was on the association between
chromium and diabetes mellitus.
Introduction

› In abundance, chromium stands in the 21st position among the minerals of the earth’s
crust.
› Theoretically, chromium may occur in all oxidation states from -2 to +6, however, it is
often found in the trivalent and hexavalent forms.
1. Trivalent chromium (Cr3+) is the most stable oxidation state in which chromium is
found in living organisms and is considered to be a highly safe form of chromium.
2. Hexavalent chromium (Cr6+) is mostly of industrial origin and is usually associated
with chromium toxicity.
Forms of Chromium

1. The primary role of chromium in metabolism is in the area of enhancing glucose
uptake by living tissues.
2. It has also been shown that chromium activates certain enzymes and stabilizes
proteins and nucleic acids.
3. Chromium supplementation reduces the negative effects of environmental stress.
4. Chromium, as an integral component of the glucose tolerance factor (GTF), helps
control appetite, hypoglycemia and protein uptake and plays a protective role against
heart disease and diabetes.
Function of Chromium

› Chromium is usually not considered as an essential trace mineral for poultry; however
studies have provided evidence that suggests a nutritional and physiological role of
chromium as a micronutrient in poultry nutrition.
› The beneficial effects of chromium can be observed more efficiently under
environmental, dietary and hormonal stress.
› NRC (1989) has recommended an intake of 50-200ppb of trivalent chromium for adult
humans.
› Currently there are no NRC recommendations for chromium in poultry diets (NRC,
1994).
› In ruminants, supplementation of chromium is recommended during heat stress
periods, early lactation and during infections.
Requirements for Chromium

› The major organic sources of chromium include;
1. Chromium propionate
2. Chromium picolinate
3. Chromium nicotinate
4. High chromium yeast
› Organic source of chromium is over ten times more bio-available than inorganic
sources.
Sources of Trivalent Chromium

Cr3+ Picolinate
› Cr3+ picolinate and niacin-boundCr3+, which are two very popular dietary supplements.
› Comparative studies reveal thatCr3+ picolinate produces significantly more;
1. Oxidative stress
2. DNA damage
› Studies have also shown that chromium picolinate can be mutagenic and a picolinic acid
moiety has been shown to be responsible for a clastogenic effect of picolinic acid in the
absence of chromium.
Cont. …

› Research findings have implicated the toxicity of chromium picolinate in;
1. Renal impairment
2. Skin blisters
3. Pustules
4. Anemia
5. Hemolysis
6. Tissue edema
7. Liver dysfunction
8. Neuronal cell injury
9. Enhanced production of hydroxyl radicals
10. Chromosomal aberration
11. DNA damage
Cont. …

Chromium Propionate
› Chromium propionate has been approved as an acceptable additive for swine feed by
US Food and DrugAdministration.
› Studies in pigs have shown significant different metabolic responses with chromium
propionate supplementation when compared to the same responses when chromium
picolinate is used as a supplement; this demonstrates excellent and reliable
bioavailability.
Cont. …

Apochromodulin:
› It is the inactive form of chromodulin, it is present in the cytoplasm, where chromodulin
is stored in this form.
Chromodulin:
› It is a naturally occurred low molecular weight “chromium binding substance”
› It is assumed to be involved in the metabolism of glucose.
› It is an oligopeptide made up of glycine, cysteine, aspartate, and glutamate.
› Despite its low molecular weight and small size, chromodulin binds four equivalents of
Cr3+
Role of Chromium in Metabolism

Chromium Mechanism of Action
› The chromium mode of action in enhancing insulin sensitivity may be explained by its
effect on:
1. Increasing membrane fluidity
2. The rate of insulin internalization
› After increase of insulin level in blood ….Cr enter is mediated by transferrin …. 4Cr ions
bind toApochromodulin which becomes chromodulin ….Chromodulin binds to insulin-
activated insulin receptor …. which activates the receptor’s tyrosine kinase activity &
also activates membrane phosphotyrosine phosphatase found in adipocyte
membranes.
› Decrease in insulin level in blood …. facilitates relaxation of the conformation of the
insulin receptor …. chromodulin is excreted from the cells into the bloodstream and
then excreted in the urine.
Cont. …

1. In response to a glucose
increase
3. The increased of circulating
insulin causes higher
chromium mobilization to
target cells, mainly mediated
by transferrin
2. Insulin is secreted into the
circulation and Insulin binds to
external side of insulin receptor
5. The chromodulin is stored in
the apo form
6. Four Cr3+ ions join the
apochromodulin making it active as
chromodulin
7. Which in turn binds to the active
site in the insulin receptor
8. Completing the activation and
amplifying the insulin signal
9. A series of phosphorylation
reactions in cascade occurs and
stimulates the translocation of glut4
to the plasma membrane
10. Carrying the glucose uptake
4. Glut-4 inside the cell without
performing the glucose
transport

