Urea Ammonia Treatment Research Articles

Livestock Farming in Coconut Plantations in Sri Lanka: Constraints and Opportunities

ABSTRACT A study was carried out to identify biological and socio-economic constraints and opportunities for livestock development in coconut plantations in Sri Lanka. One part of the study focussed on the use of participatory rural appraisal to establish felt needs of different farmer categories in terms of feeding practices. Small coconut land holders (< 0.8 ha) reared livestock mainly for direct (primary) products such as milk, while large coconut holders (> 6 ha) kept livestock for indirect (secondary) benefits such as weed control, social status and security. With an increase of land area, the objectives of keeping livestock deviate from direct to indirect benefits. The total benefits either as direct or indirect were more than double the value of live weight production. The major constraint of livestock keeping for small holders in the area was small land area, lack of grazing lands and low milk price. The major issue in livestock keeping for large coconut holders was shortage of feed during dry seasons. A second part of the study tried to establish biological production potentials based on feed supply of different farmer categories. Of the two areas selected, the coconut dominant area had lower maximum live weight production or milk production than that of the paddy dominant area despite higher availability of natural grass in coconut plantations. Natural grasses in paddy fields, with a feeding value higher than that under coconuts, combined with use of rice bran led to higher live weight production in the paddy dominant area. However, in paddy dominant areas, the small size of individual land holding is more critical and causes many farmers to give up dairying. Coconut dominant areas have a potential to keep animals for indirect benefits owing to the larger size of land holdings. In general, the nutritive value of 50% of the available feeds in both areas were below maintenance level. Part of this study aimed to assess usefulness of a few ‘on the shelf’ feeding technologies. Biologically speaking, gliricidia was found to be a potential source of feed but farmers' awareness about the potential feeding value of gliricidia was low (26%). Particularly farmers that keep livestock for indirect production (63%) found time required for collection of gliricidia a reason for low adoption of this potential feed. Farmers' awareness of urea ammonia treatment of straw was reasonable but only 3% practised this technology.

Feeding dairy heifers untreated or urea-treated fibrous sugarcane residues: effect on dry matter intake, growth, and metabolic parameters

In the Reunion Island, urea–ammonia treatment has been successfully tested as preservative of moist fibrous sugarcane residues (SCR). However, its potential as animal feed has not yet been evaluated. Two feeding trials were conducted at a commercial dairy heifer farm. In experiment 1, 22 heifers (230 kg live weight (LW)) were divided into two groups of 11 heifers. During 45 days, one group was given urea-treated SCR (TSCR) ad libitum plus 1 kg molasses; the second group was given untreated SCR (USCR) ad libitum plus 1 kg molasses–urea mixture (4% urea). In addition, both groups were also offered 3 kg concentrate plus a mineral and vitamin mixture (daily). The average voluntary dry matter intake (DMI) of roughage for TSCR and USCR were 1.72 and 1.39 kg per 100 kg LW, respectively. Daily weight gain (DWG) for TSCR and USCR was significantly different (896 versus 741 g per day, respectively, P=0.017). In experiment 2, 40 heifers (255 kg LW) were divided into two groups of 20 heifers. During two 45 days periods, one group was fed TSCR ad libitum plus 0.5 kg molasses per head; the second group was fed USCR ad libitum plus 0.5 kg molasses–urea mixture (4% urea) per head. Both groups also received a daily 4 kg concentrate plus a mineral and vitamin mixture. In addition, both groups were also offered 1 kg dehydrated lucerne in period I, which were replaced by 1 kg sugar beet pulp (SBP) in period II. During period I, the DMI in TSCR and USCR were identical to those observed in experiment 1. DWG for TSCR and USCR was not significantly different (700 versus 679 g per day, P=0.67). In period II, DMI decreased and DWG for TSCR and USCR was significantly different (806 versus 681 g per day, P=0.006). There was no significant difference ( P>0.05) for the other growth parameters. Plasma urea concentration was significantly higher ( P<0.001) in TSCR than in USCR. It is concluded that urea treatment of SCR increases DMI, but the level of concentrate supplementation may have to be lowered and/or its composition may have to be changed in order to efficiently use such roughage for growing dairy heifers.

