Processed Barley Grain Research Articles

STUDYING OF MECHANICAL PROPERTIES OF MATERIALS WITH PRONOUNCED ANISOTROPY OF STRUCTURE

Recently, the quality of grain that comes for processing has deteriorated. This is due to a decrease in the requirements for its quality. The most characteristic example is a grain of barley with pronounced anisotropy of properties and heterogeneity of structure. The feature of processing barley grain is its separation into fractions by size before further processing. The study of the mechanical properties of these fractions is relevant. (Research purpose) The research purpose is in studying experimentally the mechanical properties of barley grain using publicly available techniques and equipment. (Materials and methods) For the experiments, there were used fractions of barley grain divided by size before processing according to the known technology, collected in the flat part of the Belgorod Region of the Central Federal District of the Russian Federation in August 2020 and meeting the requirements of standards. Samples that have passed the stage of temperature treatment were selected for the study. (Results and discussion) The article presents the study of the mechanical properties of barley grains of three fractions by size after storage. The results of the research showed that the strength of barley grain having a moisture content of 14.3 percent, when tested for compression is 20 megapascals and does not depend on the grain size, and the grain itself has anisotropy. The hardness of the barley grain decreases with increasing grain size. (Conclusions) Deformation at the highest destructive compression stress does not depend on the grain size, but has a 1.6 times greater value under vertical loading than under horizontal. Studies have shown that it is possible to determine the mechanical properties of grain crops using standard techniques on modern universal testing facilities that allow measurements to be carried out with high accuracy.

Diets containing processed barley grain as a potential rumen bypass starch source enhance productive responses of lactating Holstein dairy cows.

Effect of diets containing untreated or processed barley grain [treated with sugar beet pulp extract (SBPE) or double sulphate of aluminium and potassium (ALUM)] and different levels of rumen undegradable crude protein (RUP) on production, rumen fermentation and blood metabolites of lactating Holstein cows were investigated. Untreated soybean meal (SBM) or xylose protected 'Yasminomax soy® (YAS)' was included to represent a low (LR, 4.2% DM) and high (HR, 5.4% DM) RUP diets, respectively. Experimental diet was as follows: (a) untreated barley grains with high RUP (HRCON); (b) untreated barley grains with low RUP (LRCON); (c) ALUM-treated barley grain with high RUP (HRAL; (d) ALUM-treated barley grain with low RUP (LRAL); (e) SBPE-treated barley grain with high RUP (HRSE); and (f) SBPE-treated barley grain with low RUP (LRSE). The experiment was conducted as a completely randomized design with lactating dairy cows (n=36) averaging 215±18days in milk, milk yield 31.7±5.8kg/day, 620±61kg body weight. Diets containing processed barley grain increased feed intake, while decreased both rumination and eating (p<0.001). Feed intake of dairy cows on Low RUP and High RUP were 23 and 24kg/day, respectively (p<0.01). Daily production of milk fat, protein, lactose and total solids was improved when the processed barley grain was included in the diets (p<0.05). Present study pinpointed that the inclusion of the processed barley grain in diets might improve production indices of dairy cows.

The effect of green tea waste extract on ruminal degradability and intestinal digestibility of barley grain

This study was conducted to investigate the effects of different levels of green tea waste extract (GE) on ruminal degradability and intestinal digestibility of dry matter (DM), crude protein (CP), and starch of barley grain. Therefore, barley grain was treated with 0 as control, and 5%, 10%, 15%, and 20% of GE. The potential of DM degradability (a + b) of barley grain treated with 15% and 20% of GE was significantly lower compared to other treatments (Linear [L] P < 0.05). The lowest (a + b) fraction of CP degradability was found in the barley grain treated with 20% GE (L P < 0.05). The (a + b) fraction and effective degradability of starch in barley grain treated with 15% and 20% of GE were significantly lower than those in other treatments (L and quadratic [Q] P < 0.05). The highest intestinal DM, CP, and starch digestibility were associated with barley grain treated with 10% GE (L and Q P < 0.05). Based on recent results, processing barley grain with GE leads to a decrease of DM, CP, and starch degradability. The treatment of 10% GE improved intestinal digestibility of the aforementioned nutrients; therefore, it can be used to protect barley grain against ruminal degradability.

