nutrition of dairy heifers and dairy cows

Nutrition of Nutrition of dairy heifers and dairy cowsdairy 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 Omasum

AbomasumDay 0 38 13 493rd month 64 14 22Adult 85 12 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 calf-rearing;- 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 andinsemination at age of 12-13 months.

Benefits: economical (higher milk yield, shorter genetic interval)

Control of the intensity of raising of heifersEnergy requirement: NEm, NEg,

Protein requirement: MP

(maintenance + gain)Energy:protein ratioPositive 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)/2.8Scheme of release of ammonia and energy in the

rumenBurrough 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.

Correlation between the urea level of milk (y) and the UFP of diet (x)

Urea conc. of milk

Energy releaseNH3-surplus

Feeding

NH

3-co

nc.

in r

um

en

NH3-release

NH3-deficiency

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 yearAgainst:- 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 periods1. 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

Anabolic and catabolic cycles of dairy cow

Lactation

Lactation

Drying-off

Insemination

Calving

Improvement of condition

AnabolismCatabolism

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.

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

Calculation of body condition scores

Changes of milk production, dry matter intake and weight gain during lactation

Milk production, kg

Drying-off Calving Months

Feed intake,DM kg

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%;

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

Guideline in the lactation phases 1, 2 and 3 (cont.)

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 limitingNa:K ratio: effect on ovary if K is 10× higherZn: deficiency, decreases the rate of conceptionMn: function of ovaryCu: 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 DMstraw, hay, silage, grass, brewers, bran, sugarbeat slices, green meal

2. Low crude fiber content: NDF < 400 g/kg DMsilomaize 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)