Fed Rice Straw Research Articles

Substitution of Concentrate with Mulberry Leaves in Ongole Grade Cattle Fed Rice Straw Based Diet

An experiment was conducted to assess the substitution of concentrate with mulberry ( Morus spp. ) leaves combined with rice straw offered to beef cattle. The study used 12 male Ongole grade cattle weighing 217 + 10.53 kg. Rations consisted of rice straw, mulberry leaves and concentrate. Research was carried out according to completely randomized design with 3 treatments and 4 replications for each treatment. The treatments were: P1= 50% rice straw + 50% concentrate; P2= 50% rice straw + 25% concentrate + 25% mulberry; P3= 50% rice straw + 50% mulberry. The results of the study indicated that rumen fermentation in cattlle fed on P2 ration was more effective than those receiving P1 and P3 rations. The fermentation was characterized by a higher production of total VFA and allantoin excretion in the urine. The presence of 1-deoxynojirimycin (DNJ) compound of mulberry leaves in the rumen system in treatment P2 and P3 improved digestibility of fiber fractions of rice straw-based rations. Mulberry leaves in rations also accounted for isoacids in the rumen system, which supported the development of cellulolytic bacteria. In conclusion, mulberry leaves containing concentrate had a potency to substitute concentrate when used together with fiber source feed such as rice straw.

Effects of xylanase supplementation on ruminal digestibility in fistulated non-lactating dairy cows fed rice straw

The effect of xylanase product on ruminal disappearance and rumen fermentation of rice straw based diet was evaluated in fistulated non-lactating dairy cows. Three fistulated non-lactating dairy cows were used in 3×3 Latin squares design; the trial consisted of 3 periods of 21d in each period. Treatments were: (1) control, (2) 10g xylanase/cow/d, and (3) 20g xylanase/cow/d. The commercial xylanase enzyme (endo-1, 4-beta-xylanase, EC 3.2.1.8) which was a fibrolytic enzyme powder (Porzyme® 93010; Danisco Animal Nutrition) was used in this study. Diets offered as 3kg/d of concentrate containing 17% CP together with ad libitum rice straw and clean water. Enzyme did not change dry matter intake, ruminal pH and NH3–N concentrations. DM and ADF potential disappearance fraction, DM and ADF total disappearance were unaffected by the enzyme supplementation. However, NDF potential disappearance fraction, NDF total disappearance were increased when the enzyme was added at a high dose. Hemicellulose degradability in 0, 3, 6, 12, 24, 48, 72 and 96h were unaffected by supplementation of xylanase. Total volatile fatty acids concentration, molar proportion of acetate, propionate and butyrate and ratio of acetate: propionate at each hour of incubation were unaffected by xylanase.

Feed intake, digestibility, and N retention in cattle fed rice straw and para grass combined with different levels of protein derived from cassava foliage.

Eight male cattle of Local Yellow breed with an average live weight of 121 kg and an average age of 18 months were used to evaluate the effects of different levels of sun-dried cassava foliage supplementation (Manihot esculenta) on intake, digestibility and N retention. Rice straw ad libitum and para grass (Brachiaria mutica) at 1% DM of BW comprised the basal diet. The study was arranged as a 4×4 double Latin square design, with cassava foliage contributing 0, 0.8, 1.6 or 2.4 g CP/kg BW. The cattle selected cassava leaves in preference to petioles. Petiole intake decreased from 64 to 48% of offered petioles when the cassava foliage proportion increased from the lowest to the highest level. The cattle consumed all the leaves at the two lower levels of cassava foliage inclusion and 91% at the highest level. Rice straw intake decreased significantly as the level of cassava foliage increased. Intake of DM, OM, NDF, and ADF increased significantly with increasing intake of cassava foliage. Daily DM intake per 100 kg BW increased from 2.7 to 3.2 kg with increasing cassava foliage intake. No effect on CP digestibility was detected when the level of cassava foliage increased. Digestibility of DM, OM, NDF and ADF was significantly higher in the group fed no cassava foliage than in the other groups. N retention increased from 16 to 28 g/d with the first level of cassava foliage inclusion, but levelled out at the two highest levels. N excretion increased in both faeces and urine as a response to higher intake of cassava foliage. Maximum N retention occurred when 40% of total N intake came from cassava foliage (equivalent to 1.3 g CP/kg BW).

