A study of in situ degradability: heterogeneity of variances and correlated errors

Degradation models exhibit a non-linear behavior and the selection of a model to describe the degradability depends on the coherence of the model with the involved biological events. The purpose of this study is to evaluate the behavior of the parameters of the degradation model proposed by Mertens & Loften, adjusted to the results of an in situ degradability trial. The experiment evaluated the potential degradable residue of neutral detergent fiber (NDF) of coastcross grass (Cynodon dactylon × Cynodon nlemfuensis) submitted to two cutting ages (30 and 90 days), with three replicates. For each cutting age, the potentially degradable residue of NDF was studied using fifteen incubation times (0; 0,5; 1; 3; 6; 9; 12; 18; 34; 35; 48; 56; 72; 96 e 120 hours). The experimental unit comprised one non-lactating cow with a permanent ruminal fistula. Mean and individual adjustments were obtained for the animals in three different configurations: inverse variance weight without autoregressive errors; unweighted with autoregressive errors, and unweighted without autoregressive errors. Variances of parameter estimators were also obtained by means of the mean parameter covariance matrix, providing expressions for the estimation of the confidence age for the parameters of the model. A weighting of the model by the inverse variance resulted in estimates statistically equal to zero for the colonization time. The use of a structure of second order autoregressive errors improved the fit of the model of Mertens & Loften, providing more precise estimates of the parameters.

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In situ caecal degradation of roughages in horses

Revista Brasileira de Zootecnia ◽

10.1590/s1516-35982010000200018 ◽

2010 ◽

Vol 39 (2) ◽

pp. 349-355 ◽

Cited By ~ 2

Author(s):

Vinícius Pimentel Silva ◽

Fernando Queiroz de Almeida ◽

Eliane da Silva Morgado ◽

Liziana Maria Rodrigues ◽

Tiago Marques dos Santos ◽

...

Keyword(s):

Cynodon Dactylon ◽

Pigeon Pea ◽

Neutral Detergent Fiber ◽

Desmodium Ovalifolium ◽

Randomized Design ◽

Degradation Rates ◽

Digestion Technique ◽

In Situ Degradation ◽

The Times

The present study was carried out to evaluate the in situ degradation of dry matter (DM), neutral detergent fiber (NDF) and crude protein (CP) in roughages by the in situ caecal digestion technique in horses. The roughages evaluated were: Lucerne hay (Medicago sativa), peanut (Arachis pintoi cv. Amarillo), desmodio(Desmodium ovalifolium), stylo (Stylosanthes guianensis cv. Mineirão), pigeon pea (Cajanus cajan), lime-yellow pea (Macrotyloma axillare) and coastcross hay (Cynodon dactylon cv. coastcross). The assay was conducted in a complete randomized design with seven roughages and three replications. One mare with a cannula fitted in the caecum was used, fed diet consisting of coastcross hay (80%) and concentrate (20%) at 2.0% BW, four times a day. Nylon 6.5 × 20 cm bags were used with 45 μ/pore, containing 5.2 g DM/bag, inserting 3 or 4 bags in the caecum at the times of 2, 4, 6, 8, 12, 24 and 48 hours incubation. The caecum in situ degradability parameters of nutrients were obtained by Ørskov model. The DM degradability parameters of all the roughages were significant. There was no fit to the model for pigeon pea for CP and NDF and desmodio. Peanut, stylo and lime-yellow pea presented larger potentially degradable DM with values of 53, 46.5 and 40%, respectively, and higher values for the soluble fraction of 20, 21, 28.6%, with high degradability rates of 10.36, 20.26 and 14.8% h-1. Higher NDF degradation rates were observed in these foodstuffs with values of 9.1 and 11.3, 11.2% h-1, high potentially degradable fraction with values of 55, 51.8 and 47.2%, and greater CP degradation at 48 hours with values of 87, 95, and 94.8%. Peanut, stylo and lime-yellow pea presented potential for use in horses diets.

