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The botanical and chemical composition of diets consumed by ruminants is different from the composition of plant species available in the rangeland or pastures on which they graze. Exploring alternative and improving existing methods of estimating botanical composition (diet selection) is imperative in advancing sustainable feeding practices in extensive production systems. The ability to predict the intake and digestibility of the diet consumed is important in designing grazing management for different feeding systems as well as supplementation strategies. This facilitates the efficient use of feed resources for optimal animal performance. This review assesses the merits, limitations, and potential advancements in techniques used to estimate botanical composition, forage intake, and digestibility in ruminants. Supplements containing sufficient quantity and identifiable n-alkanes can be used to determine the total forage intake in grazing ruminants without dosing the animals with synthetic even-numbered n-alkanes. When the botanical composition, intake, and digestibility of diet are estimated using internal markers, the results should be validated with those of faecal near-infrared reflectance spectroscopy (NIRS) or plant cuticular compounds to enhance the prediction accuracy. This should be done to determine the degree of error in the use of internal markers. Conclusively, the use of internal markers with automated solver routine software is a prudent approach to predicting botanical composition due to the analytical ease of the markers involved and the associated model assumptions. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate acid detergent lignin (ADL), and amylase-treated ashcorrected undigestible neutral detergent fiber after 240 h of ruminal in vitro incubation (uNDF), and near infrared spectroscopy (NIRS) scanning of feces as methods to estimate the digestibility of diets varying in forage quantity and quality when fed to beef cattle. Five total collection (TC) digestibility studies examined 17 different diets and provided individual fecal samples and the corresponding apparent total tract digestibility of nutrients (n = 229). Feed, orts, and fecal samples were analyzed for dry matter (DM), organic matter (OM), nitrogen (N), amylase-treated ash-corrected neutral detergent fiber (aNDFom), acid detergent fiber (ADF), ADL, and uNDF. Previously developed fecal NIRS digestibility calibrations were expanded with dried and ground samples using a FOSS D3F scanning monochromator (FOSS, Eden Prairie, MN). Marker estimated and NIRS predicted nutrient digestibility coefficients were regressed against those determined by TC and goodness-of-fit statistics were applied. Mean concentrations of ADL and uNDF in diets ranged from 23.4 to 96.4 g/kg DM and 67.7 to 200 g/kg DM, respectively, with mean fecal recoveries of 94.2% (SD ± 15.7%) for ADL and 87.5% (SD ± 11.1%) for uNDF. Regression fit statistics between NIRS and TC were not different from one (P > 0.05), with R² > 0.83 except for ADF digestibility (R2 = 0.63). In comparison, regression statistics between internal markers and TC were poorer with R² ranging from 0.21 to 0.78. Concordance correlation coefficients (CCC) between NIRS and TC were greater than 0.90 for DM, OM, N, and aNDFom digestibility, and 0.77 for ADF digestibility. The CCC between ADL and TC ranged between 0.63 and 0.82, and between uNDF and TC from 0.26 to 0.78. Correction bias (Cb) was high for all parameters (Cb > 0.76) except for ADF digestibility (Cb = 0.58) as estimated by uNDF. The mean square error of prediction (MSEP) for NIRS predicted digestibility were lower (< 10.7%) than those estimated by internal markers, and most of the error was attributed to random bias (> 97.9%). Random bias for ADL was also greater (>76.1%); however, for uNDF the error was more evenly partitioned into mean bias (46.4% to 49.4%) and random bias (30.4 to 41.9%). Digestibility predictions from NIRS scanning of feces were more accurate and precise than when estimated using the internal markers ADL and uNDF. In the absence of NIRS, ADL estimations appear to be more precise and accurate than uNDF for forage-based diets, with uNDF possibly of greater value for estimating the digestibility of high concentrate diets. [ABSTRACT FROM AUTHOR]

A data set of individual observations was compiled from 17 digestibility trials with sheep with the aim of evaluating the impact of the method of analysis and, within each method, the effect of dietary fibre content and trial on the faecal recovery rate (RR) of indigestible dry matter (iDM) and indigestible neutral detergent fibre (iNDF). Markers concentration in samples of diet and faeces were determined either in polyester filter bags of 40 μm of porosity incubated in situ for 144 h (method A; n = 257) or in bags of 16 μm of porosity incubated in situ for 288 h (method B; n = 321). Regardless of the incubation method, the intake of either iDM or iNDF was linearly (P < 0.05) related to the amount excreted in faeces and, for all linear relationships, the slopes were lower than 1 (i.e. between 0.53 and 0.71). Within both methods, the RR of both markers linearly decreased at increased NDF content in diet (P < 0.05). The root mean square error of the linear relationships varied from 0.147 to 0.189 which represented from 19% to 24% of the respective average RR of markers. In conclusion, regardless of the incubation method, the RR of both markers showed high individual variability and, thus, the use of average RR values obtained in controlled digestibility trials as an index to correct the individual digestibility values obtained with either marker in field trials has the potential to improve the accuracy but not the precision of the digestibility estimates. [ABSTRACT FROM AUTHOR]

