Pertemuan 4-Sifat kimia

Chemical methods Nutritive Value of Feed

Sifat Kimia Pakan

Nutritional Availability

Fraction

Anuraga Jayanegara

Monogastric

Ruminant

Sugars, Starch

Complete

Complete

Protein

High

High

Lipids

High

High

Pectin

High

Complete

Hemicellulose

Low

Partial

Cellulose

Low

Partial

Lignin / Cutin

Indigestible

Indigestible

(adapted from Van Soest, 1966 and 1967) Department of Nutrition and Feed Technology

Analisis proksimat Proximate (Weende) system of analysis, Henneberg & Stohmann 1862 Feedstuff (FS)

Drying

Substrate (DM) Kjeldahl

4h, 103°C

Acid hydrolysis NH3 distillation

Crude protein (XP)

Ether extraction

Crude lipid (XL)

Hot acid and base

Crude fibre (XF)

500°C

Crude ash (XA)

CP=N x 6.25

Water content

(estimated by mass difference)

Department of Nutrition and Feed Technology

OM=DM-XA

Nitrogen free extract (NFE, XX) Department of Nutrition and Feed Technology

Belitz et al. (2009) Food Chemistry, 4th Ed. Analisa air: Menggunakan oven dengan temperatur sedikit di atas temperatur didih air, misalnya 105oC. Analisa abu: Abu adalah bagian dari sisa pembakaran dalam tanur dengan temperatur 400-600oC yang terdiri atas zat-zat anorganik atau mineral. Analisa protein kasar: Protein kasar adalah semua zat yang mengandung nitrogen. Dalam protein rata-rata mengandung nitrogen 16%. Metode yang sering digunakan dalam analisa protein adalah metode Kjeldahl yang melalui proses destruksi, destilasi, titrasi dan perhitungan.





Analisa lemak kasar: Metode ekstraksi soxhlet dengan pelarut organik seperti petroleum ether. Analisa serat kasar: Fraksi dari karbohidrat yang tidak larut dalam basa dan asam encer setelah pendidihan masing-masing 30 menit. Bahan ekstrak tanpa nitrogen (Beta-N): Merupakan fraksi karbohidrat yang umumnya mudah tercerna antara lain pati dan gula.

Crude protein (XP)

protein, amino acids, ammonium compound, amides od acides, nitrogenous glycosides, B vitamins

Crude lipid (XL)

fats, oils, waxes, organic acids, pigments, sterols, vitamins A, D, E, K

Crude fibre (XF)

cellulose, hemicellulose, lignin

Crude ash (XA)

macro- and microminerals

Nitrogen free extract (NFE, XX)


starch, sugars, fructosans, hemicellulose, pectin, organic acids, resins, tannins, pigments, water soluble vitamins


Analisis serat Van Soest: Detergent Fibre System Van Soest 1964 Cellulose

Pectin

Protein

Lignin Lipids

(„Cross-linking glycans“), diverse group of carbohydrates, common xyloglucans and glucuronarabinoxylans, soluble in strong alkali, β-1,4 backbone + short side chains, form H-bonds with cellulose

Neutral detergent solution Neutral detergent fibre

(pectic polysaccharides), easiest to remove from wall (hot water, dilute acid), form gels, function: determining wall porosity, providing charged wall surface for cell-cell adhesion, cell-cell recognition, pathogen recognition etc. glycoproteins (polypeptide backbone + carbohydrate side chains), cross-linked to pectic substances, may have sites for lignification, extraction requires destructive conditions, function: structural role, cell signalling (growth and guidance of pollen tube) Lignin: Polymer of phenolics, esp. phenylpropanoids, strengthening agent, resists fungal/pathogen attack Suberin, wax, cutin: variety of associated lipids for strength and waterproofing

Substrate (DM)

Hemicellulose, Cellulose, Lignin, Ash Acid detergent solution

Acid detergent fibre

Cellulose

Lignin, insoluble Ash 500 °C insoluble Ash


Hemicellulose

Cellulose, Lignin, insoluble Ash 72% H2SO4

Acid detergent lignin

Soluble Protein, Lipids, Pectin


Lignin

Digestiblity

Hemicellulose

β-1,4-glucan, cellobiose + residues, forms microfibrils by intra-molecular and inter-molecular H-bonds, mechanical strength, highly crystalline or „amorphous“ regions



Comparison of Detergent & Proximate System Detergent system

Nitrogenous

Non-nitrogenous

NPN compounds, proteins ND soluble (cell contents)

Proximate system CP

lipids, ether soluble substances

CL

water soluble substances, pectins, starch

ND insoluble (cell wall) (NDF)

AD soluble

insoluble proteins

hemicellulose

AD insoluble (ADF)

H2SO4 soluble lignified proteins

alkali soluble lignin

NFE

cellulose H2SO4 insoluble


insoluble lignin (ADL)

CF Department of Nutrition and Feed Technology

Other Methods to Determine Nutrient Contents Starch/ Enzymatic: Degradation and quantification of glucose/sugar Cell wall monomers (degradability of different sources, solubilisation) Refractometer: Estimation of the concentration of a starch solution by its refraction index (solubility, co-extractions) Protein

Colorimetric assays: (Bradford, Neuhoff) reaction of protein with dyes relative to standard (different staining, extractability) Amino acid composition: Hydrolysis and quantification of AA by mass spectrometry (expensive, time consuming)

Lipids

Chromatography: Extraction and quantification by HPLC (extractability, oxidation, quantification)


Energy: Maintenance and Production Growth MJ/kg Cattle Calf Pigs

34 15 26

Lactation MJ/kg

Maintenance MJ/ kg0.75 Cattle Calf Pigs

• Fasting metabolism • Maintenance requirements Department of Nutrition and Feed Technology

Energy content (MJ/kg) gross physiological

Polysaccharides (starch)

17.6

17.6

Fat (triglycerides)

39.8

39.8

Protein

23.9

18.4


Cattle 25 Calf -Pigs 15

Cattle 5.3 Calf -Pigs 7.3

Energy Content of the Main Nutrients

Source

Reproduction MJ/kg


0.48 0.52 0.44

Determination of energy requirements

Energy in foetus, placenta…

Milk energy (protein, fat)

Fat deposit

Protein gain

Basal asal metabolic rate

Metabolisable energy

Digestible energy

Gross energy

Heat loss due to energy conversion

Urine and Gas energy DE = GE - EF ME = DE - (Eu + Eg)

Faecal energy

IME = MEm* W0.75 + MEpf* ∆W + MEc* ∆Wc + MEl* L (+ MEo* no) Department of Nutrition and Feed Technology




Thank you for your attention!

