«Dairy cattle husbandry Agrodok 14 - Dairy cattle husbandry More milk through better management Agrodok 14 Dairy cattle husbandry More milk through ...»
Crop residues like straw and stover are used as roughage for livestock, while manure is used for the crops. Natural pasture can be an important source of forage if land is not limited. Land restrictions demand intensification through the production of improved forage and better use of crop residues.
3.1 Grasses Grasses are often the most common roughage fed to cattle. Their feed value varies considerably according to management and growing season, see table.
Table 7: Quality of grass
Natural grasses Many small farmers use local grasses cut along roadsides. This roughage resource is not very reliable as the neighbours use it as well. FurRoughages thermore, traffic exhausts, excrements, parasites and garbage can easily contaminate it. Plots with local grasses are often less productive than land with well-managed improved forage. Once land becomes scarce and milk production more economically rewarding, intensification through planting, sowing and fertilization of improved grasses and forage becomes more attractive.
Improved pasture and forage: choice of species and variety The choice of which improved pasture or forage best suits your conditions depends on environment, climate, soil and the farming situation.
Choosing the right variety from within the species can also be very important. Consult the extension officer and neighbours about their experiences. Table 8 compares some grasses under East African conditions (1 = poor, 10 = excellent).
Table 8: Characteristics of commonly used grasses in East Africa
This Agrodok discusses only a limited number of types of roughage.
Elephant grass will be described in some detail, with guidelines for the establishment and management of improved pasture.
Elephant (Napier) grass
Elephant grass is recommended for zero grazing because:
? It is high yielding.
? It boosts milk production if cut at the right height and maintained well.
? It remains green during the dry season and withstands drought better than most grasses.
? It is suitable for cutting.
26 Dairy cattle husbandry Types Among the different types of Elephant grass are types with and without hairs, differences in resistance against diseases and different stem thickness. Seek out the experiences in your area.
Where can it grow Elephant grass requires high, well-distributed rainfall of at least 800 mm annually but preferably more. At altitudes higher than 2100 m, growth is slow because of low temperatures. It thrives best on deep fertile soils supplied well with manure, and prefers well-drained soils, but can grow on almost any soil. Without good nitrogen and potassium fertilization, yield and persistence will decrease after 1-2 years.
How to plant Plant Elephant grass in well prepared weed-free land at the beginning of the rains. It can be established from root splits, which is more labour intensive, or from cuttings. Root splits from an uprooted plant without leaves establish rapidly if there is enough rain. For cultivation from cuttings cut a well-matured cane into pieces with 3-4 nodes. The leafy top part should not be used. Cuttings can give good results, even if rains are irregular.
Roughages How to achieve a high yield Elephant grass grows well on fertile soils, but very poorly in fields full of weeds. Weeding during the dry season will control vigorous weeds like couch grass. Proper weeding combined with manure and fertilizer application should be carried out after every cut.
It is important to return the fresh manure of the cows to the grass to sustain high production. The best way is to dig Figure 7: Apply fresh manure after small ditches in between the every cut rows then put in the fresh manure and cover with soil.
To obtain high yields, the grass will also need additional fertilizer.
How much and when depends on soil, climate, cutting management and the amount of manure. For example, in the case of adequate rainfall in two rainy seasons, 250 kg of NPK fertilizer (20-10-10) can be applied per ha, during the middle of the long rains and at the start of the short rains. In between the long and short rains, a top dressing with 50 kg of CAN (or 25 kg urea) per ha should be applied after each cut.
When to cut The optimal cutting interval in the rainy season is about 6-8 weeks at a height of 60-90 cm. As it grows taller the quality of Elephant grass (over 1.20 m) declines, so feeding it to the cows may result in lower milk production. If forage is plentiful give only the tops as feed and leave the lower part in the field for mulching, or use it as compost. If there is a real surplus of grass, silage can be made of young leafy grass, preferably after wilting till at least 30 % DM. Due to its thick stem, Elephant grass is not suitable for hay making or grazing.