The botanical and chemical composition of diets consumed by ruminants is different from the composition of plant species available in the rangeland or pastures on which they graze. Exploring alternative and improving existing methods of estimating botanical composition (diet selection) is imperative in advancing sustainable feeding practices in extensive production systems. The ability to predict the intake and digestibility of the diet consumed is important in designing grazing management for different feeding systems as well as supplementation strategies. This facilitates the efficient use of feed resources for optimal animal performance. This review assesses the merits, limitations, and potential advancements in techniques used to estimate botanical composition, forage intake, and digestibility in ruminants. Supplements containing sufficient quantity and identifiable n-alkanes can be used to determine the total forage intake in grazing ruminants without dosing the animals with synthetic even-numbered n-alkanes. When the botanical composition, intake, and digestibility of diet are estimated using internal markers, the results should be validated with those of faecal near-infrared reflectance spectroscopy (NIRS) or plant cuticular compounds to enhance the prediction accuracy. This should be done to determine the degree of error in the use of internal markers. Conclusively, the use of internal markers with automated solver routine software is a prudent approach to predicting botanical composition due to the analytical ease of the markers involved and the associated model assumptions.

Mammography is a very useful tool to diagnose breast cancer in early stages when it is easier to treat. There are two types of evidence that radiologists look for in a mammogram, calcifications and the existence of masses. In this study, an intelligent computer‐aided diagnosis system is proposed for the detection of masses in mammographic images regardless of their nature. The proposed method uses a combination of extended maxima transformations, having different threshold values, in order to find suitable internal and external markers for a marker‐based watershed segmentation. After segmentation, a two‐stage classifier is used to distinguish the masses better from the healthy breast tissue. A feature vector based mainly on contrast and texture features is calculated and two alternative approaches, a Bayesian classifier and a support vector machine (SVM) with Gaussian kernel function, are implemented for further reduction of the false positive areas. The system was evaluated using the data from two online databases. Specifically, 73 mammographic images from the new curated breast imaging subset of digital database for screening mammography (CBIS‐DDSM) database and all the mammographic images that contain masses from the mini‐mammographic image analysis society (MIAS) database were used. The overall sensitivity, in both datasets, was near 80% when the Bayesian classifier was used and above 85% when the SVM was applied. [ABSTRACT FROM AUTHOR]

Reliable assessments of indigestible dietary components are required when using internal markers to estimate diet digestibility and determine the potentially digestible portion of the fiber. The lack of a standardized methodology and understanding of how antinutritional factors influence indigestible residues can result in erroneous estimates with inconsistent variation across trials and among studies. Previous studies have detailed suitable bag porosity and sample size (SS) with incubation length (IL) varying from 96 to 504 h, with many assuming that 288-h IL yields truly indigestible components. Recent studies have primarily investigated the variation that exists among feedstuffs, but most have failed to account for possible effects of secondary compounds. Using 2 similar concentrate diets, one of which contained supplemental condensed tannins (CT), we investigated the effect of bag type (BT ; 10 and 25 μm), SS (20 and 40 mg/cm2), and IL (288 and 576 h) on in situ indigestible DM (iDM) and neutral detergent fiber (iNDF) residues of feed and feces, and resultant DM and NDF digestibilities. There were no 3-way interactions (P > 0.05), but 2-way interactions were present for iDM and iNDF residues with BT × SS influencing the control (no CT) ration (P < 0.01), SS × IL impacting feed containing CT (P < 0.01), and BT × IL affecting both feedstuffs (P ≤ 0.01). For the control diet, only BT × SS affected DM and NDF digestibilities. Whereas the CT diet did not demonstrate any significant interactions for digestibilities. Values of iDM were largely influenced by contamination that varied greatly based on intrinsic factors associated with the bag and incubation duration. The presence of CT influenced iDM and iNDF to varying degrees due to possible trapping of CT–substrate complexes. For the control diet, the use of 25-μm bags resulted in lower fecal recoveries relative to the 10 μm (P < 0.01). However, there appears to be a dynamic relationship among BT, SS, and IL within respective diets and sample types that can affect indigestible components and resultant digestibility estimates. Based on simulations from these data, the sample size required to attain 90% power when utilizing 2 incubation animals exceeds the triplicate and quadruplicate replications commonly utilized. Further emphasizing the necessity for a more complete understanding of incubation dynamics to design biologically and statistically valid investigations. [ABSTRACT FROM AUTHOR]

