Improvement of Hay and Crops Straw Using Chemical Additives and Testing of Cassia Fistula Tree Pods as Animal Feed

ABSTRACT


INTRODUCTION
The smallholder farmers in developing countries have limited resources available for feeding to their ruminant livestock.They are unable to select the basal diet according to the requirement for production unlike their more fortunate counterparts in developed countries, but use whatever is available at no or low cost.Therefore, the strategy for improving production should be to optimize the efficiency of utilization of the available feed resources, and thereby attempt to maximize animal production (Jayasurya, 2001).
Inadequate nutrition is one of the major constraints limiting livestock production in African countries.The ruminants in the smallholder sector depend on natural pasture and fibrous crop residues for their survival, growth, reproduction and production.Since quality and quantity of the natural pasture vary with season, animals dependent on it are subjected to nutritional stress in the dry season when feed resources are senesced and in short supply leading to decreased animal productivity.(DFAS, 2000) Farmers accept that fibrous straws and stovers from cereal grain crops are a poor feed resource because their crude protein (CP) content is low and fibre levels are high.Residues are often the only livestock feed available in areas characterized by a defined dry season.The situation becomes more acute as the dry season becomes established, when protein content of the natural grazing falls, often from 12-14% to about 6-8%.The fall in crude protein content is also accompanied by an increase in fibre content.Thus, the animal is faced with insufficient amounts of a low quality and relatively indigestible feed (Saadullah et al., 2005).
In North Kordofan a large quantity of crop residues is available for livestock feeding.Crop residues are characterized by their high fiber content (>700 g of cell wall material/kg DM), low metabolized energy (<7.5 MJ/kg dry matter), low levels of crude protein (20-60 g of crude protein/kg DM) and mineral nutrients and low to moderate digestibility (<30-45% organic matter digestibility).Their daily intakes are often limited to less than 20 g dry matter/kg live weight.Most residues are also deficient in fermentable carbohydrates , reflected by the relatively low organic matter digestibility.Chemical treatment increases the potential feeding value of crop residues.(Homp, 1994).
Therefore, improvement in feeding value would substantially reduce the effects of underfeeding on both survivability and production.The nutritive value of residues can be improved by correct harvesting and storage, supplementation and physical and chemical treatment.
In vitro methods for laboratory estimations of degraded feeds are important for ruminant nutritionists.In vitro methods have the advantage not only of being less expensive than animal trials and less timeconsuming, but they allow one to maintain experimental conditions more precisely than do in vivo trials (live animal).(Makkar, 2000).The Cassia fistula tree is a medium-sized tree, growing to 10-20 metres (33-66 ft) tall with fast growth.The leaves are deciduous,.The flowers are produced in pendulous racemes 20-40 centimetres The fruit is a legume, 30-60 centimetres (12-24 in) long and 1.5-2.5 centimetres (0.59-0.98 in) broad, with a pungent odour and containing several seeds.Cassia fistula is widely grown in tropical and subtropical areas (ILDIS, 2005).Cassia fistula is found naturally in west and south Kordofan region (Elnazeir, 2013).
Attempting to improve hay and crops residues and testing Cassia fistula as feed , would enable removing feed quality constrains and improving productivity.

MATERIAL AND METHOD
In vitro digestibility trial and proximate chemical analysis for hay, crops residues and Cassia fistula pods (green and mature) were undertaken at range-livestock research laboratory, El-Obeid Agricultural Research Station.
Samples were prepared during rainy mid of September for early hay and post harvest for other crops residues in rainy season 2012.
• Hay harvested in February (dry ) • Hay harvested in early September (green) • Groundnut straw • Millet and Sorghum straws • Roselle straw • Cowpea hay All samples were treated with 6% Urea + 2% sodium hydroxide (treatment 1 include the 7 sample) urea 5 % (tr2), and Sodium hydroxide (tr3) in three fermentation periods (15, 30 and 45day).Then treated samples were kept in nylon bags kept in pits covered 30 cm below soil.The total number of samples treated was 63 arranged as factorial in an RCBD.After fermentation, the 63 samples with three replications (189 samples) were prepared for in vitro digestibility.Cassia fistula pods (green and mature) and leaves also prepared for In vitro Digestibility.