Efeito da amonização com uréia sobre os parâmetros de qualidade do feno do capim-Annoni 2 (Eragrostis plana Nees)

Este estudo visou avaliar o efeito da amonização do feno de capim-Annoni 2 (Eragrostis plana Nees) com 4% de uréia, em base de matéria seca, sobre os teores de proteína bruta (PB), fibra detergente neutro (FDN), fibra detergente ácido (FDA), hemicelulose (HEM), celulose (CEL) e lignina (LIG) e o coeficiente da digestibilidade in vitro da matéria orgânica (DIVMO), em cinco épocas de corte (30, 60, 90, 120, 150 dias). O delineamento experimental foi o de blocos completos casualisados, em número de quatro, num arranjo fatorial (2x5) com dois fatores: tratamento dos fenos (2) e épocas de corte (5). A comparação entre os dois grupos de fenos (amonizados ou não) demonstrou que a amonização propiciou aumento altamente significativo dos teores de PB. Por outro lado, a fração de FDA decresceu significantemente, juntamente com os teores de CEL, em função do tratamento com uréia. Não foram detectadas diferenças entre os tratamentos, relativamente aos teores de FDN, HEM, LIG e ao coeficiente da DIVMO. Inferiu-se que: 1. a amonização do feno de capim-Annoni 2 não afetou os teores de FDN , HEM, LIG e os coeficientes da DIVMO; 2. tratamento do feno de capim-Annoni 2 com uréia propiciou aumento nos teores de PB e decréscimo nos teores de FDA e CEL; 3. o capim-Annoni 2 pode ser fenado até os 90 dias de crescimento, sem que ocorram modificações expressivas dos parâmetros de qualidade, desde que o feno seja amonizado.

Upgrading wheat straw with urea at a tropical temperature: effects of amount of urea and moisture on in vitro digestibility and pH

Urea-ammonia treatment of straws in the tropics involves mixing 1.0 kg of air dry straw with 1.0 kg of a 40 g/kg urea solution and storing under plastic for at least 4 weeks (Schiere and Ibrahim, 1989). The economics of treatment is dependent on the cost of urea. Treatment cost would reduce, if on-farm-produced urine, e.g. cow urine, could be used as a source of urea. However cow urine is dilute and may contain only 10 g/kg urea or less (Owen, 1993). The present study therefore investigated varying concentrations of urea solution for treating wheat straw at a tropical temperature.

Upgrading wheat straw with urea at a tropical temperature: effects of amount of urea and moisture on in vitro digestibility and pH

Urea-ammonia treatment of straws in the tropics involves mixing 1.0 kg of air dry straw with 1.0 kg of a 40 g/kg urea solution and storing under plastic for at least 4 weeks (Schiere and Ibrahim, 1989). The economics of treatment is dependent on the cost of urea. Treatment cost would reduce, if on-farm-produced urine, e.g. cow urine, could be used as a source of urea. However cow urine is dilute and may contain only 10 g/kg urea or less (Owen, 1993). The present study therefore investigated varying concentrations of urea solution for treating wheat straw at a tropical temperature.

Feeding urea ammonia treated rice straw in the tropics. II. Assumptions on nutritive value and their validity for least cost ration formulation

Field application of new feeding methods, such as urea ammonia treatment of straws requires an ex-ante assessment of their economic feasibility. Animal experiments are expensive for such an analysis, therefore cheaper and quicker methods are required. One such method is least cost ration formulation (LCRF), which extrapolates from a restricted number of feeding trials to a large number of feed combinations. The assumptions underlying LCRF can, however, be challenged and this paper discusses their validity in nutritional terms. The first part reviews literature on nutritive quality of rice straw, in relation to nutrient requirements and animal performance on rice straw based diets. The second part calculates the expected performances ( P calc) on straw based rations, using measured dry matter intake (DMI) and estimated total digestible nitrogen (TDN) and crude protein (CP) values. It then compares P calc with real performance ( P real) as found in the literature. Most dose response trials indicate a rather linear response to supplementation, with exceptions particularly at low levels of supplementation. The pooled values of P calc relate linearly with P real in several feeding trials. The P calc only comes close to P real when calculated on a TDN basis, when energy requirements for liveweight gain of light tropical animals are taken to be higher than those of NRC and when digestibility of energy in straws is assumed to be low. This suggests a low utilisation of digestible energy from either treated or untreated straw for reasons that cannot easily be established. Total CP supply cannot be limiting because the P calc on the basis of CP also considerably overestimates P real. The available literature values do not allow specification of CP into fractions according to rumen degradability. At production levels around maintenance, the correlation between P real and P calc decreases, possibly because at those levels the variability of maintenance requirements exerts a bigger effect on the total performance. Also, at those levels, straw constitutes a larger part of the ration, and associative effects are more likely. The sparse literature values for milk production also indicate differences between P real and P calc. The conclusions are that, in the absence of better methods, LCRF can be useful for ranking purposes but absolute values need to be interpreted with care, and P calc tends to overestimate P real. Future performance trials should measure digestible organic matter intake, substitution rates and maintenance requirements by dose response curves in order to improve their predictive value, and to allow interpretation of differences between P real and P calc. Differences between P real and P calc can then be investigated and weighed against accuracy and cost of performance trials.

