Pangola Grass Research Articles

Evaluasi Proteksi Sabun Kalsium Sebagai Pakan Suplemen Berdasarkan Kecernaan Bahan Kering, Kecernaan Bahan Organik dan pH In Vitro di dalam Rumen dan Pasca Rumen

The research aims to evaluate calsium soap protection as feed supplement based on dry matter<br />digestibility, organic matter digestibility and pH in vitro in the rumen and post rumen. Calsium soap<br />was produced from sardine fish oil and soybean meal, through two protection methods. It was<br />saponification and microencapsulation. This research used Split Subject Repeated Measurement<br />Design with 3 treatments (calcium soap, soybean meal and pangola grass) which each treatment was<br />repeated 5 times. The observation kinetics of dry matter digestibility, organic matter digestibility, and<br />pH rumen fluid were done in incubation times (2, 4, 8, 12, 24 and 48 hours respectively). The first<br />results of the research showed that in the first step (rumen) has dry matter digestibility of calcium<br />soaps: 38.65; 40.00; 42.66; 46.32; 54.40 and 51.40% respectively; organic matter digestibility: 39.44;<br />41.27; 44, 31; 46.32; 56.62 and 52.50% respectively. Kinetics of pH rumen fluid: 6.89; 6.79; 6.78;<br />6.74; 6.71, and 6.88 respectively. In the second step (post rumen), the digestibility of calsium soap<br />production has dry matter digestibility of 74.85% and organic matter of digestibilty of 72.94%. The<br />results could be concluded that in the rumen, calcium soap is the most microbial degradation resistant<br />compared the others and it can be degraded and digested in the abomasum to the small intestine.<br />Therefore pH of rumen fluid is optimal, so it does not interfere with the fermentation in the rumen.<br />Keywords: calsium soap, in vitro, dry matter digestibily, organic matter digestibility, pH value

Effect of quantity and source of rumen nitrogen on the efficiency of microbial protein synthesis in steers consuming tropical forage

Low values for the efficiency of microbial protein synthesis (EMPS) in cattle consuming tropical forages are related to low rumen degradable crude protein (RDP) intakes. This study examined the effect on the EMPS of the quantity and source of nitrogen (N) supplied to the rumen of eight entire and four rumen-fistulated Brahman steers consuming mature tropical grass hay (57.3 g crude protein/kg DM). Four treatment diets were fed in a Latin square design and included a basal diet of mature pangola grass (Digitaria eriantha) hay (control) and hay plus supplements estimated to provide 150 g RDP/kg digestible organic matter intake (DOMI), as urea or casein, or 300 g RDP/kg DOMI as casein. The EMPS was only increased (P < 0.05) above that for the control diet (167 vs 123 g microbial crude protein (MCP)/kg DOMI) when RDP was provided at the highest rate of 293 g/kg DOMI. This increase was also associated with an ~4-fold increase in the concentration of NH3-N (277 vs 73 mg/L) and of branched-chain volatile fatty acids (44 vs 10 mmol/mol of total volatile fatty acids) in rumen fluid of the steers. However, the source of rumen degradable N (urea or casein) had no effect on the EMPS (109–115 g MCP/kg DOMI) when supplied at ~150 g RDP/kg DOMI. There was no effect of treatment on in vivo neutral detergent fibre digestibility (599 g/kg DM) or the rate (0.037/h) or extent (potential degradable fraction: 636 g/kg OM) of in sacco disappearance of pangola grass hay. In addition, rumen particle dilution rate was unaffected by treatment (0.022/h) and rumen fluid dilution rate, although showing some treatment differences (0.048–0.062/h), was poorly correlated with EMPS. It was concluded that only high amounts of RDP supply to the rumen, in the form of true protein, resulted in increased EMPS whereas at the lower intakes of RDP formulated to achieve EMPS in the range suggested in the feeding standards (130–170 g MCP/kg DOMI) there was no difference in providing the RDP as non-protein N or degradable-protein.

