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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
Index of rumen-reticulum:abomasum, %:
Age Rumen-reticulum
Day 0
38
3rd month 64
Adult
85
Omasum
13
14
12
Abomasum
49
22
4
Proportion of growth of the pre-stomachs and
the abomasum.
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.
Parameters to follow
•
•
•
•
•
Body weight
Wither weight
Body length
Hearth girth
Body condition
scores (BCS)
Definitions of body development
Allometric growth:
100 kg of BW until puberty +2-3 cycles
Isometric growth: from birth to day 90
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.
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
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.
Heifer rearing technologies
- Same rearing technology until the end of calfrearing;
- Exemption: beef calf production.
Development of the concept:
• 700 to 800-850 g/day to 1000 g/day
Heifer rearing
a. 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
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.
Experiments on raising of heifers (cont.)
• Conclusions:
1. Puberty and oestrus is correlated with body weight
but not with age or body size.
Successful insemination: at a BW >or = 350 kg
2. 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)
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)
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
Feeding of heifers
in practice
Roughages: hays, maize
stalk, silages,
pasture;
Concentrate: small quantity
NPN-supplement: at positive UFP
Goal of heifer rearing
• Optimal insemination/mating:
350 kg BW, 13-15 months,
wither height: 110 cm.
Arguments: more intense raising
is necessary????
Turn-over of protein in the ruminants
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.
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)
Energy: protein ratio
• UFP: applicable fo individual and mixed feeds;
• UFP = 0 energy 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).
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.
Urea conc. of milk
Correlation between the urea level of milk (y) and the
UFP of diet (x)
NH3-conc.in rumen
NH3-surplus
Energy release
NH3-deficiency
NH3-release
Feeding
Time
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)
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”.
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).
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.
Nutrition of dairy heifers (cont.)
5 types of rearing according to the intensity:
1. Very slow;
2. Intense;
3. Moderate;
4. Physiologically intense;
5. Combined.
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)
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.
Metabolism and regulation of milk
production
Homeostasis:
maintenance of physiological balance,
different distribution of nutrients.
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
Lactation
Improvement
of condition
Insemination
Lactation
Anabolism
Catabolism
Drying-off
Calving
Anabolic and catabolic cycles of dairy cow
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.
Calculation of body condition scores
Scores of
tail head
Scores of
hook
Diff.
Correction
Final
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
Milk production, kg
Feed intake,
DM kg
Drying-off
Calving
Months
Changes of milk production, dry matter intake
and weight gain during lactation
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.
Lactation cycle phases with corresponding changes in milk production,
milk fat percentage, milk protein percent, DM intake and body weight
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
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.
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%)
Mid- to late lactation (104 to 305 days postpartum)
1. Milk production  (8 to 10% drop per
month)
2. Early gestation period
3. Feed intake:
a. to meet milk yield requirement
b. to gain BW (to avoid over-conditioning!)
c. NPN-sources necessary?
Nutrition of dairy cows
According to the changes in the lactation
curve.
Problems during lactation:
- dry matter intake,
- energy balance,
- changes of body weight.
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.
Nitrogen balance
• In the beginning of lactation: negative
• After the first 100 days of lactation and
during pregnancy: anabolism
Guideline in the lactation phases 1, 2 and 3
1. Protein: 18-19% CP in DM;
35-40% UIP and ca. 30% in CP in early and in late
lactation, resp.
2. 7.8 MJ NEl per kg DM in early lactation, 6.6 MJ
NEl per kg DM in early lactation and 5.5 MJ NEl
per kg DM in dry period;
3. Forage amount (40% (min. 30%), 50% and 60% in
DM); crude fibre min. 20%;
Guideline in the lactation phases 1, 2 and 3 (cont.)