Повышение эффективности микронизации зерновых культур на СВЧ установке с использованием перегретого пара

В работе исследованы вопросы высокотемпературной микронизации зерновых продуктов с использованием микроволнового нагрева и комбинации тепловых методов. Исследования проведены на основе промышленной микроволновой установки «Декстрин-2» производства ЗАО «НПП «Магратеп» г. Фрязино. Установка работают на промышленной частоте 915 МГц с возможностью регулировки мощности от 10 до 25 кВт и выполнена на основе согласованной нагрузки, в которой СВЧ-энергия поглощается в малом объеме зерна. Скорость нагрева зернопродуктов при максимальной мощности в данной установке превышает 5 градусов в секунду, а производительность установки в режиме высокотемпературной микронизации превысит 300 кг/час. В работе изучена возможность повышения производительности зерна ячменя путем введения предварительного прогрева зерна ячменя перегретым паром. В экспериментальных исследованиях обнаружено, что введение в засыпной бункер форсунки с многоточечным впрыском перегретого пара позволило не только повысить производительность установки, но и увеличить степень раскрытия зерна. Установлено, что обработка зерна паром приводит к повышению поглощения микроволновой энергии и улучшению условий работы микроволновой установки. Проведен анализ физико-механических свойств обработанного зерна ячменя только с использованием микроволновой энергии и с предварительным прогревом продукта перегретым паром в засыпном бункере. При комбинированном нагреве зафиксировано увеличение геометрических размеров зерновок с раскрытием их не только по «рубчику» но и поперек. Также уменьшилась кажущаяся плотность зерновок ячменя. Таким образом, введение предварительного нагрева перегретым паром при микроволновой обработке в установке «Дикстрин-2» позволит увеличить производительность установки и улучшить характеристики зерна при высокотемпературной микронизации.

Fusarium infection of malting barley has to be managed over the entire value chain

Fusarium head blight of malting barley is difficult to diagnose and difficult to prevent by crop protection measures. However, Fusarium species cause severe problems in processing barley grain and cause contaminations of malt and malt products with fungal toxins and possibly with toxin derivates. Therefore, we briefly summarize at which stage of malt production Fusarium infections cause which kind of problems and how such problems can be possibly managed in future malt production practice. We argue for a stronger focus on innovative diagnostics and development of appropriate crop protection measures to prevent problems Fusarium species cause once infected barley grain has entered the value chain.

Effects of particle size of processed barley grain, enzyme addition and microwave treatment on in vitro disappearance and gas production for feedlot cattle.

ObjectiveThe effects of particle size of processed barley grain, enzyme addition and microwave treatment on in vitro dry matter (DM) disappearance (DMD), gas production and fermentation pH were investigated for feedlot cattle.MethodsRumen fluid from four fistulated feedlot cattle fed a diet of 860 dry-rolled barley grain, 90 maize silage and 50 supplement g/kg DM was used as inoculum in 3 batch culture in vitro studies. In Experiment 1, dry-rolled barley and barley ground through a 1-, 2-, or 4-mm screen were used to obtain four substrates differing in particle size. In Experiment 2, cellulase enzyme (ENZ) from Acremonium cellulolyticus Y-94 was added to dry-rolled and ground barley (2-mm) at 0, 0.1, 0.5, 1, and 2 mg/g, while Experiment 3 examined the interactions between microwaving (0, 30, and 60 s microwaving) and ENZ addition (0, 1, and 2 mg/g) using dry-rolled barley and 2-mm ground barley.ResultsIn Experiment 1, decreasing particle size increased DMD and gas production, and decreased fermentation pH (p<0.01). The DMD (g/kg DM) of the dry-rolled barley after 24 h incubation was considerably lower (p<0.05) than that of the ground barley (119.1 dry-rolled barley versus 284.8 for 4-mm, 341.7 for 2-mm; and 358.6 for 1-mm). In Experiment 2, addition of ENZ to dry-rolled barley increased DMD (p<0.01) and tended to increase (p = 0.09) gas production and decreased (p<0.01) fermentation pH, but these variables were not affected by ENZ addition to ground barley. In Experiment 3, there were no interactions between microwaving and ENZ addition after microwaving for any of the variables. Microwaving had minimal effects (except decreased fermentation pH), but consistent with Experiment 2, ENZ addition increased (p<0.01) DMD and gas production, and decreased (p<0.05) fermentation pH of dry-rolled barley, but not ground barley.ConclusionWe conclude that cellulase enzymes can be used to increase the rumen disappearance of barley grain when it is coarsely processed as in the case of dry-rolled barley. However, microwaving of barley grain offered no further improvements in ruminal fermentation of barley grain.

