|
Buffalo are, like cattle, ruminants. This means that they utilize micro-organisms in the rumen to digest the feed. Feed eaten by ruminants is of vegetable origin. The ruminant is an expert in converting cellulose and other fibrous materials into high quality milk and meat. Their digestive capacity is greater than the non-ruminant. Ruminants “chew the cud”, that is they regurgitate partly digested food to the mouth to chew it again, thus helping to breakdown this plant material.
Feed enters the rumen when swallowed by the animal. The rumen is an anaerobic environment, e.g. no oxygen is present. The feed is exposed to microbes such as bacteria, protozoa and fungi. These microbes attack the feed particles and by enzymatic action the components are broken down and used for their own metabolism, growth and propagation. The feed is masticated, regurgitated and exposed to microbes in the rumen. Large particles will become smaller and eventually be transported to the reticulum and further on. How long a specific feed particle will stay in the rumen depends on size, palatability and the fibre content of the feed. Buffalo have slower rumen movement than cattle, which leads to a slower rate of ingesta outflow. The pH of the rumen content is similar to that of cattle, and it is affected in the same manner. Normal pH is between six and seven, depending on feed and time of feeding.
Feed components can be divided into protein, energy (carbohydrates), fat, minerals and water. The breakdown and utilization of the different feed components are reviewed below.
The waste end products of the microbial attack are methane and carbon dioxide that are eructated. Volatile fatty acids (VFA) of which acetic, propionic and butyric acids are the predominant ones, are together with ammonia, absorbed through the rumen wall and transported via the blood to, for example, the liver and udder where they serve as building material for chemical compounds such as glucose, protein and fat. Most ammonia is utilised directly by the rumen microbes to synthesize proteins.
Ruminants are dependent on the function of the rumen microbes. Therefore, it is important to keep the rumen environment healthy. The easiest and best way is to feed a high amount of good quality roughage and a smaller amount of good quality concentrate.
Feed degradation in the ruminant animal. (Adapted from Ståhl Högberg and Lind, 2003)
Almost all protein is attacked by the microbes and utilized in their metabolism and incorporated in the microbial mass. Microbial protein is of high quality and is absorbed as amino acids after being digested by gastric enzymes in the abomasum.
Ammonia which is absorbed by the rumen wall and transported by the blood to the liver, is converted to urea. When there is protein deficiency, urea can be utilized by the rumen microbes as a non-protein nitrogen source to build protein. In this way nitrogen is circulated and efficiently used by the animal.
Protein can be protected to withstand microbial attack. It is then called “by-pass protein”. By-pass protein is only degraded in the abomasum and small intestine where it undergoes enzymatic attack similar to that of mono-gastric animals. By-pass protein is commercially available in some ready made concentrates and is usually given to high producers.
Carbohydrates are the main sources of energy for ruminants. Carbohydrates are the components of starch and fibres. Fibre is a common name for cell-wall components such as cellulose, hemi-cellulose and lignin. Starch can be degraded by animal gastric enzymes, whereas fibres cannot. Ruminants can utilize fibres to a larger extent than mono-gastric animals because of the ruminal microbes. However, lignin (wood-fibre) is not utilized. It is generally believed that buffalo utilize fibre more efficiently than cattle do. The efficiency of fibre digestion is five to eight percent higher in buffalo than in cattle.
Fat is required in small amounts for the ruminant. However, whatever fat is present in the feed undergoes microbial attack and degradation. Unsaturated fatty acids are to a large extent saturated. This is one of the reasons for the milk and body fat of the ruminant being of equal composition, largely independent of the type of feed given. If the fat can in some form be protected from ruminal degradation, and instead be utilized in the lower intestinal tract, it may be used as an additional energy source. However, it may then unfavourably alter milk fat composition. Too much unprotected fat in the diet depresses the ability of the microbes to ferment fibres, negatively influencing energy utilisation.