4. Salt. 0.5% in DM
5. Mineral: Ca and P (1% of grain);
6. Vitamins: A, D and E (according to
requirement);
7. Ration form: forages and grains not to be
chopped or ground too fine
Dry period of 60 to 14 days before calving
Goals:
1. High milk yield in the next lactation,
2. To mimimize metabolic problems.
Does precalving amino acid nutrition improve subsequent
lactation performance?
Methionine, a key role in liver energy metabolism
Key role in the synthesis of the apoprotein ß-compex
(essential in formation of VLDL);
Supplementation of MetDi:
- decrease of plasma triglycerids, NEFAs,
- reduction the risk of certain metabolic disorders (steatosis,
ketosis),
- improved energy status of dairy cows in early lactation.
DL-methionine and methionine: do not resist rumen
degradation (Loerch and Oke, 1989)
Formulating for digestible amino acids can improve dairy
herd performance:
1.
Milk protein content is increased immediately at any stage of
lactation by 1-2 g/kg;
2. Milk yield can be improved by up to 2.5 kg/day in early lactation
(the first 100 days);
3. Milk protein yield increases of 60 to 100 g/day over a complete
lactation attainable;
4. Feed efficiency can be improved by 0.05;
5. Improved reproductive parameters:
shortening of calving interval, improved uterin involution,
reduction in the numbers of inseminations needed per conception.
Protected (bypass methionine) products
Encapsulated products; mini pellets of DL-methionine:
- release in the rumen of 15 to 20%
- the majority (appr. 90%) is absorbed in the small intestine.
Measurements of rumen degradability: overestimation of protection;
New methodology to estimate bio-availability: kinetics of appearance
in plasma of post-ruminally infused methionine
Effects:
1. Body membranes turn more stabile
 immune system;
2. Optimized milk production;
3. Better reproductive efficiency.
Manipulations of protein and amino acid supply of dairy
cows
- Influencing the need for essential amino acids in dairy cows
feeding of by-pass starch sources (e.g. maize starch);
- Influence of the ruminal N-balance on rumen fermentation,
microbial protein synthesis, amount of utilizable crude protein
and N-excretion;
- Intestinal transport of amino acids, peptides and proteins.
Turnover of Ca and P
1. The higher input of Ca during drying-off,
the higher rate of absoption;
2. Decrease of secretion of parathormon;
3. Vitamin D3 is activated;
4. Activating capacity is hindered because of the
high level of Ca,
5. Ca-binding protein (CaBP) is not synthesised at
the optimal level.
Turnover of Ca and P (cont.)
• At calving: lower ratio of Ca and P
→ surplus of P decreases the activation of
vitamin D and atypical parturient parhesis;
Requirement during drying-off period
for 100 kg BW :
6.1 g Ca and 4.2 g P for maintenance and foetus.
Cation-anion balance:
[(Na + K)] - [(Cl + S)] /100 g dry matter;
Acidic chlorides and sulphates reduces occurance of parturient
parhesis.
Requirement of Ca and P
• For 1000 kg live weight:
44 g Ca,
34 g P.
• For 1 kg milk:
2.8 g Ca,
1.7 g P.
Inorganic Ca-supplement have better availability
(depending also on age).
P-deficiency can cause alimentary sterility!
How to prevent and control milk fever?
• Review of the homeostatic/homeorrhetic
control of Ca-metabolism in ruminants
• Significance of Ca-intake in the dry period
• Significance of cation-anion-balance (CAB) in
the dry period
Mineral deficiencies and dairy cow diseases
• Mineral infertility mastitis lameness and others:
• Calcium: milk fever, retained cleansing, whites,
low DMI (dry matter intake), dispaced abomasum, low
milk yield.
• Phosphorus: milk fever, retained cleansing,
fertility problems, lower milk yield, low DMI.
• Sodium: milk fever, udder oedema especially in heifers,
not optimal rumen functions, laminitis, lower milk yield.
• Potassium: milk fever, low DMI.
• Magnesium: milk fever, grass staggers,
low DMI.
Mineral deficiencies and dairy cow diseases (cont.)
