BENEFIT OF FEEDING MINERAL MIXTURE TO THE DAIRY CATTLE IN INDIA
Dairy enterprise plays a significant role, in terms of their contribution to human nutrition (milk and butter fat), plant nutrition (farmyard manure) and energy (bullock power). Dairy farming is a reliable source of livelihood for the rural poor since it has the potential to provide gainful self-employment and sustainable income. In addition, it can be maintained with minimum capital investment and labour. Feeding of dairy cattle has a direct impact on the reproduction and production of the animals. Hence,addition of mineral mixture becomes essential to achieve the full potential of milk production and productivity of the animal.
Dairy cattle require at least 17 minerals and three vitamins in their diet for optimal milk production, reproductive performance, and herd health. Although classical mineral or vitamin deficiency symptoms are rare, in many cases under- and overfeeding of certain minerals and vitamins does occur. Even small imbalances or deficiencies can develop into reproductive, health, and milk production problems.
Mineral deficiency in livestock animals is responsible for poor growth, deficiency disease, decreased milk yield, reproductive disorders, and decreased immunity. During the past decade, significant advances have been made in understanding the effects of trace-element supplements on the milk production of dairy cows . Supplementation of all the elements in diet may not be desirable always, because many of them such as Mg, S, K, I, Co, Fe and Mn are present in required concentrations in feeds and fodders of specific areas. Significant changes in major physiological and biochemical parameters have been observed due to deficiencies of minerals like Ca, Cu and Zn.
Low reproductive efficiency in cattle and buffaloes is one of the major problems in livestock production in India, resulting in poor economic returns to the livestock farmers. The deficiency and/or imbalance of micro and macro nutrients are one of the important factors responsible for the low reproductive efficiency. In India, 31% of total cattle populations are suffering from infertility. The practice of mineral supplementation to animals is not common in most parts of India. Wherever it is practiced the mineral mixture is added to the compound feed without taking into account the mineral status of the area, leading to imbalances of minerals. Supplementation of area-specific minerals most deficient in that area avoids antagonistic effects of excess levels of other minerals and could be a more practical and cost-effective approach.
Mineral Feeding
Generally, the two sources of minerals include natural feeds (forages and grains) and mineral supplements to balance the minerals present in the forages and grains. For the dairy cow, the major minerals (macrominerals) required are calcium, phosphorus, magnesium, potassium, sodium, chlorine, and sulfur. Minerals required in much smaller, trace amounts (microminerals) include iodine, iron, cobalt, copper, manganese, zinc, and selenium. Whether the requirement for a mineral is large (measured as a percent of dry matter) or small (measured in ppm), the proper level must be fed to achieve optimum performance and herd health.
Mineral Requirements
Macro-minerals
Calcium and Phosphorus.
The calcium and phosphorus requirements for the mature dairy cow depend on bodyweight, milk yield and composition, and stage of pregnancy. Calcium and phosphorus requirements need to be balanced for the complete lactation cycle. Minerals mobilized during early lactation must be replenished prior to the next calving to maintain cow health and performance. It is especially important to monitor the calcium and phosphorus levels during the late dry period (last four weeks) to reduce the incidence of milk fever. Calcium requirement during the dry period is .39 percent of ration dry matter, while the requirement for phosphorus is .24 percent. Feeding calcium levels above .39 percent may substantially increase the incidence of milk fever in your herd. For high producing cows, dietary calcium levels of .80 percent and phosphorus levels of .50 percent of dietary dry matter are needed. Phosphorus requirements given for dairy cattle incorporate a margin of safety and are adequate for maximum production. Avoid large dietary excesses because phosphorus is the most costly nutrient in most dairy rations. Maintain the calcium to phosphorus ratio between 1.4:1 and 2.5:1 for optimal health and performance during both the dry period and lactation.
Magnesium.