EFFECT OF LEVEL OF CONCENTRATE FEEDING LEVEL ON EFFICIENCY OF EATING BEHAVIOUR ON ONGOLE CROSSBRED CATTLE

Eight bulls of Ongole Crossbred (OC) cattle with initial body weight (BW) of 297 + 26 kg (CV =8.75%) fed rice straw treated with urine (RU) (ad libitum) were divided into two groups (each fourheads) to determine the effect of concentrate feeding level on efficiency of eating behavior. The cattlewas given concentrate feeding composed of beer cake and rice bran to make 14% crude protein at 1%and at 2% BW for RUC1 and RUC2 group, respectively. Eating behavior was measured for 3x24 hoursand was performed twice at weeks 2 and 6 of the study. Data obtained were analyzed by t-test. Theresults showed that the level of concentrate feeding affected the intake of urinated rice straw (P 0.05) on DMI, length time for eating(196.5 vs. 221.5 min/d), length time for rumination (351.0 vs. 449.4 min/d), efficiency of eating time(37.21 vs. 37.67 gDM/min) and efficiency rumination time (21.43 vs. 18.50 gDM/min). This researchshowed that concentrate feeding at 2% BW did not alter the efficiency of eating time and ruminationcompared to 1% BW, although able to improve BWG of OC cattle.

The level of tree legumes required to meet the maintenance energy requirements of Ongole (Bos indicus) cows fed rice straw in Indonesia

Improving the productivity and profitability of smallholder cattle enterprises in Indonesia requires greater and more efficient utilisation of underutilised feed resources such as rice straw. The experiment tested the hypothesis that an Ongole cow with low energy requirements can maintain weight (W) on a rice straw-based diet with the addition of a small amount of tree legumes. Thirty-two Ongole cross (Bos indicus) cows were allocated to one of four treatments in a randomised block design with eight cows per treatment. Cows were offered untreated rice straw ad libitum with four levels of tree legumes (0, 11, 21, and 42 g DM/kg W0.75.day) for 20 weeks. Feed intake was determined daily and liveweight was measured every second week. There was no difference in total feed intake between the treatment groups (P > 0.05). Intake of tree legumes was higher when more was offered (P < 0.05), but cows did not consume all of the legumes offered to them. The inclusion of tree legumes in the diet had no effect on organic matter digestibility, ME content of the diet, liveweight gain or estimated energy balance of the cows (P > 0.05). Rice straw alone contained insufficient ME and rumen-degradable N to meet the maintenance requirements of the cows. From the regression relating liveweight change and ME intake for all cows across all diets, the inclusion of tree legumes in the diet at ~12 g DM/kg W0.75.day or 2.8 g DM/kg W.day was enough to meet the energy requirements for maintenance of Ongole cows fed rice straw ad libitum.

Effects of days on feed, roughage sources and inclusion levels of grain in concentrate on finishing performance and carcass characteristics in cull beef cows

An experiment was conducted with 16 Japanese Black cows to determine the effects of different days on feed (89, 208, 271 and 341 days), inclusion levels of grain in concentrate (60% vs. 40%; dry matter (DM) basis) and roughage sources (hay vs. rice straw) on finishing performance. Additional four cows were slaughtered at 0 days on feed to obtain non-fed carcass data. Maximum carcass weights were observed in cows fed for 271 days; an increase in carcass weight of only 14 kg was shown from 208 days to 271 days. The marbling score increased (P < 0.05) with days on feed. The percentage of fat in the subprimal rib linearly increased (P < 0.05) with days on feed. The percentage of lean meat was higher (P < 0.05) for cows fed rice straw than for cows fed hay as a roughage source. Increasing the days on feed decreased (P < 0.05) the yellowness of the fat. The effects of the inclusion levels of grain in concentrate on the finishing performance of cows were lower than the other two factors. In conclusion, feeding improves carcass values, but feeding over 208 days is an inefficient system of production in cows.

