**3.12 Calcium (Ca)**

The majority of calcium (99 %) in organism is stored in bones and teeth. Calcium is important for activation of numerous enzymes and hormones. The calcium collaborates in processes of blood coagulation, nerves stimulation and muscles contraction. In blood serum approximately 55% of Ca is in ionised form and this is biologically active. The part of ionised Ca depends from blood pH, by decrease of pH the part of ionised Ca increase. A part of Ca in serum is bound to the albumins (40%) and smaller part (5%) to organic acids (Jazbec, 1990; Kraft, 1999b). The most of Ca is absorbed in small intestine.

In newborn calves the mean serum concentration of Ca was 3.35 ± 0.27 mmol/L. Six hours after birth the Ca level decreased to 2.41 ± 0.18 mmol/L and in the next days and weeks almost did not change (Bostedt & Schramel, 1982). Kurz and Willett (1991) observed decrease of Ca concentration in the first 24 hours of life. In the first two months of life the concentration of Ca was around 2.7 mmol/L and did not change a lot. After the 3rd month the Ca concentration started to decrease and at the age of 6 months it was 2.53 ± 0.10 mmol/L (Bouda & Jagoš, 1984). Similar dynamics was established in other study in calves which were fed with milk replacer, only they have slightly higher Ca concentration at the age of 5 days (3.02 ± 0.2 mmol/L) and from the age of 15 days to 2 months it was 2.8 ± 0.1 mmol/L (Steinhardt & Thielscher, 2000d). In sucker calves of Simmental breed the decrease of Ca concentration from birth to the age of 28 days was established (2.6 mmol/L), later the concentration almost did not change to the age of 84 days (Egli & Blum, 1998). Mohri et al. (2007) established a decrease of Ca concentration in the first two weeks of life, later the Ca concentration slowly increased.

### **3.13 Potassium (K)**

In ruminants the potassium is absorbed from rumen and small intestine and is excreted over the kidney and with faeces. The K is main cation in milk (36 mmol/L). High concentrations of K in organism have citotoxical effect. Potassium is the main intracellular ion, its concentration in the cells is 25 to 30 times higher than in plasma (Ward, 1966), 96-98 % of total amount of K is in the cells (Wirth, 1999). Potassium is important for making electrical potential for transport of nervous impulses and for maintenance of muscle tonus. Hypokalemia increase the membrane potential and cause hyper polarisation block, what influence on lower muscle tonus and paralysis (Carlson, 1997). Potassium is important for regulation of acid-base balance in the body. The forage of ruminants usually contains enough potassium; more often comes to the surplus than to potassium deficiency in the meal. Tucker et al. (1991) and Weil et al. (1988) established association between potassium amount in the meal and concentration of K in calves' serum, and between mean daily weight gains. The mean K concentration in plasma of 8 weeks old calves was from 5.13 mmol/L, at 0.35% K in the meal, to 5.60 mmol/L at 0.53 % K in the dry matter of the meal. The authors claimed that the measuring of K concentration in serum and control of daily weight gain is a good indicator of supply with this element in

concentrations are on the level of adult animals (1.6-2.3 mmol/L). The colostrum intake did not influence the iP concentration in calves' serum (Steinhardt et al., 1993). Kurz and Willett (1991) established decrease of iP concentration in first 24 hours of age. In sucker calves the increase of iP concentration in the first 14 days was established later it remained stable. The values were all the time higher as in adult animals (Egli & Blum, 1998). At the age of 60 days the concentration of iP in calves' serum was 2.6 mmol/L (Steinhardt & Thielscher, 2000d).

The majority of calcium (99 %) in organism is stored in bones and teeth. Calcium is important for activation of numerous enzymes and hormones. The calcium collaborates in processes of blood coagulation, nerves stimulation and muscles contraction. In blood serum approximately 55% of Ca is in ionised form and this is biologically active. The part of ionised Ca depends from blood pH, by decrease of pH the part of ionised Ca increase. A part of Ca in serum is bound to the albumins (40%) and smaller part (5%) to organic acids

In newborn calves the mean serum concentration of Ca was 3.35 ± 0.27 mmol/L. Six hours after birth the Ca level decreased to 2.41 ± 0.18 mmol/L and in the next days and weeks almost did not change (Bostedt & Schramel, 1982). Kurz and Willett (1991) observed decrease of Ca concentration in the first 24 hours of life. In the first two months of life the concentration of Ca was around 2.7 mmol/L and did not change a lot. After the 3rd month the Ca concentration started to decrease and at the age of 6 months it was 2.53 ± 0.10 mmol/L (Bouda & Jagoš, 1984). Similar dynamics was established in other study in calves which were fed with milk replacer, only they have slightly higher Ca concentration at the age of 5 days (3.02 ± 0.2 mmol/L) and from the age of 15 days to 2 months it was 2.8 ± 0.1 mmol/L (Steinhardt & Thielscher, 2000d). In sucker calves of Simmental breed the decrease of Ca concentration from birth to the age of 28 days was established (2.6 mmol/L), later the concentration almost did not change to the age of 84 days (Egli & Blum, 1998). Mohri et al. (2007) established a decrease of Ca concentration in the first two weeks of life, later the Ca concentration slowly increased.