Ruminal disappearance of phosphorus and starch, reticuloruminal pH and total tract nutrient digestibility in dairy cows fed diets differing in grain processing

Ruminal disappearance kinetics of nutrients such as phosphorus (P), starch and protein in cereal grains is determinant of their nutritional and health value in ruminants. The objective of the present in vivo and in situ trials was to evaluate whether feeding barley grain processed with lactic acid (LA), with or without thermal treatment, affects in situ degradation kinetics of nutrients, reticuloruminal pH dynamics, and apparent total tract digestibility (ATTD) in dairy cows. The experiment involved 6 rumen-fistulated Holstein cows in a double 3×3 Latin square design fed a diet based on differently processed barley grain: untreated grain as control (CON), or grain treated with 1% LA alone (LA diet), or 1% LA plus oven-heating (LAH diet) prior to feeding. Each experimental period lasted 21 d, with the first 11 d used for adaptation to the diets. The in situ trial consisted in the incubation of the differently treated barley grains (i.e., CON, LA, LAH) up to 48h in the rumen of cows fed diets containing the respective barleys. The reticuloruminal pH and temperature were continuously measured throughout the experiment via wireless indwelling sensors. In situ data demonstrated increased (P<0.001) disappearance of barley P, being on average more than twice as high during the first 24h of incubation with LA and LAH compared to CON barley. In contrast, the degradation of starch decreased (P<0.05) after 2h and 4h of the ruminal incubation, but not thereafter. Feed intake remained unchanged among treatment groups, whereas ATTD of dry matter was slightly greater (P=0.05) in cows fed the LA-treated barley. There was no effect of diet on reticuloruminal pH and temperature dynamics either. In conclusion, the present study indicates that treatment of barley grain with LA and LAH lowers rumen degradability of starch early after incubation, without affecting reticuloruminal pH and the ATTD of most nutrients. The improved ruminal disappearance of barley P suggests an improved solubility and faster ruminal availability of organic P of the treated grain, and warrants further investigations to tap its potential with regards to improved P nutrition and minimization of P excretion in dairy cows.

Long-term reticuloruminal pH dynamics and markers of liver health in early-lactating cows of various parities fed diets differing in grain processing