Methods to improve utilization of rice straw III. Effect of urea ammonia treatment and urea molasses blocks supplementation on intake, digestibility, rumen and blood parameters

Methods to improve utilization of rice straw III. Effect of urea ammonia treatment and urea molasses blocks supplementation on intake, digestibility, rumen and blood parameters

Studies on urea-ammonia treatment of maize straw: treatment method and potential for dry season feeding of cattle in Northern Nigeria

A method for treating maize straw with urea was developed and used to produce enough treated material for a feeding trial with native Bunaji (Zebu) cattle in the dry season. Chopped maize straw was treated with graded levels of urea of 0, 20, 40, 60 and 80 g, each dissolved in 500 ml water and applied to 1 kg of the chopped straw. The treated forages were ensiled in laboratory silos for 1, 3, 5 or 7 weeks duration. The extent of dry matter disappearance of treated material was determined by nylon bag incubation in vivo. The lowest urea concentration and shortest ensilage period which gave a maximal dry matter disappearance was 40 g urea kg −1 straw (4% urea concentration) ensiled for 1 week. Chopped corn straw treated with 4% urea and ensiled for 1 week was given in a 2 × 2 factorial feeding trial with native Zebu cattle. The factors were straw type (treated vs. untreated) and supplement type (groundnut haulms vs. no groundnut haulms). The crude protein content of chopped maize straw was 8.4% compared with 4.8% for the untreated material. Organic matter digestibility was 65.3% for treated straw and 51.0% for untreated straw. Both urea treatment and supplementation with groundnut haulms significantly increased straw intake, but did not prevent cattle weight loss. There was no significant treatment effect on cattle weight changes, although there were trends favouring such treatments. Treatment of maize straw with 4% urea ensiled for 1 week for cattle feed, coupled with the feeding of groundnut haulms for cattle in the dry season, is likely to minimise weight losses in the season.

Overcomming the nutritional limitations of rice straw for ruminants 4. Urea ammonia treatment and supplementation with gliricidia maculata for growing Sahiwal bulls

Overcomming the nutritional limitations of rice straw for ruminants 4. Urea ammonia treatment and supplementation with gliricidia maculata for growing Sahiwal bulls

Overcoming the nutritional limitations of rice straw for ruminants 1. Urea ammonia treatment and supplementation with rice bran and gliricidia for lactating surti buffaloes

Overcoming the nutritional limitations of rice straw for ruminants 1. Urea ammonia treatment and supplementation with rice bran and gliricidia for lactating surti buffaloes

The use of an artificial rumen to assess low quality fibrous feeds

The results of two fermentation experiments conducted with an artificial rumen (rumen simulation technique—Rusitec) are reported. The first experiment compared the fermentation characteristics of a medium quality hay with those of untreated or urea—ammonia treated rice straw. Urea-ammonia treatment increased the digestibility, Volatile Fatty Acid production and microbial dry matter output compared with untreated straw. While the dry matter disappearance continued almost at the same rate up to 72h with urea supplemented straw, it levelled off after 48 h in the case o f ammoniated straw. The second experiement examined the effects of level of feeding and different roughage: concentrate ratios on fermentation characteristics of urea-ammonia treated rice straw. The output of VFA increased with the increase in feed intake and the level of concentrate in the diet. This was also accompanied by a steady decline in the acetate: propionate ratio. The ratio of VFA production: methane production was slightly lower for the high straw diets compared with in vivo values reported for good quality hay. However, increasing the quality of the overall diet by increasing the proportion of concentrate tended to increase this ratio to accepted values . It is clear that although Rusitec is an in vitro technique it has advantages over other in vitro techniques as it can provide much more information on rumen fermentation characteristics of a given feed. It is concluded that Rusitec is a valuable technique for evaluating fibrous residues and testing new diets before undertaking large-scale animal experiments.