EVALUASI PAKAN SUPLEMEN MINYAK IKAN LEMURU DAN HIDROLISAT DARAH TERPROTEKSI BERDASARKAN KECERNAAN BAHAN KERING DAN KECERNAAN BAHAN ORGANIK DI DALAM RUMEN DAN PASCA RUMEN

<pre><em>Increased of ruminants energy intake can be conducted by increasing the energy density of feed by using fat (oil). Protein intake can be enhanced by increasing of protected protein that escapes degradation by rumen microbes. The Aim of this research was to evaluate protected of feed supplement based on dry matter digestibility (KcBK), organic matter digestibility (KcBO) in vitro in the rumen and post-rumen. Protected feed supplement was produced from sardine fish oil and hydrolyzed blood , throught two protection methodes. It was saponification and microencapsulation. This research uses a completely randomized design with 3 treatments (feed supplements protected, soybean meal and pangola grass), which each treatment was repeated 5 times. </em><em>The results in the first step (rumen) of the protected feed supplement showed that has dry matter digestibility</em><em> 24.46% and organic </em><em>matter digestibility</em><em> 57.17%, soybean meal has dry </em><em>matter digestibility</em><em> 75.20% and organic </em><em>matter digestibility</em><em> 75.66%, and pangola grass has dry </em><em>matter digestibility</em><em> 50 , 81% and organic </em><em>matter digestibility</em><em> 59.21%. In the second step (post rumen) the digestibility of protected feed supplement has dry matter digestibility 69.04% and organic matter digestibility 66.71 72.76%, soybean meal has dry </em><em>matter digestibility</em><em> 90.38% and organic </em><em>matter digestibility</em><em> 88.23%, and the grass pangola have KcBK 63.24% and KcBO 59.21%. The results could be concluded that in the rumen protected feed supplementation is the most microbial degradation resistant compared the other and it can be degraded and digested in the abomasum to the small intestine.</em></pre><p> </p>

Influence of Amylopectin and Nitrogen Supplementation on Digestibility and Ruminal Fermentation of Dairy Heifers Based on Diets with High Ratio of Pineapple Waste Silage to Pangola Grass Hay

Abstract Four crossbred Holstein heifers were assigned in a 4x4 Latin square design to evaluate the effects of supplementing either amylopectin (AP) or nitrogen (N),and both in mixed diets containing high ratio of pineapple waste silage (PWS) to pangola grass hay (PGH) on feed intake, apparent digestibility and ruminal fermentation. The treatments included: T1) control diet, PGH and concentrate pellet (CT) at ratio of 70:30, T2) PGH, PWS and CT at ratio of 20:50:20 plus 10% cassava chip (CC) as AP source, T3) PGH, PWS and CT at ratio of 20:50:29.5 plus 0.5% urea as N source and T4) PGH, PWS and CT at ratio of 20:50:19.5 plus 10% CC and 0.5% urea. The results indicated that feed intake was similar in all groups (P>0.05) whereas the digestion coefficient and digestible nutrient intake in the control group were lower than those fed mixed diets with PWS and PGH (P 0.05). All supplements improved digestible CP intake in heifers (P 0.05) in all groups. The results suggest that supplementing either AP or N, and both may benefit to improve feed digestion and digestible nutrient intake in dairy heifers when fed diets with high PWS to PGH ratio.

Effects of Condensed Tannins in Mao (<i>Antidesma thwaitesianum</i> Muell. Arg.) Seed Meal on Rumen Fermentation Characteristics and Nitrogen Utilization in Goats

Mao seed is a by-product of the wine and juice industry, which could be used in animal nutrition. The current study was designed to determine the effect of supplementation of mao (Antidesma thwaitesianum Muell. Arg.) seed meal (MOSM) containing condensed tannins (CT) on rumen fermentation, nitrogen (N) utilization and microbial protein synthesis in goats. Four crossbred (Thai Native×Anglo Nubian) goats with initial body weight (BW) 20±2 kg were randomly assigned to a 4×4 Latin square design. The four dietary treatments were MOSM supplementation at 0%, 0.8%, 1.6%, and 2.4% of total dry matter (DM) intake, respectively. During the experimental periods, all goats were fed a diet containing roughage to concentrate ratio of 60:40 at 3.0% BW/d and pangola grass hay was used as a roughage source. Results showed that supplementation with MOSM did not affect feed intake, nutrient intakes and apparent nutrient digestibility (p>0.05). In addition, ruminal pH and ammonia nitrogen (NH3-N) were not influenced by MOSM supplementation, whilst blood urea nitrogen was decreased quadraticly (p<0.05) in goats supplemented with MOSM at 2.4% of total DM intake. Propionate was increased linearly with MOSM supplementation, whereas acetate and butyrate were remained the same. Moreover, estimated ruminal methane (CH4) was decreased linearly (p<0.05) when goats were fed with MOSM at 1.6% and 2.4% of total DM intake. Numbers of bacteria and protozoa were similar among treatments (p>0.05). There were linear decreases in urinary N (p<0.01) and total N excretion (p<0.01) by MOSM supplementation. Furthermore, N retention was increased linearly (p<0.05) when goats were fed with MOSM supplementation at 1.6% and 2.4% of total DM intake. Microbial protein synthesis were not significantly different among treatments (p>0.05). From the current study, it can be concluded that supplementation of MOSM at 1.6% to 2.4% of total DM intake can be used to modify ruminal fermentation, especially propionate and N utilization in goats, without affecting the nutrient digestibility, microbial populations and microbial protein synthesis.

