EXAM: 1. Fundamentals

Question 1

Mycotoxins

Answer 1

• Aflatoxin - Aspergillus
• B1-blue, G1+G2-green, M1+M2-milk
• prim. liver damage: cytotoxic+carcinogenic
• warm+humid environ.: ground nut, maize, cottonseed meal
• Ochratoxin - Aspergillus+Penicillin
• Toxic to kidneys: nephrotoxic, carcinogenic, immunotoxic
• cereals
• Zearulenos or F-Z
• genital organs
• estrogenous syndrome in pigs
• fetus dystrophy, pseudoovulation
• Trichothecenes T-2 - Fusarium
• inhibit protein synt. on cellular level
• immunosuppressive effect
• cereals
• DON-deoxinNallol
• Fumitoxin
• Eq leukocephalomalacia
• Porcine exudative lung syndrome
• Chicken spiking disease
• Nephrotoxicity, hepatic cancer
• Maize, tropical areas
• Ergot - Claviceps purpurea
• Bleedings, CNS disturbance, abortion
• cereals

Question 2

Ruminal microflora

Answer 2

• Anaerobic
• pH: 6,2-6,8 (maintained by saliva, ruminal fluid, VFAs)
• Isothermal: 38,5-40 degrees
• Bacterias, protozoas, fungi
• End products: microbial proteins, VFA (acetate, proprionate, butyrate), gasses (CO2, CH4)
• Bacteriodies: digest starch+cellulose->acetate, succinate, formate
• Ruminococcus: digest cellulose->acetate
• Lactionspira: digest pectin->acetate, lactate
• Conc.diets (cereals)->amylolytic bact.->proprionate (beef prod.)
• Hay, roughage diet->cellulolytic bact.->acetate (milk prod)
• Protozoa: degr. protein and starch->NH3+VFAs
• Fungi: degr. old roughage (incr. pectin)->VFAs, CO2, H2

Question 3

Monogastric microflora

Answer 3

• Bacteria location: stomach (lactobacilli), duod/jejun. (streptococcus), ileum (bacteroides), colon/cecum (bacteroides, eubacterium, peptostreptococcus, clostridium)
• Synth. of vit.K and B
• Degr. of carbs, proteins and lipids
• Degr. of bile acids/salts, chol., antibiotics
• NH3 prod. from urea
• Modification of transit time and mitotic index
• Thickness of intestinal microvilli
• Antimicrobial effect (immune system): barrier function
• Active: strong adhesion btw bact and wall, defence against exogen bact
• Passive: acidity, pH modification of int.tract, excreta, incr. transit time
• 1.st barrier: anatomical (physical) - bacterial (enterocytes) - humoral (AB prod. cells, Ig´s) - cellular (T cells)

Question 4

Antinutritive substances

Answer 4

Proteins:
-Amylase inhibitor: interfere w. starch digestion
-Trypsin inhibitor (soya bean): activity of trypsin, pancreas hyperplasia/trophy
-Antigenic proteins: gut wall damage
-Polyphenols: decr. protein digestion
-Lectins (soya bean): gut wall damage, immune responses, metabolic toxicity
-Tannins (rape): forms complexes w. proteins/carbs and decr. digestion of them
Glycosides:
-Vicine/convicine (vicia faba): haemolytic anaemia, interfere w. fertility and egg hatchability
-Solanine (potato): soap character->hemolysis, incr. int. permeability
-Glucosinolates: impair I utiliz., affect thyroid and liver, decr. palatability
-Alkaloids: liver dam., bitter taste
-Quinolizidine: natural disturb., liver dam., bitter taste
-Scopolamine/hyoscyamine: disturb palatenes of food
Other:
-Phytate: complex w. minerals and proteins, decr. availability (P, Zn)
-Gossypol (cotton seed): complex w. Fe, anaemia, decr. egg weight
-Saponins: fishy smell and egg taste

Question 5

Antimetabolites/antivitamins

Answer 5

• Anti Vit.A - lipoxygenase - rancidity in grains, beans
• Anti Vit.D - raw soybean - rickets (young chickens)
• Anti Vit.E - gossypol - decr. B-carotene level + fertility
• Anti Vit.K - dicumarol (sweet clover or warfarin-rat pois.) - anticoagulant
• Anti Vit.B1 - thiaminase - opistothonus
• Anti Vit.B6 - linseed - decr. growth (ckicken)
• Anti Vit.B12 - raw soybean - anaemia
• Anti Biotin - Avidin (raw egg)

Question 6

Proximate analysis of feedstuff

Answer 6

• System that estimates the value of a material for feeding purposes, without using the feed in a feeding trial.
• Bases on separation of feed components into groups or fractions according to their feeding value.
  1. Dry the sample: to get DM
• If DM < 86%: weigh->dry 28-72h at 50-60degr->weigh (use 200g homog. sample, eg. silage)
• If DM > 86% weigh->dry 4h at 105degr.->cool->weigh (use low amount, like 5g, eg. grains)
• NM! If air dry, expect a artificial high water content.
  2. Burn the DM: to get ash (IM)
• DM->weigh->4h combustion 550degr.->cool->weigh (=total oxidation)
• Volatile elements like I, Hg, Se disappear
• Might be contaminated w. soil -> incr. value
  3. OM = DM - CAsh
  4. CP - Kieldahls process: to get the N content
• Boiling w.H2SO4, distilling w.NH4, titration w. HCl, measure N, True protein analysis, NPN analysis
• Nx6,25=CP
• TP-CP=NPN
  5. CF - Van Soest Method: separate NDF from the rest
  6. EE - extracted by ether then ether is evaporated
• If use gasschromatograf: different. the FA
• Fats: most valuable E source, imp. in production
  7. NFE = OM - (CP+EE+CF)
• Carbs (sugars, starch) and water soluble hemicellulose and pectin
• Carbs imp. E source and imp. in production
  8. Water = Feed - DM
• High water content: roots, silage, fresh grasses
• Air dry 12-16%: grains, hay, straw
• Dehydrated 8-10%: meal, dried pulps
• Imp. in structure, regulation and production