• Copper: retained cleansing,
reproduction, immune system, bone formation,
nervous system.
• Zinc: reproduction, hormones, ceratin production.
immune system, horn quality, rumen function.
• Selenium: reproduction, retained cleansing, immune
system, joint laminitis, muscular dystrophy in calves.
Vitamine deficiencies and dairy cow diseases
Vitamin A: reproduction,
retained cleansin, immune system, growth and
development, calf mortality.
Vitamin D: bone diseases, linked to calcium and
phosphorus, milk fever.
Vitamin E: reproduction, retained cleansing, immune
system, laminitis, linked to selenium.
Mineral requirement of dairy cows
Mg: 2.0 g/kg DM for dairy cow
1.6 g/kg DM for dried-off and for heifer
Na, K, Cl: 0.63 g/kg milk, not limiting
Na:K ratio: effect on ovary if K is 10× higher
Zn: deficiency, decreases the rate of conception
Mn: function of ovary
Cu: disturbances in oestrus and conception
I: decrease of the intensity of metabolism
Requirement of vitamines and minerals
Vitamin E: mastitis;
Vitamin A, carotine: reproduction disturbances;
Vitamin A: nidation of ovum;
ß-carotine: protection against peroxides in ovary,
production of progesteron, fertility cycle;
(Deficiency of P and Zn: unsatisfying turnover of
Vitamin A and ß-carotine);
Vitamins B: B1- in the first 100 days of lactation,
niacin: 6-8 g/day, def. of B12 :Co-supply.
Balance of minerals and vitamins
• Homeostatis of minerals:
1. Modification of absorption, surplus of Ca
is getting absorbed at a lower rate,
Fe, Zn, Mn are absorbed at a different rate;
2. Regulation by excretion in urine: Mg, F,
Se, I, Na, Cl;
3. Changes in milk according to the supply: I
and Mo;
4. Storing in tissues: Fe, Cu, F, Ca, Mo;
5. Endogenous excretion. Mn;
6. Sweating: Na;
7. Salivation: Na.
Ration formulation I: Requirements
- See recommendations, like NRC, ARC, DLG,
INRA
- prediction of dry matter intake
- energy and protein (degradability)
- crude fibre, NSC (non-starch-carbohydrates)
-Ca, P, S, NaCl
- vitamin A, beta-carotene and vitamin D
Ration formulation II: Practical
classification of feedstuffs
1. High crude fiber content:
NDF >500 g/kg DM
straw, hay, silage, grass,
brewers, bran,
sugarbeat slices, green
meal
2. Low crude fiber content:
NDF < 400 g/kg DM
silomaize silage, cabbage,
cereals, legume seeds,
gluten, extr. oilsead meals,
fat
Practical classification of feedstuffs
• Energy content
– Low (< 9.0 MJ/kg DM);
– Medium (9.0-12.0 MJ/kg DM)
– High (> 12.0 MJ/kg DM)
• Protein content
– Low (<120 g/kg DM);
– Medium (120-200 g/kg DM)
– High (>200g/kg DM)
Ration formulation III: feeding systems
A Grazing (‘buffering’ by straw, hay or silage)
B Basal ration + milking concentrate
C Flate-rate feeding: silage ad libitum, amount of
concentrate in different periods of lactation is
the same
D TMR or total mixed ration: ratio of forage and
concentrate (in DM basis), adjusted to the
lactational phase: 40/60, 50/50, 60/40
assure minimum roughage needs (2-4 kg hay)
Ration formulation IV: practical ‘tricks’
- consideration of fulfilment unit
- enhance of dry matter intake
- use of buffers in feed of fresh cow
- use of protected amino acids (Met, Met+Lys)
- use liver protection (nicotinic acid, choline)
- add extra vitamin E and selenium (dry period)
- apply vitamin D during dry period
- if required: use acidifier (e.g. NH4CL) (dry period)