Feed and fecal samples were analyzed to compare three methods of determining acid detergent fiber. Each sample was weighed into both Dacron and Ankom F58 fiber bags and then analyzed using an Ankom fiber analyzer. Results were then compared to the Van Soest beaker method. Ankom F58 bags helped reduce washout of small particles associated with Dacron bags, but fecal samples needed to be incubated in detergent for an extended amount of time to isolate acid detergent fiber material. Utilizing a technique that produces correct acid detergent fiber values is important for producers because these values are used as a proxy for calculating total digestible nutrients of feedstuffs

MacDonald, James C.

Troyer, Braden C.

Wilson, Hannah C.

English

DigitalCommons@University of Nebraska

University of Nebraska - Lincoln DigitalCommons@University of Nebraska - Lincoln Nebraska Beef Cattle Reports Animal Science Department 2020 Evaluation of Ankom F58 Filter Bags Compared to Dacron Bags and Beakers for Analysis of Acid Detergent Fiber Braden C. Troyer University of Nebraska - Lincoln Hannah C. Wilson University of Nebraska-Lincoln, hhamilton6@unl.edu James C. MacDonald West Texas A&M University & University of Nebraska - Lincoln, jmacdonald2@unl.edu Follow this and additional works at: https://digitalcommons.unl.edu/animalscinbcr  Part of the Large or Food Animal and Equine Medicine Commons, Meat Science Commons, and the Veterinary Preventive Medicine, Epidemiology, and Public Health Commons Troyer, Braden C.; Wilson, Hannah C.; and MacDonald, James C., "Evaluation of Ankom F58 Filter Bags Compared to Dacron Bags and Beakers for Analysis of Acid Detergent Fiber" (2020). Nebraska Beef Cattle Reports. 1072. https://digitalcommons.unl.edu/animalscinbcr/1072 This Article is brought to you for free and open access by the Animal Science Department at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Nebraska Beef Cattle Reports by an authorized administrator of DigitalCommons@University of Nebraska - Lincoln. 56 · 2020 Nebraska Beef Cattle Report©  Th e Board Regents of the University of Nebraska. All rights reserved.541 fi lter to isolate ADF material. Th e fi lters were dried at 100°C for 24 h and then ADF content is determined. Fecal samples were also weighed into Ankom F58 bags in trip-licate and analyzed for ADF in the Ankom machine. However, bags were exposed to 75 minutes of detergent followed by a cycle of fi ve minute washes to increase exposure to detergent and help isolate ADF material. Time of incubation was increased aft er the 60 minute incubation resulted in values that were higher than the beaker values when fecal samples were analyzed. Bags were removed from the machine and dried at 100°C for 24 h to determine ADF content.ResultsBoth types of bags produced similar ADF results when compared to beakers for feed samples (Table 1). Feed analyzed ranged from 29 to 50% ADF and diff er-ences between methods were less than 2 percentage units for all feeds. Fecal sample ADF values were diff erent between bag types (Table 2). On average, Dacron bags resulted in 12.1 percentage units lower ADF values compared to beakers. Th is suggests that there was washout of particles from the bag due to the large pore size of these bags coupled with the smaller grind size of the fecal samples. Conversely, Ankom F58 bags resulted in 6.7 percentage units greater ADF values compared to beaker values, suggesting the fecal material was not exposed to detergent for enough time to completely remove ADF soluble material. Th is may be due to the smaller pore size of these bags. To solve this problem the sec-ond set of Ankom F58 bags were incubated for 75 minutes instead of 60 minutes. Th is extended incubation in detergent resulted in ADF values that were only 2.3 percentage units greater than beaker values. Regression analysis of ADF value relative to incubation time resulted in an equation [y = (- 0.26)x + 65.25] to predict the decrease in ADF as incubation time increased. Th is could temperature, time, and the number of washes used during each cycle, which in-creases accuracy and precision across runs. Feed samples are weighed into bags and then placed in the machine to be analyzed. Traditionally Dacron bags were used, which have a pore size of 50 micrometers. Recent-ly, a new Ankom F58 bag was developed, which has a pore size of 25 micrometers. With some samples there can be washout of small particles through the larger pores, conversely, if pores are too small there may be limited removal of soluble material by the detergent solution. Th e objective of this study was to determine if samples weighed into either Dacron bags or Ankom F58 bags, then analyzed for ADF in the Ankom machine produced similar values as using the Van Soest method of beakers.ProcedureFour feed samples were collected and ground through a 1- mm screen using a Wiley Mill in order to analyze a variety of forages ranging from low quality to higher quality. Fecal samples were also collected and ground using a 0.5 mm screen in a Tecator cyclotec sample mill following freeze drying. Eight fecal samples were analyzed to help validate any issues found when analyzing samples with very fi ne grind sizes. All samples were weighed into Dacron