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Nutrition of dairy heifers and dairy cows

Nutrition of dairy heifers and dairy cows. Dr. Éva Cenkvári, Ph.D. „Szent István” University Faculty of Veterinary Sciences Institute of Animal Breeding, Animal Nutrition and Laboratory Animal Sciences. Nutrition of dairy heifers during rearing.

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Nutrition of dairy heifers and dairy cows

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  1. Nutrition of dairy heifers and dairy cows Dr. Éva Cenkvári, Ph.D. „Szent István” University Faculty of Veterinary Sciences Institute of Animal Breeding, Animal Nutrition and Laboratory Animal Sciences

  2. Nutrition of dairy heifers during rearing Index of rumen-reticulum:abomasum, %: Age Rumen-reticulum Omasum Abomasum Day 0 38 13 49 3rd month 64 14 22 Adult 85 12 4 Proportion of growth of the pre-stomachs and the abomasum.

  3. Sexual maturity • Correlates with body weight (BW) (fat percent) and not with age; • 20% in BW of females: underdevelopment of ovaria, • 25% in BW of males: no clinical signs.

  4. Parameters to follow • Body weight • Wither weight • Body length • Hearth girth • Body condition scores (BCS)

  5. Definitions of body development Allometric growth: 100 kg of BW until puberty +2-3 cycles Isometricgrowth: from birth to day 90

  6. Isometric growth: • growth organ(-part) and growth of body weight (digestive and sexual organs, mammary gland); • danger of fat deposition from birth until the 90th day (or until the first calving), • GH and mammary parenchymal DNA decreases) - onset of puberty: according to the BW (250-280 kg) Disadvantages: decrease of life span, difficulties of calving) NRC (2001): 70-75% BW of an adult cow after the first calving, 900 g gain/day.

  7. Allometric growth: growth of organs is not proportional (e.g. mammary gland); • from 80-100 kg of BW until sexual maturity (+2-3 cycles); • GH and the parenchymal part of DNA content of mammary gland (genetic stock); • Different growth rate of the body parts; • Reaching sexual maturity: at ca. 250-280 kg of BW

  8. Definitions of body development • Allometric (100 kg of BW until puberty +2-3 cycles) Isometric (from birth to day 90) Isometric: • until the first calving, • rate of growth of different parts of body. (danger of fat deposition; GH and mammary parenchymal DNA decrease) Onset of puberty: according to the BW (250-280 kg) Disadvantages: decrease of life span, difficulties of calving) NRC (2001): 70-75% BW of an adult cow after the first calving, 900 g gain/day.

  9. Heifer rearing technologies - Same rearing technology until the end of calf-rearing; - Exemption: beef calf production. Development of the concept: • 700 to 800-850 g/day to 1000 g/day

  10. Heifer rearing • Experiment (Huszenyicza and Fekete, 1988): with 3 groups: 1. „Goat” 2. Medium intensive (like NRC) 3. Small frame, but fat b. Cornell University (Ithaca, NY): more intense

  11. Experiments on raising of heifers • Results: • 1. Low BW gain, late start in breeding (after 18 months, below500 kg BW at calving); 2. Daily weight gain: 600-700 g/day, getting into breeding before the 18th month of age, BW > or = 500 kg BW; 3. Small frame, well-fattened body, successful insemination until the 18th months of age, 500 kg BW at calving.

  12. Experiments on raising of heifers(cont.) • Conclusions: • Puberty and oestrus is correlated with body weight but not with age or body size. Successful insemination: at a BW >or = 350 kg • resulted in calving at age of 23.5-24.8 months. Control of intensity level of raising: checking daily BW gain; (min. 20-21 kg per month; optimal: 22-24 kg per month)

  13. Recommendation for raising of heifers • Moderate raising +15% of intensity • („physiological” intensity); • New guideline: gain of 1000-1200 g/day and insemination at age of 12-13 months. Benefits: economical (higher milk yield, shorter genetic interval)

  14. Control of the intensity of raising of heifers Energy requirement: NEm, NEg, Protein requirement: MP (maintenance+ gain) Energy:protein ratio Positive protein balance: (negative UFP); surplus of urea is harmful for sexual organs

  15. Feeding of heifers in practice Roughages: hays, maize stalk, silages, pasture; Concentrate: small quantity NPN-supplement: at positive UFP

  16. Goal of heifer rearing • Optimal insemination/mating: 350 kg BW, 13-15 months, wither height: 110 cm. Arguments: more intense raising is necessary????

  17. Turn-over of protein in the ruminants

  18. Protein requirement • Relations to energy (ammonia, UFP) Figure: time relationships of energy and ammonia release is well shown; UFP: urea fermentation potential, urea fermentation capacity; • time and quantitative relationships; • it depends on the protein-decomposing capacity of rumen.

  19. Urea fermentation capacity Depends: - on the decomposing capacity of rumen, - on ruminal disposable energy. As formula: UFP, g = (1.044×TDN-dg)/2.8 Scheme of release of ammonia and energy in the rumen Burrough and Roffler, 1975)

  20. Energy: protein ratio • UFP: applicable fo individual and mixed feeds; • UFP = 0energy released is sufficient for processing ammonia, • UFP = „+” more energy, than needed for the assimilation of ammonia (ammonia supplementation is needed), • UFP = „-” lack of energy (waste of N-content); it burdens the liver! Not necessary to feed NPN compounds (sometimes harmful).

  21. Energy: protein ratio (cont.) • How to follow the value of UFP? - blood shows well the ammonia content of the rumen; - milk shows the ammonia content of the blood (strandard: 3-6 mmol/l) Rapid test: the smaller is the UFP, the bigger is the urea concentration of the blood and milk.