Back to top
In order to utilize animal, feed and economic resources as efficiently as possible, one must know the nutrient requirements of the animals. If an animal is wrongly fed this may lead to diseases, loss of production and thereby economic losses. By knowing what a specific animal needs, proper advice concerning purchase, cultivation and feeding systems can be given. Requirements for buffalo are more or less the same as for cattle, so nutrient requirement tables for dairy cattle may be used as a guide. A farmer must observe the animals and change the feeding system, with guidance from an extension officer, if the feed seems unsuitable.
Sources of energy are predominantly carbohydrates like fibre and starch, and fat to a lesser extent. For buffalo, fibre in the form of roughage is the most important and cheapest energy source. When calculating feed ratios for buffalo the term metabolizable energy (ME) is used. This means the amount of energy that can be used by the animal for maintenance, growth, lactation etc. The gross energy (GE) of the feed is the amount present in the feed when it enters the animal. Much of the energy is then converted into heat which is lost through thermal regulation. Energy is also lost in the faeces and urine as well as in the methane and carbon dioxide gases.
Energy is measured in calories (cal) and joules (J) (1 cal equals 4.18 J). It is most common to use the term Megacalories (Mcal) or Megajoules (MJ) which means a million cal or J. Another measurement is Total Digestible Nutrients (TDN). The unit for TDN is kg or gram.
The energy ratio in the feed may be increased by adding fat in protected form, thus transfering its digestion from the rumen to the intestinal tract. Feeding of protected fat has been proven to increase nutrient utilization. Feeding of unprotected fat in similar amounts has been shown to adversely affect nutrient utilization.
Protein is required for growth, tissue repair and milk production. Good sources of protein are leguminous forage, grain and oilseed cakes. Protein requirements are measured in Crude Protein (CP) in kg or gram (CP = nitrogen x 6.25).
Back to top
Minerals are essential for many body functions. The macro-minerals calcium (Ca) and phosphorus (P) are especially important in milk production. They are also vital for the skeleton and the function of nerve impulses. Phosphorus is the mineral included in the body’s energy metabolism, ATP. When considering Ca and P requirements for the animal it is equally important to consider the ratio in which they are given. The Ca:P ratio should be 2:1 since there is an antagonist relationship between the two minerals concerning uptake from the small intestine.
Vitamins are essential for total body function. Most vitamins are synthesized by the animal or its rumen microbes. Such vitamins, B, C and K (and to some extent D) do not need to be fed. Vitamin B is synthesized by ruminal microbes, vitamin K by intestinal microbes and vitamin C in the tissues. Vitamin D is formed when the precursor, found on the skin on animals and on grass, is exposed to UV rays, so in tropical countries vitamin D deficiency is rare. Vitamins A and E are not synthesized in the animal but must be supplied. Vitamin A is found in silage, fresh grass, dark green leaves, peas and carrots. Cereals are a source of vitamin E.
Mineral and/or vitamin mixture should always be supplied in order to fully meet the requirements. Animals which do not receive a ready made concentrate mixture with a mineral and vitamin supplement, must be fed a supplement in the form of “lick stones” to which the animals have free access, or fed a powder individually once or twice a day. Vitamins may be included in the mineral feed, but vitamins are sensitive and may be destroyed if exposed to sunlight. Care must therefore be taken to store vitamin supplements correctly.
Water is essential for most body functions, such as body temperature control, milk production and maintaining blood plasma volume. Thermal regulation of the animal is the most water consuming process. The animal receives water in three different ways:
• drinking water
• water in feed
• metabolic water = water made from feed degradation.
Drinking water is the most important water source and should be of good hygienic quality. The water available in feed is highly dependent on the dry matter in feed. Straw, hay and cereals include little water, whereas silage and fresh grass may contain as much as 70% or more.
The water requirements of buffalo depend on:
• diet (dry matter)
• environment (humidity, temperature)
• physiological function (growth, pregnancy, lactation).
Generally, buffalo require more water than cattle under the same circumstances and should have access to clean cool water ad libitum.
Restricted water intake leads to a decrease in dry matter intake and thus negatively affects milk production and growth.