bags and Ankom F58 bags in triplicate. Dacron bags had 1.25 grams of sample and Ankom F58 bags had 0.5 grams of sample. No sodium sulfi te was used in the bags. Bags were analyzed for ADF using an automated Ankom machine with samples being exposed to 60 minutes of detergent, followed by a cycle of fi ve minute washes. Bags were removed from the machine and dried at 100°C for 24 h to determine ADF content. Additionally, samples were analyzed for ADF in duplicate using the Van Soest beaker method, which utilizes 0.5 g of sample and 0.5 g of sodium sulfi te refl uxed in ADF solution for 60 minutes and then fi ltered using a Whatman  Evaluation of Ankom F58 Filter Bags Compared to Dacron Bags and Beakers for Analysis of Acid Detergent FiberBraden C. TroyerHannah C. WilsonTerry J. KlopfensteinJames C. MacDonaldAndrea K. WatsonSummary with ImplicationsFeed and fecal samples were analyzed to compare three methods of determining acid detergent fi ber. Each sample was weighed into both Dacron and Ankom F58 fi ber bags and then analyzed using an Ankom fi ber analyzer. Results were then compared to the Van Soest beaker method. Ankom F58 bags helped reduce washout of small particles as-sociated with Dacron bags, but fecal samples needed to be incubated in detergent for an extended amount of time to isolate acid de-tergent fi ber material. Utilizing a technique that produces correct acid detergent fi ber values is important for producers because these values are used as a proxy for calculat-ing total digestible nutrients of feedstuff s.IntroductionForage sources account for over 80% of the feed amounts allocated to a beef animal over their production lifetime. Th is includes the forage a cow consumes while gestating and lactating, as well as all of the forage consumed during the backgrounding and fi nishing phases of an animal’s life. Th e importance of understanding the amount of fi ber in these forages is important due to its eff ect on intake, digestibility, and energy availability. Additionally, the acid detergent fi ber (ADF) procedure is used by commer-cial labs to predict total digestible nutrients of feedstuff s. Th e Ankom Fiber Analyzer was developed to minimize the amount of human error associated with determining fi ber in feed samples. Th is instrument, which was designed to replace the Van Soest method of using beakers, monitors 2020 Nebraska Beef Cattle Report · 57 be extrapolated to predict incubation time needed to replicate beaker ADF values.ConclusionAcid detergent fi ber values of feed and fecal samples in Ankom F58 bags analyzed by the Ankom machine are similar to values determined using the beaker method if incubation of the bags is extended to 75 minutes, which allows the detergent to completely permeate the bag. When com-pared to the beakers the Ankom machine resulted in values that were within 3.0 per-centage units when the longer incubation was used. Although Ankom values were close to beaker values when using the 75 minute incubation, further research on the exact amount of incubation time needed for samples in the Ankom may improve these values. Overall, the small pore size of these bags helps mitigate issues with washout when compared to Dacron bags for fecal samples or feed samples with very fi ne particles.Braden C. Troyer, graduate student, Depart-ment of Animal Science, Lincoln, NEHannah C. Wilson, research technician, Department of Animal Science, Lincoln, NEJames C. MacDonald, professor, Terry J. Klopfenstein, professor, Andrea K. Watson, research assistant professor, Department of Animal Science, Lincoln, NETable 1. Comparing Ankom F58 bags to Dacron bags when analyzing feed samples for acid detergent fi ber (ADF) using 60 minute incubation in an Ankom fi ber analyzerSample Beaker1 Dacron Bag Ankom F58 BagsBrome 1 49.34% 48.88% 50.18%Brome 2 40.50% 42.19% 41.06%Alfalfa 29.80% 31.13% 29.25%Oats 31.37% 32.51% 30.36%Avg. Diff erence2 - 0.93 0.041Beaker— ADF value based on Van Soest beaker method2Avg. Diff erence— average ADF value diff erence between Van Soest beaker method and Ankom machine using individual bag type and incubation lengthTable 2. Comparing Ankom F58 bags to Dacron bags when analyzing fecal samples for acid detergent fi ber (ADF) using the Ankom fi ber analyzerSample Beaker1 Dacron BagAnkom F58 Bags60 min2 75 min3Fecal 1 37.22% 26.63% 45.50% 41.00%Fecal 2 44.43% 33.59% 49.03% 44.50%Fecal 3 45.26% 30.12% 53.16% 49.10%Fecal 4 43.01% 32.25% 48.69% 45.00%Fecal 5 41.90% 34.25% 48.69% 47.10%Fecal 6 46.34% 28.53% 54.78% 49.30%Fecal 7 41.33% 22.54% 46.92% 43.40%Fecal 8 48.45% 42.91% 50.75% 47.0%Avg. Diff erence4 12.14% - 6.67% - 2.30%1Beaker— ADF value based on Van Soest beaker method260 min— 60 minute incubation in the Ankom machine375 min— 75 minute incubation in the Ankom machine4Avg. Diff erence— average ADF value diff erence between Van Soest beaker method and Ankom machine using individual bag type and incubation length

Evaluation of Ankom F58 Filter Bags Compared to Dacron Bags and Beakers for Analysis of Acid Detergent Fiber

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Evaluation of Ankom F58 Filter Bags Compared to Dacron Bags and Beakers for Analysis of Acid Detergent Fiber

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