The requirement ranges from .10 percent for calves less than three months of age to .25- .30 percent for high producing cows. Higher magnesium levels may be required during early lactation, when supplemental fat is fed, or when grass tetany conditions occur. Magnesium fed as magnesium oxide is often used as a buffer and results in ration magnesium concentrations of .30% or greater for alfalfa-based rations. Research at the University of Tennessee indicates that 18 g of magnesium daily as magnesium oxide reduces udder edema in heifers when fed five to six weeks prior to calving. Soils which are low in magnesium (as determined by a soil test) or limed with calcium sources other than dolomitic limestone yield forages which are low in magnesium. Supplements such as magnesium oxide (56% magnesium) or dynamate (12% magnesium) should be fed when soil levels are low.
Potassium.
Legume forages are good potassium sources. When corn silage is the major forage, or when high levels of brewers grains are fed, potassium levels may be borderline deficient. When heat stress is a problem, potassium requirements are increased to 1.3-1.5 percent of ration dry matter.
Sulfur.
Again, legumes as well as protein feeds are good sulfur sources. An optimum nitrogen to sulfur ratio is about 10:1. Therefore, a 14 percent crude protein ration should contain about .15% sulfur. Supplemental sulfur is usually needed only when the ration contains urea, corn silage, or poor quality hay. Good sources of sulfur include calcium sulfate (19 percent sulfur), sodium sulfate (10 percent sulfur), and methionine hydroxy analog. Since trace mineralized salt contains considerable sulfur, additional sulfur should not be added to the diet unless a definite deficiency is known. Excessive sulfur increases the chances for molybdenum toxicity and interferes with copper utilization.
Sodium chloride (common salt).
The daily salt requirements for dairy cattle are met easily by adding 1 percent salt to a grain mix and offering additional salt free choice. Lactating cows need 2 to 4 ounces of salt daily (about 1 ounce of salt per 30 pounds of milk production). Dry cows need 1.5 ounces of salt daily. If udder edema is a problem, reduce salt intake during the last two weeks before calving
Micro-minerals
Generally, adding trace mineralized salt to the grain mix plus free choice trace mineral salt along with microminerals present in the feeds will meet the requirements of dairy cattle for these trace minerals.
Cobalt
. Most dairy rations will require no supplemental sources of cobalt.
Copper.
Most dairy rations need to be supplemented with copper either from trace mineralized salt or a premix containing a copper source such as copper sulfate.
Iodine.
Trace mineralized salt, or some other source of iodine, should provide 12 milligrams daily of iodine. Do not feed more than 50 milligrams because excessive iodine feeding increases iodine levels in milk and causes toxicity problems such as excessive nasal discharge and watering eyes.
Iron.
After two months of age, iron deficiencies in dairy cattle are rare. A normal dairy ration contains much more iron than is actually needed by the cow.
Manganese.
Most forages, grains and protein supplements are only fair sources of manganese so use supplements, especially with high producing cows.
Zinc.
Excessive amounts of zinc interfere with utilization of other trace minerals such as copper and iron. Generally, there is no need to feed zinc above the recommended 40-60 ppm in the ration dry matter. Zinc sulfate, zinc oxide, or Zin-Pro are good sources. Zinc methionine may improve hoof quality and milk production of cows, though more research on this product is needed.
Selenium.
Dry cows should be supplemented with three to five milligrams of selenium per day, and lactating cows with six to eight milligrams daily when soils are deficient. Selenium deficiency has been associated with white muscle disease in calves and selenium treatment may improve reproductive efficiency and reduce retained placentas in dairy cattle. Adequate dietary selenium may also contribute to lower incidence of mastitis along with proper milking management and environment. However, selenium should be used with caution because some soils are high in selenium and it is toxic if used in excess. Selenium is reported to be high in some areas in Nebraska. Levels of greater than 2 ppm cause loss of appetite, loss of hair from the tail, sloughing of hooves, and even death.
Use of Chelated Minerals.
Use of mineral chelates, or organic mineral complexes, has increased performance and decreased somatic cell counts in milk compared to inorganic forms of the same mineral in some research trials. Chelates of zinc, copper, manganese, iodine, and selenium have given variable milk production responses, and their practical utility is currently undecided. Before any definitive recommendations can be made, further research is needed to better define the management conditions where positive production or health responses are likely.
Anion-Cation Balance.