The present study aimed to investigate the long-term effect of feeding barley grain steeped in lactic acid (La) with or without thermal treatment on reticuloruminal pH dynamics and metabolic activity of the liver in 12 primiparous and 18 multiparous early-lactating dairy cows. All cows were included on d 21 postpartum and sampled until d 90 postpartum. Cows were fed a diet based on differently processed ground barley grain: untreated grain (control diet, CON), or grain treated with 1% La alone for 24 h before feeding (La), or with an additional oven-heating at 55°C for 12 h (LaH). The reticuloruminal pH and temperature were measured via indwelling sensors that allowed for continuous (every 10min) and long-term measurement from d 21 to 80 postpartum. Blood samples were taken on d 21, 40, and 90 of lactation and analyzed for liver enzymes aspartate aminotransferase (AST), gamma-glutamyltransferase, and glutamate dehydrogenase, as well as bilirubin, bile acids, and serum amyloid A. Dry matter intake was higher in multiparous cows (20.7±0.27 kg/d) compared with primiparous cows (18.2±0.33 kg/d), but was not affected by dietary treatment. Overall, the relatively short duration (51±5min/d) of reticuloruminal pH <5.8 suggests low risk of subacute ruminal acidosis throughout the experiment. Results indicated that La treatment of barley, with or without heat, lowered the time duration of pH <5.8 compared with CON, but only in primiparous cows (from 118±13 to 46±11 and 25±11min/d for CON, La, and LaH, respectively). In multiparous cows, the opposite effect of feeding the La-treated barley on time duration of pH <5.8 (11±8 vs. 46±9 vs. 57±9min/d for CON, La, and LaH, respectively) was observed. Multiparous cows generally showed higher pH readings and shorter periods in which the ruminal pH dropped below the threshold of pH 5.8. The reticuloruminal temperature was not affected by dietary treatment, whereas parity affected the time duration of reticuloruminal temperature >39.5°C, being 60±19min/d shorter in primiparous cows. The measured activities of the liver enzymes AST, gamma-glutamyltransferase, and glutamate dehydrogenase, as well as bilirubin, bile acids, and the acute phase protein serum amyloid A, were not affected by grain feeding. Additionally, only one small effect of parity on investigated serum variables was noticed, showing slightly but significantly higher values of AST in multiparous (80.5±1.4 U/L) compared with primiparous cows (76.0±1.7 U/L). In conclusion, our results indicate greater risk for primiparous cows to develop subacute ruminal acidosis-like conditions during early lactation than multiparous cows. The study also suggests limited benefits of feeding processed barley grain with La with or without thermal treatment to modulate ruminal tolerance of grain feeding, whereby differing effects in primiparous cows were observed compared with multiparous cows.

Effects of bulk density, precision processing and processing index on in vitro ruminal fermentation of dry-rolled barley grain

A study using a batch culture technique was conducted to evaluate the effects of bulk density (BD, g/L), processing method (PM; control vs. precision processing [PP]: sieving grains into large versus small kernels and rolling based on kernel size), and processing index (PI; BD after rolling/BD before rolling) on kinetics of gas production, dry matter degradability (DMD), molar proportions and total short chain fatty acids (SCFA) of dry rolled barley grain. The study was arranged in a 2×2×2 factorial design. Gas production and DMD were measured at 3, 6, 12 and 24h of incubation using rumen fluid from 3 fistulated beef heifers fed diet containing 700g barley silage and 300g of a barley grain-based concentrate. We hypothesized that incorporating other factors with PI would help improve prediction of the feeding value of processed barley grain. Barley samples were collected monthly from ten different feedlots in Southern Alberta for one year. Samples were ranked according to their BD into low (580g/L) and high (680g/L) BD which were subjected to different processing (control vs. PP) before being dry-rolled with extent of processing expressed as PI of 0.75 or 0.85±0.03. The dry-rolled samples used in the study were not subjected to further grinding. Cumulative gas production (GP; mL/g organic matter) was fitted to an exponential model GP=B(1−exp−c×[t−lag]). Processing method×PI interactions (P<0.01) were observed for asymptotic gas volume, rate, lag time and absolute initial gas produced during the first hour. In addition, a PM×BD interaction (P<0.05) was noted for asymptotic gas volume. Data from DMD at different times of incubation were fitted to a model DMD=a+b(1−e−c(t−L)). Effective degradability coefficients ranged from 0.18 to 0.26. Only PI had an effect (P<0.05) on the rate of DMD. Total SCFA values ranged from 30.2 to 40.1mmol/L. Apart from PM and PI interaction (P<0.05) on C2:C3, no other interaction was observed after 24h of incubation. Regression results showed that BD and PM were better for predicting rate of DMD than PI. This is consistent with our hypothesis that using only PI as a measurement for extensity of grain processing may not be reliable when barley grain kernels are highly variable in size.

