Pangola Grass Hay Research Articles

Effect of Feeding Roughage Hay on Production Efficiency and Economic Return in Crossbred Sheep

This study aimed to investigate the effect of feeding roughage hay on production efficiency and economic return in crossbred sheep. A completely randomized design was employed on Santa Ines crossbred sheep from 16 animals and divided into 4 groups. The average initial body weights of all animals were 16.87±0.97 kilograms and the average final weight were 23.25±1.07 kilograms under 60 days feeding period. Four groups were fed with fresh grass (para grass) at 3.5 kg/head/day (T1; Control group), para grass hay at 1.5 kg/head/day (T2), ruzi grass hay at 1.5 kg/head/day (T3), and pangola grass hay at 1.5 kg/head/day (T4). All animals received concentrate with 14 %CP 0.2 kg/head/day throughout the period of the study. The results showed that animals in the 4 groups had no difference in weight gain and average daily gain (P>0.05). Total dry matter intakes of groups 1-4 were found to be 2.86±0.08, 1.28±0.09, 1.27±0.09 and 1.34±0.08 kgDM/head/day (P<0.01), respectively. Total dry matter intakes of protein were 0.09±0.01, 0.07±0.01, 0.08±0.01 and 0.10±0.01 kgDM/head/day, respectively (P<0.01). Total dry matter intake per body weight of group 1 was 16.99% of body weight, which was significantly higher than other groups (P<0.01). Blood metabolites such as blood glucose in range 63.94-70.04 mg/dl, and blood urea nitrogen in the range 13.44-17.13 mg/dl were found to be in the normal range (P>0.05). The total production costs per head of the four groups averaged 224.78±3.72, 240.42±3.73, 240.13±3.73 and 245.71±3.72 baht/head (P<0.01) and total production costs per weight gain were found to be 38.78±7.90, 37.93±7.92, 38.85±7.92 and 48.79±7.90 baht/head, respectively.

Effect of waste mango silage on the in vitro gas production, in situ digestibility, intake, apparent digestibility, and ruminal characteristics in calf diets.

Mexico is the fifth largest producer of mangoes in the world. For the conservation of agro-industrial waste and crop residues, the ensiling technique has shown good results. This study aimed to evaluate the effect of increasing the level of mango silage (86% waste mango and 14% pangola grass hay) in calf diets on in vitro gas production, in situ digestibility, intake, apparent digestibility, and ruminal characteristics. The diets contained 0 (T0), 30 (T1), 45 (T2), and 60% (T3) mango silage. The partial (24, 48, and 72 h) and cumulative (72 h) biogas, CH4 production, and degradation were determined in the in vitro evaluation. In situ digestibility and estimators of fermentation kinetics of dry matter (DM) and organic matter (OM) were determined. Intake, apparent nutrient digestibility, and rumen parameters of calves (200 kg) were evaluated in a 4 × 4 Latin square design. Response to increased mango silage was calculated by linear and quadratic orthogonal contrasts. In vitro partial and cumulative biogas production decreased linearly (p < 0.05), and the partial and cumulative CH4 production did not show linear or quadratic contrast (p > 0.05); in vitro DM degradation, in vitro neutral detergent fiber degradation, and in vitro acid detergent fiber degradation showed a linear increase (p < 0.05). In situ dry matter digestibility (DMDis), in situ organic matter digestibility (OMDis), b, a + b, c, and effective digestibility (ED) of DMDis, a, a + b, c, and ED of OMDis increased linearly (p < 0.05). Dry matter intake, OM intake, and crude protein intake showed a linear increase (p < 0.05); NDF intake and ADF intake presented a quadratic behavior (p < 0.05). Apparent digestibility of DM, OM, CP, and hemicellulose, pH, N-NH3, total bacterial count, acetate, propionate, butyrate, volatile fatty acids, acetate: propionate ratio, cellulolytic bacteria, and protozoa did not present a linear or quadratic orthogonal effect (p > 0.05). The in vitro, in situ, and in vivo variables demonstrated that up to 60% mango silage can be used for the intensive fattening of calves in confinement.