Salinity of water is seldom a problem in dairy buffalo feeding. A salt content of up to five grams per litre of water can be used for buffalo. However, temporary diarrhoea may be caused by water approaching the higher levels.
Back to top
The main diet for buffalo is roughage such as grass, legumes and straw. The roughage can be fed either fresh as pasture or in a cut-and-carry system, or conserved as hay or silage. Roughage is often complemented with grains, concentrate and agro-industrial by-products such as oilseed cakes, sugar cane tops etc.
Roughage should form the base of the feed ration and contribute to meeting at least the total maintenance requirements. Grains and concentrate should be fed only to meet additional requirements such as growth, pregnancy and milk production. Too much non-fibrous feed will alter the rumen environment. In the long run this could lead to serious problems in feed digestion causing loss of appetite, weight loss and a drop in milk yield. This is especially important for animals under stress, for instance from high growth rate or high milk yield. The roughage should be of good quality – of both nutritional quality and hygienic quality. This cannot be emphasized enough.
The most common roughage is grass (of various species). However lucerne, berseem and clover are herbaceous legumes which have an advantage over grass as they are nitrogen fixing. This means that the plants will (with the help of bacteria) fix air-nitrogen and thus they are less dependent on the nitrogen content of the soil. These plants contain more protein than grass under the same circumstances. Lucerne (or alfalfa) has several advantages. It contains elevated amounts of calcium, vitamin E and caroteen which are of major importance for milk production.
There are also tree legumes which can be used as high quality feed, e.g. Leucaena leucocephala, Gliricida spp., Sesbania and others. However as many of the tree legumes contain anti-nutritional compounds which may depress digestibility as well as decrease feed intake, they should not be fed as the sole source of roughage. A maximum ratio of 50% tree legumes in the total diet can be considered a safe level. Since buffalo are strict grazers, the trees should be pruned and the branches or leaves given to the buffalo. Pruning with regular intervals of six to ten weeks increases re-growth of the leaves.
Straw provides lower quality roughage. Straw from rice, barley, wheat, sorghum etc. is widely used in feeding ruminants, but its protein and energy content is low. Rice or paddy straw has a high silica content in the cell walls which makes it difficult to digest.
In the beginning of the growth season, the protein and energy content of grass is high and the lignin content low. Thus, the grass is of high quality. With maturity the protein and sugar content decreases and the cell walls become lignified. The growth pattern is the same for legumes although it is a little slower. It is therefore important to harvest roughage in the optimal period and to conserve it for use in dry seasons.
Pastures should not be over or under grazed. Over grazing leads to insufficient forage in the later season and the soil will be more vulnerable to erosion and permanent damage. In the case of under grazing, the pasture is not utilized efficiently. The grass will grow more quickly than the animals can eat it. Thus the grass will age, and its nutrient composition will change unfavorably to high lignin and low protein content.
In many areas, grass is not harvested even if not grazed and is left as “standing hay”. However, this standing hay has a very low nutritive quality, close to that of straw.
Back to top
Chaffing, grinding and pelleting are ways to improve the digestibility of straws by making the nutrients available to the rumen microbes. Chemical treatments with alkali or ammonia are effective ways of improving quality. Ammonia treated, chaffed straw may even substitute for green forage for low milk producing buffalo.
The term concentrate means that a high amount of nutrients are concentrated in a small amount of dry feed. The most typical concentrates for tropical countries are different types of oilseed cakes. Oilseed cakes are derived as by-products of oil produced for human use. The remainder is pressed together to form a cake. The cakes have a relatively high energy content, but are mostly used because of their high protein content.
Other types of feed which can be classified as concentrate are molasses and urea. Urea can be used by the microbes as a source of nitrogen. The use of urea also requires an easily fermented energy source, such as molasses, for the micro-organisms. There should be an appropriate balance between protein and energy in the rumen for the efficient and proper growth and multiplying of the micro-organisms. Care should be taken to ensure that the quality of the concentrate is up to standard.
Barley, wheat, oat, rye, maize and sorghum grains are excellent feed for ruminants, given in balanced amounts. However, since they are used for human consumption their use as animal feed should be carefully considered.