In vitro gas production, in vivo nutrient digestibilities, and metabolisable energy concentrations for sheep of fresh and conserved pangola grass

In vitro gas production, nutrient digestibilities and metabolisable energy (ME) values of fresh and conserved pangola grass (Digitaria eriantha Steud., synonym D. decumbens) were studied in 16 cross-bred (Thai native×Merino) sheep. The study was designed as a completely randomized design with Napier grass (Pennisetum purpureum) as a control and pangola grass in fresh, hay and silage forms with the same cutting age (45 days growth) as treatments. Chemical composition of forages and faeces was determined and used to estimate nutrient digestibility. In vitro gas production was recorded at 3, 6, 8, 12, 24, 48, 72, 84 and 96h of incubation and used to estimate the kinetics of gas production. Chemical composition was relatively constant across treatments. Likely due to the addition of 5% sugarcane molasses before ensiling, pangola grass silage had higher (P<0.05) nutrient digestibilities and ME concentrations than the other forages when estimated from in vivo digestibility and in vitro gas production. Cumulative gas production at 12, 24, 48 and 96h of incubation was highest (P<0.05) in pangola silage followed by fresh pangola, pangola hay and Napier grass, in that order. In conclusion, pangola grass in fresh or conserved forms has a high potential to deliver energy and protein through forage and can be recommended as a nutrient source for small ruminants.

Digestion of forages in the rumen is increased by the amount but not the type of protein supplement

Three polyester bag experiments were conducted with fistulated Bos indicus steers to determine the effect of the amount and type of nitrogen (N) supplement on the digestion rate of forages different in quality. In Experiment 1, test substrates were incubated in polyester bags in the rumen of steers fed ryegrass, pangola grass, speargrass and Mitchell grass hays in a 4 by 4 Latin-square design. In Experiment 2, test substrates were incubated in polyester bags in the rumen of steers fed speargrass hay supplemented with urea and ammonium sulfate (US), branched-chain amino acids with US (USAA), casein, cottonseed meal, yeast and Chlorella algae in a 7 by 3 incomplete Latin-square design. In Experiment 3, test substrates were incubated in polyester bags in the rumen of steers fed Mitchell grass hay supplemented with increasing amounts of US or Spirulina algae (Spirulina platensis). The test substrates used in all experiments were speargrass, Mitchell grass, pangola grass or ryegrass hays. Digestion rate of the ryegrass substrate was higher than that of the speargrass substrate (P &lt; 0.05) in Experiment 1. Supplementation with various N sources increased the degradation rate and effective degradability of all incubated substrates above that apparent in Control steers (P &lt; 0.05; Experiment 2). Supplementation of US and Spirulina increased degradation rate and effective degradability of ryegrass, pangola grass and Mitchell grass substrates above that apparent in Control steers (P &lt; 0.05; Experiment 3). However, there was no further response on digestion rate of the substrates in increasing supplementation levels either for US or Spirulina. In conclusion, rate of digestion was affected by forage physical and anatomical properties. Supplementation with various N sources increased rate of digestion when the Control forage ration was very low in N but once a minimum level of N supplementation was reached, irrespective of form of N or other potential growth factors, there was no further increase in rate of digestion.

Pangola grass as forage for ruminant animals: a review

This review focuses on the introduction and investigation of pangola grass as a tropical forage species especially in Thailand. Pangola grass (Digitaria eriantha Steud., synonym D. decumbens) is one of recent examples of grasses that have been successfully introduced to Southeast Asia and is often considered as one of the highest quality tropical grasses popularly grown as pasture. Pangola grass is utilized extensively as grass for animal grazing, hay and silage making. Its crude protein content is commonly in the order of 5 to 14% of dry matter and may exceed 15% of dry matter with young regrowth under high fertilization. It has been documented that the type and number of ruminants receiving pangola grass can determine the success of its use. Results obtained when pangola grass in fresh, hay or silage form was fed to ruminant animals as supplements showed better performances in body weight gain, feed conversion ratio, carcass yield, meat quality, and milk yield and composition. In conclusion, pangola grass is a promising forage and a source of high quality feed for ruminant animals in tropical countries.

