Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Master of Science / Department of Animal Sciences and Industry / Terry Houser / Crossbred yearling steers (n = 144 initial BW 367 ± 18.46 kg) were randomly allotted by BW to a randomized complete block design with a 2x3 factorial treatment arrangement to 1) assess the impact of supplementing dried distiller grain with solubles (DDGS) while grazing late season forage for 90 d and 2) the impact of a short feeding period on animal performance, carcass characteristics and meat quality traits. Treatments consisted of DDGS supplementation during grazing (0 or 1% of BW as DDGS; DM basis) and finishing days on feed (DOF;75, 100, 125). During grazing supplemented cattle had greater (P < 0.01) ADG than un-supplemented cattle but un-supplemented cattle had greater ADG than supplemented cattle during the finishing period. There were no differences between grazing treatments for DMI (P = 0.91) during the finishing period. Supplemented cattle had decreased (P = 0.02) G:F during the finishing period compared to un-supplemented cattle. Supplemented cattle had heavier (P < 0.01) HCW and larger (P = 0.02) LM area than un-supplemented cattle. Increasing DOF linearly increased (P ≤ 0.03) HCW, 12th rib fat thickness, LM area and USDA marbling score. No differences were observed for USDA yield grade. Increasing DOF decreased (Linear; P < 0.01) carcass protein %, moisture %, and increased (Linear; P < 0.05) carcass fat %. Increasing DOF increased (Quadratic; P = 0.01) L* values, while decreasing (Quadratic; P < 0.01) a* and b* values for external fat color. No differences were observed with respect to the percentages of any fatty acids for any treatment. Increased (P = 0.01) sensory off-flavors were present at 100 DOF when compared to 125 DOF. No other differences among treatments were observed for any sensory traits, instrumental tenderness, lean color or fatty acid profile for any treatment. In conclusion, supplementing cattle with 1 % DDGS during grazing altered grazing and feedlot performance as well as impacted carcass characteristics. In addition, utilizing a shortened feeding period had minimal effects on meat quality traits, but increasing DOF resulted in a greater amount of whiter external fat.

Grãos secos de destilaria com solúveis (DDGS) são uma fonte alternativa protéica e energética, de baixo custo se comparado com a farinha de peixe e o farelo de soja. Neste estudo avaliou-se a influência dos diferentes níveis de DDGS no desempenho produtivo e reprodutivo de lambari-de-rabo amarelo, bem como analisou-se a viabilidade econômica deste produto. O delineamento experimental foi inteiramente casualizado composto de 4 tratamentos (níveis de DDGS) e 4 repetições. Foram elaboradas dietas contendo 0%, 10%, 20% e 30%, de DDGS em substituição parcial e total do farelo de soja e quirera de arroz. Um total de 2400 alevinos de lambari foram estocados em 16 tanques de 500L, contendo biofiltro e um sistema individual de recirculação de água, à densidade de 0,3 peixes/ L. Os peixes foram alimentados 4 vezes ao dia no primeiro mês e 2 vezes nos meses subsequentes durante 150 dias, à taxa diária do arraçoamento de 5% de peso vivo. Mensalmente os peixes foram pesados e no final determinou-se os parâmetros produtivos tais como: ganho de peso, índice de conversão alimentar, taxa de sobrevivência, taxa de crescimento específico, taxa de eficiência protéica, índice de crescimento instantâneo, taxa de ganho de peso, fator de condição corporal e composição química do corpo inteiro e do músculo. Após o período de alimentação foram determinados os seguintes parâmetros reprodutivos: índice gonadossomático, volume dos ovos, fertilidade inicial, fertilidade inicial relativa, taxa de fertilidade, índice de desova, fertilidade final, fertilidade final relativa, taxa de eclosão e sobrevivência, diâmetro dos ovos e do vitelo e comprimento das larvas. Foi feita a histologia das gônadas das fêmeas e dos machos e avaliação do sêmen. Também se analisou a viabilidade do uso do DDGS. Os dados foram submetidos à análise de variância (&alpha; = 0,05), à regressão e teste de tendência, e para a comparação das médias de viabilidade económica utilizou-se o teste Tukey por meio do programa SAS. A adição de DDGS não afetou os parâmetros produtivos (P &GT; 0,05), exceto para a matéria mineral do músculo (P &LT; 0,05). Ocorreram diferenças (P &LT; 0,05) para fertilidade inicial, peso, comprimento total e padrão dos machos. Histologicamente não se evidenciou diferenças entre as estruturas morfológicas dos ovários, nos testículos dos peixes alimentados com dieta de 30% de DDGS apresentaram células espermáticas abundantes, portanto o desenvolvimento gonadal não foi influenciado negativamente pelo DDGS. Economicamente as