Chromium deficiency
› It is found to cause a reduction in insulin sensitivity in the peripheral tissues as well as a
decrease in growth rate.
Fe+-transport protein (transferrin)
› The Fe+-transport protein (transferrin) has been shown to be responsible for
maintainingCr3+ levels in the blood plasma and for transporting chromium to tissues in
an insulin-responsive manner.
Cont. …

Chromium & Metformin
› The increases in plasma membrane fluidity have been shown to increase glucose transport
(Basal glucose transport is not fully active in fat cells and it can be increased by raising
membrane fluidity)
› Metformin, the antidiabetic drug, has been shown to enhance insulin action by increasing insulin
receptor sensitivity and membrane fluidity.
› As has been observed after chromium treatment, metformin treatment has been shown to
increaseGlucoseTransporter 4 (GLUT4) translocation.
› It has been hypothesized that chromium enhancesGLUT4 translocation through a cholesterol
dependent mechanism.
› Plasma membrane cholesterol content has been shown to diminish in cells exposed to
chromium and exogenous cholesterol replenishment was found to make the enhancement of
insulin action by chromium ineffective.
Cont. …

› Through a linkage of chromodulin with the insulin receptor and the increase glucose flux
into the adipocyte, chromium has been observed to;
a) Increase the synthesis of fats in adipose tissues
b) Decrease the fats net release
Chromium in Lipid metabolism

Mechanism of Action
› Metformin activates 5-AMP activated kinase (AMPK), which suppresses the expression
of a sterol regulatory element binding proteinSREBP-1
› SREBP belongs to a family of key lipogenic transcription factors directly involved in the
expression of more than 30 genes involved in the synthesis and uptake of;
1. Cholesterol
2. Fatty acids
3. Triglycerides
4. Phospholipids
– NADPH cofactor required for the synthesis of the above mentioned compounds.
Cont. …

› Chromium has been demonstrated to increase amino acid and glucose uptake by
skeletal muscles of rats.
› This increase in uptake of these nutrients is associated with the alteration of insulin
parameters which is dependent on chromium.
› It has been observed that chromium supplementation increases amino acid uptake by
tissues and also intensifies the incorporation of amino acids into the proteins of the
heart in rats.
Chromium in Protein Metabolism

› Chromium protects RNA against heat denaturation.
› Chromium increases RNA synthesis.
Cr in Nucleic Acid Metabolism

Mechanism of stress effect
› Stress factors stimulate the hypothalamus ………. leading to the production of
corticotrophin releasing factor ………. which stimulates the pituitary to produce
adrenocorticotropic hormones ………. which in turn stimulates the adrenal cortex to
increase the production and release of corticosterone.
Corticoids effect;
1. Depress the immune system function
2. Reduce serum protein concentrations
3. Increases blood glucose concentration
4. Reduces glucose utilization by peripheral tissues (thus functioning as insulin
antagonists)
Chromium and Stress

Chromium effect in relieving stress;
› Chromium is known to influence the secretion of corticosteroids.
› A number of reports have confirmed decreased sensitivity to stress in animals fed
chromium supplements as a result of reduced concentrations of cortisol in the blood.
› It has also been observed that all-stress inducing factors enhance chromium excretion in
the urine.
Cont. …

› Chromium is usually not considered as an essential trace mineral for poultry; however studies
have provided evidence that suggests a nutritional and physiological role of chromium as a
micronutrient in poultry nutrition.
› The beneficial effects of chromium can be observed more efficiently under environmental,
dietary and hormonal stress.
› Currently there are no NRC recommendations for chromium in poultry diets (NRC, 1994).
› However there is emerging evidence to suggest that pigs and poultry may have a dietary
requirement for chromium that exceeds that found in corn- soya meal diets.
› Published research has shown the beneficial effects of chromium supplementation in the diets
of poultry on carcass traits, immune responses, oxidative parameters and reduction of heat
stress.
Chromium for Poultry

› Supplementation of poultry diet with chromium has been shown to positively affect egg
production and performance in laying birds.
› The beneficial effects of chromium could be more efficiently noticed in conditions of
stress, whether dietary, environmental, or hormonal stresses.
Chromium in Poultry - Laying Hens

› Chromium supplementation alleviates the detrimental effects of cold stress especially in
laying hens reared under low ambient temperatures.
› Research findings have shown improved egg quality traits such as specific gravity,
eggshell thickness, eggshell weight and Haugh unit, with chromium supplementation in
the diets of laying hens reared under low ambient temperatures.
› Sahin et al. (2001) found that chromium supplementation increased serum insulin
concentration while markedly decreasing corticosterone concentration in laying hens
reared under low ambient temperatures.
Chromium in Environmental Stress – Cold
Stress

› Egg production and egg quality of layingJapanese quails reared under heat stress, were
found to be improved by chromium supplementation.
› Chromium supplementation in layingJapanese quails reared under heat stress was
found to improve feed efficiency.
› Sahin et al. (2002) observed improved egg quality traits in layingJapanese quails
exposed to heat stress.
Chromium in Environmental Stress – Heat
Stress

