1. Management of the rumen: the main aspect of future performance Ing. Dana Kumprechtová, PhD. University of Veterinary and Pharmaceutical Sciences Brno, Czech Republic

2. CONTENTS Digestive tract of ruminants Rumen microflora Main processes in the rumen RUMEN MANAGEMENT HEAT STRESS

3. COW polygastric animal

5. 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

6. Ruminant nutrition host animal Feed ruminal microflora

7. Main goal of dairy cow nutrition: ensure OPTIMUM CONDITIONS FOR RUMEN FERMENTATION

8. RUMEN 150 l digesta natural fermentation tank and feed reservoir microorganisms adhere to feed particles and mucosal papillae

9. 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)

11. Ruminal microflora BACTERIA 10 7 – 10 12 / ml rumen fluid cellulolytic bacteria bacteria producing VFA and lactic acid methane producing bacteria proteolytic bacteria lipolytic bacteria

12. Ruminal microflora PROTOZOA 10 5 /ml rumen fluid () 10 6 /ml (concentrates) utilize readily soluble sugars and polysaccharides ? cellulose utilize starch – prevent a decrease in pH stabilize rumen fermentation

13. Ruminal microflora FUNGI high celullolytic and hemicellulolytic activity

14. Main processes in the rumen SACCHARIDES VFA CRUDE MICROBIAL PROTEIN

15. Energy nutrition of cattle 70 % VFA of bacterial origin 20 % microbial mass 10 % feed nutrients that escaped microbial fermentation

16. Volatile Fatty Acids Lactating 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

17. Volatile Fatty Acids ACETATE fatty acids milk fat PROPIONATE glucose lactose BUTYRATE milk fat ketone bodies

18. Crude Protein DEGRADABLE microbial protein NH3 ruminal wall blood saliva rumen NON-DEGRADABLE small intestine amino acids

19. Nitrogen metabolism

20. Factors affecting ruminal fermentation

21. Temperature microorganisms require stable temperature for the growth heat stress: temperature in the rumen

22. Water 80 – 90 % rumen contents VFA resorption in the rumen rumen motorics and turnover access to drinkers for all the cows

23. Ruminal motorics Structural fibre (optimum particle size 4 – 5 cm) regurgitation motoric stimulation digesta mixing fermentation

24. 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

25. Fermentation products Lactic acid: pH ACIDOSIS ruminal mucosa ulceration liver damage lameness mastitis

26. Fermentation products Ammonia: too high levels of soluble protein in feed high NH3 levels RUMEN ALCALOSIS (pH > 7)

27. Rumen management

28. 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

29. 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

30. 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

31. Saccharomyces cerevisiae Effects : stability of the rumen environment fermentation VFA production lactate production utilization of ammonia microbial protein synthesis

32. Saccharomyces cerevisiae dry matter intake milk production mastitis occurrence SCC growth acidosis

33. Milk production kg/head/day

34. Heat stress

35. THERMAL COMFORT ZONE IN CATTLE: 5 - 25 °C

36. 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

37. Heat stress Increased water requirement Decreased feed intake Decreased performance Lower percentage of milk protein and fat

38. Milk composition NMilk yield kg.l -1 Fat % Protein % SCC 10 -3 /ml Heat stress 12428,23,423,02460 Health 12032,54,023,46162

39. Heat stress Worse condition Reproduction disorders Impaired general health status

40. 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

41. Heat stress Warm feed oxidation growth of yeasts and fungi use feed stabilizers (propionic acid, formic acid, monopropyleneglycol)

42. 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.