In vitro Digestibility
The method used in this study was done according to Tilley and Terry (1963).250 mg from each sample were taken to a 50ml centrifuge tube.Ten ml of buffer-nutrient solution were added to them.The contents were then gently mixed.The tubes were allowed to stand at 39°C for a short period to permit saturation of the substrate.The rumen fluid was filtered through two layers of cheese cloth to remove detached fragments then kept in thermos ready for incubation.The PH of the buffernutrient solution was carefully maintained at 6.8-7.0.Five ml of rumen fluid inoculums were added to each tube, and then the tube surface was flushed with CO2 for approximately 10 seconds before stopped with gas release valve, and then incubated at 39°C for 48 hours.The tubes were gently rotated approximately 2, 4, 20, and 28 hours after initiation of incubation to disperse the forage particles.
After 48 hours incubation, 1ml HgCl2 solution, 2ml of Sodium carbonate solution were added, and then centrifuged for 15 min at 2000x gravity to sediment the suspended dry matter.Then 25 ml of acid-pepsin solution were added and mixed gently rotated to resuspend the residue at approximately, 2, 4, 20 and 48 hours after the beginning of incubation.
After 48 hours, the tube contents were filtered through tarred fritted glass crucibles, and then dried to a constant weight at 102°C.The residue retained on the filter is indigestible dry matter; crucibles were weighted after cooling in desiccators.Then In vitro dry matter and organic matter digestibility were calculated using the following formula, (Tilley and Terry, 1963).

Statistical Analysis:
Data were analyzed using SPSS software.

Proximate chemical analysis and in vitro digestibility for hay and crop residues:
Proximate chemical composition and minerals content for hay and crops residues are presented in Table (1).Crops residue analyzed included cowpea, sorghum straw, groundnut haulms, millet straw, roselle, early hay and lately hay.Groundnut haulms ,sorghum straw and millet straw had the highest crude fiber content (53%, 47.5%and 42%, respectively) Crude protein of these crops residues varies from low to high .Cowpea and groundnut haulms recorded the highest crude protein content (16.5 and 14.5% respectively).While lately hay, sorghum straw, millet straw and roselle had the lowest crude protein content (7.5, 6.3, 4.5 and 4%, respectively).Millet straw had the highest ash value 12% while lately hay had the lowest value (9.1%).Jayasurya, (2000) stated that protein content less than 10% is considered as low protein content.A critical value of about 6.6% crude protein in feed is required (NRC, 1981), below which the apparent crude protein digestibility declines.
In vitro Dry Matter Digestibility (IVDMD) for hay and crops straw fermented with sodium hydroxide plus urea with different fermentation periods are illustrated in Table (2).The highest (IVDMD) was recorded after 30 and 45 days of fermentation in all samples followed by 15 days of fermentation and control (non fermented).Cowpea recorded the highest (IVDMD) (65, 70, 88 and 87%) for control, 15, 30 and 45 days of fermentation respectively; while roselle recorded the lowest values in (IVDMD) (34, 45, 69 and 69%) respectively for control and the three above mentioned periods.
The results indicated that there were significant differences in (IVDMD) between periods (P≤0.05).High values achieved by cowpea; this is mainly attributed to the effect of high protein content .Chimwano,(2000) who stated that, high protein content positively affect (IVDMD).Low values achieved by Roselle; this is mainly due to high fiber content (47%) and the effect of low protein content (4%).NRC, (1981) stated that a critical value of about 6.6% crude protein in feed is required, below which the apparent crude protein digestibility declines.No significant differences were found between 30 and 45 day of fermentation.This in agreement with Smith 2000 who stated the best period for incubation for tropic is from 14 to 42 days.
In Vitro Dry Matter Digestibility (IVDMD) for hay and crops straw fermented with urea with different fermentation periods are shown in Table (3).The highest (IVDMD) was recorded after 30 and 45 days of fermentation in all samples followed by 15 days of fermentation and control (non-fermented).Groundnut and cowpea recorded the highest (IVDMD) (60, 65, 83 and 79%) and (60, 69, 80 and 81%) for control, 15, 30 and 45 days of fermentation respectively; while roselle recorded the lowest values in (IVDMD) (39, 55, 63 and 65%) respectively for control, 15, 30 and 45 days of fermentation.The results indicated that there were significant differences in (IVDMD) between the second and third periods compared to control (P≤ 0.05), but no significant differences between second and third periods.The highest values achieved by groundnut and cowpea; this is mainly due to the high protein content and to the effect of urea treatment.Saadullah et al. (2005) noted that dry matter digestibility could be increased by six units when urea was added as a supplement at the point of feeding but by 11% units when it was added to the straw 10 days previously.Low values recorded by Roselle were mainly due to high fiber content and the effect of low protein content .Roy, 1979, stated that high crude fiber content and poor source of energy limits the digestibility.
In vitro Dry Matter Digestibility (IVDMD) for hay and crops straw fermented with sodium hydroxide with different fermentation periods are illustrated in Table (4).The highest (IVDMD) was recorded after second and third periods of fermentation in all feed stuff under study followed by first period and control (nonfermented).Ground nut and cowpea recorded the highest (IVDMD) (61, 65, 71 and 69%) and (63, 65, 70 and 69%) for control, first, second and third periods, respectively; While roselle recorded the lowest values in (IVDMD) (40,50,59 and 59.33%) for control, first, second and third periods.There were significant differences in (IVDMD) between periods first, second and third compared to control (P≤ 0.05); but no significant differences between second and third period.High values recorded by ground-nut and cowpea; this is mainly attributed to protein content and the effect of sodium hydroxide.This agreed with Homb (1994) who stated that sodium hydroxide treatment increases the potential feeding value of crop residues.Low values recorded by roselle; this is mainly due to high fiber content and the effect of low protein content.Jackson, (1980) stated that the situation becomes more acute as the dry season becomes established, when protein content of the natural grazing falls, often from 12-14% to about 6-8%.The fall in crude protein content is also accompanied by an increase in fiber content.
Thus, the animal is faced with insufficient amounts of a low quality and relatively indigestible feed.Elnazeir(2007), stated that sheep grazed under range condition the daily weight (IVDMD 52%) 0.5 g to -0.52 (optimum to critical period).

