FEEDING MANAGEMENT OF DAIRY CATTLE - PART-2
Compiled by Dr PK Shrivastava, Dairy Business Consultant, Bangalore
In our article “feeding management of dairy cattle -Part 1", we have covered the basic information about the anatomy and physiology of “stomach of dairy cattle”. The present article will include “Ration, feed intake, feeding methods, DMI prediction and concentrate feed calculation”.
(i) WHAT IS RATION:
It is the allowance of feed given to the animal for a period of 24 hours. Technically it should contain all the required ingredients of food (carbohydrates, proteins, fats, major and trace minerals, vitamins and other essential elements). Once a ration contains all the above elements of nutrients in required proportions, form and quantity for 24 hours, it is called a “balanced ration”.
(ii) QUALITY OF RATION FOR DAIRY ANIMALS:
It should be fairly bulky (optimally fibrous content) to maintain peristaltic movement of gut. It is required for satisfaction of hunger of animal and passage of digested and un-digested material causing healthy bowel. It should be fresh free from dust, fungus and off-odour.
b. Adequate nutrients in ration
Ration should be properly balanced with all necessary nutrients, with varieties of feed stuffs, green + dry fodders (legume + non-legume) + concentrate + min mixtures + feed additives + water (always available). Any nutrient’s deficiency may lead to health disorders. It should satisfy the total dry matter requirement of an animal based on its live body weight. Avoid toxic ingredients.
c. Digestible and Palatable
It should be properly, chaffed, treated to increase nutritive value, palatability and digestibility of feed-stuffs to ensure optimum feed intake. It should produce desirable flavor to milk, silage which has smell, must be fed after milking. Prefer feeding grains at milking time, it works as stimulus for milk laid down.
It should be economical, using locally available feed ingredients in proper proportions, to ensure health & optimum feed intake. Animals must be fed at regular intervals (no sudden change in schedule), if possible, individually (at least in small and mid-sized farms).
(iii) TYPES OF RATIONS FOR ADULT DAIRY ANIMALS:
(a) Maintenance Ration:
It is minimum allowance of ration given to the animal for carrying out its essential body processes at optimum rate without gain or loss in body weight. It is the ration required by every non-productive and productive animal. It is just to maintain anatomy and physiology of the body (usually given to dry non-producing animals). It barely satisfies the nutrient requirement for body maintenance.
(b) Production ration:
It is the additional allowance of ration given to the animal, over and above the maintenance ration for the purpose of production like; milk, meat, wool and work. It is given to meet the nutrient losses through milk /non-milk (wool) production or energy losses through work. It helps to maintain milk production (quality and quantity) to optimum level.
(c) Gestation or Pregnancy or Transition Ration:
It is additional allowance of ration given to the pregnant animal in addition to maintenance and production ration during the last quarter of pregnancy. It is given to satisfy nutrient requirement of pregnant animals. It is required for optimum foetal growth. It helps in proper development mammary system for future lactation.
(B) RATION INTAKE:
Whatever, we keep feeding to animals, unless the animal take-it-in, it is of no use. As such, the intake of ration becomes very important. The intake of ration should be easy, sumptuous, filling and optimum.
Milk yield is positively correlated to dry matter intake. Roughly for every 400 gm of additional intake that a cow consumes, we can expect about 1 litre of additional milk. In other word the concentrate feeding in production ration is calculated @ 400 gm for every litre of milk yield.
(i) Factors affecting feed intake:
There are several factors that affect feed intake, two of these are dependent on the cow;
(1) Animal Factor:
(a) Body weight of the cow (larger cows consume more feed and vice versa).
(b) Positive correlation to milk production, means, more milk production, more the intake.
(2) Feed Factor:
(a) Quality of ration: high or low moisture feed reduces intake.
(b) Low palatability (Example: Excess feeding of corn silage, spoiled feed, more humus feed can be unpalatable).
(c) The acidic ration lowers rumen’s pH and reduces intake. (Example: excess grain is fed, rumen's pH declines, passage rate of feed in the GI tract declines, rumination will decline and intake will reduce).
(d) Too much fat in the diet can reduce the intake.
(e) Bulk density: Too little fiber or too high fiber, can decrease the intake. Too much fiber leads to quick filling feeling and reduces the intake and also too little fiber (means too much grain) can lower the intake
(f) Densities are low: too low nutrient, energy, crude protein density decrease the intake.
(3) Management factor:
(a) Manger management (bunk cleaning): It should be cleaned daily. The refused feed should be cleaned immediately after the feeding is over.
