Voluntary feed intakes of Feeds

1. Voluntary feed intakes of Feeds Prof. Dr. Metha Wanapat Dr. Anusorn Cherdthong 130740 Tropical Feed Resources and Feeding Technology Department of Animal Science, Faculty of Agriculture Khon Kaen University

2. Voluntary feed intake Voluntary feed intake (VFI), voluntary dry matter intake (VDMI) • Amount of feed which animals are allowed to adapt for suitable time to consume such feed until consistent level achieved and measured when feed is given on ad libitum basis and about 10% of feed remaining

3. Intake • Essential factor to measure uptake of feeds and nutrients by animal • measured as • kg DM/hd/d • % of body weight /hd/d • g/W.75/hd/d

4. 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 Intake increase as adaptation time advances * * * * * * * * Roughage Intake Kg/d * * * * * * 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Day Adaptation of ruminants to obtain consistent DM intake of roughages

5. Palatability and Taste • Responses which animals show in accepting and consuming any given feeds • Influenced by numerous factors: sight/visual, smell, flavors, tastes, chemical compositions etc

6. Regulation of feed intake • Short-term control • long-term control Current concept: • energy intake will be regulated to maintain consistent level of lipids stored in adipose tissue in adult animals • adult animals tended to adapt to high energy diets in order to maintain consistent level of body stored lipids

7. The various mechanisms postulated to regulate voluntary intake. --Energy balance is governed by the input of digestible nutrients, the output, and the cost of work of digestion and metabolism. --Hormonal factors in blood are a composite of responses to absorbed nutrients, components that regulate mobilization of energy from depot in case of negative energy balance, and the factors secreted by the anterior pituitary the regulates eating. --The central nervous system (CNS) and hormones regulate gastrointestinal motility and probably passage, causing some alleviation of fill by passing coarser material at higher intakes and set points

8. The more the feeds can be digested, the higher feed intake will be, well true in roughages but not for concentrates • Ad libitum feeding will result in best measure of roughage intake • Adaptation period for any animals / species should be given and will be variable

9. CNS Body Adipose Muscle Blood-borne Liver Hindbrain Gl tract Mechanoreceptors Chemoreceptors Taste Texture Sight Odour Eating Digestion Metabolism FOOD DIGESTA NUTRIENTS STORES Time Regulation of feed intake

10. Receptors CNS Feeding behavior Feed intake Digestion absorption VFA + energy balance - Hormones mobilization Fill Time limit Rumination Passage Appetite set point integration Hypothalamus Output maintenance growth, work lact., stress Work of digestion Regulation of feed intake

11. Feedback for energy balance regulation • Lipostasis • balance of stored fat • fat animals eat less than thin animals • Humoral factors • Central nervous system (CNS) regulates energy balance by receptors • CNS regulates • Hunger-physiological and psychological state resulting in initiation of feeding • Satiety-opposite to Hunger, resulting in termination of feeding

12. Factors affecting on voluntary feed intake • Rumen distention/gut-fill • the ability of rumen to expand to fill in feed particles until compacts and depends on feed bulkiness • Rumen conditions • pH < 6.0 intake < 5.5 severe intake - VFAs C2 > C3> C4 intake

13. Chemostatic factor • rumen VFAS • plasma VFAS • Thermostatic factor • rumen temperature intake • body tempereture intake

14. Thermostatic Chemostatic (VFA) Distension/Gut Fill Inflection point DMI DM Intake g/kg W.75 In the tropics DEI 5065% TDN Nutritive value Relationship between DM roughage intake (DMI) , digestible energy intake (DEI) and nutritive value

15. Strategies to improve feed intake of roughage • Treatment / processing • supplementation • concentrates • strategic supplement

16. Supplementation and substitution effects 3.0 2.5 2.0 1.5 1.0 0.5 Roughage intake, %BW 0 0.5 1.0 1.5 2.0 2.5 3.0 Kg/hd/d Concentrate supplementation

17. Treatments of Roughages • Physical treatment • Chopping • Grinding • Pelletting • Watering • Cubing

18. Chemical treatment • NaOH • Ca(OH)2 • Aqueous NH3 (NH4OH) • Anhydrous NH3 • Urine • Urea

19. Biological treatment • White-rot fungi • mushroom culture • industrial enzymes : cellulase , pectinase, xylanase etc

20. Caloric density (CD) • CD = DE x D kcal/ml • DE = kcal/g • D = density of ground feed when replaced in water, g/ml

21. 30 25 20 15 10 5 Milk yield kg/d Mean milk yield DM intake kg/d 20 15 10 5 Mean DM intake BW,kg 500 400 300 Mean body weight 1 2 3 4 5 6 7 8 9 10 Lactation, month Trends in milk production, DM intake, body weight change in lactating dairy cows

22. REQUIREMENT POR : 630 KG COW 45 kg milk 800 700 600 500 400 300 200 100 36 kg milk 27 kg milk Digestide energy intake (Kcal/W kg3/4) 18 kg milk 9 kg milk 0.5 1.0 1.5 2.0 2.5 3.0 Ration DE X D, Kcal / ml

23. Problems in feeding lactating dairy cows • Low DM intake of roughages • Low quality of roughages • low overall DM intake during peak • milk persistency • low milk yield and milk quality, fat, protein, solids-not-fat (SNF)

24. Possible solutions/ strategies of feeding • Increase roughage intake • Improve roughage quality • treatment/supplementation • improve rumen ecology and fermentation efficiency • Manipulate VFAs microbial protein synthesis • etc

25. Good luck!!!