Highlights • Water-soluble carbohydrates were apparently digested up to approximately 80% by the time reaching the end of the stomach. • Compartmental apparent digestibility of nutrients was well estimated by 4 N acid insoluble ash and plant alkanes compared with other markers. • Plant alkanes are best suited to estimate apparent digestibility of fiber in diets for horses. • Estimations of apparent digestibility by external markers (Cr 2 O 3 or TiO 2) were accurate only for the total tract. Abstract Partitioning of apparent digestibility is helpful to assess the nutritive value of feedstuffs and to identify possible risks for digestive disorders. In horses, information on partial digestibility is less available and address less on carbohydrate fractions. It is suggested that large parts of water-soluble carbohydrates (WSC) are degraded already in the stomach, which elevates the risk for mucosal ulceration. Our objective was to investigate apparent digestibility of dry matter (DM), proximate nutrients, and WSC along the digestive tract using internal and external markers. Twelve adult horses were adapted for 20 d to meadow hay (1.5 kg/100 kg body weight per day) and crushed oats (1.2 g starch/kg body weight per day), which were offered 2 times a day. Six horses on the treatment group also received 0.15 g of fructooligosaccharides + inulin (via Jerusalem artichoke meal) per kg body weight per day. The other 6 horses on the control group received corncob meal without grains. The tested markers were 4 N acid insoluble ash (AIA), acid detergent lignin (ADL), n -heptacosane, n -nonacosane, n -hentriacontane, and n -tritriacontane. Additionally, Cr 2 O 3 (approximately 2.8 g/bolus) and TiO 2 (approximately 2.5 g/bolus) were provided as a bolus 2 times a day. The horses were euthanized at d 21 approximately 1 h after the morning meal. Samples of digesta were collected from the stomach (pars nonglandularis and pars glandularis), cecum, ventral and dorsal colon ascendens, and colon transversum. Feces were sampled at 5 d ante mortem. Compartmental and total tract apparent digestibility was calculated for each horse. The stomach seemed to be considerably involved in nutrient degradation with particular great disappearance of simple sugars, starch, and fructans (apparent digestibility was up to 78, 74, and 56%). No WSC were measured in the cecum. In the hindgut, apparent digestibility increased from the cecum to the colon transversum (e.g., for DM: 0.49–0.79 with AIA, and 0.44–0.56 with n -tritriacontane; for crude protein: 0.51–0.82 with AIA, and 0.47–0.63 with n -tritriacontane; and for neutral detergent fiber: 0.43–0.76 with AIA, and 0.37–0.50 with n -tritriacontane; P < 0.05). Supplying of fructooligosaccharides and inulin had no effect on apparent digestibility. Differences among apparent digestibility estimates did mainly belong to the gut compartments (P < 0.05) and the markers (P < 0.001). For all nutrients, apparent digestibility estimates did differ less among the plant alkanes, but they had a vast variation among the horses when based on Cr 2 O 3 or TiO 2. The extensive disappearance of WSC, including starch, in the stomach should be considered for dietary composition and risk assessment concerning stomach ulceration. Parts of WSC possibly had not been degraded in the stomach, but rapidly flowed with the liquid phase into the intestine. The probable underestimation of apparent digestibility by ADL confirms the known instability of ADL during the digestive process. Acid insoluble ash probably overestimated apparent digestibility along the hindgut, especially for the fiber fractions. Thus, apparent digestibility seemed to be best estimated by cell wall-associated plant alkanes. The estimations made by Cr 2 O 3 and TiO 2 were only accurate for the total tract, considering mealtime feeding of mixed diets. [ABSTRACT FROM AUTHOR]

Two experiments were conducted to evaluate the number of days required for total fecal collection and the viability of using the indigestible dry matter (iDM), indigestible neutral detergent fiber (iNDF), and indigestible acid detergent fiber (iADF) internal markers to determine the fecal excretion of dry matter (FEDM) and digestibility in nutritional trials with small ruminants. Eight sheep in the first experiment and eight goats in the second experiment were distributed into two 4 × 4 Latin square designs. There were no significant differences between days of total fecal collection for FEDM; digestibility of dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), neutral detergent fiber corrected for ash and protein (NDFap), and non-fibrous carbohydrates corrected for ash and protein (NFCap); and total digestible nutrients (TDN) in both species. The results suggest that only 1 day of total collection is sufficient to obtain the FEDM and the digestibility of the nutritional components in sheep and goats. The markers are efficient in determining fecal production and digestibility in these animal species. [ABSTRACT FROM AUTHOR]

The objective of this study was to assess the variability among animals regarding the critical time to estimate the undegradable fraction of fiber (ct) using an in situ incubation procedure. Five rumenfistulated Nellore steers were used to estimate the degradation profile of fiber. Animals were fed a standard diet with an 80:20 forage:concentrate ratio. Sugarcane, signal grass hay, corn silage and fresh elephant grass samples were assessed. Samples were put in F57 Ankom® bags and were incubated in the rumens of the animals for 0, 6, 12, 18, 24, 48, 72, 96, 120, 144, 168, 192, 216, 240 and 312 hours. The degradation profiles were interpreted using a mixed non-linear model in which a random effect was associated with the degradation rate. For sugarcane, signal grass hay and corn silage, there were no significant variations among animals regarding the fractional degradation rate of neutral and acid detergent fiber; consequently, the ct required to estimate the undegradable fiber fraction did not vary among animals for those forages. However, a significant variability among animals was found for the fresh elephant grass. The results seem to suggest that the variability among animals regarding the degradation rate of fibrous components can be significant.