Precision processing barley grain did not affect productivity of lactating dairy cows

Schlau, N., Duineveld, L., Yang, W. Z., McAllister, T. A. and Oba, M. 2013. Precision processing barley grain did not affect productivity of lactating dairy cows. Can. J. Anim. Sci. 93: 261–268. This study evaluated the effects of precision processing (PP; processing based on kernel size) barley grain on ruminal fermentation and productivity of lactating dairy cows. Twenty multiparous Holstein cows, including eight ruminally cannulated cows, were used in a replicated 4×4 Latin square design with 21-d periods. Diets contained light barley grain processed precisely using a narrow roller setting (LB), heavy barley processed precisely using a wide roller setting (HB), processed HB and LB mixed at equal proportions (PP), or equal parts of light and heavy barley grain processed at a single narrow roller setting (CON). All diets consisted of 40% barley grain, 40% barley silage, and 20% of a supplement premix. Comparisons were made between LB and HB to evaluate the effect of barley quality, and between PP and CON to evaluate the effect of precision processing. Dry matter intake, sorting index, ruminal fermentation characteristics, and nutrient digestibility were not affected by diet. In addition, milk yield and concentrations of milk fat, protein, and lactose were not different, although milk urea nitrogen concentration was greater for PP vs. CON and for LB vs. HB. These results suggest that precision processing barley grain based on kernel size may not drastically affect ruminal fermentation and milk production in lactating dairy cows.

