Post on 11-Jan-2016
Management of the rumen: the main aspect of future
performance
Ing. Dana Kumprechtová, PhD.
University of Veterinary and Pharmaceutical Sciences Brno, Czech Republic
CONTENTS
• Digestive tract of ruminants
• Rumen microflora
• Main processes in the rumen
• RUMEN MANAGEMENT
• HEAT STRESS
Digestive tract of ruminants
• perfectly adapted to the utilization of plant origin foodstuffs, rich in cellulose• symbiotic microflora: digestion of cellulose, hemicellulose, non-protein nitrogen
RUMEN
• 150 l digesta
• natural fermentation tank and feed reservoir
• microorganisms adhere to feed particles and mucosal papillae
Ruminal motorics
• 2 – 3 contractions/minute
• contact of bacteria with the substrate
• stability of the rumen environment
• large particles are regurgitated
• rumination: 8 – 13 hours/day mechanical desintegration of feed buffering effect of saliva
• eructation (30 – 50 l gas/hour)
Ruminal microflora
BACTERIA
• 107 – 1012/ ml rumen fluid• cellulolytic bacteria
• bacteria producing VFA and lactic acid
• methane producing bacteria
• proteolytic bacteria
• lipolytic bacteria
Ruminal microflora
PROTOZOA
• 105/ml rumen fluid () 106/ml (concentrates)
• utilize readily soluble sugars and polysaccharides
• ? cellulose
• utilize starch – prevent a decrease in pH stabilize rumen fermentation
Energy nutrition of cattle
• 70 % VFA of bacterial origin
• 20 % microbial mass
• 10 % feed nutrients that escaped microbial fermentation
Volatile Fatty AcidsLactating cow – 3.5 kg/day
• acetate 55-75 % - from structural saccharides• propionate 15-20 % - from starch, sugar, pectines• butyrate 10 % - - from structural saccharides, sugar• valerate, isovalerate... 5%• lactate – readily converted to propionate
Volatile Fatty Acids
ACETATE fatty acids milk fat
PROPIONATE glucose lactose
BUTYRATE milk fat
ketone bodies
Crude Protein
DEGRADABLE microbial protein
NH3 ruminal wall
blood saliva rumen
NON-DEGRADABLE small intestine amino acids
Temperature
• microorganisms require stable temperature for the growth
• heat stress: temperature in the rumen
Water
• 80 – 90 % rumen contents
• VFA resorption in the rumen
• rumen motorics and turnover
• access to drinkers for all the cows
Ruminal motorics
Structural fibre (optimum particle size 4 – 5 cm)
• regurgitation
• motoric stimulation
• digesta mixing
• fermentation
Ruminal motorics
Impaired motorics: RUMEN TYMPANY
ACIDOSIS
Causes:
• high levels of non-structural saccharides in feed
• not enough structural fibre
• high doses of concentrate given separately from roughage
Fermentation products
Lactic acid: pH
ACIDOSIS
• ruminal mucosa ulceration
• liver damage
• lameness
• mastitis
Fermentation products
Ammonia:
too high levels of soluble protein in feed
high NH3 levels
RUMEN ALCALOSIS (pH > 7)
Rumen management
Optimum pH: 6.2 – 6.8
• buffering effect of saliva (bicarbonate): - structural fibre (60% cows in the herd ruminate 2 hours post feeding) - TMR – more even saliva production - alfalfa hay
• feeding several times a day
• optimum ratio roughage : concentrate
Rumen management
• dry matter intake
• pH in the rumen
• rumen degradable protein + readily fermentable sugars
• no changes in the diet
• selection of diet components by cows
Rumen management
Feed components• alfalfa hay• cotton seed
Feed supplements:Buffers:• sodium bicarbonate• magnesium oxide
Direct-fed microbials (probiotics)• lactic acid bacteria• yeasts – Saccharomyces cerevisiae• fungi – Aspergillus oryzae
Saccharomyces cerevisiaeEffects:
stability of the rumen environment
fermentation
VFA production
lactate production
utilization of ammonia
microbial protein synthesis
Milk production kg/head/day
30
32
34
36
38
40
42
44
46
week
mil
k p
rod
ucti
on
(kg
)
s.cervisiae
kontrola
Heat stress
• Increased respiration, heart rate (especially in high-producing and older cows)
• Increased metabolism
• Activation of sweat glands
• Increased body temperature
• Decreased physical activity
Heat stress
• Increased water requirement
• Decreased feed intake
• Decreased performance
• Lower percentage of milk protein and fat
Milk composition
N Milk yieldkg.l-1
Fat%
Protein%
SCC10-3/ml
Heat stress 124 28,2 3,42 3,02 460Health 120 32,5 4,02 3,46 162
Heat stress
Nutrition
• High quality fibre
• High quality concentrated feeds (by-pass fat, by-pass protein)
• Optimizing rumen function: structural fibre, roughage/concentrate ratio
• Feed should be placed in the trough early in the morning and in the evening when the ambient temperature is lower
Heat stress
Warm feed
• oxidation
• growth of yeasts and fungi
• use feed stabilizers (propionic acid, formic acid, monopropyleneglycol)
CONCLUSION
Good care of the ruminal health is a complicated task.The creation of optimum rumen conditions is based mainly on proper nutrition (balanced diet, high quality components, structural fibre, roughage : concentrate ratio, right feed additives). The healthy rumen helps eliminate the adverse effects of heat stress and achieve optimum health, performance and profitability.