Effects of Hydrolysable Tannin Supplementation on Nutrient Intake, Milk Production and Milk Somatic Cell Count in On-farm Dairy Cows

This study examined the effects of hydrolysable tannin (HT) supplementation on nutrient intake, milk production and milk somatic cell count in on-farm dairy cows. Fifty-four Holstein Friesian crossbred cows weighing 450 to 500 kg and were subjected to an experiment for 49 days. Dairy cows were divided into 3 groups, which were 1) the control group without HT supplementation and the HT supplementation groups, which received HT products (15 g/day), 2) one contains 3.15 g/day of HT and 3) another contains 6.30 g/day of HT. Hydrolysable tannin was extracted from sweet chestnut wood (Castanea Sativa Mill.). Dairy cows received HT products on the top of concentrate (22 % CP) in the morning after milking. Total mixed ration (TMR), pangola grass (Digitaria eriantha) hay and concentrate were offered according to animal nutrient requirements. The results showed that supplementation of HT has no influence (p &gt; 0.05) on the nutrient intake, milk yield and milk composition when compared to the control group. In addition, the increased levels of HT caused quadratic increases in fat:protein at pre-treatment and treatment periods (p &lt; 0.05; p = 0.06, respectively), while differential somatic cell count (DSCC) at treatment and post-treatment periods showed a quadratic decrease (p &lt; 0.05; p &lt; 0.05, respectively), with supplementation of HT product containing 6.30 g HT/day (p &lt; 0.05) being the lowest. Therefore, it can be concluded that supplementation with HT product does not affect nutrient intake, milk yield, however, it could reduce DSCC and probably improve udder health in on-farm dairy cows.&#x0D; HIGHLIGHTS&#x0D; &#x0D; A quantitative performance comparison of Radio over Free Space Optical links&#x0D; WDM increases the capacity while the MIMO links help to maintain the transmission range&#x0D; A combination of WDM and MIMO RoFSO links is identified to be the best&#x0D;

Effects of rice straw fermented with spent Pleurotus sajor-caju mushroom substrates on milking performance in Alpine dairy goats.

ObjectiveTo improve the feeding value of rice straw (RS), this study evaluated the potential of rice straw fermented with Pleurotus sajor-caju (FRS) as dairy goat feed.MethodsSpent Pleurotus sajor-caju mushroom substrate was used as fungi inoculum to break the lignocellulose linkage of rice straw, which was solid-fermented at 25°C to 30°C for 8 weeks. The ruminal degradation of pangolagrass hay (PG), FRS, and RS were measured in situ for 96 hours in three dry Holstein cows, respectively. Effect of fungi fermented RS on milking performance was studied in feeding trials. A total of 21 Alpine goats a trial were divided into 3 groups: a control group in which PG accounted for 15% of the diet dry matter, and FRS or RS was used to replace the PG in the control group. Goats were fed twice a day under two 28-day trial in individual pens. Meanwhile, a 3×3 Latin square trial (14 days/period) was conducted to study the rumen digestion of three diets by using three fistulated dry goats. Rumen contents were collected for metabolite analyses every one to three hours on the last two days.ResultsIn situ study showed that fermentation could elevate the rumen degradable fraction and effective degradability of RS (p<0.05). Effective degradability of FRS dry matter was significantly increased from 29.5% of RS to 41.7%. Lactating trial results showed that dry matter intake and milk yield in the PG group and FRS group were similar and higher than those in RS group (p<0.05). The concentration of propionic acid and total volatile fatty acid in the RS group tended to be lower than those in PG group (p<0.10). There were no differences in rumen pH value and ammonia nitrogen level among the groups tested.ConclusionFermentation of rice straw by spent Pleurotus sajor-caju mushroom substrate could substantially enhance its feeding value to be equivalent to PG as an effective fiber source for dairy goat. The fermented rice straw is recommended to account for 15% in diet dry matter.