보리의 사료가치평가와 한우 거세우 급여에 의한 발육 및 육질개선효과 구명

본 연구는 보리의 급여수준 또는 가공 형태가 반추위 내 발효특성과 소화율 및 한우의 성장과 육질에 미치는 효과를 조사하고자 실시하였다. 분쇄보리와 압편보리를 이용하여 반추위 fistula를 장착한 한우암소 4두를 이용하여 4종류 시험사료(옥수수구, Corn; 분쇄보리구, GB; 압편보리구, DRB; 분쇄압편보리구, GDRB)에 대한 소화시험을 수행하였고(시험 1), 아울러 19개월령 거세한우 40두를 공시하여 비육후기 한우 거세우의 보리 급여가 육질에 미치는 효과를 구명하기 위한 사양시험을 실시하였다(시험 2). 시험 1: 보리첨가 시험사료의 소화 및 영양학적 가치 조사1.사료 섭취에 따른 반추위 내 pH의 변화는 GB와 DRB에 비해 Corn 및 GDBR 형태에서 pH의 저하 폭이 더 컸으며, GDRB구는 최저 pH가 5.5까지 떨어져 반추위 내에서 사료분해가 급격하게 이루어지는 경향을 보였다. 2.암모니아농도의 변화는 시험사료에 따른 차이는 없었으나, GR구와 DBR구에서는 꾸준하게 다른 두 처리구에 비해 비교적 낮은 농도로 안정적인 발효환경을 보였다. 시험 2 : 비육후기 한우 거세우의 가공보리 첨가사료 급여에 따른 증체 및 육질 개선효과 1.시험 개시 후 280일이 지난 28개월령의 DRB구 거세한우의 평균 체중이 683kg로 가장 높았고, 분쇄 및 압편보리를 첨가한 GDRB구의 평균 체중이 653.3kg로 가장 낮았다. 2.옥수수구(Corn)와 분쇄보리(GB)를 섭취한 거세한우는 전 기간 비슷한 일당증체를 보였으며, GDRB구의 일당증체가 가장 낮았다. 그러나 DRB 사료를 섭취한 거세한우의 19~23개월령 평균 일당증체가 0.89kg이었고, 24~28개월령 사이에는 0.43kg로 다른 처리구에 비해 높은 증체 효과를 보였다. 3.보리의 가공 형태는 생체중, 냉도체중, 도체율, 등지방두께 및 육량지수 등에 영향하지 않았으나 등심단면적은 분쇄보리를 급여한 GB구에서 92.5cm2로서 현저히 증가되었는데(P< .015), 가장 작았던 GDRB구에 비해 16% 증가되었다 4.분쇄보리가 함유된 GB구의 근내지방도는 평균 5.5로서 가장 높았다. 육색은 RDB와 GDRB가 공히 4.6으로 다른 처리구에 비해 0.2정도 밝았으며, 지방색 역시 보리를 더 많이 섭취된 GDRB에서 현저히(P<.002) 밝은 것으로 나타났다. 그러나 성숙도 면에서는 근내지방이 가장 높았던 GB에서 가장 좋았다(P<.018). 5.옥수수와 보리위주의 비육후기 사료를 섭취한 거세우 등심근육에서 수분과 조단백질 함량은 처리간 차이가 없었으나 지방 함량은 GDRB의 거세한우에서 18.55%로 타 처리구에 비해 높았다(P<.01). 6.등심근의 육색 중 적색도(a*)는 처리간 거의 비슷한 수준이었으나, 보리급여와 급여량이 많을수록 명도(L*)와 황색도(b*)가 증가하여 육색이 개선되는 경향이었는데, 등심의 육색소 함량은 oxy-myoglobin 함량이 보리 급여구에서 현저히(P<.015) 높았다. 전단력은 DGB 처리구가 가장 낮아 연도가 가장 좋았으나 보수력, 가열감량 등에서는 처리간 차이가 없었다. 7.지방산 조성의 경우 GDRB 처리구에서 linolenic acid(C18:3 n3)및 n6/n3 비율이 각각 현저(P<.049, P<.009)하게 높았으나 다른 지방산은 처리간 유의차가 없었다. This study was carried out to determine the effects of processing methods of barley as a proper source of grain in diets of Hanwoo on fermentation pattern in the rumen fluid and digestibility of the diets, the growth performance and carcass characteristics of Hanwoo. The degree of ruminal pH change in the cows fed diets of the Corn(corn basis) and GDRB(ground and dry-rolled barley) tended to be greater than those in the cows fed other two diets (ground barley, GB and dry-rolled barley, DRB). The diet of GDRB showed the lowest ruminal pH(5.5), indicating the rapid degradation of the diet in the rumen. Although ammonia concentration was not affected by diet, the GR and DBR diets maintained the low concentrations of ruminal ammonia compared with other two treatments. And the effects of feeding processed barley grain on body weight gain and meat quality of Hanwoo steers were as follows. Steers fed DRB diet had the highest body weight, 683.0kg at 28 months old, while those fed the GDRB showed the lowest body weight, 653.3kg. The average daily gain(ADG) was similar between the steers fed Corn and GR throughout the whole period, but the GDRB showed the lowest ADG. The steers fed the DRB showed the significant increase in ADG(0.89kg/d from 19 to 23 months old and 0.43kg/d from 24 to 28 months old) compared with those fed other diets. Feeding diets containing corn and/or barley did not influence live body weight, cold carcass weight, carcass yield, back-fat thickness and carcass grade of Hanwoo steers.

Extent of processing of barley grain did not affect productivity of lactating dairy cows

The objective of this experiment was to evaluate effects of extent of processing of barley grain on productivity of lactating dairy cows. The barley grain (Metcalf variety; 168 g/kg neutral detergent fiber assayed with a heat stable amylase and expressed exclusive of residual ash (aNDFom); 68.3 kg/hL in test weight) was either finely or coarsely steam-rolled. The Processing indices were 0.825 ± 0.007 and 0.687 ± 0.003 (mean ± standard deviation) for coarsely steam-rolled barley grain (CR) and finely steam-rolled barley grain (FN), respectively. Sixty Holstein cows (191 ± 10.6 days in milk; 643 ± 10.8 kg body weight) were used in a cross-over design with 14 d periods. The experimental diets contained either CR or FN at 384 g/kg of dietary dry matter. The in situ starch disappearance was greater for FN compared with CR, but the extent of processing barley grain did not affect productivity of dairy cows in this study; neither dry matter intake, milk yield, milk energy output, nor milk fat concentration was affected by treatments. Although, statistically significant differences were observed for some production parameters, the magnitude of the differences between treatments was not large enough to be of practical importance. Animal responses in milk yield and milk fat concentration were similar among cows varying in pre-trial milk yield; treatment effects were not observed even for high producing cows. It is speculated that barley grain with low aNDFom concentration requires less processing with marginal benefits from more extensive processing. Effects of extent of processing barley grain have been extensively evaluated for beef cattle, but little is known for the effects on productivity of dairy cows. The interaction between extent of processing and quality of the grain prior to processing warrants further investigation.