The definition of voluntary intake is the amount of feed an animal can eat per day. It is commonly expressed in kg of dry matter or in percent of live weight.
After having considered the nutrient requirements of the animal and the feed stuff to be used the proper feeding regime can be calculated. However, one must take into consideration how much the animal can eat. There is a physical limit as to how much feed the animal can eat in one day.
Factors affecting voluntary intake. (Adapted from Ståhl Högberg and Lind, 2003)
A high producing lactating buffalo can eat more than a low producing one. Similarly a growing heifer may eat more than a dry buffalo. As pointed out before, feed intake decreases with high environmental temperature and humidity. Individual feeding usually results in higher feed intake, since there is less competition for feed and a more relaxed atmosphere.
A rough estimate of voluntary intake for a buffalo heifer is 2.2 to 2.5% of its live weight per day, if provided with a small portion of straw, a large portion of green feed and some concentrate. A milk producing buffalo should be able to consume up to three percent of its live weight in good quality feed. Too high a ratio of straw in the diet reduces voluntary intake. A protein content of less than six percent also reduces intake of that feed.
Back to top
Lactating buffalo should be given the best feed the farm can offer. Producing milk is one of the most energy demanding biological processes. Weight loss is common in high producing animals during the first month of lactation because they can not consume a sufficient amount of energy. A popular term is that the animals are milking off the fat. It is therefore important that the buffalo is in good health status at partus. In Table 6, examples of various feeding regimes for lactating buffalo are given. A well balanced ratio of protein, energy, vitamins and minerals in a palatable and tasty feed is the best way of increasing milk production and live weight, as well as improving health and fertility.
Traditional feeding patterns for buffalo all over the world are subject to seasonal forage and crop production, which affects the level of milk production. Forage is insufficient during the dry season and abundant during the rainy season. Shortages are overcome by conserving forages as hay or silage.
Formulating feed ratios for milk producing buffalo starts with theoretical calculating of the requirements. As there are no standardized international tables for dairy buffalo requirements, the calculations in Table 3, are based on dairy cattle nutrient requirement tables (NRC, 1988).
It is important to know the buffalo live weight. This is most accurately done by weighing the animals three times in one week and calculating the average. However, this requires an animal scale and is very time consuming. Weighing the animals once is good as a guide. Once the weight is known, requirements for maintenance can be extracted from Table 3. Milk yield should also be known, as well as fat percentage. Recommendations are to use at least three days of milk records to calculate the average yield and fat percentage. For simplicity, the yield is then calculated as four percent fat corrected milk (shown in Table 3). Total requirements are gained by summing the requirements for maintenance and for milk production. The requirement for milk production is based upon the calculation of fat corrected milk (FCM) using the formula:
4% FCM, kg = 0.4 x (milk yield, kg) + 15 x (milk yield, kg x fat%/100)
(Tables 3 to 9 are all adapted from Ståhl Högberg and Lind, 2003)
For a buffalo weighing 550 kg and yielding 7 kg of milk with 7.2% fat per day, the amount of 4% fat corrected milk comes to 0.4 x 7+15 x (7 x 0.072) = 10.36 kg per day. Nutrient requirements for this animal could be calculated as follows:
If the animal seems to be too fat at the time of weighing, the maintenance requirements may be reduced by ten percent. Similarly, if the animal is too skinny, ten percent may be added to the maintenance requirements. The feeding regime of the buffalo can then be decided. Primarily, crops grown on the farm should be included in the diet. For optimal economic feeding regimes the feed should be analyzed at a laboratory for dry matter content, energy and crude protein, and for calcium and phosphorus. The example in Table 4, uses feedstuff analyses from NRC’s tables (1988) for dairy cattle.
Back to top
Taking the previous example: the 550 kg buffalo yielding 7 kg milk with a fat percentage of 7.2 giving 4% FCM of 10.36 kg, the daily requirements are:
28.15 Mcal of metabolizable energy,
7.32 kg TDN,
1.32 kg crude protein,
50.28 g calcium and
33.40 g phosphorus (Table 5).