28 Dairy cattle husbandry How to feed and how much milk from Elephant grass Big cows like Friesians eat about 60 kg of fresh grass per day while smaller breeds like Jerseys and crossbreds eat less. For a high milk production supply the grass liberally to allow cows to eat sufficiently.
Fed on grass alone a cow of about 500 kg can produce about 5-7 kg of milk daily. Young Elephant grass will allow a higher milk production (about 10 kg), while old grass may just provide feed for maintenance.
Older grass with many stems can be chopped into pieces of 15-20 cm to reduce losses.
Figure 8: Good quality grass results in high milk yields while tallstemmed grass causes weight loss if fed without concentrates.
3.2 Leguminous forage Legumes constitute a common source of good roughage. Moreover, they contain more protein than grasses because their root nodules fix nitrogen from the air. They also improve soil fertility.
Roughages Legume seeds often need an application of inoculants before sowing to stimulate nitrogen fixation. It is quite difficult to maintain a good mixture of grass and legumes in the tropics, so legumes are often grown on a separate plot – a so-called ‘protein bank’ – to supply additional roughage and to increase a ration’s protein content when needed. Protein banks are cut for zero grazing or grazed only for a limited time each day by animals needing it most, for example cows in milk, or during the dry season.
Glyricidia, Sesbania and Leucaena are examples of tree/shrub legumes. Desmodium, Alfalfa and clovers are herbal legumes. Multipurpose tree legumes are useful where land is scarce because they can be planted on field and farm borders, providing good dry season fodder.
Leguminous crop residues like straw from beans, groundnuts, cowpea and soybeans can be used as feed. Some legumes contain substances that may cause illness or bloating if consumed in excess. Leucaena, for example, should never make up more than 30% of the daily ration.
A Desmodium and Elephant grass mixture is an example of a rather successful combination under favourable conditions.
3.3 Crop residues and dry season Year-round availability of forage is essential for sustained high animal production. On mixed farms, crop residues from grains (maize, cowpea), fruits (banana) or roots (sweet potato) can be important to supplement shortages in the roughage supply.
Residues of many crops can be fed to cows, either fresh or dry, in the field or in the stable. There are, however, large variations in quantity and quality, depending on climate, region, crop species and variety and harvest stage.
Rather good feeds: stems and leaves of legumes like cowpeas and groundnuts, sweet potato vines and green maize leaves.
Acceptable feeds: bean and soybean straw, maize stover if green and leafy sugarcane tops. (Sugarcane tops may be an important resource in 30 Dairy cattle husbandry certain areas when huge quantities become available in the dry season).
Low value crop residues: old, brown maize stover, cereal straw.
Very poor feed: rice straw, even if treated with urea. It may help animals survive the dry season, but it is definitely not good feed for lactating cows.
Conclusion: the nutritional value of most crop residues is low with the exception of legumes (see Table 3). Supplementation with protein rich concentrates is necessary to enable your cows to produce.
3.4 Important aspects of forage utilization ? Land has to be prepared well before planting or sowing forage. This includes: weed and bush control, ploughing, harrowing and sometimes ridging. Fast establishment during the rainy season is recommended and helps to control weeds.
? Improved forage only produces well if fertilized with manure and/or fertilizers. Nitrogen is important for grasses, phosphorus for legumes and potassium for both. Without manure or fertilization grass production will decrease rapidly.
? Grazing or cutting management of grass should be adapted to the species. Compromise between quantity (low cutting frequency) and quality (high cutting frequency) (see Table 9). Cutting grass, not too early, will increase yield, stimulate re-growth and help to control weeds. Less frequent cutting results in higher DM yields but decreasing crude protein (CP) content.
? Legumes have a high protein content and can fix nitrogen from the air. They can be used as protein banks or intercropped. Tree legumes like Leucaena can be grown as hedgerows and field borders to save land.