Saponin 함유 식물 추출물의 첨가가 반추위 발효성상과 메탄생성에 미치는 영향

본 연구는 saponin 함유 식물 추출물을 이용하여 반추위 발효성상과 메탄생성에 미치는 영향을 알아보고자 실시하였다. 반추위액은 볏짚과 농후사료를 5:5 비율로 급여한 거세한우 2두의(체중: <TEX>$803{\pm}0.5$</TEX> kg) 반추위 cannula를 통하여 채취하였다. 채취한 반추 위액은 buffer와 1:2 (V/V)의 비율로 혼합하여 배양액으로 사용하였으며, 15 ml 배양액에 옥수수 전분 0.2 g를 첨가하고, saponin 함유 식물 추출물 (비누풀, 오가피, 유카, 인삼 및 차나무)을 0.5% 첨가하여 <TEX>$39^{\circ}C$</TEX>에서 24시간동안 배양하였다. 반추위 발효성상에 있어서 pH 값은 배양 시간동안 모든 처리구가 대조구에 비해 유의적(p<0.05)으로 낮게 나타났으며, 총 휘발성 지방산의 함량은 배양 12시간부터 모든 처리구에서 유의적 (p<0.05)으로 높았다. Acetate의 농도는 배양 6시간부터 처리구에서 낮았고, propionate의 농도는 높아 역의 관계를 나타내었다. 암모니아의 농도는 최종 발효시간인 24시간에 오가피와 유카추출물 처리구는 대조구와 비슷한 수준이었지만, 다른 처리구는 유의적(p<0.05)으로 낮았다. 반추위 protozoa의 수는 비누풀 추출물 처리구를 제외한 모든 처리구에서 대조구에 비해 유의적(p<0.05)으로 적었다. 총 가스 발생량은 배양 12시간부터 처리구에서 높은 경향이었지만, 메탄 발생량은 오가피와 비누풀 추출물 처리구를 제외한 나머지 처리구에서 낮게 나타났다. 따라서 본 시험 결과를 볼 때 saponin의 첨가에 의해 메탄 발생량이 감소하는 것은 반추위 protozoa의 감소에 의해 나타난 것으로 생각된다. This study was conducted to evaluate the effects of saponin contained plant extracts on in vitro rumen fermentation characteristics and methane production. Ruminal fluid was collected from rumen cannulated Hanwoo steers fed rice straw and concentrate (5:5). Collected rumen fluids, corn starch and buffer including saponin contained plant extracts (ginseng, Ogapi, soapwort, tea plant and yucca; 0.5%/15 ml) were incubated at <TEX>$39^{\circ}C$</TEX> for 24 h. All incubations were repeated five times. Rumen pH in all treatments was lower (p<0.05) compared with that of the control (no addition) during incubation time. The concentration of total VFA in all treatments was higher (p<0.05) than that of the control after 12h incubation. Compared with the control, the concentration of acetate and propionate in all treatments was lower and higher after 6h incubation, respectively. The concentration of <TEX>$NH_3$</TEX>-N in all treatments was lower (p<0.05) than that of the control except for Ogapi or yucca extracts supplementation. The number of protozoa in all treatments was significantly (p<0.05) lower than that of the control except for soapwort extract supplementation. The total gas production and methane production in all treatments was higher (p<0.05) and lower (p<0.05) compared with the control, except for ogapi or soapwort extracts supplementation after 12h incubation, respectively. Therefore, reduction in methane production by saponins may could be results from decreased protozoal population without any negative in vitro fermentation.

Effect of legume (Phaseolus calcaratus) hay supplementation on rumen microorganisms, fermentation and nutrient digestibility in swamp buffalo

The objective of this research was to evaluate the effect of Phaseolus calcaratus hay (PCH) supplementation on the intake, digestibility, rumen fermentation, microbial population (bacteria, protozoa, and fungi) and methane production in swamp buffaloes fed on rice straw based diet. Four, 2.5year old rumen fistulated male buffaloes were randomly assigned according to a 4×4 Latin square design. The treatments were level of PCH supplementation at 0, 300, 600 and 900g DM/hd/d as supplements. The PCH contained 18.3% crude protein (CP) and 2.8% condensed tannins (CT). All buffaloes were fed with rice straw ad libitum while additional concentrate (12.6% CP) was fed at 0.3% body weight (BW). The study revealed that PCH supplementation had no effect on rumen temperature, pH, NH3-N and blood urea N. Volatile fatty acid (VFAs), especially those of propionic acid and acetic acid concentrations in the rumen were maximized (P<0.05) at 600g/hd/d feeding level. However, concentrations of each VFA and the acetate to propionate ratio did not differ among treatments. Bacterial, protozoal and fungal zoospore populations were maximized (P<0.05) at the intermediate PCH feeding levels. Rumen methane gas production was decreased linearly (P<0.05) with increasing level of PCH supplementation. N utilization in the buffaloes differed among treatments, with PCH supplementation linearly increasing N retention and efficiency of microbial N supply. Furthermore, PCH supplementation linearly increased (P<0.05) in terms of total DM intake, apparent digestibility of CP and OM, while, DM, NDF and ADF digestibilities were not affected. Supplementation of PCH at 600g/hd/d was beneficial in swamp buffaloes fed rice straw as a basal roughage, as it resulted in increased DM intake, reduced protozoal and methane gas production in the rumen, increased N retention as well as efficiency of rumen microbial CP synthesis.

