mPro or mPro plus: Unique solution for dietary nitrogen supply
and economizing nitrogen use in ruminants
Author: A. B. Mandal, Mukesh Mundhra, Ashim Das,Suresh Chandra Bera, Subrata Parai, ARCL Organics Ltd, Budge Budge Trunk Rd, Rampur, Santoshpur, Kolkata, West Bengal 700141
Livestock sector, in India, is one of the largest sector in the world and about 20.5 million people depend upon livestock for their livelihood in India. Indian Livestock sector provides livelihood to about 65% of rural people besides providing employment to about 8.8 % of the population.In India, the dairy market reached INR 14899.8 Billion in 2022 and likely to grow (CAGR) at the rate of 13.2% to reach INR 31185.7 Billion by 2028.
However, the major limitations in dairy production are shortage of feeds and fodders, cost and quality of feeds as feed cost represents 60 to 70% of total milk production cost. Reduction of feed cost is the major means by which milk production cost can be reduced as other costs are difficult to cut down. Continues shrinkage in pasture land and allocation of available land for fodder production has aggravated the situation. Again high yielding cows and buffaloes are reared under intensive production system. Those animals require high density quality feed and green fodders to meet their nutrient requirements to sustain optimum milk production. Besides those animals require rich nutritional packages for growth to have required body weight at appropriate age for conception and subsequent gestation period.The concentrate part constitutes 20 to 70% of total mixed ration depending upon different physiological state of the animals and milk production. However, minimum level of fibre (17 to 18% crude fibre or 21 to 22% ADF) in the ration is necessary to maintain milk-fat percentage. The concentrate mixture generally constitutes energy supplements, protein supplements, minerals, vitamin (s) and additives. About 45-50% of the total cost of concentrate mixture is contributed by protein supplements and almost equal cost (45-50%) is contributed by energy supplements, while mineral, vitamin (S) and additives constitutes 3-4% of total cost of concentrate mixture.
There is little scope for reduction of cost of energy supply. However, there is scope of reduction of cost of protein supply in concentrate mixture. Though energy supplements also provide some part of protein, but to meet the protein requirements different protein rich ingredients like rapeseed (or mustard) cake, cottonseed meals, gingili cake, groundnut cake, soybean meal, sunflower meal, dried distillers’ grain with solubles (DDGS), gluten meals, guar meal, guar korma, etc. Whole seeds rich in protein and oil like cottonseed, full-fat soya, sunflower seed, linseed, etc. are also used in feed formulation of high yielding animals. However, increasing scarcity and cost of different protein supplements have led to increased production cost. The situation will further be deteriorated in future as the growth rate of production of those commodities are at much lower rate than the annual growth rate of milk. Moreover, the poultry sector as well aqua sector are growing annually at the rate of 6-8% and 8%, respectively. The average growth rates of production during past years were 5.0% for rapeseed (2010 to 2021), 0.146% for soybean seed (2010 to 2021), 8.06% for groundnut(2010 to 2021), 4.36% for cottonseed (2016-2021). In fiscal year 2022, India produced an estimated 0.71 million metric tons of sesame (2022). Therefore, as a whole, the annual growth rates of protein supplements are much lower than the projected growth rate of milk, egg, poultry meat and aqua production. Moreover, area expansion for cultivation have such commodities has almost exhausted, there is liberal movement of goods due to globalization & economic integration, fluctuating production due to frequent monsoon failure, over rain, low productivity, insects, environmental concerns, cost efficiency, sustainability, declining area under cultivation, etc., diversion towards cash and commodity crops, diversion of certain protein meals for human food resulting ultimately in escalation of feed prices.
Dairy animals, being ruminants, have unique capacity of utilize non-protein nitrogen (NPN). We owe to ArtturiIlmari Virtanen, Finnish chemist and recipient of the 1945 Nobel Prize in Chemistry, for his pioneer research published in Science (1966 Sep 30 ;153 (3744):1603-14) on “Milk production of cows on protein-free feed.” He reported “the synthesis of bacterial protein in the rumen of lactating cows fed on purified carbohydrates, with urea and ammonium salts as the sole sources of nitrogen, can be increased, through feed adaptation, to a level adequate not only for the maintenance of the cow but also for a relatively high milk production. The best annual milk yield per cow on the experimental feed has, so far, been 4217 kilograms, calculated as standard milk (684 kilocalories per kilogram of milk)”. Since then lot of research has been conducted on feeding of urea and other NPN compounds to reduce feed cost and also to save protein supplements. One kg of urea (technical grade) is equivalent to 2.9 kg of crude protein, equivalent to about 7.5 kg of de-oiled mustard cake, 6.5 kg of solvent extracted soybean meal (45%CP), decorticated cottonseed meal (44% CP) or groundnut meal. Generally urea was initially recommended at a level of 3% of concentrate mixture or 1% of total dry matter intake. However, BIS (ISI) has specified maximum level of inclusion of urea at 1% level both in type II and Type I compounded cattle feed as there are certain limitations in feeding urea. Excess or abrupt production of ammonia due to feeding of urea, does not simulate with the availability of carbon chains required for synthesis of amino acids as well microbial population to convert ammonia to amino acids. The efficiency of nitrogen utilization in ruminants is also very low due to deamination of most of the amino acid nitrogen entering the rumen, resulting in a high rate of ammonia production exceeding the capacity of rumen microorganisms for utilization of ammonia for protein synthesis. Increase urea level in feed increases rumen pH and thus growth of microbes is reduced, pH of rumen liquor is increased, and absorption of volatile fatty acids is reduced (acidic pH helps in more absorption of volatile fatty acids (VFA) as VFAs are absorbed in anionic form. Moreover, level of urea in milk and urine is increased. Serum urea nitrogen level exceeding 20 to 24 mg per dl is believed to be detrimental to fertility in dairy cows.Severalmechanisms by which urea may lead to affect fertility of dairy cows have been explained. Feeding high rumen degradable protein to heifers resulted in increased concentration of blood urea nitrogen and decreased uterine pH that adversely affect the motility and viability of sperms and hence the pregnancy rate. There is also possibility of repeat breeding in cows due to impaired oocyst (morphological abnormalities in oocytes) associated with increased blood urea levels.In modern dairy farms, high yielding cows are reared. High yielding cows are often bred more times and are given more opportunities for conception than are low yielding cows. Moreover, in the high producing herds, the milk urea nitrogen (MUN) levels remain higher than in the low producing herds. Poor fertility has been reported in high yielding (>9000 kg milk) cowswhosemilkcontained more than 30 mg urea per dl (equivalent to 14 mg of MUN per dl).Therefore, there is need for slow release nitrogen to meet requirements of nitrogen for ruminants without affecting rumen environment, nitrogen utilization, productive and reproductive efficiencies. Different approaches have been tried to reduce nitrogen release include use of urease inhibitor (acetohydroxamic acid) as well as developing different compounds such as biuret, urea formaldehyde, urea phosphate, substrate bound urealikeurea phosphate, starea, urea-corn-carboxy-resin, uromol, coated urea (vegetable oil coated, fatty acid coated, sulphur coated, zinc coated, herbal coated, molasses coated), lactosylurea, urea-polyvinyl-alcohol, Urea lignocellulose complex, etc.