› However Lien et al. (1996) reported that shell thickness was not affected by chromium
picolinate supplementation under thermally neutral conditions.
› Other studies (Southern and Page, 1994) observed that chromium supplementation did
not affect significantly egg quality traits such as Haugh units and specific gravity, this
could suggest that marked beneficial effects of chromium on egg quality is observed
only under conditions of stress.
Chromium in Environmental Stress –
Thermally Neutral

Chromium and corticosterone
› Sahin et al (2002) have shown a significant reduction in serum corticosterone levels in
layingJapanese quails supplemented with chromium.
Chromium and cholesterol
› Chromium supplementation markedly decreased blood cholesterol concentrations in
Japanese quail under thermoneutral zones.
› A lowering trend in egg cholesterol levels was also observed in hens when the diets
were supplemented with 100 or 200ppb organic chromium.
Cont. …

Chromium dosage
› 100-200 ppb of chromium has been recommended as an optimum requirement for
enhanced egg production in layers.
Cont. …

› Studies have revealed that heat stress has detrimental effects on the performance of
broilers;
1. Reducing feed intake and growth rate
2. Affecting feed efficiency, carcass quality and the general health.
› Chronic heat stress;
1. Affects the time to reach market weight, since growth rate is affected
2. Increases the rate of mortality
Chromium in Poultry - Broiler Performance

› Chromium supplementation has been shown to alleviate the adverse effects associated
with heat stress in broilers.
› In broilers under conditions of heat stress, chromium supplementation has also been
shown to;
1. Improve body weight gain
2. Improve feed efficiency
3. Increase feed intake of broilers
4. Increase in carcass yield
5. Decrease in abdominal fats
6. Improve feed conversion ratio
Cont. …

› In ruminants, supplementation of chromium is recommended during;
1. Heat stress periods
2. Early lactation
3. During infections
› The sufficient amounts are;
– 4-5mg/head/day of supplemental chromium during the last three weeks pre-partum
– 5-6 mg/head/day of supplemental chromium during the first few weeks post-
partum
Chromium for Ruminants

› During the early lactation stages, high producing dairy cows are subjected to
tremendous pressure and stress.This results in;
1. Negative energy balance
2. Increased production of non esterified fatty acids (NEFA)
3. Increased production of β-hydroxybutyric acid (BHBA)
› These effects result in ketosis and other metabolic disorders leading to stress.
› Supplementation of the diets with chromium has been shown to be beneficial during
such periods.
Chromium in Ruminants - Milk Production

› Several studies have shown that insulin resistance (Insulin resistance is when cells in
muscles, fat, and liver don’t respond well to insulin and can’t use glucose from your
blood for energy) begins before parturition and continues during early lactation.
› Thus, during peri-parturition, insulin resistance may be an important factor in the
establishment of catabolic activities.
› Supplementation with organic chromium at 0.5ppm in primiparous cows;
1. Improved glucose tolerance
2. Improved milk yield
3. Reduced blood cortisol, NEFA and BHBA levels in the blood.
Cont. …

› In transition dairy cows, it has been shown that supplementation with chromium;
1. Reduced blood cortisol concentrations
2. Improved immunological activities
› Supplementing diets with organic chromium;
1. Increased milk yield by 11% during the first 14 weeks of lactation in first parity cows.
2. Increase dry matter intake in first parity cows during the first 4-6 weeks
postpartum.
› Increased milk production might be an indirect effect of increased glucose production.
Cont. …

› Increased production as a result of chromium supplementation is observed in
primiparous cows (first 3 milking seasons) and not multiparous cows.
› It has been observed that first lactation cows supplemented with 4mg/day of an organic
chromium supplement had higher average daily milk yield and higher milk fat, protein
and lactose values when compared to a control group.
Note

› Normal husbandry practices in calf rearing, such as weaning, crowding and feedlot
acclimation could lead to physiological stress and in turn to a deficiency of chromium.
› The excretion of chromium in the urine during such stress periods normally increases
the requirements of chromium.
› In stressed calves, chromium supplement;
1. Increased total weight gain
2. Increased average daily weight gain
3. Decreases serum cortisol in chromium deficient diets.
4. Decreased plasma cholesterol concentration
5. Improves the antibody response to infectious bovine rhinotracheitis vaccination in
newly weaned calves
Chromium in Ruminants - Calf Growth

› Chromium has been shown to play a vital role in the metabolism of carbohydrates,
proteins and lipids and in improving the immune function in livestock.
› Organic sources of chromium have been found to be highly bioavailable and the
beneficial effects of chromium supplementation have been proven by various studies
carried out with livestock.
› Chromium supplementation has been shown to alleviate the negative effects of stress
thereby improving the performance and health of livestock.
Conclusion

Chromium_Animal_Nutrition.pptx

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