The objective of this experiment was to evaluate estimates of concentration of indigestible dry matter (iDM), indigestible neutral detergent fiber (iNDF) and indigestible acid detergent fiber (iADF) in samples of cattle feed and feces processed at different particle sizes (1-, 2-, and 3-mm) using bags made from nylon (50 μm), F57 (Ankom®), and non-woven textile (NWT - 100 g/m²) in a in situ evaluation procedure. Eight samples of concentrates, seven samples of forages and two samples of cattle feces were used. The samples were put in the bags according to a ratio of 20 mg of dry matter/cm² of surface by using three bags of each textile for each size of particle, totaling 405 bags, which were submitted to ruminal incubation for 264 hours. The contents of indigestible compounds in the samples were evaluated sequentially. Blank bags were used for microscopic evaluation of textile physical integrity and for evaluation of the physical resistance. The presence of contaminants caused high variability of results of iDM, indicating that its using as internal marker should not be recommended. By using the textiles F57 and NWT, similar estimates for contents of iNDF and iADF were obtained whereas by using nylon (50 μm), the concentration of iNDF was underestimated, possibly because of loss of particles due to its porosity. Nylon presented loss of resistance in all analytical stages, expanding its probality of rupture, especially after extraction with acid detergent. For in situ evaluation of indigestible compounds, it is suggested grinding samples in 2-mm screen sieves.Objetivou-se avaliar as estimativas de concentração de matéria seca (MSi), fibra em detergente neutro (FDNi) e fibra em detergente ácido (FDAi) indigestíveis em amostras de alimentos e fezes bovinas processadas em diferentes tamanhos de partículas (1, 2 e 3 mm) utilizando-se sacos confeccionados com os tecidos nylon (50 μm), F57 (Ankom®) e tecido não-tecido (TNT - 100 g/m²) em procedimento de avaliação in situ. Foram utilizadas oito amostras de alimentos concentrados, sete de alimentos volumosos e duas de fezes bovinas. O material foi acondicionado nos sacos numa relação de 20 mg de matéria seca/cm² de superfície utilizando-se três sacos de cada tecido para cada tamanho de partícula, totalizando 405 sacos, que foram submetidos a incubação ruminal durante 264 horas. Os teores dos compostos indigestíveis nas amostras foram avaliados sequencialmente. Sacos em branco foram utilizados para avaliação microscópica da integridade física dos tecidos e para avaliação da resistência à tração. A presença de contaminantes causou alta variabilidade dos resultados de MSi, o que indica comprometimento de sua aplicação como indicador interno. Utilizando os tecidos F57 e TNT obtiveram-se estimativas similares para os teores de FDNi e FDAi, enquanto com o tecido nylon (50 μm) a concentração de FDNi foi subestimada, possivelmente em decorrência da perda de partículas devido à sua porosidade. O nylon apresentou perda de resistência em todas as etapas analíticas, o que amplia sua probabilidade de ruptura, principalmente após extração com detergente ácido. Para procedimentos in situ de avaliação de compostos indigestíveis, sugere-se a moagem de amostras em peneiras com porosidade de 2 mm.

Foram conduzidos dois experimentos com o objetivo de avaliar os indicadores internos fibra em detergente neutro indigestível (FDNi) e fibra em detergente ácido (FDAi), obtidos por incubação in situ durante seis dias, e os indicadores externos óxido crômico (Cr2O3), dióxido de titânio (TiO2) e lignina isolada, purificada e enriquecida (LIPE®) em dois esquemas de coleta total de fezes (3 ou 5 dias) para estimativa da digestibilidade em bovinos. O delineamento experimental foi o de blocos ao acaso com parcelas subdivididas. No primeiro experimento, foram utilizadas cinco novilhas mestiças alimentadas com cana-de-açúcar com 1% de ureia/sulfato de amônio e concentrado (1% do peso vivo). Não houve diferenças entre as metodologias de coleta para a digestibilidade da matéria seca. Quando estimada utilizando-se FDAi, a digestibilidade dos nutrientes foi subestimada, mas, quando estimada utilizando-se FDNi e os indicadores externos (óxido crômico, dióxido de titânio e LIPE®), não diferiu significativamente daquela determinada por coleta total de fezes. No segundo experimento, foram utilizadas oito vacas em lactação alimentadas com silagem de milho e 4 kg de concentrado. Não houve diferença na digestibilidade da matéria seca entre os períodos de coleta. A digestibilidade dos nutrientes, quando estimada utilizando-se FDNi, foi superestimada, mas, quando estimada utilizando-se FDAi e os indicadores externos (óxido crômico, dióxido de titânio e LIPE®), não diferiu significativamente daquela determinada por coleta total de fezes. Três dias de coleta são suficientes para estimativa da digestibilidade e os indicadores testados são eficientes na determinação da digestibilidade.Two studies were carried out to evaluate indigestible neutral detergent fiber (iNDF) and indigestible acid detergent fiber (iADF) as internal markers obtained by 144-h incubation in situ and chromium oxide (Cr2O3), titanium dioxide (TiO2) and isolated, purified and enriched lignin (LIPE®) as external markers, and two total fecal collection schemes (3 or 5 days) to estimate digestibility in bovines. The experimental procedure was a randomized block design in a split plot arrangement. In the first trial, five crossbreed heifers fed sugar cane plus 1% of urea/ammonium sulfate and concentrate (1% of body weight) were used. There was no difference for dry matter digestibility when the collection schemes were compared (5 days vs 3 days). The nutrient digestibility estimated by iADF was underestimated and those estimated by iNDF, chromium oxide, titanium dioxide and LIPE®, did not differ from the digestibility calculated on total fecal collection. In the second trial, eight lactating cows fed corn silage and concentrate (4 kg/cow/day) were used. There was no difference for dry matter digestibility when the collection schemes were compared (5 days vs 3 days). The nutrient digestibility estimated by iNDF was overestimated and those estimated by iADF, chromium oxide, titanium dioxide and LIPE®, did not differ from the digestibility calculated on total fecal collection. Three days of fecal collection and the markers tested can safely be used to estimate digestibility.