The effect of sucrose addition on intake of a tropical grass hay by sheep

Increasing levels of sucrose (15, 30, 45, and 60% of the total dry matter intake, DMI) were added to a Control diet of a tropical grass hay (pangola grass, Digitaria eriantha) to examine the effect on DMI and digestible organic matter intake (DOMI). A pelleted lucerne (Medicago sativa) diet provided a positive Control diet with a higher metabolisable energy intake. There were positive linear and quadratic effects of sucrose addition on DMI and DOMI, reflecting increasing values from Control to 45% sucrose, which then decreased for 60% sucrose. Intake values at 45% sucrose were equivalent to 49% (DMI) and 60% (DOMI) of those shown by animals fed on pelleted lucerne. At the same time there was a decrease in hay intake and neutral detergent fibre digestibility. Rumen concentration of butyric acid increased with sucrose addition. Eating pattern changed with increasing sucrose inclusion in that meals extended over the whole day rather than most food being consumed within 5 h as occurred with the high roughage diet. Intake of sucrose was similar for all diets by 5 h, but by 24 h high sucrose diets had resulted in a higher intake of sucrose. It was suggested that the underlying characteristics of the neutral detergent fibre present in the diet regulate intake by posing a limit, which cannot be overridden.

Determination of in Vitro Digestibility of Tropical Feeds Using Cattle Faeces as Rumen Fluid Alternative

The research was conducted to compare the ability of faeces dissolved in distilled water (P1), saline solution (P2), artificial saliva (P3), and rumen fluid (RF) as sources of inoculant in in vitro organic matter digestibilities (IVOMD) of rice straw, corn stover, napier grass, and pangola grass. The rumen fluid was collected from two rumen fistulated Ongole Crossbred Cows of 306 and 333 kg body weight (BW). The cows were fed 3% of BW consisted of 70% napier grass and 30% concentrate. At the end of 30 days feeding, faecal solution was made out of 350 g fresh faeces dissolved in 1 l of each solvent, homogenized using blender for 30 second, while rumen liquor were collected directly from fistula. After straining with four layers of cheesecloth both faecal solution and rumen liquid were mixed with artificial saliva (1:4 v/v). Fifty ml of each inoculants was pipetted into each incubator tube (100 ml) containing 500 mg sample. The tubes were then incubated at 39 o C for 48 h. Value of IVOMD of napier grass, rice straw, corn stover, and pangola grass did not differ among the faecal solvents, but significantly lower (Pin vitro organic matter to predict digestibility of fibrous feed determination. However, the faecal solvent as inoculant produced lower in vitro digestibility than that of rumen fluid.

Energy and Protein Supplementation Can Improve Liveweight Gain of Steers Grazing Good Quality Tropical Pasture in the Wet Season

This experiment aimed at maximising wet season liveweight gain (LWG) of cattle grazing good quality tropical pasture. Twenty-five Brahman crossbred steers (203 ± 4.2 kg) were allocated into 5 treatments, namely control (Con; grazing only), grazing + molasses/urea mixture (MU) at 0.5% liveweight (LW) (5MU) or 1% W (10MU), and grazing + mixture of molasses/urea (55%), fish meal (25%) and whole cottonseed (WCS; 20%) at 0.5% W (5MWF) or 1% W (10MWF). Steers grazed fertilized pangola grass pasture (Digitaria eriantha cv. Steudal) for 84 days. Pasture DM availability was maintained at > 1.5 t/ha. The Mean green leaf yield was 1.9 t DM/ha, in vitro DM digestibility was 64%, and crude protein content was 15%. The LWG of Con steers was 960 g/d. Providing MU did not increase LWG, but inclusion of fishmeal and whole cottonseed markedly improved LWG above control by 34% and 39% for 5MWF and 10MWF, respectively. Levels of supplement had no affected on LWG. It is concluded that supplementing rumen fermentable energy and protein alone did not increase LWG of steers grazing good quality tropical grass pasture, but the inclusion of rumen bypass protein and energy in supplement significantly increased LWG, as a result of the higher bypass protein and energy intake.