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Degradability study of neutral detergent fiber of coast cross (Cynodon dactylon x Cynodon nlemfunensis)

Ciência e Agrotecnologia ◽

10.1590/s1413-70542007000400035 ◽

2007 ◽

Vol 31 (4) ◽

pp. 1184-1190 ◽

Cited By ~ 1

Author(s):

Taciana Villela Savian ◽

Joel Augusto Muniz ◽

Luiz Henrique de Aquino ◽

Vera Lúcia Banys ◽

Daniel Furtado Ferreira

Keyword(s):

Confidence Intervals ◽

Incubation Time ◽

Cynodon Dactylon ◽

Block Design ◽

Neutral Detergent Fiber ◽

Parameter Estimates ◽

Degradation Model ◽

Early Stages ◽

Plot Design

The objective of this work was to fit the degradation model proposed by Orskov & McDonald (1979) to data of an in situ degradability trial. Neutral detergent fiber degradations (NDF) of coast cross grass (Cynodon dactylon x Cynodon nlemfunensis) were submitted to twelve cutting ages (30, 60, 90, 120, 150, 180, 210, 240, 270, 300, 330 and 360 days) in a complete block design. At each cutting age, NDF degradation was investigated using nine incubation times (0, 3, 6, 12, 24, 48, 72, 96 and 120 hours) in a split-plot design, taking cutting age as main plots and incubation time as subplots. Each plot comprised a non-lactating cow with a permanent ruminal fistula. Variances of the parameter estimates were also obtained, as well as expressions for the estimation of confidence intervals for parameters in the model. A good fit of the model to the data of neutral detergent fiber degradability in the most cutting ages was found. The cutting ages of the coast cross grass influenced the degradability of different fractions, benefiting early stages. In advanced cutting ages the parameters estimates were less precise.

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Ruminal degradation of elephant grass silages added with faveira pods

Acta Scientiarum Animal Sciences ◽

10.4025/actascianimsci.v40i1.39946 ◽

2018 ◽

Vol 40 (1) ◽

pp. 39946 ◽

Cited By ~ 1

Author(s):

Bruno Spindola Garcez ◽

Claudiane Morais dos Santos ◽

Cicero Nicolini ◽

Francisco Araújo Machado ◽

Ernando De Oliveira Macedo ◽

...

Keyword(s):

Crude Protein ◽

Dry Matter ◽

Time Lag ◽

Neutral Detergent Fiber ◽

Elephant Grass ◽

Ruminal Degradation ◽

Ruminal Degradability ◽

Colonization Time ◽

Matter Basis

The objective of this study was to evaluate in situ ruminal degradability of elephant grass silages with addition of 8, 16 and 24% of faveira pods in experimental silos of 100x50 mm, equipped with bunsen valves. The content of crude protein (cp) and neutral detergent fiber (ndf) were determined on a dry matter basis. To evaluate the in situ degradability of dm, cp and ndf, nylon bags containing 4 g sample were incubated in the rumen of three fistulated cattle for 6, 24 and 72h. The dm and cp content of elephant grass silages increased (p < 0.05) from 8% inclusion associated with a higher concentration of constituents in faveira pods (77.25 and 9.61% dm). The ndf fraction reduced 10.91% (p < 0.05) when adding 24% pods. The potential degradation (pd) of dm and cp increased with inclusion of faveira pods, with 75.97 and 95.21%, respectively, for the level of 24%. There was increased potentially degradable fraction (bp) of ndf by 7.07% with inclusion of 24% faveira pods, as well as a reduced colonization time (lag) from 3.81 to 3.44 hours. The addition of up to 24% faveira pods to elephant grass silages improves rumen microbial degradation, and it is indicated this level of addition to obtain better quality silage.

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Ruminal parameters and in-situ degradability of rations with wheat middling substitution for corn

Semina Ciências Agrárias ◽

10.5433/1679-0359.2021v42n3supl1p1707 ◽

2021 ◽

Vol 42 (3Supl1) ◽

pp. 1707-1724

Author(s):

Vinicius Campachi Brito ◽

◽

Leandro das Dores Ferreira da Silva ◽

Maria Carolina Gonçalves de Arruda ◽

Dagiale Kelly de Souza Tagliatella ◽

...