Dois trabalhos foram conduzidos para estimativa do consumo individual de vacas em lactação alimentadas em grupo. No primeiro, para validar a metodologia, foram utilizadas oito vacas, alojadas em baias individuais recebendo silagem de milho e 4 kg de concentrado. Dois indicadores externos (óxido crômico e dióxido de titânio) foram avaliados para estimativa do consumo individual de concentrado. A fibra em detergente ácido indigestível (FDAi) foi utilizada para estimativa do consumo de silagem. A produção de matéria seca fecal (PMSF) foi determinada pela coleta total de fezes e estimada pelo LIPE®. Tanto o óxido crômico quanto o dióxido de titânio permitiram estimar com eficiência o consumo de concentrado, independentemente do método para estimativa da PMSF. A FDAi estimou de forma satisfatória o consumo de silagem de milho. No segundo experimento, foram utilizadas 31 vacas, distribuídas em três grupos de alimentação, alojadas em estábulo tipo free stall e alimentadas com silagem de milho e concentrado de acordo com a produção de leite (8,0; 5,5 e 4 kg, para os grupos 1, 2 e 3, respectivamente). Não houve diferença entre o óxido crômico e o dióxido de titânio no consumo de MS do concentrado, que foi muito próximo da quantidade média fornecida por vaca/dia (6,99 vs 7,12; 4,81 vs 4,96 e 3,49 vs 3,52 kg/vaca/dia). Verificou-se grande variação individual no consumo de concentrado, silagem e matéria seca total, independentemente do grupo de alimentação. Não foi verificada relação entre o consumo de matéria seca, a produção de leite e o peso metabólico dos animais. O óxido crômico e o dióxido de titânio podem ser usados para estimativa do consumo individual de concentrado e a FDAi é adequada para estimativa do consumo de silagem de milho por vacas em lactação alimentadas em grupo.Two studies were carried out to evaluate individual dry matter intake of group-fed lactating dairy cows. In the first trial, eight cows were housed in individual pens and fed corn silage and 4 kg of concentrate meal. Two external markers (chromium oxide and titanium dioxide) were used to predict individual concentrate intake. Indigestible acid detergent fiber (iADF) was used to estimate individual silage intake. Fecal dry matter output (FDMO) was determined by total collection and also by LIPE®. Chromium oxide and titanium dioxide were able to estimate individual concentrate intake, regardless of the FDMO method. The iADF marker was able to estimate the individual silage intake. In the second trial, 31 cows were distributed in three groups, housed in a free stall and fed corn silage and concentrate according to milk yield (8.0, 5.5, and 4 kg, for groups 1, 2 and 3, respectively). There was no difference between chromium oxide and titanium dioxide in the estimates of individual concentrate intake which were similar to the observed values (7.12 vs 6.99, 4.96 vs 4.81 and 3.52 vs 3.49 kg/cow/day). Individual intakes of concentrate, silage and total dry matter varied considerably, regardless of the group. There was no relationship among dry matter intake, milk yield and metabolic body weight. Chromium oxide and titanium dioxide and iADF can be used to estimate individual intakes of concentrate and corn silage, respectively, by group-fed lactating dairy cows.

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The aim of this research is to compare indigestible internal markers acid insoluble ash (AIA) and acid detergent lignin (ADL) and total collection of faeces (TCF) for apparent digestibility estimation in Caspian horse. Analyses were carried out on wheat straw, alfalfa, barley and maize, for dry matter (DM), organic matter (OM), crude protein (CP), ether extract (EE), neutral detergent fiber (NDF) and acid detergent fiber (ADF). Using change over design including 4 ration diet, 4 period and each period was 12 days with 4 Caspian horse with 3-5 years age and reared in individual cages. The results digestibility of DM, OM, NDF, ADF did not show any significant differences among the ADL, AIA and total collection of faeces methods, but digestibility of CP and EE were significantly higher than the ADL and AIA methods. A weak correlation was found between total collection techniques and AIA, for crude fat (EE) and ADF, whereas there was a high correlation (R2=0.89) between AIA and total collection of faeces for the digestibility of crude protein. The results obtained in this study show that there were no significant difference between internal markers (acid-insoluble ash and acid detergent lignin) and total collection techniques of faeces for estimation apparent digestibility of nutrients in Caspian horses. [ABSTRACT FROM AUTHOR]