Integration of minimum tillage, crop rotation and organic amendments into a ginger farming system: Impacts on yield and soilborne diseases

Ginger ( Zingiber officinale) production is facing increasing disease and pest pressure and declining yield with continuing intensive cultivation practices. A four year experiment was established in south-eastern Queensland on a red ferrosol that had a long (>60 years) history of ginger farming. Minimal tillage and organic amendments were compared with conventional practice that involved frequent tillage and soil fumigation using 1,3-dichloropropene (Telone ®). Ginger crops were grown in the second and fourth year of the experiment, following an annual rotation with different cover crops including oats ( Avena sativa), Brassica spp., soybean ( Glycine max) and forage sorghum ( Sorghum bicolour X S. sudanese). A pasture ley of Pangola grass ( Digitaria eriantha subsp. pentzii) provided a treatment continuum from major to minor disruption in the soil's physical fertility and biological communities, and was therefore only planted to ginger in the fourth year of the experiment. Ginger seed-pieces (sections of the rhizome used for planting) were planted into both tilled and untilled beds using a double disc opener on a specially designed ginger planter. Rhizome yield in the final year was greatest (74.2 t/ha) and losses to pathogens ( Pythium myriotylum and Fusarium oxysporum f. sp. zingiberi) minimal (7.0%) in the pasture ley that had been cultivated prior to planting ginger. Furthermore, the minimum-tilled cover cropped treatment, which likewise had been cultivated prior to planting ginger, yielded well (62.0 t/ha), with few losses (5.0%) from rhizome rots. Conversely the fumigated treatment had the highest losses (35.9%) due to Pythium Soft Rot and lowest yields (20.2 t/ha). Minimum-tilled plantings of ginger, however, resulted in poor yields (30.9–43.1 t/ha) but had acceptable levels of disease.

The value of Leucaena leucocephala bark in leucaena—grass hay diets for Thai goats

The study assessed the value of Leucaena leucocephala bark in leucaena-grass hay diets fed to Thai goats. Thai goats in metabolism pens were fed diets containing leucaena leaf (55%) + pangola grass hay (hay, 45%); leucaena leaf (48%) + leucaena bark (9%) + hay (43%); leucaena bark (57%) + hay (43%); and hay only. Feed percentages are expressed on a dry weight basis. The digestibilities of dry matter (DM) and crude protein (CP) were measured for the four diets. Leucaena bark had lower CP concentration than the leaf (11.7 vs. 25.9), and the leucaena bark + hay diet had lower DM and CP digestibility than the other diets. The calculated bark digestibilities of DM and CP of 44.1% and 38.2%, respectively, were much lower than the values for the leucaena leaf of 62.9% and 89.1%, respectively. The lower than expected CP digestibility was attributed to higher tannin levels in the bark compared to the leaves. Despite this, the bark was well accepted by the goats and was often preferred to the hay. Stripping of the bark by goats also results in stems that dry quicker and have higher calorific value as fuel. However, if leucaena branches are fed as a sole diet, the goats may consume up to 30% of bark on a DM basis and this would reduce nutritive value and animal productivity.

Intake, retention time in the rumen and microbial protein production of Bos indicus steers consuming grasses varying in crude protein content

Feed intake, rumen function, microbial protein (MCP) production and the efficiency of MCP production were determined in steers fed four different forage hays varying markedly in crude protein content. Low quality tropical forage (speargrass and Mitchell grass) hays had lower crude protein content, higher neutral detergent fibre content and lower digestibility than a medium quality tropical forage (pangola grass) hay and a temperate forage (ryegrass) hay. Steers fed speargrass and Mitchell grass hays had lower MCP production (80 and 170 g MCP/day, respectively) and efficiency of MCP production [78 and 79 g MCP/kg digestible organic matter (DOM), respectively] than steers fed pangola grass (328 g MCP/day; 102 g MCP/kg DOM) and ryegrass (627 g MCP/day; 135 g MCP/kg DOM) hays, which was directly related to the supply of DOM and rumen degradable protein. Intake was greatest for ryegrass hay, followed by pangola grass, Mitchell grass and speargrass hays [17.6, 15.6, 10.1 and 5.5 g DM/kg W.day, respectively]. The retention time of DM in the rumen was 72.1, 47.7, 28.6 and 19.1 h for speargrass, Mitchell grass, pangola grass and ryegrass hays, respectively, with a similar trend apparent for the retention time of neutral detergent fibre, lignin, chromium-EDTA and ytterbium labelled digesta. The difference in the protein : energy ratio of absorbed substrates (measured as efficiency of MCP production) did not appear to account for all the differences in intake, nor did a purely physical mechanism.