The growth of Java bulls fed rice straw and concentrates containing different levels of protein.

This study was performed to determine the growth of Java bulls fed rice straw and concentrates at different levels of protein. Twelve heads of Java bulls, one and a half years old, with initial body weight ranging from 113.83-191 kg were used in this experiment. They were grouped into four replications based on the initial body weight. The rice straw (30%) and concentrates (70%) diet containing three different levels of protein (8.27; 11.03 and 14.43%) were fed during nine weeks. Data gathered were the average daily gain and the average body measurements (chest girth, shoulder height and body length). Result of this study showed that the increase of protein levels from 8.27 to 14,43% did not significantly influence the average daily gain, shoulder height, and body length of Java bulls (P > 0.05), but it influenced daily chest girth (P < 0.05). The average daily gain (ADG), shoulder height and body length were 0.633 kg, 0.08 cm, and 0.09 cm, respectively. The highest average of daily chest girth of Java bulls was T2 = 0.19 cm, followed by T3 = 0.15 cm, and T1 = 0.12 cm. It is concluded that the increase levels of protein from 8.27 to 14.43% did not affect the average daily gain, shoulder height and body length of Java cattle. However, the highest chest girth was achieved by Java cattle which fed concentrate containing 11.03% of protein. Key Words : Growth, Java Bull, Rice Straw, Concentrate, Levels of Protein

Effects of Dietary Protein on Ruminal Fermentation, Nitrogen Utilization and Crude Protein Maintenance in Growing Thai-indigenous Beef Cattle Fed Rice Straw as Roughage

Effects of Dietary Protein on Ruminal Fermentation, Nitrogen Utilization and Crude Protein Maintenance in Growing Thai-indigenous Beef Cattle Fed Rice Straw as Roughage

Protein Requirements for Maintenance of Thai Native Male Cattle Fed Rice Straw Based Diets

Protein Requirements for Maintenance of Thai Native Male Cattle Fed Rice Straw Based Diets