Avaliaram-se o consumo alimentar, a digestibilidade parcial e total e o balanço de nitrogênio, em novilhos confinados. Foram utilizados três novilhos de corte cruzados, canulados no rúmen e no duodeno, distribuídos em dois delineamentos em quadrado latino 3 x 3. As dietas experimentais foram constituídas de 60% de silagem de milho, tendo como fonte de proteína o farelo de girassol e, como fonte de energia, o milho (MI). O milho foi substituído parcialmente pela casca de soja (CS) ou pelo farelo de gérmen de milho (FGM). Quatro indicadores internos (lignina e FDA, FDN e lignina indigestíveis) foram submetidos a 144 horas de digestão in vitro, para estimativa da digestibilidade parcial e total das dietas. Houve maior ingestão dos componentes fibrosos na dieta CS, porém não foi observado efeito sobre o consumo de matéria seca. A lignina subestimou significativamente a digestibilidade. A utilização da FDAi, FDNi e lignina-i para estimar a digestibilidade total é viável, no entanto, a FDAi e lignina-i não estimaram adequadamente as digestibilidades parciais. Houve efeito significativo na digestibilidade ruminal da FDA, com valores mais elevados para CS e semelhantes para FGM, em relação à dieta MI. A digestibilidade total da FDA foi maior na dieta CS, porém, as digestibilidades dos demais componentes não foram afetadas pelas diferentes fontes energéticas. Não houve diferença significativa para a digestibilidade da energia e nos valores obtidos de NDT, com média de 61,5%. A casca de soja e o farelo de gérmen de milho, em substituição parcial do milho, mostraram-se fontes alternativas satisfatórias para a inclusão na dieta de bovinos.Feed intake, partial and total digestibility and nitrogen balance were evaluated in confined steers. Three crossbreed steers, rumen and duodenum cannulated, were allotted to two 3 x 3 Latin square experimental design. The experimental diets were composed by corn silage (60%) and concentrate with sunflower meal as protein source and ground corn as energy source (MI). The ground corn was partially substituted by soybean hulls (CS) or by corn germ meal (FGM). Lignin and indigestible ADF (iADF), NDF (iNDF) and lignin (i-lignin) determined by 144 h of in vitro digestion were used as markers to estimate the total and partial diet digestibility of diets. The fiber intake was higher on CS diet, however no effect on dry matter intake was observed. Lignin underestimated significantly the digestibility. Indigestible ADF, iNDF and i-lignin was able to estimate total digestibility, however iADF and i-lignina did not estimate adequately the partial digestibility. Ruminal ADF digestibility was influenced by diets with higher values for CS and similar values for FGM, in relation to MI. Total ADF digestibility was higher in diet CS, but the other nutrients digestibility were not affected by different energy sources. Energy digestibility and NDT values did not differ among diets, with average of 61.5%. Soybean hulls and corn germ meal, on partial substitution of ground corn, were satisfactory alternative sources for inclusion on steer diets.

Objetivou-se comparar a fibra em detergente ácido (FDAi) indigestível com o óxido crômico para estimar a produção de matéria seca fecal e as digestibilidades dos nutrientes de dietas de bovinos, em dois esquemas de coletas (2 ou 6 dias). Foram utilizados cinco bovinos da raça Nelore, não-castrados, com 165 kg, fistulados no rúmen, abomaso e íleo. O delineamento foi em blocos casualizados com quatro tratamentos e cinco períodos de coleta. Os tratamentos consistiram de quatro níveis de concentrado na dieta (20, 40, 60 e 80%), usando-se feno de capim-Tifton 85 como volumoso. A digestibilidade aparente da matéria seca (MS) foi menor quando estimada pelo óxido crômico, enquanto as digestibilidades da MS no rúmen e nos intestinos não diferiram entre os indicadores. Quando se comparou a metodologia de coleta (6 dias vs. 2 dias), não houve diferença para as digestibilidades totais e parciais dos nutrientes e também para a eficiência microbiana, demonstrando assim que a metodologia alternativa de dois dias de coleta pode ser utilizada para estimar a produção fecal e os fluxos de MS no abomaso e no íleo.It was aimed to compare the internal markers, indigestible neutral detergent (NDFi) and acid fiber (ADFi), and ADFi with oxide chromic to esteem the dry matter fecal production and nutrients digestibility of diets of bovine, in two outlines of collections (2 or 6 days). For the comparison among internal markers, 32 Nelore growing bulls, with 240 kg, were maintained under feedlot, receiving diets with different concentrate levels (20, 40, 60 and 80%). For the comparison among internal and external marker, five 165 kg Nelore growing bulls, rumen, abomasum and ileum fistulated, were used. The design was in blocks with four treatments and 5 collection periods. The treatments consisted of four concentrate levels (20, 40, 60 and 80%). The roughage used was Tifton 85 hay. The apparent digestibility of dry matter (DM) was smaller, when was estimated by oxide chromic, however the DM digestibility in the rumen and intestines did not differ among markers. When the collection methodology was compared (6 days vs. 2 days), there was not difference in all the studied variables, demonstrating the suggested alternative methodology as soon as can be used with safety for the estimates of fecal production and DM flows in the abomasum and ileum.