The effect of method of urea-ammonia treatment on the subsequent utilization of rice straw by cross bred bull calves

An experiment was carried out with sixty cross bred draught bull calves of 163 kg average liveweight to investigate the effect of six different methods of urea-ammonia treatment on the subsequent utilization of rice straw. Straw treated with 4% urea solution for 3, 9 and 27 days in closed pits and 3 or 9 days in open heaps was compared with untreated straw supplemented with 8·5% ground soyabean. Both 3-day treatments involved 8·5% ground soyabean added at the time of treatment as an external source of urease. Calves fed straw treated with urea and soyabean urease for 3 days in closed pits showed a daily gain of 336 ± 83 g while those on the 27-day closed, 9-day closed, 9-day open and 3-day open treatments showed daily gains of 213 ± 68 g, 307 ± 114 g, 207 ± 65 g and 308 ± 73 g, respectively. Calves on untreated straw supplemented with soyabean powder showed the lowest body weight gain of 141 ± 78 g day −1. It appears that an additional source of urease can reduce the reaction time of urea-treated straw. The 27-day closed system of treatment in cement-lined pits was not only expensive but gave weight gains similar to the 9-day open system of treatment. It is concluded that the economics of treatment and the production potential of the animal concerned should be the final factors in deciding upon the most appropriate method of treatment for farmer's use.

Effects of chemical pretreatments on the composition and In vitro digestibility of crop by-products

Samples of barley straw, pea straw, sugar cane bagasse and sunflower hulls were treated with sodium hydroxide, calcium hydroxide, ammonium hydroxide, anhydrous ammonia, urea, sodium chlorite, sodium chlorite plus ammonia, sulphur dioxide and chlorine gas. Different levels of the chemicals and different methods of application were used. Responses were assessed in terms of changes in chemical composition and in vitro organic matter digestibility (IVO MD) values. Treatment with anhydrous or aqueous ammonia increased the nitrogen contents of the materials; with urea-ammonia treatment the highest amount of nitrogen was retained when the samples were ensiled for 1 day, compared with those ensiled for 7, 14 or 28 days. With increases in the levels of the chemicals used the hemicellulose contents decreased, thereby decreasing the neutral detergent fibre contents. Treatment with chlorine gas resulted in higher acid detergent fibre values compared with their corresponding neutral detergent fibre values, resulting in apparently negative hemicellulose values. With barley straw (IVO MD, untreated 38%), treatment with sodium hydroxide, calcium hydroxide (by the soaking method), anhydrous ammonia, urea or sodium chlorite plus ammonia increased the IVO MD values by 18, 15, 18, 14 and 23 digestibility units, respectively. In pea straw and bagasse the maximum increases of 13 (42 versus 55) and 23 (33 versus 56) digestibility units, respectively, were obtained by treating with sodium hydroxide. In sunflower hulls (IVO MD untreated 17%), the highest IVO MD of 41% was obtained by treating with sodium chlorite followed by ammoniation.

Urea-ammonia treatment of rice straw to improve its nutritive value for ruminants

Three experiments were conducted to evaluate the effectiveness of urea as a source of ammonia in an ‘ensiling’ process for improving the nutritive value of chopped rice straw. In Experiment 1 rice straw treated with six levels of urea was ensiled in sealed polythene bags for periods varying from 1 to 6 weeks. In vitro digestibility increased significantly with increasing level of urea but ensiling beyond 3–4 weeks had no further effect. The optimum level of treatment appeared to be around 4% urea with an ensiling period of 3–4 weeks. In Experiment 2 two levels of urea (4% and 8%) were used to ensile rice straw for 4 weeks. These two treatments were compared with a control treatment having 4% urea sprinkled over the straw prior to feeding, using growing sheep fed ad libitum on straw with 100 g concentrate mixture per animal per day. The ensiling process had a significant effect on digestibility. Doubling the quantity of urea had no effect on digestibility but voluntary dry matter (DM) intake increased by 25%. In Experiment 3 the loss of urea as ammonia, on exposure of ensiled straw to the atmosphere, was estimated as 25% over a period of 2h. It is concluded that rice straw can be successfully upgraded in feeding value by urea-ensiling for 3–4 weeks. More research is, however, required before the method is extended to the farmer.