  22. Urea conc. of milk Correlation between the urea level of milk (y) and the UFP of diet (x)

  23. Energy release NH3-surplus NH3-deficiency NH3-conc.in rumen NH3-release Feeding Time

  24. Arguments for the more intensive raising • Role of of the fat tissue in the metabolism of sexual steroids • The first lactation, it will be better • Less need for replacement heifer in a year Against: • Shorter longevity • Dystocia (difficult calving)

  25. Nutrition of dairy heifers (cont.) Same rearing technology until the end of calf-rearing; exemption: beef calf production; It should not be intense or „white-meat calf”.

  26. Nutrition of dairy heifers (cont.) Feeding of concentrate: lower VFA in blood (9 mg/l), especially propionate: gluconeogenesis in liver; - high blood glucose level (C3 in liver: glucose: glycogen; lactic acid: cronic, slight acidosis. Feeding of roughages: higher volatile fatty acid (VFA) concentration in the blood (13 mg/l), especially acetate (C2).

  27. Nutrition of dairy heifers (cont.) • Calves for breeding: balanced rearing: milk replacer + concentrate (ad libitum), hay Difference: in the intensity of rearing having the aim of 1. breeding or 2. fattening.

  28. Nutrition of dairy heifers (cont.) 5 types of rearing according to the intensity: • Very slow; • Intense; • Moderate; • Physiologically intense; • Combined.

  29. Life cycles of a dairy cow • Calving interval: - 365 days (first calving: 400 days); - 305 days of lactation + 60 days of drying-off Conditions: - successful insemination on the 85th day of lactation (between 60 and 90 days in a herd)

  30. Life cycles of a dairy cow (cont.) 3 periods 1. Mobilization of body tissues: decrease of BW (BCS: 3.5); 2. Covering of nutrients released from milk (for 1 kg of BW gain to supply a surplus of 26.8 MJ NEl and 276 g MP); 3. Drying-off: syndrome of „thin” and „fat” cow.

  31. Metabolism and regulation of milk production Homeostasis: maintenance of physiological balance, different distribution of nutrients.

  32. Metabolism and regulation of milk production(cont.) Homeorhesis: harmonized metabolic changes on tissue level, „redistribution” of nutrients. During lactation: - growth hormonal (GH) regulation; - increase of milk production and of lypolitical activity, - synthesis of glucose in liver, nutrient uptake of mammary gland. Examples: elephant seals, polar bears

  33. Lactation Improvement of condition Insemination Anabolic and catabolic cycles of dairy cow Lactation Anabolism Catabolism Drying-off Calving

  34. Body condition scoring of dairy cows • It reflects the changes of body composition more precisely than weighing of BW Time of scoring: 1. After calving; 2. In the first 100 days of lactation, 3. After the 200th day of lactation; 4. At drying-off; 5. During drying-off.

  35. Calculation of body condition scores Scores of Scores of Diff. Correction Final tail head hook scores 4.0 2.5 1.5 - 0.5 3.5 1.5 2.5 1.0 + 0.5 2.0 3.0 2.5 0.5 - 3.0

  36. Milk production, kg Changes of milk production, dry matter intake and weight gain during lactation Feed intake, DM kg Drying-off Calving Months

  37. Stages of lactation and gestation 1. Early lactation: 0 to 70 days (peak milk production) after calving (postpartum). 2. Peak DM intake: 70 to 140 days (declining milk production) postpartum. 3. Mid- and late lactation: 140 to 305 days (declining milk production) postpartum. 4. Dry period: 60 to 14 days before the next lactation. 5. Transition or close-up period: 14 days before parturition.

  38. Lactation cycle phases with corresponding changes in milkproduction, milk fat percentage, milk protein percent, DM intake and body weight

  39. Early lactation 1. Feed intake: a. energy (but too much grain may cause acidosis); b. protein (ca. 20% in the daily ration) c. crude fiber (min. 18% in DM). Occuring problems: a. Milk production: low peak production→ ketosis  low lactation production b. Feed intake: too much grain fed too rapidly  off-fed, acidosis, dislocation of abomasum

  40. Early lactation(cont.) Practical tools to increase feed intake: - top quality forage, - diets contain adequate amounts of CP, DIP and UDP, • increase of grain intake at a constant rate, • adding fat (0.45 to 0.7 kg/cow/day), • constant access to feed, • minimizing of stress condiditons.

  41. Second 10 weeks postpartum Goals: to reach peak DM intake, to maintain peak lactation, no longer losing body weight. Optimal daily ration: Grain intake (max 2.5% of BW) Good qality forage (highly digestible fibre) Non-fiber carbohydrate (max. 40%)

  42. Mid- to late lactation (104 to 305 days postpartum) Milk production  (8 to 10% drop per month) Early gestation period Feed intake: a. to meet milk yield requirement b. to gain BW (to avoid over-conditioning!) c. NPN-sources necessary?

  43. Nutrition of dairy cows According to the changes in the lactation curve. Problems during lactation: - dry matter intake, - energy balance, - changes of body weight.

  44. Results of negative energy balance Change of body weight : - decrease of 1 kg releases 20.60 MJ NEl and 138 g MP; - dominance of GH and ACTH. Prerequisites of successful insemination: - stopping of decrease of BW - dominance of gonadotropic hormon and insulin.

  45. Nitrogen balance • In the beginning of lactation: negative • After the first 100 days of lactation and during pregnancy: anabolism

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