The role of chromium element in livestock and poultry nutrition


  Chromium plays an important role in the metabolism of carbohydrates and lipids, which is one of the most important low-consumption mineral elements in human and livestock nutrition. Feeding chromium supplements to domestic animals may improve health and increase the immune response, strengthen the growth of calves, and increase production. Milk in dairy cows and improvement of carcass traits. Other studies have shown that chromium acts as an insulin enhancer. Trivalent chromium is the most stable and less toxic, and because of its role in metabolic activities, it is fed to animals as a supplement. Chromium can be added up to 0.5 mg/kg of dry matter. Organic forms of chromium (chromium propionate and chromium picolinate) are more accessible in the intestine than inorganic forms (chromium chloride or chromium nicotinic acid).

Chromium absorption and mechanism of action

Chromium improves the action of insulin. Some researchers predict that chromium increases the response of insulin receptors by increasing sensitivity, while a number of other researchers believe that chromium increases the number of insulin receptors. It has also been shown that chromium increases the sensitivity of pancreatic beta cells, so We will increase insulin secretion. When chromium is absorbed, it moves from the blood into insulin-dependent cells in muscle and fat tissues. Transferrin binds to chromium and helps to transfer it.

Transferrin receptors are also sensitive to insulin, and when insulin increases, transferrin moves to the membrane.

The main reason for using chromium in the ration

Cows in the transition period (21 days before calving to 21 days after calving) and high-yielding cows are more prone to insulin resistance. Because these cows are in a negative energy balance and their body faces a decrease in the level of glucose in them. Glucose in the diet in the form of starch, sugar and fiber is converted into volatile fatty acid (VFA) by rumen microbial fermentation. In addition, propionic acid is converted into glucose by the liver.

Adding chromium supplement can reduce insulin resistance in cows under negative energy balance and reduce the possibility of ketosis. For this reason, breeders and nutritionists suggest adding chromium in the diet.

Chromium and its role in milk production

In the studies in which the increase in milk production was observed, an increase in dry matter consumption before birth was also observed. By supplementing with chromium, the level of (NEFA )free fatty acids in the blood was also reduced. The researchers suggested that with the effect of chromium on increasing the flow of glucose in fat tissue. Lipolysis can be reduced, which increases feed consumption and reduces the use of body reserves in early lactation, as a result, more raw materials will be available to the mammary gland, which increases milk production. Chromium supplementation also increased milk protein production. Chromium is involved in protein metabolism and exerts its positive effect through the increase of serum albumin and the ratio of albumin to globulin. The increase of serum albumin may be due to the increased synthesis of amino acids in the liver, which itself has its effect from the increase of insulin by chromium. .

Chrome and reproduction

As mentioned, chromium supplementation improves immune function and reduces tissue mobilization, which may lead to improved cow fertility. Cows with a weak immune system are more likely to suffer placental abruption, and the remaining placenta reduces the cow’s fertility. The results show that chromium helps to reduce the effects of anestrus on fertility. Increased insulin sensitivity through chromium reduced follicular degeneration, which is related to the stimulating effects of this hormone on cell proliferation. In addition, insulin increases the ovulation rate due to its effect on the release of LH.

The effect of chromium on the immune system

Moving cattle and especially growing calves at any distance can cause tension. Stresses often increase glucose metabolism. The increase in the use of glucose leads to an increase in the mobilization of chromium, and after that, the mobilized chromium is not reabsorbed and excreted in the urine, and because in stressful conditions, urine excretion is high, as a result, we will have a deficiency of chromium in the body. Stress also increases cortisol levels. Cortisol is a glucocorticoid that inhibits growth. When blood glucocorticoid levels increase, protein synthesis also decreases, the researchers reported. Glucocorticoids also suppress the immune system.

Chromium reduces cortisol levels, thus improving performance and increasing immune response in stressful situations. The mechanism of cortisol reduction by chromium is not well defined. During the time of stress (for example, early breastfeeding), the immune system is challenged and the need to make essential proteins such as albumin and globulins increases for the transport of nutrients and the defense system, respectively.