In ruminants the potassium is absorbed from rumen and small intestine and is excreted over the kidney and with faeces. The K is main cation in milk (36 mmol/L). High concentrations of K in organism have citotoxical effect. Potassium is the main intracellular ion, its concentration in the cells is 25 to 30 times higher than in plasma (Ward, 1966), 96-98 % of total amount of K is in the cells (Wirth, 1999). Potassium is important for making electrical potential for transport of nervous impulses and for maintenance of muscle tonus. Hypokalemia increase the membrane potential and cause hyper polarisation block, what influence on lower muscle tonus and paralysis (Carlson, 1997). Potassium is important for regulation of acid-base balance in the body. The forage of ruminants usually contains enough potassium; more often comes to the surplus than to potassium deficiency in the meal. Tucker et al. (1991) and Weil et al. (1988) established association between potassium amount in the meal and concentration of K in calves' serum, and between mean daily weight gains. The mean K concentration in plasma of 8 weeks old calves was from 5.13 mmol/L, at 0.35% K in the meal, to 5.60 mmol/L at 0.53 % K in the dry matter of the meal. The authors claimed that the measuring of K concentration in serum and control of daily weight gain is a good indicator of supply with this element in

(Jazbec, 1990; Kraft, 1999b). The most of Ca is absorbed in small intestine.

**3.12 Calcium (Ca)** 

**3.13 Potassium (K)** 

calves. In calves with diarrhoea comes to hyperkalemia which is connected with grade of acidosis (Maach et al., 1992).

The colostrum intake influence on increase of K concentration in calves' serum, what is most likely, the consequence of higher amount of this mineral in the colostrum (Steinhardt et al., 1993). In the age from 1 week to 2-3 months the K concentration in calves' serum almost did not change and was around 5 mmol/L (Maach et al. 1991). Bouda and Jagoš (1984) measured slightly higher values, around 5.4 ± 0.4 mmol/L, at the age of 6 month K concentration slightly decreased to 4.7 ± 0.4 mmol/L. Reece (1980) Established a decrease of K concentration from the 1st week of age when it was 7.2 mmol/L to the age of 15 weeks when it fell to 4.4 mmol/L.

#### **3.14 Sodium (Na)**

The sodium is the most important cation in extracellular fluid, where it is responsible for maintenance of osmotic pressure. Together with chlorine (Cl) collaborates in metabolism of water and regulation of acid-base balance in the organism (Jazbec, 1990). In ruminants a big part of Na which comes in to digestive tract originates from saliva (rotation in the organism). The rumen could contain up to 50% of whole amount of Na which is available for the organism. From the body is excreted with the urine, faeces and milk (Underwood & Suttle, 2001). At diarrhoeas the calves lose higher amounts of Na. Maach et al. (1992) established significantly lower concentration of Na in serum of calves with acute diarrhoea (131.2 ± 7.2 mmol/L) in comparison to healthy calves of same age (140.0 ± 9.9 mmol/L). In newborn calves after colostrum intake the Na concentration increased what was attributed to absorption from the colostrum (Steinhardt et al., 1993). But Maach et al. (1991) established higher concentration of Na before colostrum intake when it was 145.7 ± 3.7 mmol/L as then after (137.8 ± 6.8 mmol/L), later it almost did not change. The concentration of Na did not change a lot in the first three months, it was about 145 mmol/L, and at the age of 6 months it was slightly lower, about 136.6 ± 5.1 mmol/L (Bouda & Jagoš, 1984). Reece (1980) established higher concentration of Na in serum of calves which received milk replacer in comparison to the calves which were fed with milk.

#### **3.15 Chlorine (Cl)**

Chlorine is the most important anion in the extracellular fluid, inside the cells there is only 12% of total amount in organism. Together with Na it is responsible for maintenance of osmotic pressure in extracellular fluid. Chlorine is absorbed in small intestine, and is excreted mainly through the kidney (Wirth, 1999). The calves with acute diarrhoea, in which the volume of faeces can increase for 40 times, with the fluid lose also electrolytes. In such calves significantly lower concentration of Cl was established (95.6 ± 6.9 mmol/L) in comparison to healthy calves (103.3 ± 6.9 mmol/L) (Maach et al., 1992).

In calves immediately after birth higher concentration of Cl was established (107.3 ± 12.3 mmol/L), then it decreased to the 7th day of age to 95.9 ± 6.6 mmol/L, later it increased slightly to 102.3 ± 6.2 mmol/L at the age of 2 months (Maach et al., 1991). In suckler calves the concentration of Cl increased with age from 98.0 mmol/L in the 1st week of age to 102.4 mmol/L at the age of 14 weeks (Reece, 1984). In calves which were fed with limited amounts of milk the increase of Cl concentration was established to the age of 5 weeks, later it decreased slightly and oscillated between 97.7 and 99.3 mmol/L (Reece, 1980).