The corresponding estimated feed intake would be 550 x 0.03=16.50 kg dry matter (DM). In this example, forage should cover the energy requirements of 15.3 Mcal.
It is important to note that silage should not form the sole source of roughage because it has a high amount of easily fermentable carbohydrate and a physical structure which does not really stimulate rumen contraction. As a rule of thumb, the amount of silage in a diet should not exceed 30% of the total dry matter intake if concentrate is also given. If the diet is solely made from roughage the silage ration may be increased to 60%. On the other hand, alfalfa hay contains much too much protein and therefore it is important to give a mixture of silage, hay and perhaps straw.
In this example the maintenance requirements can be met by giving 5 kg wheat straw and 5 kg maize silage on a dry matter basis. Alfalfa hay of 2 kg and 8 kg of wheat straw would also provide the requirements, but it is not likely that the buffalo would eat it, because of its texture.
We need to provide another 12.85 Mcal for the milk production. This can be provided by increasing the amount of forage if it is of good quality, or it may be provided by concentrate. However, the costs for different fodder should be taken into account. If the farm can produce sufficient forage of good quality it is probably wiser to increase the amount of home grown forage in the diet instead of purchasing expensive concentrate.
In accordance with Table 5, dry matter from 4 kg maize silage together with 5 kg alfalfa hay and 5 kg wheat straw gives a balanced diet containing the necessary nutrients. Only phosphorus needs to be added. The Ca:P ratio should be approximately 2:1, so another 22 g P needs to be provided in this diet. It is also clear in this example that the buffalo should be able to produce milk without being fed any concentrate. The total amount of dry matter comes to 14 kg here, and we had calculated on 16.5 kg. To increase the dry matter intake some of the wheat straw may be replaced by some maize silage and/or alfalfa hay (Table 6).
Back to top
Table 5 Diet calculation for milk yield up to 10 kg to 7.2% fat milk.
Including urea in the diet may be a cheap and good way to “help up” a low protein diet. One must remember, however, that a source of highly soluble carbohydrates such as molasses must be included in a urea diet. The maximum level of urea should correspond to less than 25% of the crude protein. An alternative is to feed ready made urea-molasses blocks.
Controlling the animals’ intake of feed is a good practice. Low yielders tend to eat more than they require and at the same time it is difficult for the high yielders to eat enough. It is therefore vital that the feed is analyzed and the milk yield known, in order to provide the correct nutrient requirement for each animal.
Calf mortality can be very high in some countries. In India it is often 30 to 40% before three months of age, and in Italy the figures may be higher. This is caused by malpractice such as negligence, limited milk feeding, injuries and diseases. By increasing the amount of feed to the calf’s requirements and by following sound calf management practices as outlined here, mortality can be decreased.
Colostrum is the most important and most suitable feed for the newborn calf. It contains all the nutrients needed along with the vital antibodies. It is crucial for the survival of the calf that it receives colostrum during the first 12 hours of its life, the earlier the better. The calves should be given colostrum as long as the mother provides it, e.g. three to four days. Any surplus colostrum can be frozen and then thawed and carefully heated to 39°C before feeding. If no freezing facilities are available colostrum can stay fresh for a couple of days if it is cooled in a hygienic container. Colostrum can be fermented with living lactic acid culture. Fermented colostrum can be kept for at least a week and up to two weeks if cooling facilities are available.
If the calf is not allowed to suckle its mother it should be provided with colostrum as soon as possible after birth. If it is not possible to feed the calf directly after milking the buffalo, colostrum should be cooled in order to maintain hygienic quality. When it is time to feed the calf, the milk should be carefully heated to no more than 39°C. Colostrum must never be boiled. Boiling the milk destroys the antibodies which are needed for the calf.
The natural eating behaviour of the calf is to suckle its mother often, and to consume a small amount of milk at each suckling period. It is best for the calves reared under artificial conditions if their eating behaviour can be as “natural” as possible. Colostrum should be fed to the calf several times a day, preferably more than twice a day, at equal intervals.