dietas contendo DDGS (10, 20 e 30%) foram respetivamente 2; 7 e 11% menos onerosas do que a dieta com farelo de soja e quirera de arroz. As médias do custo do ganho não diferiram (P &GT; 0,05) entre si, indicando que se pode substituir o farelo de soja e quirera de arroz com o DDGS sem grandes prejuízos no desempenho e a baixo custo de alimentação. / Distillers dried grains with solubles (DDGS) is a protein and energy source alternative, is used to formulate diets to feed fishes in replecement of fish meal and soya, and the cost is low. This research was carried out to investigate the influence of dietary inclusion of DDGS levels on growth and reprodution performance and evaluate its economical value of lambari. The experimental delineament were four isonitrogenous diets were formulated that contain 0%, 10%, 20%, and 30% of DDGS in substituation of soja meal and broken rice. A total of 2400 lambari were stored in 16 tanks 500L, provided with a biofilter and a single system of water recirculation, density were 0,3 fish / L. During 150 days the groups of fish were fed with experimental diets until visual satiety four times per day for the first month and twice in the remaining months, the daily rate of feeding were 5% of body weight. Each month the fish were weighed for determination of production parameters such as: weight gain, feed conversion rate, survival rate, specific growth rate, protein efficiency ratio, instantaneous growth rate, weight gain rate, condition factor physical and chemical composition of the whole body and muscle. After the feeding period terminated reproductive parameters such as: gonadossomatic index, egg volume, initial fertility, relative initial fertility, fertility rate, spawning rate, final fertility, final relative fertility, hatching and survival rate, diameter of eggs and length of the larvae. It was made the histology of the gonads (females and males) and semen evaluation. Also analyzed the economic viability of using DDGS in the diets. The data were subjected to ANOVA, regression and trend test, economical value analised by Turkey test (&alpha; = 0,05). Addition of DDGS did not affect the productive parameters (P &GT; 0,05) except for the mineral of muscle (P &LT; 0,05). There were differences (P &LT; 0,05) in initial fertility (FI), weight, total and pattern length of males. Histologically no detectable morphological differences between the structures of the ovaries, but testes of fish fed with diet of 30% DDGS showed abundant sperm cells, therefore gonadal development was not negatively influenced by the DDGS. Economically diets containing DDGS (10, 20 and 30%) were respectively 2; 7:11% cheaper than the diet with soy meal and broken rice. The cost gain was no significant (P &GT; 0.05). The result from this resarch shows that DDGS can replace soybean meal and broken rice without major losses in performance and low cost supply.

L'arsenic, existe dans l'environnement sous une grande variété de formes et à divers degrés d'oxydation. Aux pH naturels, l'arsenic libre se rencontre essentiellement sous forme inorganique aux degrés d'oxydation +III (arsénite) et +V (arséniate). Il est reconnu que l'efficacité des processus d'élimination de l'arsenic dépend fortement de la possibilité de convertir les espèces de l'arsenic (III) en celle de l'arsenic (V), plus faciles à extraire. La recherche développée au cours de cette thèse démontre d'abord qu'il est possible d'éliminer l'arséniate de solutions aqueuses par extraction par des polymères solubles (LPR : liquid-phase polymer-based retention). La technique LPR utilise l'ultrafiltration sur membrane pour la séparation, basée sur des effets de taille, d'espèces ioniques suite à leur complexation par des polyélectrolytes solubles. Les espèces oxo-anioniques de l'arsenic(V), associés à des polyélectolytes du type polyalkyammonium, ne passent pas à travers la membrane et peuvent être ainsi séparés des espèces non-complexées de plus petite taille. Nous avons aussi montré la grande activité catalytique des matériaux composites du type nanoparticules de Pt0 et Pd0 dispersées dans des matrices de poly(pyrrole-alkylammonium), pour l'oxydation électrochimique de l'arsénite en arséniate. En particulier, des microélectrodes de carbone modifiées par des films de ces nanocomposites ont été appliquées à l'analyse de l'arsenic(III). Enfin, l'oxydation exhaustive de solutions d'arsénite a été réalisée sur des électrodes de carbone modifiées de grande surface. L'utilisation de sels poly(alkyl-ammonium) jouant le rôle à la d'électrolyte support et d'agent d'extraction des espèces de l'arsenic(V) a permis de combiner les processus d'électrocatalyse et d'extraction par LPR, permettant ainsi d'extraire efficacement des traces d'arsenic de solutions aqueuses.