Keyword(s):

Latin Square ◽

Neutral Detergent Fiber ◽

Average Weight ◽

State University ◽

Passage Rate ◽

Ruminal Ph ◽

Linear Behavior ◽

C 50 ◽

Minimum Points

This study aimed to evaluate the effect of substituting corn with wheat middling on the in-situ degradability of foods and ruminal parameters of cattle. The experiment was conducted at the Ruminant Studies Unit and the Laboratory of Food Analysis and Animal Nutrition of Londrina State University. Five rumen-fistulated cattle with an average weight of 521 ± 38.22 kg were housed in individual stalls. The experimental design used was a Latin square with five treatments (100% C, 75% C 25% WM, 50% C 50% WM, 25% C 75% WM, and 100% WM) and five periods of 25 days each. The pH and ammoniacal nitrogen (N-NH3) concentration in ruminal fluid was measured before feeding and 2, 4, 6, and 8 h after feeding in subdivided parcels. The in-situ degradability of dry matter (DM), organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), and acid detergent fiber (ADF) were determined by incubating silage samples and measuring concentrates in the rumen of cattle. The levels of substitution of corn by wheat middling did not alter the pH and N-NH3 values but was influenced by the collection time. The N-NH3 presented quadratic behavior with a point of maximum rumen concentration (5.31 mgdL-1) reached 1.12 h after feeding. The pH presented quadratic behavior with a point of minimum (6.04) reached 4.32 h after feeding. The effective degradability (ED) of DM with 2, 5 and 8%h-1 of passage rate was influenced by the substitution of corn by wheat middling, with increasing linear behavior. The ED 2%h-1 varied from 46.19% to 50.24%, the ED 5%h-1 varied from 33.76% to 38.68%, and the ED 8%h-1 values ranged from 28.16% to 32.92% for the 100% C and 100% WM treatments. Higher values, for treatments with higher levels of substitution of corn by wheat middling, occurred owing to the lower fiber content and to the largest soluble fractions and degradation rate of DM in rations with wheat middling. The ED of CP and NDF with passage rates of 2, 5 and 8%h-1 presented quadratic behavior. The ED 2, 5 and 8%h-1 of CP presented maximums of 75.9%, 77.9%, and 86.2%, with averages of 52.02%, 45.93%, and 42.23%, respectively. The ED 2, 5 and 8%h-1 of NDF presented minimum points of 29.6%, 34.7%, and 35.2%, with averages of 41.60%, 33.43%, and 27.76%, respectively. Wheat middling can be used for total substitution of corn without damaging ruminal pH and N-NH3, in addition to improving the degradability of rations.

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Potential degradation and colonization time of ruminal microorganisms on the particles of different oilseeds-crushed, and its chemical composition

Bioscience Journal ◽

10.14393/bj-v37n0a2021-48122 ◽

2021 ◽

Vol 37 ◽

pp. e37001

Author(s):

Rafael Henrique de Tonissi Buschinelli de Goes ◽

Kennyson Alves de Souza ◽

Milene Puntel Osmari ◽

Thiago José de Lira Cardoso ◽

Raquel Tenório de Oliveira ◽

...

Keyword(s):