Values of Blood Variables in Calves 313

CK U/L

168.8 ± 211 2

99.6 ± 69.7 1

121.9 ± 48.4 24

106.3 ± 71.8 16,20,24

113.3 ± 69,9 16,24

106.9 ± 46.9 16,20,24

1,2,3,16,20,24 140.4 ± 70.5 216.2 ± 97.7

1,2,3,4,6,20,24 154.5 ± 103.1 196.9 ± 67.9

181.9 ± 94.2 2,4,5,6

166.5 ± 96.3 2,4,6

177.0 ± 115.5 2,3,4,5,6

> Creatinin μmol/L

113.76 ± 36.20 3,4,5,6,8,12,16,20,24

> 116.53 ± 19.41 3,4,5,6,8,12,16, 20,24

100.79 ± 21.66 1,2,5,6,8,12,16,20,24

93.55 ± 16.66 1,2,8,12,16,20,24

89.35 ± 16.67 1,2,3,12,16,20

87.89 ± 15.67 1,2,3,12,16,20

Urea mmol/L

3.64 ± 1.33 2,3

5.90 ± 2.01 1,4,5,6,8,12,16, 20,24

5.12 ± 3.42 1,4,5,6,8,12

4.01 ± 1.21 2,3

3.85 ± 1.34 2,3

3.79 ± 1.26 2,3

ALP U/L

262.2 ± 185 2,3,4,5,12,16,20,24

143.1 ± 61.3 1,6,8

132.8 ± 57.0 1,5,6,8,12

157.8 ± 79.7 1,8

189.5 ± 93.4 1,3

208.1 ± 104.3 2,3

2,3,4,20

1,4

175.6 ± 65.2 1

158.9 ± 55.4 1,8

162.4 ± 58.5 1

> TSP g/L

52.09 ± 7.09 8,12,16,20,24

52.92 ± 5.48 8,12,16,20,24

52.71 ± 4.85 8,12,16,20,24

52.41 ± 3.91 8,12,16,20,24

53.77 ± 4.47 8,12,16,20,24

54.95 ± 5.21 12,16,20,24

GGT U/L

329.8 ± 358.1 2,3,4,5,6,8,12,16,2024

> 79.8 ± 72.1 1

> 45.1 ± 34.5 1

> 30.5 ± 18.3 1

> 24.6 ± 11.2 1

20.2 ± 7.7 1

16.1 ± 3.5 1

13.4 ± 3.0 1

13.0 ± 2.6 1

13.9 ± 3.4 1

14.2 ± 4.9 1

> Alb g/L

26.35 ± 2.10 2,3,4,5,6,8,12,1620,24

28.94 ± 2.79 1,4,5,6,8,12,16, 20,24

30.24 ± 2.48 1,16,20,24

30.99 ± 2.53 1,2,20,24

31.67 ± 2.48 1,2

31.79 ± 2.91 1,2

LDH U/L

483.2 ± 108.8 8,12,16,20,24

451.3 ± 105.2 5,6,8,12,16,20,24

459.8 ± 88.9 5,6,8,12,16,20,24

503.1 ± 160.9 12,16,20,24

532.9 ± 125,9 2,3,16,20,24

544.9 ± 115.3 2,3,12,16,20,24

575.8 ± 122.4

633.6 ± 100.9

671.1 ± 102.7 1,2,3,4,5,6,8

> 722.6.,3 1,2,3,4,5,6,8,12

770.7 ± 125.5 1,2,3,4,5,6,8,12

The age group differs significantly (P<0.05) from age groups in superscript

Fe μmol/L

16.91 ± 10.95 8,12,16,20,24

14.52 ± 7.16 5,8,12,16,20,24

16.61 ± 7.88 8,12,16,20,24

20.97 ± 12.16 12,16,20,24

22.84 ± 13.47 2,12,16,20,24

20.93 ± 11.81 12,16,20,24

Age (weeks) <sup>n</sup> AST U/L

3,12,16,20,24

8,12,16,20,24

1,8,12,16,20,24

8,12,16,20,24

12,16,20,24

12,16,20,24

2,3,4,12,16,20,24

1,2,3,4,5,6,8

1,2,3,4,5,6,8

1,2,3,4,5,6,8

1,2,3,4,5,6,8

Bilirubin μmol/L

2,3,4,5,6,8,12,1620,24

1,12,16,20,24

1

1

1

1

Table 2. Activity of enzymes in calves (Ježek, 2007)

1 64 38.7 ± 16.1

2 64 32.7 ± 11.1

3 59 31.5 ± 6.2

4 62 33.3 ± 11.0

5 63 33.9 ± 12.1

6 63 35.7 ± 7.4

8 64 40.3 ± 10.2

12 61 47.6 ± 9.2

16 61 48.4 ± 8.1

20 56 50.2 ± 10.3

24 39 53.6 ± 10.1

1 64 16.08 ± 13.16

2 64 8.23 ± 3.41

3 59 6.99 ± 1.94

4 62 6.96 ± 1.52

5 63 6.88 ± 2.11

6 63 6.79 ± 3.05

Age (weeks) <sup>n</sup>