답리작 재배 청보리 사일리지 급여가 거세 한우의 증체, 사료요구량 및 육질에 미치는 영향

본 연구는 답리작에서 보리를 재배하여 사일리지를 조제하고 거세 한우에게 청보리 사일리지를 급여하여 성장, 사료이용성, 도체특성 및 육질개선 효과를 구명하고자 전북 정읍 농가에서 4개월령 거세 한우 육성우 21두를 공시하여 27개령까지 사육하였다. 대조구(일반볏짚구), 청보리 사일리지구, 생볏짚 사일리지+청보리 사일리지구 등 3처리를 두었으며, 배합사료는 육성기는 체중의 1.5%, 비육전기는 1.8%, 비육후기는 자유 채식하도록 하였고, 조사료는 사육기간 자유채식을 원칙으로 하였다. 청보리 사일리지의 평균 생산량은 ha당 사일리지 17,135 kg, 건물 6,011 kg 이었으며, 사일리지의 품질등급은 청보리에서 2~3등급, 생볏짚은 4등급이었다. 청보리 사일리지 급여로 거세 한우증체와 배합사료 절감효과가 뚜렷하였는데, 육성기에는 일당증체 65% 증가, kg 증체당 배합사료 35% 절감, 비육전기는 일당증체 7% 증가, kg 증체당 배합사료 19% 절감, 그리고 전기간으로는 일당증체 8% 증가, kg 증체당 배합사료 18% 절감효과가 있었다. 또 청보리 사일리지구에서 육질 1등급 이상 출현율은 62.5%로 대조구(37.5%)에 비해 높았으며, 근내지방도도 4.38로 대조구(2.75)에 비해 높았고, 고기의 보수력, 가열감량, 다즙성, 연도, 향미 등도 우수하였다(p<0.05). 답리작 재배 청보리는 양질 사료작물로 거세 한우의 증체와 배합사료 절감, 육질개선에 효과적이었으며, 육성기와 비육전기 위주 급여가 바람직하였고, 답리작을 이용한 월동 사료작물 재배확대가 기대되었다. This study was carried out to investigate the effect of feeding whole crop barley silage (WBS) on the growth performance, gain, feed requirement, carcass grade and beef quality of Hanwoo steers in 1999 to 2001. Twenty one steers were allocated, and divided into three treatment groups which fed rice straw only (control), WBS only, and fresh rice straw silage plus WBS during overall period ad libitum. Concentrates were fed at 1.5% level of live-body weight during growing stages, 4~12 months of age, at 1.8% level of live-body weight during early fattening stages, 13~18 months of age, and ad libitum after late fattening stages, 19~27months of age. The production yields of WBS were 17,135 kg as a silage, and 6,011 kg as a dry matter per ha, and the quality of WBS was 2~3 grade, while that of rice straw silage was 4grade. The daily gain with feeding of WBS (0.70 kg) during experimental period was higher than that of control group (0.65 kg), and the concentrate requirement (7.31 kg) per kg gain in WBS was lower than that of control (8.95 kg). The effects of gain and feed efficiency were very distinct during growing stage. i.e., the daily gain of WBS (0.84 kg) was increased by 65% compared to control (0.51 kg), and the concentrate requirement (4.16 kg) per kg gain in feeding of WBS was decreased by 35%, compared to control (6.39 kg). Meat quality with WBS was higher than that of control. Frequency rate of 1 and/or <TEX>$1^+$</TEX> grade, and marbling score of feeding of WBS were 62.5% and 4.38, while those of control were 37.5% and 2.75, respectively. The results of the sensory evaluation showed that Hanwoo beef fed with WBS were better than that of control. In conclusion, feeding of WBS was desirable to improve daily gain, reduction of concentrates, feed efficiency and meat quality of Hanwoo steers.

Intermediary Metabolism of Plasma Acetic Acid, Glucose and Protein in Sheep Fed a Rice Straw-based Diet

The present study was conducted to determine plasma acetate, glucose and protein metabolism using dilution of isotopes [[1- 13 C]Na acetate, [U- 13 C]glucose and [1- 13 C]leucine (Leu)] in sheep fed rice straw (Oriza japonica L.). Four sheep were assigned to either rice straw (RS-diet) or mixed hay (MH-diet) with a crossover design. Nitrogen (N) intake and N digestibility were lower (p = 0.002 and p = 0.02, respectively) for RS-diet than MH-diet, but N retention did not differ (p>0.10) between the diets. Concentrations of rumen acetate tended to be lower (p = 0.07), and propionate was higher (p = 0.02) for RS-diet than MH-diet. Concentrations of plasma lactate, non-esterified fatty acids, Leu and α-ketoisocaproic acid did not differ (p>0.10) between the diets, but plasma glucose and urea concentrations were lower (p = 0.01 and p = 0.003, respectively) for RS-diet than MH-diet. Turnover rate of plasma acetate did not differ (p = 0.39) between the diets, and plasma glucose and Leu turnover rates were numerically lower (p = 0.15 and p = 0.14, respectively) for RS-diet than MH-diet. Whole body protein synthesis and degradation did not differ (p>0.10) between the diets. Thus it can be concluded that the intermediary metabolism of acetate, glucose and protein on rice straw is comparable to mixed hay in sheep.