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Background: The effect of time of fecal sampling on the accuracy of acid-detergent insoluble ash (ADIA) and alkaline-peroxide lignin (APL) for the prediction of fecal output (FO) in cattle was evaluated. Eight ruminally cannulated cows (594 ± 35.5 kg) were allocated randomly to 4 bermudagrass [Cynodon dactylon (L.) Pers.] hay diets markedly different in crude protein concentration (79-164 g/kg) with 2 replicates per diet for 3 periods. Cows were offered hay individually at 20 g DM/kg of body weight daily in equal feedings at 08:00 and 16:00 h for a 10-d adaptation period followed by 5-d of total fecal collection. Fecal grab samples also were taken each day during the fecal collection period at 06:00, 12:00, 18:00, and 24:00 h either directly from the rectum or from freshly voided feces. Samples were composited within cow and time across the 5 d total fecal collection period. Additionally, forage, ort, and fecal samples were analyzed for concentrations of APL and ADIA. Results: Fecal concentrations of ADIA and APL were not affected by sampling time (P = 0.22), even though diet affected (P < 0.01) fecal ADIA and APL concentrations. There were no diet × sampling time interactions (P = 0.60). Estimates of FO and dry matter digestibility (DMD) from ADIA and APL were not affected (P = 0.16) by sampling time or the diet × sampling time interaction (P = 0.74). Estimates of FO and DMD from markers from different sampling times or all different combinations of sampling time were not different (P = 0.72) from those of total collection among internal markers. Conclusion: Little variation in concentrations of ADIA and APL in daily fecal excretion across time increases flexibility in fecal grab sampling schedules for predicting FO and DMD. [ABSTRACT FROM AUTHOR]

Summary Estimation of herbage intake is a challenge both under practical and experimental conditions. The aim of this study was to estimate herbage intake with different methods for cows grazing 7 h daily on either spring or autumn pastures. In order to generate variation between cows, the 20 cows per season were either allocated to low or high stocking rate. At low stocking rate, there were 6.7 and 3.5 cows per hectare during spring and autumn, respectively, and at high stocking rate, there were 8.8 and 4.6 cows per hectare during spring and autumn, respectively. The experiment lasted 16 days in each season, and the herbage intake was estimated twice during each season. Cows were on pasture from 8:00 until 15:00, and were subsequently housed inside and fed a mixed ration (MR) based on maize silage ad libitum . Herbage intake was estimated with nine different methods: (1) animal performance (2) intake capacity, (3) content of 13 C in faeces and diet, (4) 13 C in faeces and diet, and with assumption of 13 C discrimination in the digestive tract, (5) 13 C in faeces and diet, with assumption of 13 C discrimination and in combination with in vitro organic matter digestibility (IVOM), (6) simultaneous use of two internal markers (ingestible neutral detergent fibre (INDF) and acid detergent lignin (ADL)), (7) titanium oxide in combination with IVOM, (8) titanium oxide in combination with INDF and (9) titanium oxide in combination with ADL. Furthermore, grazing time of the individual cows was recorded. The estimated average herbage dry matter intake (DMI) varied from 2.2 kg for the method using the INDF:ADL ratio to 7.6 for the methods using 13 C and intake capacity. There was a low correlation between the different methods. Dry matter intake of herbage was not affected by stocking rate except for the method using titanium oxide and ADL as markers. Milk yield was not affected by stocking rate either. It was concluded that methods based on animal performance, 13 C including discrimination factor or in combination with IVOM as well as methods based on titanium oxide gave similar estimates of the average herbage DMI intake during grazing in systems with indoor concentrate and forage feeding during night. [ABSTRACT FROM AUTHOR]

Os ensaios de digestibilidade são importantes para o desenvolvimento e avaliação de rações animais. Estes podem ser realizados através do método convencional, ou de coleta total, e pelo método dos indicadores, dividindo-se os últimos em externos (adicionados ao alimento), e internos (presentes naturalmente no alimento). Com a finalidade de buscar métodos alternativos, menos trabalhosos e com resultado seguro, o presente estudo objetivou comparar o método de coleta total com o dos indicadores para a determinação da digestibilidade de rações para gato doméstico, testando como indicadores a fibra bruta (FB) e a fibra em detergente ácido (FDA). Utilizou-se 4 gatos (2 machos e 2 fêmeas) adultos jovens, mantidos em gaiolas metabólicas individuais durante 30 dias (24 de adaptação e 6 de coleta total de fezes), alimentados ad libitum com ração comercial seca extrusada para gatos. Os coeficientes de digestibilidade aparente obtidos pela coleta total, FDA e FB foram, respectivamente, 74,0, 71,4 e 75,0% para a matéria seca, 77,0, 74,8 e 77,9% para a matéria orgânica, 79,2, 77,2 e 80,0% para a proteína bruta, 81,7, 80,4 e 82,8% para o extrato etéreo e 78,8, 76,6 e 79,6% para os extrativos não nitrogenados. A análise estatística não detectou diferenças significativas entre os três métodos estudados (p > 0,2). Recuperou-se 96,1% da FDA e 104,3% da FB ingeridas, sendo estes valores estatisticamente iguais pelo teste t (p > 0,49). O método dos indicadores naturais apresenta vantagens práticas sobre a coleta total, entretanto, para generalizar com segurança o uso dos indicadores testados, ainda são necessários outros estudos, com dietas apresentando diferentes níveis e fontes de FB e FDA.The digestibility trials are important in the development and evaluation of animal feed. They are carned out through the total collection method (TC) or by the use of indicator methods (IM), where the indicators can be classified as external (added to the feed), or internal (already present in the feed). In the present work, the comparison of both methods was made, aiming the search for simpler and safer methods for the determination of the digestibility of commercial cat feed. We tested the TC and IM using, for the latter, the crudefibre (CF) and the acid-detergent fibre (ADF) as internal indicators. We used 4 young adult cats (2 males and 2 females) held in individual metabolism cages for 30 days (24 for adaptation and 6 for total collection of faeces) and fed ad libitum with a commercial dry extruded cat feed. The results for the TC, CF and ADF were, respectively, 74.0, 71.4 and 75.0% for dry matter, 77.0, 74.8 and 77.9% for organic matter, 79.2, 77.2 and 80.0% for crude protein, 81.7, 80.4 and 82.8% for ether extract and 78.8, 76.6 and 79.6% for nitrogen-free extract. The statistical analysis did not show significant diffèrences between the methods (p > 0.2). It was recovered 96.1% of the ADF and 104.3% of the CF, and these figures could be considered statistically equivalents by the t test (p > 0.49). The internal markers method presents some practical advantages when compared to the total collection method. However, further studies are required in order to check the efficiency of the tested markers, using diets with different amounts and sources of CF and ADF.