Effects of frequency of polyethylene glycol and protein supplementation on intake and digestion of Acacia cyanophylla Lindl. foliage fed to sheep and goats

Five Noire de Thibar sheep and five local breed goats (initial average BW 41 and 39.5 kg, respectively) were used in two 5×5 simultaneous Latin squares designs to test the effect of the frequency of polyethylene glycol 4000 (PEG) supply and protein supplementation on intake and digestion of Acacia cyanophylla (acacia) based diets. All animals received on DM basis, 280 g of oat-vetch hay, 230 g of processed barley grain and freshly cut acacia ad libitum (D0). Animals on diets D1, D2 and D3 received 40 g of polyethylene glycol 4000 (PEG) once daily, every 2 days and every 3 days, respectively. Diet D4 included only 50 g of soybean meal. The experimental period comprised 21days for adaptation and 7 days for measurements. Feed intake, apparent digestibility of OM, CP and CF and N-retention were measured. Sheep and goats consumed similar amounts of acacia ( P>0.05) averaging 53.8 g DM/kg BW 0.75. Irrespective of the frequency of administration, PEG had no effect on acacia and water intakes for both animal species. While OM and CF digestibility of diets was not affected by PEG supply, there was a significant increase of CP digestibility of acacia-based diets in animals receiving PEG daily (D1) or every 2 days (D2). N balance was positive in all diets. Compared to the control diet (D0), animals given PEG daily or at 2 days-frequency or soybean meal exhibited improved N retention ( P<0.05). It is concluded that PEG supply improved the N value of acacia-based diet. This improvement could be obtained when PEG was supplied daily or at 2-day intervals. Further research is needed to confirm these findings on growing lambs and kids.

The effect of ammoniated and roasted barley on rumen pH, milk yield and milk composition of lactating dairy cows

Cereal grains can provide the major source of energy in diets in order to meet the nutrient requirements of high producing dairy cows. However the amount of starch that can be included in the diets of dairy cows is limited particularly if starch is rapidly fermented such as barley starch. Reduction of feed intake, rumen pH, milk fat test, microbial growth and other metabolic disorders are expected if ruminally degradable starch is fed in amount that cant be efficiently metabolized by rumen microbs. Various techniques for processing barley grain have been developed to decrease the degradability of dry matter in rumen without reducing its extent of digestion. McNiven (1995) showed roasting of barley is more effective treatment. The objective of this experiment was to study of effects the roasting and ammoniation of barley grain on rumen pH, feces pH, milk yield and milk composition in dairy cows.

Effect of dietary factors on distribution and chemical composition of liquid- or solid-associated bacterial populations in the rumen of dairy cows.