L'arboriculture en milieu méditerranéen nécessite un apport d'eau via l'irrigation important, notamment pendant la période estivale. Pour améliorer l'efficience d'utilisation de l'eau, il convient de mieux connaître les besoins en eau de l'arbre et les zones d'exploration et d'exploitation des racines. La croissance des racines varie dans le temps et dans l'espace en lien avec des facteurs endogènes, en particulier la disponibilité en assimilats carbonés, et des facteurs exogènes comme les propriétés du sol. Ces facteurs sont modulés par les pratiques culturales, et en particulier l'irrigation, le compactage du sol et l'éclaircissage, qui affectent la croissance racinaire, et d'une manière générale le fonctionnement global de l'arbre. La dynamique de croissance des racines est ponctuée par deux périodes de croissance intense. La première période de croissance intense se situe tôt dans la saison, en avril-mai, pendant la phase de durcissement du noyau des fruits. En début de saison la demande en carbone à l'échelle de l'arbre est importante (forte croissance des feuilles, fruits, rameaux, racines) et nécessite la mobilisation intense des réserves carbonées présentent sous forme d'amidon. La charge en fruits affecte la croissance des racines et des fruits, et la restriction hydrique affecte surtout la croissance de la partie aérienne. La deuxième période de croissance racinaire intense intervient après la récolte en juillet-août, quand les feuilles et les rameaux ont finis leur croissance. La compétition est moins forte et l'amidon s'accumule, surtout chez les arbres sous restriction hydrique. L'accumulation d'amidon résulte d'une plus grande sensibilité de la croissance au déficit hydrique que la photosynthèse. Pendant les périodes de croissances racinaires intenses, le diamètre apical et la longueur de leur zone apicale non ramifiée des racines sont augmentés, ainsi que les teneurs en sucres solubles dans les pointes racinaires. Les paramètres architecturaux racinaires et les teneurs en sucres solubles dans les pointes racinaires sont de bons indicateurs de la dynamique de croissance racinaire. La répartition des racines au verger est très variable et dépend des propriétés du sol. Les racines des arbres bien alimentés en eau ont colonisé surtout les volumes de sol sous le rang des arbres (proches des goutteurs) jusqu'à 1 m de profondeur. Au contraire les racines des arbres sous-alimentés en eau ont colonisé surtout les 50 cm en profondeur sous le rang et vers l'inter-rang. Les racines se sont réparties dans les zones les moins contraignantes pour leur croissance, qui sont plus restreintes quand l'irrigation est restrictive. En conditions non contraignantes, de par une faible densité de sol ou une forte teneur en eau, la vitesse de croissance, et notamment des grosses racines, est forte. Par contre, les fines racines ont une vitesse de pénétration des sols contraignants plus rapide. La contrainte mécanique entraîne aussi une baisse de la hiérarchisation des systèmes racinaires, les racines latérales seront davantage ramifiées

This study assessed the value of triticale dried distillers grains with solubles(DDGS) in a feedlot finishing diet using 144 intact, and 16 ruminally cannulated crossbred yearling steers. Substituting triticale DDGS for a portion of dry-rolled barley grain (20% diet DM) decreased the prevalence of ruminal acidosis and tended to increase dry matter intake and fat deposition, but increased the incidence and severity of liver abscesses. Further substitution of triticale DDGS for barley silage (5 and 10% diet DM) increased the prevalence of ruminal acidosis, but tended to improve feed efficiency without affecting carcass characteristics. These findings suggest that feedlot finishing diets containing triticale DDGS allow producers to decrease dietary forage inclusion without affecting performance, but may require use of an antimicrobial to control liver abscesses. / Animal Science

Owing to the increasing demand for alternative fuel additives, the Canadian ethanol industry has grown tremendously. In Western Canada, wheat has been the dominant feedstock for ethanol production because of steadily increasing domestic production and higher ethanol yields. Low protein and high starch wheat varieties have further increased the potential of grain-based ethanol production. As a consequence, the increased ethanol production has demonstrated an exponential increase in the availability of its co-products. Depending on the processes used, several co-products are produced, such as bran, condensed distillers solubles (CDS), and distillers dried grains with solubles (DDGS). Wheat bran is obtained as the co-product when debranning is incorporated in ethanol production. Debranning of wheat feedstock may be integrated into the ethanol production process to improve ethanol quality and yield. Debranning follows the principles of abrasion and friction. It improves the starch content of the feedstock and the fermentation efficiency of the ethanol plants. Several abrasive