Effect of the concentration of Spirulina (Spirulina platensis) algae in the drinking water on water intake by cattle and the proportion of algae bypassing the rumen

Spirulina, a freshwater microalgae, has previously been shown to increase the efficiency of microbial protein production in cattle fed hay with a low crude protein content. The present study was carried out to determine the effect of increasing the concentration of Spirulina in the drinking water on the intake of water and the amount of water containing Spirulina bypassing the rumen of cattle. Five rumen-cannulated steers were given a fixed amount of pangola grass hay (14 g DM/kg W.day–1) and water containing 0, 1, 2, 2.7 and 3.5% (w/w) Spirulina in an incomplete Latin square design. Water intake by the control steers (0% Spirulina) was 29.7 and 49.3 g/kg W for the first drinking event after it was made available and over 24 h, respectively. For steers receiving the algae, intake of water plus Spirulina increased linearly (P &lt; 0.01) from 42.7 to 60.2 g/kg W during the first drinking event, as the concentration of Spirulina in the drinking water increased, but over 24 h was not affected by Spirulina concentration and averaged 74.4 g/kg W. The bypass of water through the rumen, as determined using chromium-EDTA as a marker, averaged 20.5 ± 1.2% and was not affected by the concentration of Spirulina in the drinking water. Increasing inclusion of Spirulina was associated with a decrease in rumen pH, an increase in urea concentration in blood serum, and an increase in ammonia-N concentration, propionate and branched-chain fatty acids, and a decrease in butyrate proportions in rumen fluid. Spirulina inclusion in the drinking water increased water intake and may provide a potential safe and inexpensive alternative to urea for extensively grazed ruminants.

Production of Agaricus bisporus on substrates pre-colonized by Scytalidium thermophilum and supplemented at casing with protein-rich supplements

The objective of this study was to evaluate performance of Agaricus bisporus ( Ab) on substrates pre-colonized by Scytalidium thermophilum ( St), a thermophilic fungus known to enhance yields of Ab and increase selectivity of the substrate. The radial extension rate (RER) of the mycelium of three strains of St and their influence on the growth of a brown strain of Ab were evaluated. We also determined the time required for colonization of pangola grass by St in a compost pile and the influence of three protein-rich supplements on yield of Ab on pangola grass ( Digitaria decumbens) colonized by St. RER of St ranged from 10.1 mm/d on grass to 18.9 mm/d on potato dextrose yeast extract agar, with significant differences among substrates and among strains. Ab grew faster on substrate colonized for 1, 2, or 3 days by St (RER of 3.31, 3.29, 3.23 mm/d, respectively) compared to non-colonized substrate (1.85 mm/d). Ab was cultivated on substrate samples selected daily from the St-inoculated pile, with biological efficiencies (BE) ranging from 4% (day 0) to 73.9% (day 2). Protein-rich supplements (soybean, black beans and cowpeas) added at casing significantly stimulated mushroom yield on St-colonized substrate compared to the non-supplemented control. BE varied from 26.1% on substrate non-supplemented to 73.1% on compost supplemented with ground soybean. There were no significant differences in mushroom yield observed among supplements evaluated.

Effect of Frequency of Meals on Intake and Digestion of Tropical Grass Consumed by Rams

Eight Black Belly rams (45.2 kg) fitted with permanent ruminal cannulae were used in a 2x2 factorial design to determine the effects of feeding frequency and regrowth age on intake and digestion. Rams were fed with 21- or 35-day old fresh pangola grass offered ad libitum two or four times a day. Irrespective of the regrowth age, there was a tendency for intake to be positively correlated with increase in meal frequency. Differences were not significant (p>0.25). Significant effects of meal frequency were observed in NDF and ADF total tract digestibility of the 35-day grass which decreased as the number of meals increased. Meal frequency had no visible effect on feeding behaviour. Total rumen content increased when animals were fed twice a day as opposed to four times a day. Similarly, an accumulation of small and very small particles was observed in the rumen of rams fed twice a day in comparison with those fed four times a day. These results suggest that studies of digestive dynamics performed at a steady state are not representative of the rumen loading observed in farm rams which have two important peaks of meal.