Productive Response of Pelibuey Sheep to Supplementation in the Stretching Season in the Dry Tropic

Sheep meat production in the dry tropics of Mexico is low in the dry season, due to lack of forage, therefore, strategic supplementation is important to avoid weight loss in animals; The research was carried out from August 15 to December 15, 2020 in order to evaluate the productive response of pelibuey sheep in confinement, fed with pangola grass hay (GH), plains grass silage (PGS) and supplemented with commercial feed (CF) in the dry season. 16 sheep of the same weight and age were used, four treatments were evaluated in them, in a completely random design; the treatments were four levels of supplement 0, 0.1, 0.2 and 0.3 kg of AC fed with HP and PGS. Sheep were dewormed at the beginning of the experiment and housed in individual cages. The variables were: dry matter intake, daily weight gain (DWG) and DM digestibility. DM consumption was different (P -1 in T1 and a higher value of 0.112 kg in T4. The apparent digestibility of the dry matter showed a difference (P

Effect of forage source and dietary rumen-undegradable protein on nutrient use and growth in dairy heifers

Thirty-two Holstein heifers with mean (± standard error of the mean) age of 6.5 months (±0.12) and live weight (LW) of 166 kg (±1.6) were divided into four groups of eight animals to evaluate the effect of forage source and the concentrations of rumen-undegradable crude protein (RUP) in the diet with a 2 × 2 factorial design. As forage sources cowpea hay (Vigna sinensis L.) or pangola grass hay (Digitaria decumbens Stend) were added to the diet at 250 g/kg dry matter (DM). Also, 350 g/kg DM of chopped fresh King grass (Pennisetum purpureum Schum.) was included in all diets. The RUP proportions were 260 or 360 g/kg of total crude protein (CP). Heifers were housed in metabolism cages. The trial lasted ten weeks, with the first two weeks used for adaptation and the last week for data collection and sampling. Diets had a forage to concentrate ratio of 60:40 (on DM basis), and were offered as total mixed rations ad libitum. Fish meal or urea were used to produce varying concentrations of RUP at similar dietary CP content. Diet ingredients (i.e., hay, grass, and concentrate) and feces were sampled for nutrient analysis. Total collection of feces was performed to estimate apparent total tract nutrient digestibility (ATTD). Urinary purine derivative excretions were determined from urine spot samples to estimate rumen microbial protein synthesis. The effects of forage source, RUP, and its interactions were determined by general linear model analysis. Replacing dietary pangola grass hay with cowpea hay increased daily intakes of DM, organic matter, CP, acid detergent fiber (ADF), and digestible organic matter, and ATTD of DM, organic matter, neutral detergent fiber, and ADF (P < 0.05). Duodenal flow of RUP also increased when substituting cowpea hay for pangola grass hay (P < 0.01). Similarly, inclusion of cowpea hay in the diet improved live weight gain (LWG; P < 0.05), and decreased feed costs per kg of LWG (P < 0.01). The increase in RUP decreased rumen microbial protein synthesis (P < 0.01), but tended to increase LWG, feed conversion and nitrogen use efficiency, and feed costs per unit of LWG (P < 0.10). The use of cowpea hay in the diet of dairy heifers increases nutrient intake and ATTD, leading to improved LWG and lower feed costs per kilogram of LWG. Increasing RUP proportions may reduce rumen microbial protein synthesis, but may enhance LWG, feed conversion efficiency, and nitrogen use efficiency. There were no interactions between forage source and RUP proportion on intake and ATTD, but some synergistic effects were observed for the performance parameters.

Nitrate supplementation of rations based on rice straw but not Pangola hay, improves growth performance in meat goats.