equipment that generate products having good quality and desirable ethanol yield are being used commercially. Among these, the Satake mill and the tangential abrasive dehulling device (TADD) are prominent, having high debranning efficiency, levels of sanitation, and improved production rates. In this thesis, the laboratory debranning process using these two equipment was optimized by varying the process variables in order to improve the ethanol production process. In the Satake mill, the sample size (30 and 200 g), rotational speed (1215, 1412, and 1515 rpm), grit size (30, 36, and 40), and retention time (30, 60, and 90 s) were varied. In the TADD mill, the sample size (30 and 200 g), grit size (30, 36, 50, and 80), and retention time (120, 180, 240, and 300 s) were varied while maintaining a constant rotational speed of 900 rpm. The experimental results indicated that in the Satake mill, 200 g sample size, 1515 rpm rotational speed, 30 grit size, and 60 s retention time provided optimal debranning and starch separation efficiency. For the TADD mill, 200 g sample size, 900 rpm rotational speed, 50 grit size, and 240 s retention time provided optimal results. Increased availability of ethanol co-products from the pretreatments and other processes brings forth the need for broadening the areas of application of these co-products. Among the various applications, the usage of the co-products as animal feed is predominant. Ethanol co-products have been traditionally incorporated as ingredients for animal feed. This thesis is aimed at combining the wheat bran and CDS in varying proportions (70:30, 80:20, and 90:10) and producing high quality animal feed pellets. Laboratory-scale pelleting was done at varying pelleting temperatures, 60, 75, and 90°C, to optimize the pelleting process. The results of laboratory-scale single pelleting indicated that 90:10 bran-CDS ratio and 90°C pelleting temperature produced pellets having good physical properties. Pilot-scale pelleting was done to verify the optimized variables, and to produce dimensionally stable and highly durable feed pellets. The results showed that 70:30 bran-CDS mixture produced pellets with high nutrient content and physical properties (760.88±2.04 kg/m3 bulk density and 97.79±0.76% durability). Similar to the single pelleting results, high pelleting temperatures (75°C) produced pellets with desirable physical properties. However, on cooling, the bulk density and durability change was the highest for 70:30 bran-CDS pellets, indicating an improvement in the physical characteristics. In conclusion, the bran and CDS, the two co-products of the ethanol industry, could be combined to produce feed pellets having good physical and nutritional properties.

Three experiments were conducted to determine the effects of supplementing wheat-based dry distillers grains with solubles (DDGS) on cow performance, forage utilization, and production costs. In the first two experiments, 48 dry, pregnant Black Angus cows (mean BW±SD; 598.2±4.2 kg) stratified by body weight (BW) and days pregnant were allocated randomly to one of three replicated (n=2) treatments. Cows were managed on stockpiled crested wheatgrass pasture (TDN=49.0, CP=7.3 (% DM)) in experiment one (EXP 1) and barley straw-chaff residue (TDN=45.4, CP=8.6 (% DM)) in experiment two (EXP 2). EXP 1 supplement treatments were (1) 100% DDGS (70:30 wheat:corn blend; DDGS); (2) 100% commercial supplement (COMM); or (3) control no supplement (CONT). EXP 2 supplement treatments were (1) 100% DDGS (70:30 wheat:corn blend; DDGS); (2) 50% DDGS + 50% rolled barley (50:50); or (3) 100% rolled barley grain (control; BARL). Forage utilization was measured for both trials using the herbage weight disappearance method. Cow BW, body condition score (BCS), and rib and rump fat were measured at the start and end of trial and cow BW was corrected for conceptus gain based on calving data. There was no effect (P > 0.05) of treatment on forage utilization in either experiment. In EXP 1, cow performance was not affected (P > 0.05) by supplement strategy. In EXP 2, BW change was 11.3, 6.8, and -6.5 (P < 0.01) for DDGS, 50:50, and BARL, respectively. Because forage utilization was not affected, the difference in cow BW was the result of supplement type. Costs per cow per day in EXP 1 were $0.66, $0.68, and $0.60 for DDGS, COMM, and CONT, respectively. In EXP 2, costs per cow per day were $0.79, $0.80, and $0.80 for DDGS, 50:50, and BARL treatments, respectively.