Proximate analysis and in vitro digestibility for
Cassia fistula green, mature pods and leaves: The proximate analysis for Cassia fistula is shown in table (5) Mature pods recorded 19, 19.5, 2.6 , 5 and 52% for CP, CF, ash, E.E and NFE respectively; while green pods recorded 17, 17, 5.5, 6 and 54.5% for the same components respectively.Jayasurya, (2000) stated that protein content greater than 10% and crude fiber less than 30%; this give the feed the class of high protein less fiber.The high values for crude protein and NFE (carbohydrates), are of value when planning for ration formulation, because those can be added as alternative cheap source of protein and carbohydrates, also this source is not competing the human foods.Mineral content for Cassia fistula mature pods is shown in table (5).Proximate analysis indicated that Calcium, Phosphorus and Potassium, for cassia fistula mature pods were 2.7, 0.8 and 0.75ppm, respectively.This reflect that the pods are rich in mineral which could be used in animal feed.
In vitro digestibility dry matter (DM) and organic matter (OM) for the mature, green pods and leaves for Cassia fistula are illustrated in table (6).The in vitro dry matter digestibility for green pods (68%) was higher than leaves (62.6%) and mature pods (61.48%).In vitro OM digestibility for mature pods (79.75) was the highest followed by the leaves (79.11%) and green pods (77.47%).The values for both in vitro digestibility dry matter (DM) and organic matter (OM) could be considered as high values compared to that of range plants, approximately 51% and 57% for IVDMD and OVDM, respectively (Elnazeir 2007).High protein and less fiber class; this indicates that cassia fistula can be used as ruminant and poultry feed.Cassia fistula pods reflect good indicator in reducing the ration cost up to 25 % when tested in Feedsoft@2010 program for ration formulation.

CONCLUSIONS
Based on the presented data it can be concluded that urea, sodium hydroxide mixture and sodium hydroxide improve hay and crops residues digestibility (10-35%).Cassia fistula is a promising tree due to high nutritive value particularly in protein content and high IVDMD.
Therefore; we highly recommend the use of 2 %sodium hydroxide ,6%urea and urea sodium hydroxide mixture to improve hay and crops residues by fermentation for (30) days.

Table ( 4) The In vitro Dry Matter Digestibility (IVDMD for hay and crops straw fermented with sodium hydroxide
DM=Dry Matter, IVDMD=In Vitro Dry Matter Digestibility, Proximate analysis for cassia fistula is in table (5)

Table ( 6) The In vitro Dry Matter Digestibility (IVDMD for Mature pods, Green pods and leaves of Cassia fistula tree.
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