Organic Matter ◽

Chemical Composition ◽

Crude Protein ◽

Dry Matter ◽

Neutral Detergent Fiber ◽

The Other ◽

Biodiesel Production ◽

Ether Extract ◽

Colonization Time

This study was carried out to evaluate by-product of the biodiesel industry as canola, safflower, forage turnip, and soybean crushed on the chemical composition, in situ degradability, and colonization time. Canola (Brassica napus L. var. oleifera), safflower (Carthamus tinctorius L.), forage turnip (Raphanus stivus L. var. oleiferus Metzg), and soybean (Glycine max) grains went through the oil extraction process by means of a cold pressing, resulting in the oilseeds-crushed. The treatments identification included: CAN – Canola crushed; SAF – Safflower crushed; TUR – Forage turnip crushed; and SOY – Soybean crushed. The oilseed-crushed treatments were quantified about mineral (calcium, magnesium, copper, iron, manganese, zinc, phosphorus and potassium), chemical composition (dry matter, ash, organic matter, crude protein, ether extract, neutral detergent fiber, acid detergent fiber, total carbohydrates, non-fibrous carbohydrates, and total digestible nutrient contents), In situ degradability, and colonization time. Magnesium, phosphorus, and zinc showed the greater values for TUR treatment 3.46, 27.4, 39.8, respectively, when compared to the other oilseed-crushed treatments. The TUR treatment had the lowest organic matter, whereas had the greater (p≤0.05; TUR and SOY treatments) for the non-fibrous carbohydrates. Ether extract was not affected (p>0.05) with the different oilseed-crushed treatments. Neutral detergent fiber was affected (p≤0.05) for CAN and SAF treatments with the greater values, 344 and 500 g/kg of dry matter, respectively. Soluble and potentially degradable fractions for SAF treatment showed similar results. Whereas the constant rate of degradation, presented the lowest value when compared to the other treatments. Effective degradability of crude protein was greater for CAN 63.2% than SOY 65.9% treatment, which had the lowest value. Potential degradability of crude protein did not differ between treatments. Colonization time for dry matter and crude protein were similar between TUR and SOY treatments. In conclusion, oilseeds-crushed from the biodiesel production can be targeted/used, as feed with great protein and energetic potential in the ruminant’s production, considering the need of correct formulation and ingredients knowledge.

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“In-Situ Raman Spectroscopy of Electronic Processes in Fullerene Thin Films

MRS Proceedings ◽

10.1557/proc-725-p10.8 ◽

2002 ◽

Vol 725 ◽

Author(s):

S.B. Phelan ◽

B.S. O'Connell ◽

G. Farrell ◽

G. Chambers ◽

H.J. Byrne

Keyword(s):

Thin Film ◽

Indium Tin Oxide ◽

Low Temperatures ◽

In Situ Raman Spectroscopy ◽

State Reduction ◽

In Situ Raman ◽

Linear Behavior ◽

Current Voltage ◽

Solid State Reduction

AbstractThe current voltage characteristics of C60 thin film sandwich structures fabricated by vacuum deposition on indium tin oxide (ITO) with an aluminium top electrode are presented and discussed. A strongly non-linear behavior and a sharp increase in the device conductivity was observed at relatively low voltages (∼2V), at both room and low temperatures (20K). At room temperature the system is seen to collapse, and in situ Raman measurements indicate a solid state reduction of the fullerene thin film to form a polymeric state. The high conductivity state was seen to be stable at elevated voltages and low temperatures. This state is seen to be reversible with the application of high voltages. At these high voltages the C60 film was seen to sporadically emit white light at randomly localized points analogous to the much documented Electroluminescence in single crystals.

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Determining the Rate of Ergot-alkaloid Degradation in Toxic Endophyte-infected Tall Fescue Hay and Haylage During Long Term Storage

Journal of Animal Science ◽

10.1093/jas/skab096.038 ◽

2021 ◽

Vol 99 (Supplement_2) ◽

pp. 22-22

Author(s):

Charles A Zumbaugh ◽

Susannah A Gonia ◽

Kathryn M Payne ◽

Thomas B Wilson

Keyword(s):