Associative effects of supplementing rice straw‐based diet with cornstarch on intake, digestion, rumen microbes and growth performance of Huzhou lambs

Thirty-six male Hu lambs consuming a rice straw-based diet were used in a 60-day trial to study the associative effects of cornstarch supplementation on intake, digestion, ruminal microbial population and growth performance. All animals were fed rice straw ad libitum together with 160 g/day of rapeseed meal and supplemented with cornstarch at levels of 0 (control), 60, 120 or 180 g/day, respectively. Increment of supplementary cornstarch showed little influence on rice straw intake. Optimal growth performance and highest apparent digestibility of organic matter was achieved in the 120 g/day cornstarch group (P < 0.05), while the digestibilities of neutral detergent fiber and crude protein were significantly decreased by 180 g/day cornstarch (P < 0.05). Similar results were observed for carboxymethyl cellulose activity and relative populations of cellulolytic bacteria (Ruminococcus albus, Ruminococcus flavefaciens and Fibrobacter succinogene). Blood urea nitrogen was reduced by supplementary cornstarch, indicating enhanced protein utilization efficiency. Carcass traits were all significantly improved by supplementary cornstarch. These results suggested that proper amounts of starch supplementation (within 0.5% BW) has little adverse effect on forage utilization, but could effectively improve growth performance. High levels of cornstarch, however, would decrease cellulase activity and populations of cellulolytic bacteria, and hence the digestibility of forage.

조사료원과 출하시기가 거세한우의 발육과 도체특성에 미치는 영향

본 시험을 수행하기 위해서 6개월령 거세한 우 64두를 공시하여 주구는 조사료원으로 목건초와 볏짚 처리구를 배치하였으며, 세구는 출하시기로 24개월, 26개월, 28개월 및 30개월 배치하였다. 본 시험은 조사료원 및 출하시기별 발육 및 육질에 미치는 영향을 구명하기 위하여 수행하였다. 발육 및 사료이용성은 목건초 급여구가 볏짚 급여구에 비하여 동일 출하월령에서 10~12% 정도 더 발육이 향상되었으며(p<0.05), 배합사료 요구량에서도 목건초 급여 구가 볏짚 급여구에 비하여 kg 증체당이 향상 되는 결과를 얻었다. 또한 도체등급에서도 등 지방두께 및 배최장근단면적은 출하월령이 증가할수록 증가하였으며, 근내지방도 역시 출하월령이 증가할수록 증가하는 경향을 보였다. 따라서 한우 고급육을 생산하기 위해서는 볏짚 보다는 목건초 급여로 출하시기를 28개월령 이상 사육하는 것이 바람직한 것으로 사료된다. This study examined the influence of forage source (grass hay and rice straw) and shipping time (24, 26, 28 and 30 months) on feed conversion ratio, growth performance and carcass characteristics of Hanwoo steers. Sixty four Hanwoo steers at 6 months age were fed either grass hay (n=32) or rice straw (n=32) for 24, 26, 28 and 30 months of age. Steers fed on mixed grass hay gained significantly higher body weight at 24, 26, 28 and 30 months compared with those fed on rice straw. Feed efficiency was slightly better in steers fed mixed grass hay compared to those fed rice straw. Back fat thickness and marbling score were increased with the age of steers (p<0.05). Carcass quality traits (meat color, fat color, texture and maturity) were not affected by forage source and shipping time. Shear force, cooking loss and water holding capacity of beef were reduced with advancing age of steers (p<0.05). Moisture content was lower and fat content was higher in beef produced from steers fed mixed grass hay than those fed rice straw (p<0.05). Beef juiciness was reduced with the advancing shipping time of steers. In conclusion, it would be beneficial to feed hay compared with rice straw during whole period of Hanwoo steer to produce high quality beef.

Effect of feeding rice straw and supplements on the performance of cattle under small farmer conditions

Tropical Agricultural Research and Extension is a peer-reviewed international scientific journal covering a wide range of subject areas in tropical and subtropical agriculture published quarterly by the Faculty of Agriculture, University of Ruhuna, Sri Lanka. The journal is also available on the Faculty of Agriculture, University of Ruhuna website https://www.agri.ruh.ac.lk/tare/index.htm .

Evaluation of mineral status in feed resources and effects of supplementation to farm animals in northern Ghana