ObjectiveSupplemental nitrate is known to be an effective tool to mitigate methane emission by ruminants. Based on theoretical considerations, supplemental nitrate can improve but also deteriorate the growth performance. The overall effect of supplemental nitrate on growth performance, however, is not yet known. The objective of the current study was therefore to evaluate the effect of a higher dose of NO3− on overall growth performance when feeding either Pangola grass hay or rice straw.MethodsThirty-two crossbred, 3-month-old Thai native×Anglo-Nubian crossbred male goats were used. The experiment had a 2×2 factorial design with an experimental period of 60 days. Eight goats were randomly allocated to each dietary treatment, i.e. a ration containing either Pangola hay (Digitaria eriantha Steud) or rice straw (Oryza Sativa) as a source of roughage, supplemented with a concentrate containing either 3.2% or 4.8% potassium nitrate. The rations were formulated to be isonitrogenous. The animals were weighed at the start of the experiment and at days 30 and 60. Feces were collected during the last five days of each 30-day period.ResultsHigh-nitrate increased overall DM intake by approximately 3%, irrespective the source of roughage, but only the goats fed a rice straw-based ration responded with an increase in body weight (BW). Thus, the overall feed conversion ratio (kg feed/kg BW gain) was influenced by roughage source ×nitrate and decreased by almost 60% when the goats were fed rice straw in combination with a high versus a low dietary nitrate content. The digestibility of macronutrients was only affected by the source of roughage and the digestibility of organic matter, crude protein, and neutral detergent fibre was greater when the goats were fed Pangola hay.ConclusionIt was concluded that the replacement of soybean meal by nitrate improves the growth performance of meat goats fed rations based on rice straw, but not Pangola hay.

EVALUACIÓN DE LAS CARACTERÍSTICAS DE CALIDAD Y BROMATOLÓGICAS DE ENSILADOS ELABORADOS CON RESIDUOS DE CALABAZA (Cucurbita argyrosperma)

Pumpkin pulp shell (PPS) is an agricultural by-product with contaminating potential that can be used to ensile. The objective of this study was to determine the quality and bromatological characteristics of ensilages made with PPS, pangola grass hay, urea and two percentages of fermented molasses during 14 and 21 days. Ensilage types (2 kg) were E1 (72.5% PPS, 22.5% grass, 3% molasses and 2% urea) and E2 (72.5% PPS, 19.5% grass, 6% molasses and 2% urea). Both ensilages were fermented for 14 and 21 days. The pH was evaluated, along with dry matter (DM), lactic acid, ash (As), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and hemicellulose content. The statistical analysis was a completely randomized 2 × 2 design with ensilage types and fermentation time as factors. The pH of E2 did not vary (p > 0.05) at 14 and 21 days of fermentation, averaging 3.85. A higher production of lactic acid was quantified with E1 at 14 days, and it also presented a higher DM than E2 (p ≤ 0.05). The content of CP, NDF, ADF, As and hemicellulose did not show differences (p > 0.05) by ensilage type or fermentation times. It is concluded that PPS can be ensiled with pangola grass hay, urea and up to 6% sugarcane molasses fermented for 14 or 21 days without affecting its quality and bromatological characteristics.

Chemical composition, and in vitro fermentation of ripe mango silage with molasses

The objective was to evaluate the in vitro fermentation in silage of ripe mango with pangola grass hay and levels of sugar cane molasses as additive. The treatments were: 0 (T0%), 3 (T3%), 6 (T6%) and 9% (T9%) molasses. The ensilage was fermented for 21 days. Dry matter (DM), pH values, lactic acid, crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), and ashes (As), partial and the accumulated biogas and methane production, DM degradation (DMD) and NDF degradation (NDFD) were determined in the ensilages. Variables were analyzed in a completely random design. T0% showed lower DM and As content, as well as a higher lactic acid concentration. T3% and T6% had different CP content. The higher NDF and ADF content was found in T0% and T3%. With regard to partial biogas production, T0% had the higher partial biogas production at 6 h, while T3% and T6% had the higher production at 9 and 48 h; meanwhile, T0% and T3% had the higher production at 24 h, and T9% at 72 h. The higher partial methane production happened in T0% at 48 h and in T3% and T9% at 72 h. T0% and T3% had a higher DMD and NDFD. The lower accumulated biogas production took place in T3% and T6% (p < 0.05). Therefore, ripe mango ensilages (using pangola grass) do not require an additive (such as molasses) to improve the bromatological and fermented quality of the ensilage.