The calf should be trained to drink from a bucket. The easiest way to do this is to dip clean fingers into the milk and then allow the calf to lick and suck the fingers. The hand is then gradually drawn into the milk in the bucket while the calf is still suckling. Once the calf has learnt to drink it is easy to feed. The calf may need assistance for five days. There are special nipples that can be put in the bucket. Once the calf suckles those, it will need less assistance from the trainer.
After the colostrum period, whole milk should be provided to the calf until 15 days of age at a level of 1/8th to 1/10th of the calf’s body weight (see Table 7). Milk replacer can be fed along with the whole milk provided that it has a certain composition of nutrients. It is not advisable to completely substitute whole milk with milk replacer. Milk and/or replacer should be offered to the calf on at least two occasions per day. The milk and/or replacer should be served at body temperature (38-39°C). At two weeks of age, the calf should be introduced to good quality green feed and concentrates, as a calf starter (Table 9). This stimulates the rumen to grow and function properly. By following the feeding schedule in Table 8 and ensuring the feed contains the nutrient requirements listed in Table 7 a daily gain of 0.35 kg can be expected in Murrah calves.
An alternative method is to rear calves with foster mothers. In Italy, 40% of calves are reared by suckling an old and less productive buffalo or even a cow. This has several advantages, particularly that little labour is required to feed the calf and the calf will secure its own nutrient intake. Calf starters similar to those mentioned in Table 9 can also be used to feed buffalo calves.
Buffalo calves fed with stovers of maize, bajra and oat cannot meet their nutrient requirements and are often in negative energy and protein balance. However, feeding the calves treated stovers with a urea-molasses-salt complex both enhances the palatability of the stovers as well as the digestibility and nutrient value. Buffalo male calves weighing 150 to 200 kg have been proven to increase their intake of treated stovers compared to untreated ones, thus increasing weight gain and improving nitrogen balance and health.
See DeLaval 2002, Efficient Calf Management.
The heifer is a future milk producer and has to be given a fair chance to produce well. She must have an average daily gain of at least 500 grams per day in order to reach the optimum size for calving within a reasonable time (500 kg at 32 to 40 months). Unfortunately, many farmers consider heifers to be unproductive and hence they are not properly fed. Since lack of feed is often a reality, it is not possible to feed all animals in the herd with high quality feed. The following advice could be considered as a rule of thumb, bearing in mind that the quantity and quality of feed varies with the season. Furthermore, the condition and growth rate of the heifer should be checked regularly to see that she has the appropriate growth rate. If not, her feeding schedule should be adjusted.
Heifers should be fed seasonal green feed of about 4 to 7 kg dry matter (DM) together with some straw and concentrate or grain per day. If the green feed is leguminous the ration of green feed and concentrate or grain can be reduced and the amount of straw increased. However it is important to feed the heifers a small amount of grain or concentrate, not less than 0.5 kg per day, to help both them and their rumen to become accustomed to this type of feed prior to partus.
If available, ammonia treated straw could be given along with low quality green feed and concentrate. Silage could be given to heifers, but it is often a very valuable feed saved for milk producing animals. However, a few months before partus the heifer should slowly be introduced to the feed she will have as a milk-producing buffalo.
Maximum voluntary intake for the heifer is obtained at approximately 1 to 1.5 kg DM of straw together with 3 kg DM of green feed and 1 kg concentrate.
Straw fed to appetite is not enough to keep or increase the body weight of growing buffalo. Straw fed to growing stock should preferably be ammoniated and further supplemented with green feed or hay and some kind of concentrate to give the best result.
Feeding the dry buffalo is concerned with preparing for partum and high milk production. In the last two months of gestation the buffalo has increased requirements for nutrients for foetal growth. Experiments with Murrah buffalo has shown that the best economical way of feeding dry buffalo two months before calving is at 125 percent of the recommended level for cattle (NRC, 1988). By giving the dry buffalo a little more than she needs, her chance of building up body reserves and being in good physical condition is improved.
Back to top
|
