if EI<0 then EI=0

MUD2 code factor 1=1.0 HIDE code factor 1=0.8

MUD2 code factor 2=0.8 HIDE code factor 2=1.0

MUD2 code factor 3=0.5 HIDE code factor 3=1.2

MUD2 code factor 4=0.2

if t=30, TI=2.5

if t>30 and =183, TI=6.5

if t>183 and =363, TI=5.1875+(0.3125 * CS)

if t>363, TI=5.25+(0.75 * CS)

LCT=39-(IN * HE * 0.85)

IN=TI+EI

if LCT>Tc, then MEcs=SA * (LCT-Tc)/IN

otherwise, MEcs=0

or if heat stressed (panting):

where

a1 is thermal neutral maintenance requirement (Mcal/day/SBW0.75);

a2 is maintenance adjustment for previous ambient temperature, (Mcal/day/SBW0.75);

Tp is previous average monthly temperature, °C; t is days of age;

NEm is net energy required for maintenance adjusted for acclimatization;

BE is breed effect on NEm requirement (Table 10–1);

L is lactation effect on NEm requirement (1 if dry, 1.2 if lactating);

SEX is 1.15 if bulls, otherwise 1;

CS is condition score, 1–9 scale;

COMP is effect of previous plane of nutrition on NEm requirement;

NEmact is activity effect on NEm requirement (Mcal/kg);

DMI is dry matter intake kg/day;

pI is pasture dry matter intake, kg/d;

TDNp is total digestible nutrient content of the pasture, %;

TERRAIN is terrain factor, 1=level land, 2=hilly;

pAVAIL is pasture mass available for grazing, T/ha;

Im is I for maintenance (no stress), kg DM/day;

Imtotal is I for maintenance (with stress), kg DM/day;

RE is net energy available for production, Mcal/day;

NEma is net energy value of diet for maintenance, Mcal/kg;

ADTV is 1.12 for diets containing ionophores, otherwise, 1.0;

NEga is net energy value of diet for gain, Mcal/kg;

YEn is net energy milk (Mcal/kg);

NEpreg is net energy retained as gravid uterus (Mcal/kg);

Table 10–1 Breed Maintenance Requirement Multipliers, Birth Weights, Peak Milk Productiona

Breed

Code

NEm (BE)

Birth wt. kg (CBW)

Peak Milk Yield, kg/day (PKYD)

Angus

1

1.00

31

8.0

Braford

2

0.95

36

7.0

Brahman

3

0.90

31

8.0

Brangus

4

0.95

33

8.0

Braunvieh

5

1.20

39

12.0

Charolais

6

1.00

39

9.0

Chianina

7

1.00

41

6.0

Devon

8

1.00

32

8.0

Galloway

9

1.00

36

8.0

Gelbvieh

10

1.10

39

11.5

Hereford

11

1.00

36

7.0

Holstein

12

1.20

43

15.0

Jersey

13

1.20

31

12.0

Limousin

14

1.00

37

9.0

Longhorn

15

1.00

33

5.0

Maine Anjou

16

1.00

40

9.0

Nellore

17

0.90

32

7.0

Piedmontese

18

1.00

38

7.0

Pinzgauer

19

1.00

38

11.0

Polled Here.

20

1.00

33

7.0

Red Poll

21

1.00

36

10.0

Sahiwal

22

0.90

38

8.0

Salers

23

1.00

35

9.0

S.Gertudis

24

0.95

33

8.0

Shorthorn

25

1.00

37

8.5

Simmental

26

1.20

39

12.0

South Devon

27

1.00

33

8.0

Tarentaise

28

1.00

33

9.0

aVariable names (BE, CBW, PKYD) are used in various equations to predict cow requirements.

 

MEC is metabolizable energy content of diet, Mcal/kg;

SA is surface area, m2;

HE is heat production, Mcal/day;

MEI is metabolizable energy intake, Mcal/day;

LCT is animal’s lower critical temperature, °C;

Ttnz is temperature at thermal neutral zone, °C,

IN is insulation value, °C/Mcal/m2/day;

TI is tissue (internal) insulation value, °C/Mcal/m2/day;

EI is external insulation value, °C/Mcal/m2/day;

WIND is wind speed, kph;

HAIR is effective hair depth, cm;

MUD2 is mud adjustment factor for external insulation;

1=dry and clean, 2=some mud on lower body, 3=wet and matted, 4=covered with wet snow or mud;

HIDE is hide adjustment factor for external insulation; 1=thin, 2=average, 3=thick;

Tc is current temperature, °C;

EATc is current effective ambient temperature, °C;

MEcs is metabolizable energy required due to cold stress, Mcal/day;

km is diet NEm/diet ME (assumed 0.576 in derivation);

NEmcs is net energy required due to cold stress, Mcal/day;



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