<p> In experiment three (EXP 3), four ruminally cannulated beef heifers were individually fed a basal ration of 75% ground barley straw and 25% ground grass hay (TDN=46.3, CP=7.5 (% DM)). Heifers were supplemented with either (1) DDGS (70:30 wheat:corn blend; DDGS); (2) commercial range pellet (COMM); (3) barley grain and canola meal (BAR+CM); or (4) control no supplement (CONT). Forage intake, apparent total tract digestibility, and passage rate; rumen fermentation parameters; and the rate and extent of forage degradation were measured. Forage intake, passage rate, and apparent total tract digestibility of DM, NDF, and ADF were not affected (P > 0.41) by treatment. Apparent total tract digestibility of CP was increased (P = 0.02) by supplementation, but was not different between DDGS, COMM, and BAR+CM treatments. Ruminal pH was not affected (P = 0.20) by treatment diet, but rumen ammonia-N was increased (P < 0.01) by supplementation. The potentially degradable and undegradable forage fractions were affected (P < 0.02) by supplementation, reducing the extent of forage degradation. Also, there was a tendency (P = 0.06) for the rate of forage DM degradation to increase when supplements were fed. The results of these experiments indicate that wheat-based DDGS can be used as a supplement for beef cows consuming forages with similar or greater effects compared to a commercial pellet and barley grain. DDGS had similar effects on rumen metabolism as the commercial range pellet or barley grain and canola meal, suggesting DDGS can be substituted on a unit basis with these supplements. As such, the inclusion of wheat-based DDGS as a supplement for beef cows will depend on the initial price of the supplement.

Actualmente, en el área de los biomateriales destinados a la fijación y regeneración ósea, existe un interés creciente en el desarrollo de materiales que sean reabsorbibles y a su vez, capaces de estimular la regeneración del hueso. En el caso de los materiales para fijación ósea, la idea es crear un material que sea capaz de soportar las cargas iniciales y luego se degrade de forma gradual y transfiera las cargas de forma progresiva al nuevo hueso, evitando así una segunda intervención quirúrgica para la extracción del implante. En el caso de los materiales para regeneración ósea, el objetivo final es diseñar materiales que sean reemplazados de forma paulatina por el nuevo tejido.Esta tesis reúne una serie de estudios, realizados con el fin de desarrollar diferentes materiales biodegradables basados en el polímero PLA y el vidrio G5, que es un vidrio de fosfato de calcio dentro del sistema P2O5-CaO-Na2O-TiO2. Se han elaborado materiales compuestos biodegradables no porosos y porosos (andamios tridimensionales), para la fijación y regeneración del tejido óseo respectivamente. Así como también, se han desarrollado estructuras porosas de vitrocerámica, también para aplicaciones en ingeniería de tejidos. Cada uno de los materiales desarrollados ha sido caracterizado inicialmente en función de sus propiedades físico-químicas. Dado que son materiales para implantación y biodegradables, también se ha evaluado tanto la respuesta biológica, como el comportamiento de los mismos a lo largo de diferentes períodos de degradación in vitro, es decir, simulando condiciones fisiológicas. Los resultados obtenidos a partir de los diferentes estudios, indican que se han desarrollado una variedad de materiales biodegradables, con un amplio rango de aplicaciones y un gran potencial en el campo de la regeneración ósea principalmente. Por lo que, los estudios realizados a lo largo de esta tesis doctoral, forman parte de lo que sería un primer acercamiento al desarrollo de nuevos materiales biodegradables, y constituyen el punto de partida para la investigación de nuevos materiales porosos para aplicaciones en ingeniería de tejidos. / Nowadays, research on materials for bone fixation and regeneration has focused increasingly on the development of materials that are reabsorbable and at the same time, capable of stimulating bone tissue regeneration. In the case of materials for bone fixation, the objective is the creation of a material that supports the initial loads and then undergoes a gradual degradation, transferring the loads progressively to the new bone tissue. Avoiding in this way, second surgical procedures for the retrievement of the implant. In the case of the materials for bone regeneration, the objective is to design a material that stimulates bone formation and is gradually replaced by the bone tissue.This thesis put together several studies that have been performed for the development of different biodegradable materials based on PLA and a calcium phosphate glass, coded G5, which is in the system P2O5-CaO-Na2O-TiO2. Non-porous and porous (3D scaffolds) materials for bone fixation and bone tissue regeneration respectively, have been elaborated, as well as porous glass-ceramic structures for bone tissue engineering. Each one of the developed materials has been characterized in terms of its physico-chemical properties, its behaviour along in vitro degradation and its biological response.The results obtained through the different studies, suggest that the variety of biodegradable materials that have been developed, present a wide range of applications and regenerative potential. Thus, the studies performed along this PhD thesis, are the first approach to the development of new biodegradable materials, and represent the starting point for their optimisation and development of new porous structures for tissue engineering applications.