Effects of dietary factors including kernel thickness of processed barley grain, ratio of forage to concentrate, and forage particle length on chemical composition of bacteria, bacterial colonization of feed particles and distribution in the rumen, and duodenal flow of bacteria in dairy cows were evaluated. The experiment was designed as a double 4 x 4 quasi-Latin square with a 2 x 2 x 2 factorial arrangement of treatments using eight lactating cows with ruminal and duodenal cannulas. Barley grain was steam-rolled to two thicknesses: coarse (1.60 mm) or flat (1.36 mm); ratio of forage:concentrate was low (35:65) or high (55:45) (DM basis); and forage particle length was long (7.59 mm) or short (6.08 mm). Cows were offered ad libitum access to a total mixed diet. Chemical composition was different (P < 0.01) between liquid-associated bacteria (LAB) and solid-associated bacteria (SAB). Reduced barley thickness increased (P < 0.05) N content and 15N enrichment, but a high ratio of forage:concentrate decreased (P < 0.01) 15N enrichment of both the LAB and SAB. Significant differences between AA composition of the LAB and SAB were observed for 15 out of 17 AA studied. Bacterial colonization was linearly increased (P < 0.01) from about 5 to 70% as particle length of rumen contents was reduced from 3.35 mm to 0.15 mm (sieve size). The degree of colonization on each fraction of the rumen particulate matter was only affected (P < 0.10) by the ratio of forage:concentrate, with consistently higher (P < 0.10) bacterial colonization noted for high than for low forage:concentrate diets. Of the total bacterial mass within the rumen, less than 20% was associated with the liquid and over 70% was associated with the small particles that passed through the 0.6-mm sieve. Although the bacterial pool in the rumen was lower (P < 0.04) when flatly rolled barley rather than coarsely rolled barley was fed, bacterial flow to the duodenum was greater (P < 0.10) with increasing ratio offorage:concentrate. The present results confirm the differences of chemical composition and biomass for LAB and SAB. Manipulation of dietary factors such as ratio of forage:concentrate have the potential to alter bacterial colonization of rumen particles and the relative proportion of LAB to SAB, which were positively correlated to bacterial flow to the duodenum.

Effect of processing barley and wheat grain on the digestion of silage-based diets by breeding ewes

AbstractFifty-six individually penned pregnant ewes were offered silage ad libitum with wheat or barley in a replicated experiment. Each of these cereals was either unprocessed or processed by rolling or milling and was offered at 300 g/day from 6 weeks before lambing and at 600 g/day from 3 weeks before lambing. Five and 2 weeks before lambing, total faeces were collected over 6-day periods. On average proportionately 0·18 of the unprocessed wheat and 0·20 of the unprocessed barley consumed was recovered as intact grain in the faeces. Mean digestibility of the organic matter in the complete diet increased from 726 g/kg on whole to 748 g/kg on rolled and 759 g/kg on milled cereal (P &lt; 0·01) at the 300 g/day level and from 721 g/kg on whole to 766 g/kg on rolled and 772 g/kg on milled cereals (P &lt; 0·001) at the 600 g/day level. When the effect of egested whole grain was removed there was no evidence of an effect of cereal processing on organic matter digestibility and although digestibility of fibre was higher with whole than with processed grain the effect was not significant. Wheat-based diets were more digestible than barley-based diets and, compared with barley, wheat appeared to have a beneficial effect on fibre digestion.

The utilization of whole or bruised barley grain of different moisture contents given to beef cattle as a supplement to a forage-based diet

SUMMARY1. Fifty-four weaned single-suckled steer calves aged 11 to 14 mo were individually fed 2 kg wet distiller's grains, 10 kg swedes and an average of 11·5 kg grass silage daily. The quantity of silage offered was adjusted during the experiment in accordance with a live weight related scale. There were six treatments differing in the physical form, moisture content and level of barley grain offered. A nil barley supplement was compared with 2·5 kg barley dry matter daily offered either whole or bruised having been prepared for storage by drying (84·6% DM) and by treatment with propionic acid (79·9% DM); dried barley was also offered whole (at approximately 50% DM) after soaking in water for 24 hr. Each replicate of six cattle, one animal from each treatment, was slaughtered when all its members were subjectively estimated to have the required minimum body condition and minimum estimated carcass weight (186 kg) for marketing.2. A supplement of barley grain caused increases in daily live-weight gain, slaughter weight, carcass weight and carcass fat content; and reduced carcass lean and bone content. These effects were increased if the barley grain was processed by bruising compared to being consumed unprocessed (whole). There was no indication that the method of preparation for storage or the moisture content of the barley grain when consumed affected the results of the experiment. It was concluded that the costs of processing barley grain by bruising for feeding to growing cattle for slaughter will be exceeded by the value of the additional animal performance obtained in comparison to feeding whole barley grain.