(b) Frequency of feeding in 24 hrs: more number of feedings per day increases intake?
(c) Cows are feed shorter: Frequent pushing of feed towards the animals will increase the intake.
Size of the hay-lage or silage: Most forage particles in silage and haylage should range from 3/8 to 3/4 inch in length. Forage particles that are very fine, or grain that is too coarse or whole, should be avoided in the ration. Cows generally sort against long particles due to their less palatable nature and sort for finer particles in the ration. This behavior can lead to metabolic problems such as subacute ruminal acidosis (SARA).
(d) Easy accessibility to clean & healthy drinking water will increase feed intake.
(e) Over-crowding can reduce intake due to social stress or social pressure within the groups.
(f) Cow should have access to feed (except concentrate) 24 hours a day for better intake.
(g)Behavioral characteristics: Grouping of animals (like 1st lactation heifers, older in-milk animals, pregnant animals), the intake increases.
(4) Environment effect:
Higher temperatures and high humidity decreases feed intake. It can be mitigated by providing comforts during high temperature and humidity.
(5) Disease factors:
The animal first drops feed intake in case it is not feeling healthy. Keep your keen observation in resolving the disease factor. Post vaccination, post parturition, post stress also the feed intake reduces.
(C) FEEDING METHODS:
Various feeding methods are prevalent in our country. While world-wide TMR (Total Mixed Ration) method is very common. It is mainly due to the reason that developed countries has large size animal farms and India has mostly small and medium sizes of farms. The TMR system of feeding is more suitable for larger farms. There are advantages and disadvantages for using TMR method of feeding, however, in India majority of small and medium farm holders use conventional system of feeding. TMR is very common in Punjab dairy farms.
(i) Ration feeding systems for dairy farms in India vary a lot
a. Small units till 10 animals uses individual feeding system, where the ration is fed in divided doses to individual animals. Water is also supplied individually to animals in buckets. “Sani” (mixed concentrate) type of feeding method is used, where animals are reared mainly on home available Agri-residues and purchased concentrate like-chunni, churri, khal (cakes), etc. Green and dry fodders are mostly fed un-chaffed. Other farm activities are also handled on individual animal basis like; cleaning & washing, milking (generally hand milking by family member), etc. Here there is no stocking of feed ingredients, as such, the feed varies almost daily or every 3-4 days.
b. The farms holding 10-30 animals starts affording mechanization bit by bit. Concentrate ration mixing, milking, animal grouping, etc observed. Here the chaffing of green fodder starts, dry fodder still given whole, raw materials for cattle feed are stored, ready CF are procured from market, dry fodder are stocked, green fodder are fed as& when they are available, contents of the concentrates are mixed and provided to every individual (generally un-measured). They have single, some time double head milking machines, some time they have the grinder or simply floor mill type arrangement for grinding, mixing is done manually. Mineral mixture fed separately.
c. The farms holding above 30-50 animals operates more organized way, in terms of maintaining the type of feed ((Roughage and concentrates), they stock materials, have compulsorily milking machine, feed mill, stocks of mash variety of cattle feed, min mixture is fed separately, auto chaffing available, feed additives used, some kind of established feeding methods are visible in such farms.
d. Farms having more than 50-100 animals are generally try to function as organized farms. With all above (ref para c), feed mill, machine milking vacuum line, milk room/BMC room, individual milk testing & recording system, vaccination and disease recording, established dispensary, disposal of dead animals, dung management, hay & silage, etc. are seen. Feeding something like TMR; means farm manufactured concentrates + measured fodder as per the DMI are fed to various groups of animals. Disease monitoring, breeding line & Dam-shire yield data recording, etc. are visible.
Figure 3: An example of a line feed bunk with head locks.
Note: Here feed is available in the reach of the cow.
e. Farms above 100 animals generally follow most of the farm mechanization with precisely observing the farm parameters. Full automation is adopted generally under compulsion, as the ever-rising labor cost pushes the promoter to adopt complete mechanization at the farm. Automated milking parlor with large scale green fodder cultivation, bailing of hay plus Cattle feed formulation & manufacturing (also its sale to other farms), etc. are seen in such farms. In these farm TMR method of feeding is adopted to curb labor cost and save time.
Figure 4: Take a look at this feeding bunk.
Note: Most of the feed is out of the reach of the cows
(f) Tips for feeding forage to dairy cows:
(a) Maximum quantity of green fodder that can be given to a cow varies from 35 to 40 kg/day, depending upon feed quality, palatability and demand of the animals.