Recently ARCL has come with two slow release nitrogen products mPro and mPro plus containing 38% and 34.5% nitrogen equivalent to 237.5% and 215.6% crude protein, respectively. mPropulsalsocontains slow release sulphur at the ratio of 10N:1S.The solubility (in 2% Hcl), degradability (in rumen liquor) and ammonia release (in vitro) of these products are slow and linear with time.
Sulphur is an essential constituent of several organic nutrients (amino acids like cysteine, cystine and methionine, and vitamins thiamine and biotin) and enzyme systems.Inclusion of non-protein nitrogen replacing native feed proteins needs special care for sulphur supplementation as the sulphur containing amino acids present in proteins are the major sources of sulphur in feed. Moreover, methionine has been identified as first limiting amino acid in microbial protein. Sulphur is an essential (requirements of sulphur for ruminants is 0.18 to 0.24% of feed dry matter) for normal growth and multiplication of rumen bacteria. Sulphur deficiency leads to decreased appetite due to reduced growth of rumen microflora and rumen function. It is to add that sulphur dioxide is a preservative that is sometimes added to molasses but molasses available in market may be sulphured or unsulphured one. Distillers’ grains are also rich sources of sulphur. Therefore, use of mPro plus (containing sulphur) is recommended for compound feeds formulated with unsulphured molasses or insufficient amount of Distillers’ grains for better results. The sulphur present in mPro plus is converted to sulphide by rumen bacteria and utilized for synthesis of sulphur containing molecules (amino acids, vitamins and enzyme system) in rumen.
The advantages of feeding mPro or mProplus to the ruminants are:
• Being slow release nitrogen degraded slowly in rumen thus effectively utilized for increasing microbial population in rumen.
• As the degradability of mPro or mPro plus is slow, the rumen ammonia level does not increase sharply and thus helps rumen microbes to cope with the liberated ammonia for increased microbial protein synthesis and microbial population growth ultimately leading to more metabolizable protein available in small intestine for absorption, economizing nitrogen use.
• Increased microbial population in rumen on feeding mProormPro plus causes more efficient digestion of carbohydrates especially fibre and thus increases production of volatile fatty acids (VFA) in rumen.
• Increased absorption of volatile fatty acids as mProormPro plus does not increase rumen pH (keeps rumen pH stable and slightly in acidic side i.e. below 7.0) due to slow release of ammonia.
• Increased growth and milk production due to more microbial protein synthesis in rumen and thus more metabolic protein (microbial protein + feed bypass protein), as well as supply of more energy due to higher fibre digestion, more volatile acid production and absorption.
• Increased milk fat contents dueto higher fibre digestion, more volatile acid production in rumen and their absorption from the rumen.
• Increased milk protein content dueto more metabolizable protein reaching to lower tract for digestion and absorption.
• Improved reproductive efficiency due to decreased blood urea level.
• Helps in clean milk production as the urea concentration in milk is reduced (much below 15 mg/100 ml of milk) on feeding mPro or mPro plus.
• Providing animal welfare by reducing urea stress especially encountered during summer (generally buffaloes are more prone to urea stress).
• Environment friendly due to reduction of urinary excretion of urea.
• One kilogram of mPro is equivalent to 2.37 kg of crude protein while one kilogram of mPro plus is equivalent to 2.15 kg of crude protein. Use of one kilogram of mPro in one quintal of feed (i.e. 1% of feed) will help in replacing 6.0 and 7.8 kg of protein supplements containing 45% and 38% protein, respectively, by high (grains) or low energy supplements (de-oiled-rice bran or wheat bran) to enrich feeds with energy and phosphorus.
• Similarly, use of one kilogram of mPro plus in one quintal of feed (i.e. 1% of feed) will help in replacing 5.3 and 7.0 kg of protein supplements containing 45% and 38% protein, respectively, by high (grains) or low energy supplements (de-oiled-rice bran or wheat bran) to enrich feeds with energy and phosphorus.
• Ultimately feeding mPro is unique solution for efficient and economizing nitrogen use in the feeds of ruminants.