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 &lt; 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.

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 (&lt;i&gt;Antidesma thwaitesianum&lt;/i&gt; 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.

Nutrient digestibility and rumen fermentation of Thai native purebred compared with Thai native x Lowline Angus crossbred beef cattle

ABSTRACTThe aim of this study was to compare voluntary feed intake, nutrient digestibility, and rumen fermentation of Thai native and Thai native x Lowline Angus crossbred beef cattle fed with different diets. Three different diets consisting of ad libitum rice straw (RS), ad libitum RS supplemented with 0.5% body weight (BW) concentrate (RS+C), and ad libitum Pangola grass hay (PH). The experiment was conducted as 3 × 3 replicated Latin square design with a factorial arrangement of dietary treatment and breed. It was found that Thai native and Thai native x Lowline Angus crossbred beef cattle had comparable roughage intake, BW change, nutrient digestibility, and all parameters from rumen fluid. Cattle fed with different type of feed showed similar roughage intake, BW change, and number of protozoa and fungal zoospore in rumen fluid. However, nutrient intake and digestibility of cattle supplemented with concentrate were higher than those fed the roughage alone. Accordingly, concentration of total volatile fatty acid and proportion of propionic acid in rumen fluid of cattle received concentrate was higher than cattle fed only RS (P < .05) but not for cattle fed with PH. Moreover, the PH-fed group had a higher ammonia concentration in rumen fluid than did the RS-fed group (P < .05). Therefore, the two breeds of beef cattle showed comparable feed response while supplementation of concentrate at 0.50% BW was a useful alternative feeding pattern.

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.

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.

Supplementation strategies to improve efficiency of rumen microbial protein synthesis on cattles fed with tropical grass hay

This experiment aimed at increasing rumen microbial protein supply into intestine through ration manipulation. Four Santa Gertrudis steers with a mean liveweight (W) of 218 (±5.6) kg were used in a latin square design (4 x 4) to observe the effect of four diets on the efficiency of rumen microbial protein synthesis (E MPS ). The steers were given pangola grass hay (8.5% protein) as the basal diet. The treatments were 1) pangola grass hay alone (KON), 2) pangola grass hay + 19 g urea/kg dry matter (DM) hay (URE), 3) as for treatment URE + a supplement mix at 0.5% W (SUP), and 4) as for treatment SUP + salt at 0.15% W (SUG). Urea was added into the hay to support a theoretical E MPS of 160 g MCP/kg digestible organic matter (DOM) whereas supplement mix contains fast, medium, and slow rumen fermentable energy and protein to synchronise energy and protein release in the rumen. Salt was added to alter passage rate of digesta. Addition of urea alone or with supplement mix increased E MPS significantly compared to KON (77 g MCP/kg DOM) but no difference between URE (119 g MCP/kg DOM) and SUP (110 g MCP/kg DOM). Addition of salt into supplement mix increased E MPS by 84% (140 g MCP/kg DOM). It might be concluded that rumen degradable protein (RDP) was deficient in steers fed low quality grass hay hence urea supplementation significantly increased E MPS to a similar extent as that of the supplement mix formulated to have a synchrony in protein and energy release. Increasing fluid dilution rate, by adding salt, also had a dramatic affect on E MPS as observed in treatment SUG. It increased up to the level suggested in the International feeding standards. Key Words: Microbial Protein, Soluble Protein, Dilution Rate, Supplement, Tropical Grass

