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7.2 Rice Straw as a Feed Source
7.2.1 Availability and Carrying Capacity
Rice straw is abundantly produced by rice farmers in many agricultural countries
worldwide. In Southeast Asia, about 30–40% of the total rice straw production is
commonly used to feed more than 90% of the ruminant population in the region
including other countries such as China and Mongolia, (Devendra and Thomas
2002). Rice straw is lean-month stuff to ruminant when supply of good quality forages is inadequate. It can be fed as the sole diet to meet the dry matter requirement
but it is not a guarantee that other essential nutrients needed for normal body functions by the animal are met. Rice straw can also be offered, up to 60%, in combinations with other feed ingredients, such as concentrates, molasses, or legumes to
improve palatability, protein content, and intake and digestibility by the animals.
Every after rice harvest, livestock farmers collect and stock-pile rice straw in a
simple shed usually made from locally available materials or stored in piles outdoors. The conserved straw is normally used as animal fodder during the lean
months of January through May or when the paddies are already planted with rice
in July and August. The extent of rice straw utilization as fodder is dictated by the
availability of forage gardens as well as the number of animals being fed. Since the
average landholding of the average crop farmer is 1–2 ha, the expected rice straw
production annually is only about from 10 to 15 tons, which can support only three
or four animal units whether cattle or buffalo. If a farmer has more animals, additional fodder should be sourced out, such as silage, corn stover or hay, or other feed
supplements, such as concentrates or legumes, to achieve normal animal
performance.
7.2.2 Nutrients in Rice Straw
Basically, rice straw has low protein content ranging from 3% to 6%. Is has high cell
walls, the neutral detergent fiber (ADF) and acid detergent fiber (ADF) which consisted of the degradable carbohydrate fractions such as starch, cellulose and hemicellulose. It also contains an indigestible phenolic substance called lignin. When
used as fodder, rice straw primarily serves as bulk or filler to meet the dry matter
requirement of ruminants. This contains 80% substances which are potentially
degradable and a source of energy. It has high dry matter (DM) contents of 92–96%
but with a low CP content ranging from 3% to 7% (Shen et al. 1998). The lignin and
silica contents provide structure to the rice plant during the growing and fruiting
stage but these components are in an indigestible form when ingested by animals.
As fodder, rice straw has low energy and protein contents. Its utilization is limited due to minimal contents of digestible nutrients and various characteristics such
as palatability, variable nutritional values, high silica and oxalates, and sometimes
7 Rice Straw-Based Fodder for Ruminants
7.2 Rice Straw as a Feed Source
7.2.1 Availability and Carrying Capacity
Rice straw is abundantly produced by rice farmers in many agricultural countries
worldwide. In Southeast Asia, about 30–40% of the total rice straw production is
commonly used to feed more than 90% of the ruminant population in the region
including other countries such as China and Mongolia, (Devendra and Thomas
2002). Rice straw is lean-month stuff to ruminant when supply of good quality forages is inadequate. It can be fed as the sole diet to meet the dry matter requirement
but it is not a guarantee that other essential nutrients needed for normal body functions by the animal are met. Rice straw can also be offered, up to 60%, in combinations with other feed ingredients, such as concentrates, molasses, or legumes to
improve palatability, protein content, and intake and digestibility by the animals.
Every after rice harvest, livestock farmers collect and stock-pile rice straw in a
simple shed usually made from locally available materials or stored in piles outdoors. The conserved straw is normally used as animal fodder during the lean
months of January through May or when the paddies are already planted with rice
in July and August. The extent of rice straw utilization as fodder is dictated by the
availability of forage gardens as well as the number of animals being fed. Since the
average landholding of the average crop farmer is 1–2 ha, the expected rice straw
production annually is only about from 10 to 15 tons, which can support only three
or four animal units whether cattle or buffalo. If a farmer has more animals, additional fodder should be sourced out, such as silage, corn stover or hay, or other feed
supplements, such as concentrates or legumes, to achieve normal animal
performance.
7.2.2 Nutrients in Rice Straw
Basically, rice straw has low protein content ranging from 3% to 6%. Is has high cell
walls, the neutral detergent fiber (ADF) and acid detergent fiber (ADF) which consisted of the degradable carbohydrate fractions such as starch, cellulose and hemicellulose. It also contains an indigestible phenolic substance called lignin. When
used as fodder, rice straw primarily serves as bulk or filler to meet the dry matter
requirement of ruminants. This contains 80% substances which are potentially
degradable and a source of energy. It has high dry matter (DM) contents of 92–96%
but with a low CP content ranging from 3% to 7% (Shen et al. 1998). The lignin and
silica contents provide structure to the rice plant during the growing and fruiting
stage but these components are in an indigestible form when ingested by animals.
As fodder, rice straw has low energy and protein contents. Its utilization is limited due to minimal contents of digestible nutrients and various characteristics such
as palatability, variable nutritional values, high silica and oxalates, and sometimes
7 Rice Straw-Based Fodder for Ruminants