A survey was conducted on the mineral concentration of available feed resources at three locations in the northern Guinea Savannah Zone between 1992 and 1997. The feeds were categorized into cereal crop residues, legume crop residues, grass forages, legume forages, and legume browse and agro-industrial by-products. Experimentscarried out involved balanced groups (age, sex and breed) of sheep using some of such forages and with or without access to commercial mineral licks. The animals were monitored for any changes in their live weightperformance. Dry matter (DM) intake by sheep of supplementary fed rice straw was also determined. Average concentration of calcium (Ca) in the feed samples surveyed was highest in the browse forages (1.21%) andlegume forages (1.13%). The lowest was recorded for the agroindustrialby-product (0.20%). However, phosphorus (P) was highest (1.6%) in the browse forages compared to that recorded in the cereal crop residues(0.06%). Copper (Cu) levels of 2.57, 7.1, and 7.6 mg kg-1 DM were observed for cereal forages, legume crop residues, legume forages and browse forages, respectively. The cereal crop residues contained 40.7 mg kg-1 of zinc (Zn) compared to 24.33 mg kg-1 in the browse forages.Manganese (Mn) concentration was 97.5, 143.3, 163.7, 231.4, 271.2, and 314.4 mg kg-1 DM for agro-industrial by-products, browse forages, grass forages, legume crop residues, forage legumes, and cereal crop residues in that order. Sheep exposed to commercial mineral lick consumed 4.7-8.0 g head-1 day-1. However, total supplementary rice straw intake was 7.0 per cent lower in animals on mineral lick. Sheep in the study generallyconsumed 13.5 per cent more of straw in the dry season (November-February) compared to the wet season (July -October). Sheep on natural grazing in the dry season and supplemented with rice straw with or without mineral lick gained 65.5 and 63.7 g head-1 day-1, respectively. Asignificantly (P< 0.001) lower daily gain of 26.7 g head-1 was recorded for sheep grazing natural pasture without any form of supplementation.

Effects of protein-free energy supplementation on blood metabolites, insulin and hepatic PEPCK gene expression in growing lambs offered rice straw-based diet

This study was conducted to investigate the effects of increasing levels of protein-free energy supplementation on blood glucose, urea nitrogen, insulin and gene expression of hepatic phosphoenolpyruvate carboxykinase (PEPCK) in growing lambs offered rice straw-based diet. Thirty-six male Hu lambs (3.5 months old) were divided into four equal groups according to body weight. All animals were fed rice straw&lt;I&gt; ad libitum&lt;/I&gt; and supplemented with cornstarch at levels of 0 (control), 60, 120, and 180 g/day, respectively, along with 160 g/day of rapeseed meal. The trial lasted for 60 days with the first 15 days for adaptation. Body weight change and feed intake were recorded. Blood samples were taken at different time points after feeding at the end of the trial, and analyzed for blood glucose, total protein, urea nitrogen and insulin. Liver samples were collected and analysed for the mRNA abundance of hepatic PEPCK. Increasing cornstarch showed a low effect on rice straw intake, but increased average daily gain of lambs significantly (&lt;I&gt;P&lt;/I&gt; &lt; 0.05). Blood glucose tended to increase with starch supplementation, but altered within a narrow range. Blood urea nitrogen was decreased significantly (&lt;I&gt;P&lt;/I&gt; &lt; 0.05) with increment in supplemental starch. Supplementation of starch at 120 or 180 g/day significantly increased the insulin concentration (&lt;I&gt;P&lt;/I&gt; &lt; 0.05) compared with the control. The abundance of cytosolic PEPCK (PEPCK-C) mRNA increased 2.47 times and 3.98 times with 60 and 120 g per day of starch supplementation compared with the control, respectively, while the supplementation of 180 g per day of starch showed a low effect on PEPCK-C gene expression (&lt;I&gt;P&lt;/I&gt; &gt; 0.05). Amounts of mitochondrial PEPCK (PEPCK-M) mRNA were not affected by the supplementation of starch at any level (&lt;I&gt;P&lt;/I&gt; &gt; 0.05). These results indicate that proper energy supplementation increases the expression of PEPCK-C, and consequently gluconeogenesis and blood glucose increase, while excessive energy may have an inhibitory effect on gluconeogenesis through insulin-involved mechanisms.

The stimulatory effect of the organic sulfur supplement, mercaptopropane sulfonic acid on cellulolytic rumen microorganisms and microbial protein synthesis in cattle fed low sulfur roughages