(b) Green fodders especially the improved varieties and legumes, such as hedge lucerne, Lucerne, berseem and cowpea could be fed to dairy animals to replace concentrates @ 1 kg concentrate for 12 kg of greens.
(c) Leguminous green fodder like berseem, lucerne, cowpea, etc., must not be fed on empty stomach to dairy animals as this may upset the digestion and cause bloat. Always either the dry fodder like bhusa (wheat/ paddy straw) is mixed or fed first and then the greens.
(d) Animals should not be over fed with concentrate, as it would not be economical. High forages and low concentrate, is an economical system of feeding.
(e) Feeding hay (straws) must not be done just before or at milking time, as it may create dusty atmosphere in barn and adversely affect the microbial quality of raw milk.
(f) Most dairy farmers prefer feeding grains at milking time, as this becomes part of stimulus for laid-down of milk.
(D) DRY MATTER INTAKE
(i) What is Dry Matter (DM):
Every feed material (dry, green or concentrate) has some moisture into it. If we remove the moisture from these feeding materials, the balance we get is the dry matter. When we feed a cow, we feed the feeding materials as whole (without removing its moisture). As such, what the cow get is the only dry part of it, balance is used for physiological process and excreted through urine, sweat or breath. For animal feeding nutrients are calculated on dry matter intake basis and not on the “as is” basis.
(ii) How to calculate the DMI for a milk cow:
Milk yield is positively correlated to dry matter intake (DMI)(Refer para “A (iii)” above where 3 types of rations are described). The weight of cow, production of milk and pregnancy needs to be compensated by proper DMI calculation. Roughly for every 2.5 litre milk production 1 kg of dry matter is fed. The concentrate has about 90% of DM, so while calculating the correct DMI requirement for a particular animal, one has to take all these factors into consideration.
(a) Let’s look at the formula to calculate the DMI for milk yield and body weight of the cow:
The equation is dry matter intake, in kilos per day, equals 0.0968 times body weight to the three fourth power. That means cows that weigh more will consume more dry matter. The second component of the equation is 0.372 times kilograms of fat-corrected milk. Fat-corrected milk is milk that has been adjusted for or corrected on a 4% fat basis. The reason we correct milk, is that the cows those give higher fat percentages in their milk are secreting or are producing more energy in the milk and therefore need to consume more energy or more dry matter and vice versa.
In this system of calculation, there are 2 parts of equation, after we calculate the FCM correlated milk value. The equation is 0.0968 times 635 to the three-quarter power plus 0.372 times 32.8 kilos of fat corrected milk.
A cow weighing 635 kilo body weight, producing 36 kg of milk that contains 3.5% of fat. Calculate it's DMI. First, we determine how many kilos of fat corrected milk she is producing:
It would be = 0.4 (36 kilograms milk yield) + 15 (1.26 kilograms of fat) = comes to 33.30 Kilo fat correlated milk (FCM).
See below the calculations and explanations:
We determined first the factor 1.26: 36 kilos of milk X 0.035 (3.5% fat), which gives us 1.26 (36 kilo milk x 0.035 = 1.26)
If you do the multiplication and sum these two parts (0.0968 times 635 to the three-quarter power + 0.372 times 33.30 kilos of fat corrected milk). We will arrive at 24.63 Kgs of DM the cow needs per day.
(1) Dry Matter Intake/day=0.4 (36) + 15 (1.26) = 14.40 + 18.90 = 33.30 (FCM correlated milk value)
(2) Now, calculate part 1: multiply body weight (635 Kg) with three-quarter power. We get 126.50. Now multiply this value with factor 0.0968. We get 12.24 (Part 1)
(3) Now, calculate part 2. FCM correlated value of milk (33.30) multiply with factor 0.372, we get 12.38 (Part 2). By adding both the values 12.24 + 12.39 we get 24.63 Kg. The Dry matter required per day for this cow.
This is a better way of calculating the DMI for a Dairy cow.
(iii) THUMB RULES FOR DRY MATTER FEEDING IN INDIAN CONDITIONS:
DMI in cows and buffaloes is calculated based on animal's body weight and production basis (just as in above formula).
DMI of 400 kgs of cow would be in the range of 8 to 16 kgs/day (2 to 4% of body weight) depending on milk production, forage concentrate ratio, stage of lactation, pregnancy, etc. In general, DMI can be calculated @ 2.5% of body weight of the animal (@3.5-4% of body weight for high yielding animals-above 25 litres/day/milk yield).