Three experiments were conducted to determine the effects of supplementing wheat-based dry distillers grains with solubles (DDGS) on cow performance, forage utilization, and production costs. In the first two experiments, 48 dry, pregnant Black Angus cows (mean BW±SD; 598.2±4.2 kg) stratified by body weight (BW) and days pregnant were allocated randomly to one of three replicated (n=2) treatments. Cows were managed on stockpiled crested wheatgrass pasture (TDN=49.0, CP=7.3 (% DM)) in experiment one (EXP 1) and barley straw-chaff residue (TDN=45.4, CP=8.6 (% DM)) in experiment two (EXP 2). EXP 1 supplement treatments were (1) 100% DDGS (70:30 wheat:corn blend; DDGS); (2) 100% commercial supplement (COMM); or (3) control no supplement (CONT). EXP 2 supplement treatments were (1) 100% DDGS (70:30 wheat:corn blend; DDGS); (2) 50% DDGS + 50% rolled barley (50:50); or (3) 100% rolled barley grain (control; BARL). Forage utilization was measured for both trials using the herbage weight disappearance method. Cow BW, body condition score (BCS), and rib and rump fat were measured at the start and end of trial and cow BW was corrected for conceptus gain based on calving data. There was no effect (P > 0.05) of treatment on forage utilization in either experiment. In EXP 1, cow performance was not affected (P > 0.05) by supplement strategy. In EXP 2, BW change was 11.3, 6.8, and -6.5 (P < 0.01) for DDGS, 50:50, and BARL, respectively. Because forage utilization was not affected, the difference in cow BW was the result of supplement type. Costs per cow per day in EXP 1 were $0.66, $0.68, and $0.60 for DDGS, COMM, and CONT, respectively. In EXP 2, costs per cow per day were $0.79, $0.80, and $0.80 for DDGS, 50:50, and BARL treatments, respectively.<p> In experiment three (EXP 3), four ruminally cannulated beef heifers were individually fed a basal ration of 75% ground barley straw and 25% ground grass hay (TDN=46.3, CP=7.5 (% DM)). Heifers were supplemented with either (1) DDGS (70:30 wheat:corn blend; DDGS); (2) commercial range pellet (COMM); (3) barley grain and canola meal (BAR+CM); or (4) control no supplement (CONT). Forage intake, apparent total tract digestibility, and passage rate; rumen fermentation parameters; and the rate and extent of forage degradation were measured. Forage intake, passage rate, and apparent total tract digestibility of DM, NDF, and ADF were not affected (P > 0.41) by treatment. Apparent total tract digestibility of CP was increased (P = 0.02) by supplementation, but was not different between DDGS, COMM, and BAR+CM treatments. Ruminal pH was not affected (P = 0.20) by treatment diet, but rumen ammonia-N was increased (P < 0.01) by supplementation. The potentially degradable and undegradable forage fractions were affected (P < 0.02) by supplementation, reducing the extent of forage degradation. Also, there was a tendency (P = 0.06) for the rate of forage DM degradation to increase when supplements were fed. The results of these experiments indicate that wheat-based DDGS can be used as a supplement for beef cows consuming forages with similar or greater effects compared to a commercial pellet and barley grain. DDGS had similar effects on rumen metabolism as the commercial range pellet or barley grain and canola meal, suggesting DDGS can be substituted on a unit basis with these supplements. As such, the inclusion of wheat-based DDGS as a supplement for beef cows will depend on the initial price of the supplement.