Abstract: Background and purpose: Positional uncertainties related to the set-up of the prostate, using internal markers and either 2D–2D or 3D images, were studied. Set-up using direct prostate localization on CBCT scans is compared to set-up using internal markers. Material and methods: 20 patients with prostate cancer were enrolled in the study. After each daily session, a set of 2D–2D and 3D images were acquired. The images isocenter was compared to reference images isocenter. For the set-up error analysis the systematic error, μ, and the set-up uncertainties, Σ and σ, were determined for the translational shift in the three directions, lat, lng and vrt. The set-up errors and uncertainties were calculated in the same way for rotations around the three axes, lat, lng and vrt. Results: Set-up uncertainties were evaluated for four different set-up methods. The systematic error uncertainties were found to be in the range 0.38–1.14mm and for the random error 0.79–1.48mm. For rotations the uncertainties ranges were 0.38–1.59° and 0.91–2.18° for systematic and random uncertainties, respectively. Set-up uncertainties, using internal markers or prostate itself to position the target in the isocenter, were comparable. The correlation between the two methods was better for translational shifts of the isocenter than for rotational shifts. Conclusions: The study shows that the precision of the 2D–2D set-up is equivalent to the precision of the 3D images. It also shows that the soft-tissue based set-up needs 1mm larger set-up margins than the marker based set-up for the prostate patients, when CBCT is used for daily verification of the location of the prostate. [Copyright &y& Elsevier]

• Comparison of grain boundary sliding effect on surface and body of the samples. • Development of internal markers located in grain body before superplastic deformation. • Decreased grain boundary sliding in AA5083 alloy as compared to AA7475 alloy. The grain boundary sliding as a main mechanism of superplastic deformation is typically studying by the microstructural analysis of the samples with surface markers. It is important to compare the effects related to the deformation mechanisms on the surface and in the body of the samples. Present study investigates the microstructural evolution of the samples of Al-Zn-Mg-Cu (AA7574) and Al-Mg-Mn (AA5083) alloys with both surface FIB-grids and internal Al 3 Ni-particles markers at superplastic deformation. The grain switching and grain rotation effects are found on the surface and in the body of both the studied alloys. The results, based on both surface and internal markers, suggest the decreased role of the grain boundary sliding in AA5083 alloy as compare with AA7475 alloy. [ABSTRACT FROM AUTHOR]

Indigestible components, including indigestible dry matter (iDM) and indigestible neutral detergent fiber (iNDF), play an integral role as internal markers for determining ruminal kinetics and digestibility estimations. However, the accuracy of internal markers is dependent upon the incubation technique utilized as bag type (BT) and incubation length (IL) can be significant sources of error. Previous studies have primarily focused on iDM and iNDF as digestibility markers, but few studies have compared digestibility estimates to those of acid detergent insoluble ash (ADIA). Therefore, our objective was to investigate the effect of BT (F57, F58, and Dacron) and IL (288 and 576 h) on iDM and iNDF residues, DM and NDF digestibilities, and fecal recoveries when using in situ incubations. Additionally, we evaluated the accuracy of digestibility estimates when using iDM, iNDF, and ADIA. For iDM and iNDF, feed residues demonstrated a BT × IL interaction (P < 0.01). However, fecal residues were only influenced by the main effects of BT and IL (P < 0.01), with the F58 BT and 288-h IL having the greatest residues for both iDM and iNDF. The variation in residues was greatly reduced when using iNDF compared with iDM. Fecal recovery estimates most closely approximated 100% recovery when utilizing ADIA and iDM using the F57 × 576 h incubation method (P < 0.01), although recovery was overestimated for all incubation combinations. Fecal NDF recovery estimates better represented the excretion profiles when the F57 × 576 h combination was used with iDM as the internal marker (P < 0.01). Estimates of DM and NDF digestibility were the most accurate when utilizing ADIA (P < 0.01) relative to all other treatments. Our results indicate that the proper methodological application is specific to the purpose of the inferences. When evaluating fecal recoveries and digestibility, ADIA or iDM with F57 at 576-h in situ incubation provides the greatest accuracy., (© The Author(s) 2020. Published by Oxford University Press on behalf of the American Society of Animal Science. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)