Therefore, chromium participates in maintaining protein synthesis and increases the immune system while maintaining peak milk production. Dairy and beef cows that received chromium supplementation had higher concentrations of immunoglobulins.

The availability of glucose is also effective for the immune system. Because the immune system uses glucose as its energy source. Cornell University scientists have shown in a study that the use of chromium supplements increases the immune response to bacterial contamination of the uterus during early lactation.

In fattening cows, adding chromium supplement (400-1000ppb) by reducing blood cortisol reduces the stress of animals when they enter cattle breeding.

Stress and increased immune system function require more energy and glucose.

Chromium and metabolic abnormalities

Chromium may prevent ketosis and fatty liver by increasing insulin sensitivity. Insulin is an anabolic hormone that increases lipid production and decreases its breakdown. Supplementing the diet of dairy cows with chromium-methionine reduces plasma free fatty acids (NEFA) concentrations 7 to 10 days before calving. Dairy cows fed diets containing chromium picolinate had lower plasma concentrations of beta-hydroxybutyrate than the control group. They have control in the postpartum period, and the concentration of liver triglycerides is also lower.

Effect of chromium on ketosis

Ketosis disease occurs as a result of a decrease in blood sugar and causes the release of body fat in the blood. If the insulin receptors do not work well, a condition known as insulin resistance is created and can have a negative effect on the cow. Researchers have shown that insulin resistance in cows that are in close-up, the beginning of lactation and in the middle of lactation is more than in cows that are at the end of lactation and far-off.

The role of chromium in poultry nutrition

Glucose metabolism in birds differs from mammals due to lower insulin levels and much higher blood glucose concentrations. Chromium element increases insulin sensitivity (insulin sensitivity) by body cells of birds and mammals. In the case of broilers, stress, especially temperature fluctuation and high or low ambient temperature, causes the release of corticosterone, and the increase in the level of this hormone in the blood causes a decrease in insulin acceptance. For this reason, the tension in poultry that is kept in open halls with wide temperature changes in countries such as Indonesia and India is much higher, and for this reason, the need for antioxidants increases in them. Since the cost of cooling the poultry room, especially in humid areas, is very high and its efficiency is low, there is a strong desire to increase the resistance of poultry to temperature stress through nutrition.

The high temperature of the environment increases the need for vitamins and minerals in birds, and their possible deficiency symptoms often appear during temperature stress. This higher requirement is mainly due to the increased excretion and metabolism rate of vitamins and minerals in the tissues during heat. Trivalent chromium (pentavalent chromium is toxic and mutagenic) is necessary for the normal function of insulin and protein, carbohydrate and fat metabolism, and because of this role, it is also used as a supplement in human nutrition. The most important role of chromium is regulating the metabolic role of insulin in the body, and for this reason it is named as the Glucose Tolerance Factor. In different studies, the use of inorganic salt and organic form of chromium have different absorption rates, and organic chromium has a much higher bioavailability in broilers. The bioavailability of chromium mineral resources such as chromium chloride is very low and is estimated at 0.5 to 2%. This number is higher for organic sources such as chromium picolinate and is around 10 to 25%. Adding chromium supplement to poultry feed improves the growth rate and food conversion ratio, and on the other hand, the relative weight of internal organs and muscle tissue increases and carcass fat decreases. Among the blood components, the intake of chromium in food reduces cholesterol levels and increases high-density lipoprotein (HDL).

With the increase of stress on poultry, the need for antioxidants such as vitamin E and C increases, and the role of chromium element can be vital.

Chromium poisoning

As a toxic compound, pentavalent chromium can greatly accelerate the aging process, reduce fertility, and seriously damage the liver. Miscarriage, fetal abnormalities, and fetal nervous system problems are other effects of this toxic element. Pentavalent chromium is considered among compounds with high mutability. Destruction of the microflora of the digestive system is another effect of pentavalent chromium. Minor poisoning causes a decrease in production performance in livestock and poultry.

Sources of chromium for livestock

The only FDA-approved sources of chromium are organic sources or chromium propionate. The use of this source is up to 500 parts per billion or 5-8 mg in close-up, newborn and lactating cows, depending on the dry matter used.

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