QUANTIFICATION OF THE EFFICIENCY OF RUMEN MICROBIAL PROTEIN SYNTHESIS IN STEERS FED GREEN TROPICAL GRASS

MULLIK, M.L., POPPI, D.P. and S.R. MC LENNAN. 2009. Quantification of the efficiency of rumen microbial protein synthesis in steers fed green tropical grass. JITV 14(2): 110-117. The rate of rumen microbial crude protein (MCP) supply to the intestines is a crucial element in the current rumen models to predict respond of ruminants to a certain diet. Data from tropical pastures are always below predicted results from the existing rumen models. Thus, quantification of the rumen MCP supply from tropical forage will improve predictive rate under tropical feeding conditions. Four Brahman crossbred steers (457 ± 20.1 kg) were used in a metabolism study. Pangola grass (Digitaria erianthe cv. Steudal) was harvested every morning and fed to the animals soon afterward. Parameters measured were EMPS, intake, fractional passage rates, and rumen ammonia concentration. The EMPS was estimated using purine derivative excretion in urine. Mean crude protein and water soluble carbohydrate was 6.3 and 7.4% of dry matter (DM) respectively. Mean DM intake was 1.6% liveweight. Average rumen ammonia concentration was 69 mg/L whilst rumen passage rates were 7.84 and 6.92%/h for fluid and solids respectively. Mean EMPS was only 72 g MCP/kg digestible organic matters. It is concluded that EMPS in steers consuming green pangola grass was at the level below the minimum recommended value for forage diets adopted in the current feeding standards.

Estimación del valor nutricional de pastos tropicales a partir de análisis convencionales

Samples of grasses, Panicum maximum (Guinea), Digitaria decumbens (Pangola), Cynodon dactylon (Bermuda), and Panicum maximum var Tanzania (Tanzania) from Northeastern Mexico (Veracruz State) were harvested in triplicate at the beginning of the flowering stage and analyzed through both conventional laboratory and in vitro gas production procedures. Data were analyzed through ANOVA for a completely randomized design. Pangola grass recorded the highest (P<0.05) OM (91 %) and CP (7.6%) content and the lowest NDF values (65 % DM). Moreover, Pangola also recorded the highest (P<0.05) cumulative in vitro gas production (76 ml 500 mg-1 DM), gas produced from fraction b (149 ml), and potential gas production (a + b = 143 ml). The greater concentrations (mM L-1) for acetic (16.0), propionic (4.20), butyric (2.18) acids and total VFA (23.2), together with a lower A:P ratio (3.8) may indicate a greater energy availability in Pangola. Higher (P<0.05) apparent ruminal DM degradability (38 %), microbial biomass production (1.0 mg RNA100 mg-1 of DM apparently degraded) and ME content (1.6 Mcal ME kg-1) were also observed in Pangola. Conventional chemical analyses (Weende + Van Soest) added to the in vitro gas production technique allowed obtaining specific information on digestive processes in rumen and a better knowledge of nutritional properties such as microbial protein production and metabolizable energy content, of the forages being studied.

In Vivo Nutritive Value of Pangola Grass (Digitaria eriantha) Hay by a Novel Indirect Calorimeter with a Ventilated Hood in Thailand

A new animal calorimeter using a ventilated hood was constructed in Thailand. The recovery rates of our head cage were 96.5%, 97.0%, 95.7%, and 101.8%. The recovery rates of our head cage (95.7-101.8%) are reliable compared with Japanese whole-body chambers. The 99% CO2 recovery time of our head cage was an average 14 min. It was shorter than whole-body chambers because of smaller effective volume and higher flow rate. Our head cage system excels at dynamic measurement of heat production. We started accumulating data concerning the energy value of Pangola grass (Digitaria eriantha) using 4 Brahman steers (body weight, 372.8 ± 34.4 kg, mean ± standard deviation; age, 3 years old). They were fed Pangola grass for 21 days; the grass was harvested approximately 45 days after cutting in several farms around Bangkok. Digestible energy and metabolizable energy of Pangola grass hay in our study were 10.28 and 7.99 MJ/kg dry matter. The average volume of methane production was 228.3 L/day and energy loss in the form of methane was 0.097 of the gross energy intake. These values are acceptable when compared with those obtained when low-quality tropical feed is provided to the steers.