Metabolizable energy of roughage in Taiwan

The fixed metabolizable energy (ME) values from the NRC do not represent the true ME values of the various feedstuff used in livestock rations. Therefore, a rapid and effective method for evaluating the ME value of forage crops is required for proper ration formulation to improve production efficiency. Dairy goat digestion trials were conducted as the in vivo reference using the method of Menke and Steingass (1988) [Menke, K.H., Steingass, H., 1988. Feed Sci. Technol. 28, 91–97] which derived the amount of gas produced from in vitro fermentation. This method was adapted in this study to evaluate the ME value. In the goat digestion trial, six dairy goats were used for each roughage sample in a total fecal collection trial to determine the digestible nutrients, including energy (DE) and total digestible nutrient (TDN). The in vivo ME value was calculated using the method of Shiemann et al. (1971) [Shiemann, R., Nehring, K., Hoffmann, L., Jentsch, W., Chudy, A., 1971. Energetische Futterbewertung und Energienormen. VEB Deutscher Land-wirtschaftsverlag, Berlin, p. 75. (in German)] (ME 1 (MJ/kg) = 5.2DCP + 34.2DEE + 12.8DCF + 15.9DNFE, g/g). The in vitro ME value was then estimated from the chemical composition of the feed and amount of gas produced (G b) from in vitro fermentation. The value calculated from both with (ME 3) and without (ME 2) the inclusion of nitrogen free extracts (NFE) in the prediction equation. (ME 2 (MJ/kg) = 0.145G b + 4.12CP + 6.5CP 2 + 20.6EE + 1.54, g/g; ME 3 (MJ/kg) = 0.118G b + 8.75CP + 19.21EE + 3.38NFE + 0.691, g/g). The 12 roughage samples consisted different growth stages of Napier grass Taishi No. 2: (day of harvest; 40, 50, 60 and 65), dwarf Napier grass Taishi No. 1: (Day 40 and 65) and Pangola grass (Day 45) hay (Day 70), corn silage, imported alfalfa hay, timothy hay and Bermuda hay. The correlation between the ME values calculated from in vivo and in vitro without NFE was lower than with NFE inclusion in the equation. A higher correlation between the ME values calculated from in vivo and in vitro without NFE inclusion than with NFE inclusion in the prediction equation was obtained when alfalfa and corn silage were not included. This indicated that the ME value of forage could be estimated rapidly using this in vitro gas method adapted from Menke and Steingass (1988) [Menke, K.H., Steingass, H., 1988. Feed Sci. Technol. 28, 91–97] for practical applications in ration formulation.

Extent of digestion and rumen condition as factors affecting passage of liquid and digesta particles in sheep

Two experiments were carried out at Mt. Cotton, The University of Queensland, from November 1992 to July 1993, to study the effect of extent of digestion or feed type (grass or legume) on particle kinetics in the rumen. Small (0·5–1·18 mm) Yb-labelled grass or legume particles, either digested or undigested, were injected into the rumen of sheep fed on different diets, and their retention time in the reticulo-ruminal compartment measured. In Expt 1, four intact wethers were fed on either pangola grass hay, chaffed lucerne hay, pelleted lucerne hay or commercial pelleted concentrate. Digested particles from the faeces of animals fed on pangola or lucerne and undigested material from the same diets were wet-sieved and the fraction 0·5–1·18 mm collected, labelled with Yb-acetate and injected into the animals together with a solution of Cr-EDTA. Faecal samples were taken and analysed for marker concentrations. In Expt 2, four similar animals, fitted with duodenal and ruminal cannulae, were fed on different proportions of pangola grass hay and lucerne hay, and Cr-EDTA and the above mentioned labelled particles were injected through the rumen cannula. Samples were taken from the duodenum and analysed for marker concentrations.The results indicated that diet characteristics rather than extent of digestion or particle type had the greatest influence on rates of passage of both liquid and particulate phases. Different proportions of pangola and lucerne did not result in marked differences in either the volumes of rumen contents or the rates of passage of the solid phase marker but altered the rates of passage of Cr-EDTA. Increasing the proportion of legume increased intake and decreased retention time markedly, with no additive effects on digestibility.Particles of the same small size escaped with the same fractional passage rate within each diet, irrespective of type (grass or legume) or status (undigested or digested), indicating identical kinetics within each rumen type.It was concluded that rumen conditions as influenced by diet type have most influence on water and particle kinetics and that extent of digestion of the small particles used in our experiments was not important. Particles of legume or grass of the same size behaved similarly within a diet type.