Tall Fescue ◽

Ergot Alkaloid ◽

Fixed Effects ◽

High Performance ◽

Nutritive Value ◽

Day Treatment ◽

Random Effect ◽

Storage Period ◽

Neutral Detergent Fiber ◽

Experimental Unit

Abstract The objectives of this experiment were to determine changes in the nutritive value and ergot alkaloid concentrations of endophyte-infected tall fescue hay and haylage during a 180-d storage period. Forage from a single field of Kentucky-31 tall fescue was cut for hay in late June and allowed to dry in the field. The dry matter (DM) of the windrow of cut forage was measured every 2 h after clipping. Forage was sampled from the windrow in 6 location blocks once forage DM reached target levels for haylage and hay treatments. Haylage and hay samples were taken when the DM of the windrow reached 50% and 80%, respectively. Seven subsamples of each treatment within block were chopped to 1.91 cm in length with a lettuce chopper and vacuum sealed in oxygen-excluding bags. Sample bags were stored indoors and opened at 30 d intervals over the 180-d storage period. Samples were analyzed for pH, nutritive value, and individual ergot alkaloid concentrations using high-performance liquid chromatography. Within each storage day, treatment within block was considered the experimental unit. Data were analyzed in SAS using the MIXED procedure with fixed effects of treatment, day, and the treatment by day interaction. Location block was considered a random effect. As expected, pH was decreased for haylage compared to hay at all time points (P < 0.01) and DM was greater (P < 0.01) for hay compared to haylage. Neutral detergent fiber values were greater (P < 0.01) for hay compared to haylage and declined during storage (P < 0.01). Total ergot alkaloid concentrations did not differ by treatment (P = 0.61), but ergovaline concentrations declined (P < 0.01) during storage. Collectively, these results indicate minimal differences in nutritive value and ergot alkaloid concentrations between hay and haylage during storage, and that ergovaline concentrations decline during storage.

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Evaluation of the Nutrient Composition, In Vitro Fermentation Characteristics, and In Situ Degradability of Amaranthus caudatus, Amaranthus cruentus, and Amaranthus hypochondriacus in Cattle

Animals ◽

10.3390/ani11010018 ◽

2020 ◽

Vol 11 (1) ◽

pp. 18

Author(s):

Kim Margarette C. Nogoy ◽

Jia Yu ◽

Young Gyu Song ◽

Shida Li ◽

Jong-Wook Chung ◽

...

Keyword(s):

Crude Protein ◽

Dry Matter ◽

Gas Production ◽

Nutrient Composition ◽

Neutral Detergent Fiber ◽

Amaranthus Cruentus ◽

Amaranthus Caudatus ◽

Amaranthus Hypochondriacus

The amaranth plants showed high potential feed value as forage for ruminants. An in-depth study of this plant, particularly in cattle, will help extend its utilization as an alternative protein and fiber feed source in cattle feeding. In this study, the nutrient compositions of three different species of amaranth, Amaranthus caudatus L., Amaranthus cruentus L., and Amaranthus hypochondriacus L.—two varieties for each species, A.ca 74, A.ca 91, A.cu 62, A.cu 66, A. hy 30, and A. hy 48—were evaluated. The in vitro technique was used to evaluate the fermentation characteristics such as total gas production, total volatile fatty acids (VFA) concentration, pH, and ammonia concentration of the rumen fluid. Moreover, the effective degradabilities of dry matter (EDDM) and crude protein (EDCP) of the amaranth forages were determined through in situ bag technique. The amaranth forages: A. caudatus, A. cruentus, and A. hypochondriacus showed better nutritive value than the locally produced forages in Chungcheong province of Korea. The CP of the amaranth ranged from 11.95% to 14.19%, and the neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents ranged from 45.53% to 70.88% and 34.17% to 49.83%, respectively. Among the amaranth varieties, A. hypochondriacus 48 showed the most excellent ruminant feed nutrient quality (CP, 14.19%; NDF, 45.53%; and ADF, 34.17%). The effective degradabilities of dry matter (EDDM; 33–56%) and crude protein EDCP (27–59%) of the amaranth were lower compared to other studies, which could be due to the maturity stage at which the forages were harvested. Nonetheless, A. hypochondriacus 48 showed the highest EDDM (56.73%) and EDCP (59.09%). The different amaranth species did not differ greatly in terms of total VFA concentration or molar proportions, total gas production, or ammonia-N concentration. The high nutrient composition, and highly effective degradability of dry matter and crude protein, coupled with the favorable fermentation characteristics, suggest that the amaranth forages showed good to excellent feed quality for cattle.

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Forage yield and nutritive value of Elephant grass, Italian ryegrass and spontaneous growing species mixed with forage peanut or red clover

Ciência Rural ◽

10.1590/0103-8478cr20131347 ◽

2014 ◽

Vol 44 (10) ◽

pp. 1845-1852 ◽

Cited By ~ 1

Author(s):

Michelle Schalemberg Diehl ◽

Clair Jorge Olivo ◽

Carlos Alberto Agnolin ◽

Ricardo Lima de Azevedo Junior ◽

Vinícius Felipe Bratz ◽

...