Two metabolism trials (experiments 1 and 2) were conducted to examine the effect of the organic S compound, sodium 3-mercapto-1-propane sulfonic acid (MPS) on feed intake, fiber digestibility, rumen fermentation and abundance of cellulolytic rumen microorganisms in cattle fed low S (<0.11%) roughages. Urea was provided in all treatments to compensate for the N deficiency (<0.6%) in the roughages. In experiment 1, steers (333 ± 9.5 kg liveweight) were fed Angleton grass (Dicanthium aristatum) supplemented with S in equivalent amounts as either MPS (6.0 g/day) or sodium sulfate (9.56 g/day). Supplementation of Angelton grass with either sulfate or MPS resulted in an apparent increase in flow of rumen microbial protein from the rumen. Sulfur supplementation did not significantly change whole tract dry matter digestibility or intake, even though sulfate and MPS supplementation was associated with an increase in the relative abundance of the fibrolytic bacteria Fibrobacter succinogenes and anaerobic rumen fungi. Ruminal sulfide levels were significantly higher in the sulfate treatment, which indicated that the bioavailability of the two S atoms in the MPS molecule may be low in the rumen. Based on this observation, experiment 2 was conducted in which twice the amount of S was provided in the form of MPS (8.0 g/day) compared with sodium sulfate (6.6 g/day) to heifers (275 ± 9 kg liveweight) fed rice straw. Supplementation with MPS compared with sulfate in experiment 2 resulted in an increase in concentration of total volatile fatty acids, and ammonia utilization without a change in feed intake or whole tract fiber digestibility even though S and N were above requirement for growing cattle in both these treatment groups. In conclusion, supplementation of an S deficient low-quality roughage diet with either MPS or sodium sulfate, in conjunction with urea N, improved rumen fermentation, which was reflected in an increase in urinary purine excretion. However, MPS appeared to have a greater effect on stimulating short-chain fatty acid production and ammonia utilization when provided at higher concentrations than sulfate. Thus, the metabolism of MPS in the rumen needs to be investigated further in comparison with inorganic forms of S as it may prove to be more effective in stimulating fermentation of roughage diets.

Supplementing Maize or Soybean Hulls to Cattle Fed Rice Straw: Intake, Apparent Digestion, In situ Disappearance and Ruminal Dynamics

Steers with ad libitum access to rice straw were assigned to four diets to evaluate the effects of maize or soybean hull supplementation on intake, in vivo digestibility, ruminal pH, VFA, ammonia-nitrogen (NH 3 -N) and in situ ruminal disappearance of feed nutrients by cattle consuming rice straw. Supplement treatments were: no supplement (RS); soybean meal at 0.127% BW (SBM); cracked maize at 0.415% BW plus 0.044% BW soybean meal (MAIZE); or soybean hulls at 0.415% BW plus 0.044% BW soybean meal (HULLS). The MAIZE and HULLS diets were formulated to provide approximately 4 MJ of NE m per kg of diet. Rice straw DMI was not affected (p = 0.34) by supplement. Apparent dry matter (DM) digestibility was greater (p<0.001) for MAIZE and HULLS (56.6 and 60.0%, respectively) than for steers consuming SBM or RS (51.8 and 44.4%, respectively). Apparent NDF digestibility was greater (p<0.0004) for HULLS than MAIZE (61.7 vs. 58.0%, respectively) and apparent ADF digestibility was greater (p<0.0008) for HULLS than MAIZE (61.1 vs. 49.2%, respectively). There was no difference in apparent hemicellulose digestibility (p = 0.43). Analysis of ruminal fluid collected 0, 2, 4, 6, and 8 h post-feeding revealed ammonia-nitrogen was greatest (p<0.05) for steers on SBM and HULLS diets at 2 h (24.08 and 22.57 mg/dl, respectively) and total volatile fatty acids was greatest (p<0.05) for HULLS at 4 h (230 mM/L). In situ disappearance, measured at 0, 2, 4, 6, 8, 16 and 24 h, indicated that SBM, MAIZE and HULLS tended to enhance the digestibility of DM and fiber components of rice straw. In situ disappearance of rice straw DM was greatest for SBM and/or HULLS from 4 to 24 h (p = 0.03). Rice straw NDF and ADF disappearance was enhanced by supplementation from 16 to 24 h (p<0.02). Rice straw DM, NDF and ADF disappearances at 24 h were similar for MAIZE and HULLS treatments. When feeding cattle rice straw diets, energy and protein-based supplements are essential. This study showed that fiber-based supplements are just as, if not more, effective as starch-based supplements in rice straw utilization. This study shows that soybean hulls, in spite of their high fiber content, are as efficient as maize for supplementing rice straw primarily because fiber in soybean hulls is highly digestible as shown by in vivo digestibility and in situ disappearance.