? Properly handled and stored crop residues, for example from legumes, stover and sugarcane tops, are good options, particularly during the dry season.
? Seek the extension worker’s advice on the best forage for your farm and its management.
Roughages Table 9: Effects of cutting frequency on DM yield en CP content of Elephant grass with adequate rainfall and fertilizer application.
Management is prevention of diseases.
Taking good care of an animal does not only mean treating it when it is sick; it means preventing it from becoming ill. Even though treatment may cure the animal, the disease might have affected its body and these effects may last longer than curing the disease itself. Consequently, production losses may continue after the animal has seemingly recovered. Retarded growth in calves and a permanently reduced milk production are examples.
4.1 Disease prevention It is strongly recommended to call for veterinary assistance for disease prevention as well as when health problems are suspected (veterinarian, veterinary assistant or animal health assistant). Most diseases can
be prevented by the same management measures that enhance production. General preventive measures are:
? Hygiene, cleaning and disinfecting. Remember disinfection is useless without proper cleaning beforehand.
? Free access to clean and fresh drinking water.
? Providing good and sufficient feed and water at regular times.
? Protection against predators, parasites and adverse weather conditions like rain, wind, cold, and intensive sunshine.
? A comfortable environment without unrest and stress.
? Avoiding contact with sick animals and game because many diseases are contagious.
Other preventive measures are quarantine, vaccinations and preventive treatments.
Quarantine means isolating sick animals and newcomers from the rest of the herd. This helps to avoid the spread of contagious diseases to Animal health other animals. Take special care of dung, urine, milk, blood and aborted material as these may transmit the disease to other animals.
Some diseases, like tuberculosis, brucellosis and rabies, are also dangerous to humans (see Agrodok 46: Zoonoses: diseases transmitted from animals to humans). Assure proper cleaning and disinfecting.
Dry and clean floors with bedding are important. Sick animals need special care. Provide them with shade, protection against wind, clean water and adequate feed.
Vaccination against a specific disease helps the animal’s body withstand an attack by this disease. Sometimes it will protect the animal during its entire life, but many vaccinations have to be repeated. Unfortunately, vaccinations are not available against all diseases.
Preventive treatment can be useful for some seasonal diseases. Examples are treatment of young animals against worms, and tick control.
4.2 Regular observations To detect health problems in animals, it is necessary to observe them frequently, several times per day. This can be combined with observations for heat detection (see Chapter 6). When observing the animal,
check the following:
? Behaviour: does it react normally to its environment and in the group or is it acting strangely?
? Attitude: does it carry its head, ears, body and tail as usual? Does it walk normally?
? Condition: is the animal in good condition and is it well muscled, neither too thin nor too fat?
? Does it eat, drink and ruminate properly?
? Does it urinate and defecate normally?
? If a cow is milked, is the milk normal and is there any sudden drop in production?
? Any other abnormal signs?
34 Dairy cattle husbandry General examination Be very careful with sick animals and pay attention to hygiene while
examining the following aspects:
? Breathing frequency. A breathing frequency (breathing in + breathing out) of 10 to 30 times per minute is normal in adult cattle. In calves, 30 to 50 breaths per minute are normal. Breathing can be observed best at the animal’s right flank, seen from behind.
? Pulse or heartbeat. The normal rate per minute is 50 to 80 pulse beats in adult cattle, 80 to 110 in animals between 2 months and 1 year of age and 100 to 130 in younger animals. The pulse should be regular. The pulse can best be felt at a blood vessel just below the bottom jawbone (see Figure 9).
? Chewing the cud (rumination). Healthy cattle regurgitate a ball of food (cud) from their rumen stomach and start chewing it. This is called ruminating. If the cow chews the cud less than 40 times per minute, there might be a problem. Rumen activity can be felt by pressing lightly with the fist on the upper part of the left flank. The movement of the expanding rumen can be felt; normal frequency is 2 to 3 times per minute.