(a) The Cattle feed (CF) requirement for an average cow (250-300 Kg body weight):
(1) For body maintenance: 1.25-1.50 kg CF/animal/day
(2) For milk production: 400 gm CF per litre of milk produced or 1 kg of CF for 2.5 litre of milk produced. If a cow is of 300 Kg body weight (2.5% of 300 Kg = 7.5 Kg of Concentrate/ day).
(3) Allowance for pregnancy: add 500 gm to 1.00 Kg per day CF in addition to the maintenance + production ration (during 7th, 8th & 9th month of pregnancy). During the advance pregnancy months, fodder should be reduced, especially legumes.
(b) For buffaloes (body weight about 550 kg) CF requirement:
(1) Body maintenance: 2 kg /animal/day
(2) Milk production: 500 gm per litre of milk or 1 kg cattle feed for every 2 litre of milk production.
(3) Allowance for pregnancy: 1 Kg extra during 7th, 8th and 9th months of pregnancy (with reduced fodder, especially legumes).
(c) The Forage concentration ratio:
The forage concentrate ratio is fully dependent on availability of forage. If greens are plenty the mix ration would be different compared to the situation, when green are less available. For detail look at the Table 1.
Table 1: Feeding schedule for different categories of adult cows (approx. body weight-250 kg)
(d) DMI varies during weeks of lactation: The DMI in cows in develop countries is more on account of their heavy body weight. Look at the Figure 1 to understand as how the DM requirement varies during weeks of a lactation. Figure 2 indicates that keeping high yielding cows are beneficial.
Figure 1, shows result of an experiment on cows, to validate the hypothesis that “the DMI varies during the weeks of a lactation”. In the chart two different lines are visible. One is a dark orange line that eventually meets the lighter orange line at about 19 to 22 weeks of lactation. Taking reference of the just talked equation (refer Example 1 above) and putting the value of DMI for milk yields, maintenance as per the body weights of the cow, it is expected that the cows would consume on the lighter orange line (high DMI). However, the experiment shows that the cows have suppressed intake in early weeks of lactation. Actually, there is a lag in intake and it takes about 20 weeks or so for cows to catch up to where they would be as per the DMI requirement (refer the light & yellow lines in the following chart).
Figure 1: The dry matter intake curve of an average cows.
(1 pound = 0.454 gm)
Figure 2: Graph depicts how many pounds of dry matter goes toward maintenance and milk for different levels of milk yield (MY).
Figure 2 shows five different groups of cows, yielding milk daily as 0, 70, 80, 90, and 100 (lb) and their DM requirement has been compared, which is plotted on the left axis. Cows giving no milk, or at maintenance, need about 10 pounds of dry matter per day to meet their body maintenance requirements (in fact all cows do, regardless of whether they are producing 70 pounds or 100 pounds of milk daily).
Then, we have the DM requirement for milk yield, which are the orange colour bars above the dark orange bar area. We observe that a cow producing 70 pounds of milk, would be expected to consume about 36 pounds of dry matter and a cow producing 100 pounds, needs about 46 pounds of dry matter for milk yield plus the additional 10 pounds for the maintenance. If we club both DM requirements, a 100-pound milk yielding cow, needs about 46 pounds of dry matter for production and an additional 10 pounds for body maintenance, so a total of 56 pounds of dry matter for both milk and body maintenance.
The blue line and the right axis in the graph depict, how many pounds of milk one can get per pound of dry matter intake? The graph explains; if the cows are producing about 70 pounds of milk, 1 pound of DMI produces about 1.95 pounds of milk and if the cows are producing about 100 pounds milk, the amount of producing milk from 1 pound of DMI increases to about 2.15 pounds. We observe here that this slight increase is because the 10 pounds maintenance DM value, which is spread to more pounds of milk produced (100 lb). Means higher yielding cows proves more economical.
Consultant’s comment: In Indian situation of farming;
(1) Keeping the tropical disease resistance in mind, it is better to rear exotic cross breed medium yielding cows (15-22 litres per day), compared to keeping pure high yielding exotic breeds.
(2) Indigenous milk breeds of cows could be reared as pure breeds, as they imbibe the tropical disease resistance quality.
(3) As far possible keeping medium body weight dairy cows (300-400 Kg) should be preferred to reap the benefits of feed conversion ratio.
(1) https://courses.ecampus.oregonstate.edu/ans312/seven/cows_5_trans.htm#:~:text=Fat%2Dcorrected%20milk%20is %20milk, energy%20or%20more%20dry%20matter.-on dry matter intake (2) http://www.agritech.tnau.ac.in/expert_system/cattlebuffalo/Fodder%20Production.html#Cereal- on fodder crops
Please wait for the "Article on feeding management" PART-3