Dietary electrolyte balancing is a new concept being used as a tool for reducing milk fever in early lactation. Dietary electrolytes may have either a positive or negative electrical charge. Anions are negatively charged electrolytes, and cations are positively charged. By using different amounts of these electrolytes, a ration is formulated to be either positive or negative in charge. Feeding a slightly negative-charged ration for three to four weeks prior to calving, properly balanced for calcium, phosphorus, and magnesium, should reduce the incidence of milk fever after calving. During the three to four weeks before calving, the dry cow is usually fed more liberally to adapt her to a higher level of intake. At this time, it is critical to provide adequate amounts of coarse roughage to maintain normal rumen function and to prevent metabolic problems. The best way to balance a wellformulated, close-up dry cow ration for anion-cation levels is to use compounds such as ammonium chloride, ammonium sulfate, and magnesium sulfate. These minerals should be fed only for three to four weeks prior to calving at about 200 g per head daily of a combination containing 40 to 50 percent ammonium chloride. Do not use for longer periods. These compounds are quite expensive and unpalatable when fed alone, so they need to be well mixed into a ration. To formulate a dry cow ration based on anion-cation balance, contact a nutritionist, veterinarian, or local Extension office. Studies indicate that when cows are fed negatively charged diets, incidence of milk fever is less than for positive diets. Anionic diets seem to promote higher blood calcium levels at calving. Keep in mind, however, that specific guidelines and feeding recommendations are not yet available and that the producer should evaluate dietary calcium and phosphorus levels first to reduce milk fever problems.
Mineral Feeding Methods
Force Feeding.
This is the recommended way of feeding minerals to dairy cows. This method eliminates palatability problems, daily and cow-to-cow variation in intake, and over-consumption of minerals. The producer determines the amount of various mineral supplements based on forage and grain mineral levels and milk production. A properly formulated, carefully mixed ration is critical. The optimal method of force feeding is in a total mixed ration. Another commonly used method of force feeding is use of a grain carrier. Avoid using moist forage alone as a mineral carrier because forage intake (and hence mineral intake) decreases as milk production and grain intake increases.
Free Choice.
This method is not as accurate as force feeding, and only trace mineralized salt should be fed free choice in most instances. Cows may choose a supplement because of true appetite, learned appetite, or simple preference due to flavor, odor, and particle size.
Topdressing.
This method is used often in stall or stanchion barns. Cows are fed 1 to 3 ounces of a trace mineralized salt or mineral-vitamin premix and 1 to 6 ounces of a calcium-phosphorus supplement on top of their daily ration. This allows extra nutrients to be fed before maximum dry matter intake occurs in early lactation.
Functions of different minerals
Minerals Functions
Calcium Essential for milk production Necessary for bone & teeth formation Required for contraction of muscles
Phosphorus Essential for milk production Required in energy metabolism Required for bone & teeth formation
Magnesium Important for the integrity of bone & teeth
Involved in protein synthesis and metabolism of carbohydrates & lipids
Sulphur Required for protein synthesis and metabolism of carbohydrates & lipids
Sulphur is a part of B-complex vitamins, thiamin & biotin
Sodium &
potassium Required for maintenance of osmotic balance
Required in acid- base equilibrium
Copper Required for haemoglobin synthesis
Necessary for tissue pigmentation & component of several metallo-enzymes
Required for normal reproductive functions
Zinc Spermatogenesis & the development of primary & secondary sex organs
Required for normal functioning of epithelial tissue
Activates vitamin A & its deficiency leads to night blindness
Manganese Co-factor for many enzymes involved in carbohydrate metabolism
Activator in the synthesis of fatty acids
Iodine Required for the synthesis of thyroid hormone (T &T )
Necessary for reproduction & growth of animals
Cobalt Required for the synthesis of vitamin B by the rumen microbes
Essential for haemoglobin synthesis
Chromium Component of Glucose Tolerance Factor (GTF)
Required for the metabolism of carbohydrates, protein and fat
Helps in improving immune status of animals
Benefit of Feeding Mineral And Vitamin
Reference-On request
