Kjeltec 2300 analyzer

The chemical composition of the raw materials and pasta samples was performed using the AACC and AOAC methods [29 ,30 ].
Moisture content and ash content was determined using the AACC method 44-15A and 08-01, respectively [29 ].
Protein content was measured using the Kjeldahl method using the Kjeltec 2300 analyzer (FOSS, Höganӓs, Sweden) (Method AACC 46-08). The protein content was calculated from the total nitrogen content with the use of a conversion factor of 5.7.
Fat content was determined by continuous extraction in SoxtecTM8000 (FOSS, Höganäs, Sweden) with hexane as a solvent.
Total dietary fiber (TDF), insoluble dietary fiber (IDF), and soluble dietary fiber (SDF) contents were determined according to the enzymatic methods (AACC 32-05, AACC 32-21, AOAC 991.43, and AOAC 985.29) as described Krawęcka et al. [10 (link)].
Digestible carbohydrate content was calculated from the difference by subtracting the sum of all macronutrients (protein, fat, ash, total dietary fibre) from 100, according to Krawęcka et al. [4 (link)].

A total of 829 samples of plant feed materials, which included corn DDGS (N = 196), corn germ meal (N = 97), corn gluten meal (N = 198), DDG (N = 73) and rapeseed meal (N = 265), were collected from 23 provinces of China in 2008–2013. All feed materials were directly collected from public market in different provinces and no specific permissions were required for the locations/activities. Each sample was well mixed, ground using a Retsch ZM 100 mill (Retsch GmbH, Haan, Germany) and sieved through a 1.00-mm sieve for further analysis.
The protein content was analyzed according to the standard analytical method for feedstuff (GB/T 6432–94) [9 ] using a Kjeltec 2300 analyzer (FOSS Tecator AB, Höganäs, Sweden) with two duplicates for each sample.

Dried shoot tissues (0.05 g) were digested with a Kjeldahl tablet in concentrated sulfuric acid for 60 min at 350°C (Allen, 1989 ), and the mixture was allowed to cool before TRN was determined by a Kjeltec 2300 analyzer (Foss Tecator AB, Höganäs, Sweden) through titration.

Dried shoot tissues (0.05 g) were digested with a Kjeldahl tablet and 5 ml of concentrated sulphuric acid for 60 min at 350° C and the mixture was allowed to cool before TRN was determined by a Kjeltec 2300 analyzer (Foss Tecator AB, Höganäs, Sweden) through titration. The concentration of TRN was calculated as a unit of mg g^-1 DW.

Chromic oxide as an indigestible marker was added in pigs’ diet to determine the apparent total tract digestibility (ATTD) of dry matter (DM), nitrogen (N), and gross energy (GE). Pigs diets were mixed with chromic oxide 7 days earlier to collect samples and fresh excreta samples were randomly collected from 2 pigs per pen at week 10 and stored at −20 °C until analyzed. Before starting the chemical analysis, the fecal samples were thawed and dried at 60 °C for 72 h. All feed and fecal samples were finely ground to pass through a 1-mm screen size and analyzed for DM and N following the procedures outlined by the AOAC [16 ]. Chromium was examined through UV absorption spectrophotometry (Shimadzu, UV-1201, Shimadzu, Kyoto, Japan). The GE was determined by measuring heat of combustion in the samples, using a bomb calorimeter (Parr 6100; Parr Instrument Co., Moline, IL, USA). Nitrogen content was determined by using a Kjeltec 2300 Analyzer (Foss Tecator AB, Hoeganaes, Sweden). ATTD = {1 − [(Nf × Cd)/(Nd × Cf)]}, formula was used to determine ATTD. Herewith, Nf stands for (nutrient concentration in feces), Nd stands for (nutrient concentration in diet), Cd stands for (chromium concentration in diet), and Cf stands for (chromium dioxide concentration in feces).