Keyword(s):

Repeated Measures ◽

Nutritive Value ◽

Red Clover ◽

Experimental Period ◽

Italian Ryegrass ◽

Forage Yield ◽

Neutral Detergent Fiber ◽

Elephant Grass ◽

Grazing Systems

The objective of this research was to evaluate of three grazing systems (GS) with elephant grass (EG), Italian ryegrass (IR) + spontaneous growing species (SGS); EG + IR + SGS + forage peanut (FP); and EG + IR + SGS + red clover (RC), during the winter and summer periods in rotational grazing with dairy cattle. Experimental design was completely randomized with three treatments, two replicates with repeated measures. Lactating Holstein cows receiving 1% BW-daily feed supplement with concentrate were used in the evaluation. Eight grazing cycles were performed during the experimental period. The values of pre forage mass and stocking rate were 2.52, 2.60 and 2.99 t ha-1 and 2.64, 2.77 and 3.14 animal unit ha-1, respectively for GS. Samples of forage were collected by hand-plucking technique to analyze the crude protein (CP), neutral detergent fiber (NDF), in situ dry matter digestibility (ISDMD), in situ organic matter digestibility (ISOMD) of forage present between rows of elephant grass, in the rows of elephant grass and the legumes. Higher value of CP, ISOMD and lower of NDF were observed for the grazing systems mixed with legumes forage.

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Modification of the summative equation to estimate daily total digestible nutrients for bermudagrass pasture

Journal of Animal Science ◽

10.1093/jas/skaa354 ◽

2020 ◽

Vol 98 (11) ◽

Author(s):

Prem Woli ◽

Francis M Rouquette ◽

Charles R Long ◽

Luis O Tedeschi ◽

Guillermo Scaglia

Keyword(s):

Nutritive Value ◽

Cynodon Dactylon ◽

Perennial Grass ◽

Warm Season ◽

Neutral Detergent Fiber ◽

Systematic Bias ◽

Grazing Season ◽

Nutritive Values ◽

Plant Maturity ◽

Daily Total

Abstract In forage-animal nutrition modeling, diet energy is estimated mainly from the forage total digestible nutrients (TDN). As digestibility trials are expensive, TDN is usually estimated using summative equations. Early summative equations assumed a fixed coefficient to compute digestible fiber using the lignin-to-neutral detergent fiber (NDF) ratio. Subsequently, a structural coefficient (φ) was added to the summative equations to reflect an association between lignin and cell wall components. Additional modifications to the summative equations assumed a constant φ value, and they have been used as a standard method by many commercial laboratories and scientists. For feeds with nutritive values that do not change much over time, a constant φ value may suffice. However, for forages with nutritive values that keep changing during the grazing season owing to changes in weather and plant maturity, a constant φ value may add a systematic bias to prediction because it is associated with the variable lignin-to-NDF ratio. In this study, we developed a model to estimate φ as a function of the day of the year by using the daily TDN values of bermudagrass [Cynodon dactylon (L.) Pers.], a popular warm-season perennial grass in the southern United States. The variable φ model was evaluated by using it in the TDN equation and comparing the estimated values with the observed ones obtained from several locations. Values of the various measures of fit used—the Willmott index (WI), the modeling efficiency (ME), R2, root mean square error (RMSE), and percent error (PE)—showed that using the variable φ vis-à-vis the constant φ improved the TDN equation significantly. The WI, ME, R2, RMSE, and PE values of 0.94, 0.80, 0.80, 2.5, and 4.7, respectively, indicated that the TDN equation with the variable φ model was able to mimic the observed values of TDN satisfactorily. Unlike the constant φ, the variable φ predicted more closely the forage nutritive value throughout the grazing season. The variable φ model may be useful to forage-beef modeling in accurately reflecting the impacts of plant maturity and weather on daily forage nutritive value and animal performance.

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